Граф коммитов

731 Коммитов

Автор SHA1 Сообщение Дата
Michael S. Tsirkin 01f2188037 kvm: add kvm_set_irq_inatomic
Add an API to inject IRQ from atomic context.
Return EWOULDBLOCK if impossible (e.g. for multicast).
Only MSI is supported ATM.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2012-12-05 15:10:45 +02:00
Alex Williamson 5419369ed6 KVM: Fix user memslot overlap check
Prior to memory slot sorting this loop compared all of the user memory
slots for overlap with new entries.  With memory slot sorting, we're
just checking some number of entries in the array that may or may not
be user slots.  Instead, walk all the slots with kvm_for_each_memslot,
which has the added benefit of terminating early when we hit the first
empty slot, and skip comparison to private slots.

Cc: stable@vger.kernel.org
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-29 23:30:32 -02:00
Marcelo Tosatti 42897d866b KVM: x86: add kvm_arch_vcpu_postcreate callback, move TSC initialization
TSC initialization will soon make use of online_vcpus.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-27 23:29:14 -02:00
Marcelo Tosatti d828199e84 KVM: x86: implement PVCLOCK_TSC_STABLE_BIT pvclock flag
KVM added a global variable to guarantee monotonicity in the guest.
One of the reasons for that is that the time between

	1. ktime_get_ts(&timespec);
	2. rdtscll(tsc);

Is variable. That is, given a host with stable TSC, suppose that
two VCPUs read the same time via ktime_get_ts() above.

The time required to execute 2. is not the same on those two instances
executing in different VCPUS (cache misses, interrupts...).

If the TSC value that is used by the host to interpolate when
calculating the monotonic time is the same value used to calculate
the tsc_timestamp value stored in the pvclock data structure, and
a single <system_timestamp, tsc_timestamp> tuple is visible to all
vcpus simultaneously, this problem disappears. See comment on top
of pvclock_update_vm_gtod_copy for details.

Monotonicity is then guaranteed by synchronicity of the host TSCs
and guest TSCs.

Set TSC stable pvclock flag in that case, allowing the guest to read
clock from userspace.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-27 23:29:13 -02:00
Guo Chao 807f12e57c KVM: remove unnecessary return value check
No need to check return value before breaking switch.

Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-13 22:14:29 -02:00
Guo Chao 18595411a7 KVM: do not kfree error pointer
We should avoid kfree()ing error pointer in kvm_vcpu_ioctl() and
kvm_arch_vcpu_ioctl().

Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-13 22:14:28 -02:00
Xiao Guangrong 81c52c56e2 KVM: do not treat noslot pfn as a error pfn
This patch filters noslot pfn out from error pfns based on Marcelo comment:
noslot pfn is not a error pfn

After this patch,
- is_noslot_pfn indicates that the gfn is not in slot
- is_error_pfn indicates that the gfn is in slot but the error is occurred
  when translate the gfn to pfn
- is_error_noslot_pfn indicates that the pfn either it is error pfns or it
  is noslot pfn
And is_invalid_pfn can be removed, it makes the code more clean

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-10-29 20:31:04 -02:00
Marcelo Tosatti 19bf7f8ac3 Merge remote-tracking branch 'master' into queue
Merge reason: development work has dependency on kvm patches merged
upstream.

Conflicts:
	arch/powerpc/include/asm/Kbuild
	arch/powerpc/include/asm/kvm_para.h

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-10-29 19:15:32 -02:00
Linus Torvalds 3d0ceac129 KVM updates for 3.7-rc2
-----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.12 (GNU/Linux)
 
 iQIcBAABAgAGBQJQhnb/AAoJEI7yEDeUysxlCLsQAI4EFZWJiWwY6TtYfGuhWvzi
 XvaCwdH8NYE1YWEqWmu7B864gKJb4AEjJ9Du3zj52IRkurBEstIM9trnr/WjLkEP
 mSC5AIqFzy0Wjyqy8aUDzkMGEoA2QOMk/FCHKYIF57genRLP6p8+p57MmMKkgSSZ
 6FUwYWLcJEUIGg4VVnYkEf6rWQYDgBUCBOwLx/+h03B2ff/U4648dVIlJaA2SCt8
 B8mXV8mgb1soRkuleE8/p0b/pj+tHBO0f2oZkvg60/JXMpiTopec+5LZncEz45C9
 fqel3bk2RZW8IIHh+Ek/I2VxrZmalJ8aHhZfkivHp3DCAgggdJ9oviR8xyRhj29l
 5eFeLibbOvvDscWxA9pSJsIGwwRjtHbj38YEAAZwm23E0WVPwICC+ePVMDW33R0T
 3L8kXDFVLHEjupjJz4CYFeUHrC9dkf74FxqJ9v9jW3iY+F+1xX5c5KJL3NNKAI6M
 kTgSzFKUmgcNVCAOFFKRugjcRmS5dEKX6FXxa3NHnYrMEcaI2pQE6ZJtuKs54BPN
 euVhtK1tLXfnWrrpkYyZMfIZPVv3dIFddORrlh5GE1oTtwfV5MUUM2U6QPreqVuM
 2EU1MfW92su82CcsRuGzfjSLD/NpJGfF1tSle8xVEIn1xuS6aAAsnl/uP+zMuVal
 rMVJGBwBD0O2OyPwVXT9
 =qz8+
 -----END PGP SIGNATURE-----

Merge tag 'kvm-3.7-2' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm fixes from Avi Kivity:
 "KVM updates for 3.7-rc2"

* tag 'kvm-3.7-2' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM guest: exit idleness when handling KVM_PV_REASON_PAGE_NOT_PRESENT
  KVM: apic: fix LDR calculation in x2apic mode
  KVM: MMU: fix release noslot pfn
2012-10-24 04:08:42 +03:00
Xiao Guangrong f3ac1a4b66 KVM: MMU: fix release noslot pfn
We can not directly call kvm_release_pfn_clean to release the pfn
since we can meet noslot pfn which is used to cache mmio info into
spte

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-10-22 18:03:25 +02:00
Shuah Khan d151f63f20 KVM: change kvm_assign_device() to print return value when iommu_attach_device() fails
Change existing kernel error message to include return value from
iommu_attach_device() when it fails. This will help debug device
assignment failures more effectively.

Signed-off-by: Shuah Khan <shuah.khan@hp.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-10-10 15:45:40 -03:00
Takuya Yoshikawa b74ca3b3fd kvm: replace test_and_set_bit_le() in mark_page_dirty_in_slot() with set_bit_le()
Now that we have defined generic set_bit_le() we do not need to use
test_and_set_bit_le() for atomically setting a bit.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Cc: Avi Kivity <avi@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-06 03:04:56 +09:00
Linus Torvalds ecefbd94b8 KVM updates for the 3.7 merge window
-----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.12 (GNU/Linux)
 
 iQIcBAABAgAGBQJQbY/2AAoJEI7yEDeUysxlymQQAIv5svpAI/FUe3FhvBi3IW2h
 WWMIpbdhHyocaINT18qNp8prO0iwoaBfgsnU8zuB34MrbdUgiwSHgM6T4Ff4NGa+
 R4u+gpyKYwxNQYKeJyj04luXra/krxwHL1u9OwN7o44JuQXAmzrw2tZ9ad1ArvL3
 eoZ6kGsPcdHPZMZWw2jN5xzBsRtqybm0GPPQh1qPXdn8UlPPd1X7owvbaud2y4+e
 StVIpGY6wrsO36f7UcA4Gm1EP/1E6Lm5KMXJyHgM9WBRkEfp92jTY5+XKv91vK8Z
 VKUd58QMdZE5NCNBkAR9U5N9aH0oSXnFU/g8hgiwGvrhS3IsSkKUePE6sVyMVTIO
 VptKRYe0AdmD/g25p6ApJsguV7ITlgoCPaE4rMmRcW9/bw8+iY098r7tO7w11H8M
 TyFOXihc3B+rlH8WdzOblwxHMC4yRuiPIktaA3WwbX7eA7Xv/ZRtdidifXKtgsVE
 rtubVqwGyYcHoX1Y+JiByIW1NN0pYncJhPEdc8KbRe2wKs3amA9rio1mUpBYYBPO
 B0ygcITftyXbhcTtssgcwBDGXB0AAGqI7wqdtJhFeIrKwHXD7fNeAGRwO8oKxmlj
 0aPwo9fDtpI+e6BFTohEgjZBocRvXXNWLnDSFB0E7xDR31bACck2FG5FAp1DxdS7
 lb/nbAsXf9UJLgGir4I1
 =kN6V
 -----END PGP SIGNATURE-----

Merge tag 'kvm-3.7-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Avi Kivity:
 "Highlights of the changes for this release include support for vfio
  level triggered interrupts, improved big real mode support on older
  Intels, a streamlines guest page table walker, guest APIC speedups,
  PIO optimizations, better overcommit handling, and read-only memory."

* tag 'kvm-3.7-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (138 commits)
  KVM: s390: Fix vcpu_load handling in interrupt code
  KVM: x86: Fix guest debug across vcpu INIT reset
  KVM: Add resampling irqfds for level triggered interrupts
  KVM: optimize apic interrupt delivery
  KVM: MMU: Eliminate pointless temporary 'ac'
  KVM: MMU: Avoid access/dirty update loop if all is well
  KVM: MMU: Eliminate eperm temporary
  KVM: MMU: Optimize is_last_gpte()
  KVM: MMU: Simplify walk_addr_generic() loop
  KVM: MMU: Optimize pte permission checks
  KVM: MMU: Update accessed and dirty bits after guest pagetable walk
  KVM: MMU: Move gpte_access() out of paging_tmpl.h
  KVM: MMU: Optimize gpte_access() slightly
  KVM: MMU: Push clean gpte write protection out of gpte_access()
  KVM: clarify kvmclock documentation
  KVM: make processes waiting on vcpu mutex killable
  KVM: SVM: Make use of asm.h
  KVM: VMX: Make use of asm.h
  KVM: VMX: Make lto-friendly
  KVM: x86: lapic: Clean up find_highest_vector() and count_vectors()
  ...

Conflicts:
	arch/s390/include/asm/processor.h
	arch/x86/kvm/i8259.c
2012-10-04 09:30:33 -07:00
Linus Torvalds 033d9959ed Merge branch 'for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue changes from Tejun Heo:
 "This is workqueue updates for v3.7-rc1.  A lot of activities this
  round including considerable API and behavior cleanups.

   * delayed_work combines a timer and a work item.  The handling of the
     timer part has always been a bit clunky leading to confusing
     cancelation API with weird corner-case behaviors.  delayed_work is
     updated to use new IRQ safe timer and cancelation now works as
     expected.

   * Another deficiency of delayed_work was lack of the counterpart of
     mod_timer() which led to cancel+queue combinations or open-coded
     timer+work usages.  mod_delayed_work[_on]() are added.

     These two delayed_work changes make delayed_work provide interface
     and behave like timer which is executed with process context.

   * A work item could be executed concurrently on multiple CPUs, which
     is rather unintuitive and made flush_work() behavior confusing and
     half-broken under certain circumstances.  This problem doesn't
     exist for non-reentrant workqueues.  While non-reentrancy check
     isn't free, the overhead is incurred only when a work item bounces
     across different CPUs and even in simulated pathological scenario
     the overhead isn't too high.

     All workqueues are made non-reentrant.  This removes the
     distinction between flush_[delayed_]work() and
     flush_[delayed_]_work_sync().  The former is now as strong as the
     latter and the specified work item is guaranteed to have finished
     execution of any previous queueing on return.

   * In addition to the various bug fixes, Lai redid and simplified CPU
     hotplug handling significantly.

   * Joonsoo introduced system_highpri_wq and used it during CPU
     hotplug.

  There are two merge commits - one to pull in IRQ safe timer from
  tip/timers/core and the other to pull in CPU hotplug fixes from
  wq/for-3.6-fixes as Lai's hotplug restructuring depended on them."

Fixed a number of trivial conflicts, but the more interesting conflicts
were silent ones where the deprecated interfaces had been used by new
code in the merge window, and thus didn't cause any real data conflicts.

Tejun pointed out a few of them, I fixed a couple more.

* 'for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (46 commits)
  workqueue: remove spurious WARN_ON_ONCE(in_irq()) from try_to_grab_pending()
  workqueue: use cwq_set_max_active() helper for workqueue_set_max_active()
  workqueue: introduce cwq_set_max_active() helper for thaw_workqueues()
  workqueue: remove @delayed from cwq_dec_nr_in_flight()
  workqueue: fix possible stall on try_to_grab_pending() of a delayed work item
  workqueue: use hotcpu_notifier() for workqueue_cpu_down_callback()
  workqueue: use __cpuinit instead of __devinit for cpu callbacks
  workqueue: rename manager_mutex to assoc_mutex
  workqueue: WORKER_REBIND is no longer necessary for idle rebinding
  workqueue: WORKER_REBIND is no longer necessary for busy rebinding
  workqueue: reimplement idle worker rebinding
  workqueue: deprecate __cancel_delayed_work()
  workqueue: reimplement cancel_delayed_work() using try_to_grab_pending()
  workqueue: use mod_delayed_work() instead of __cancel + queue
  workqueue: use irqsafe timer for delayed_work
  workqueue: clean up delayed_work initializers and add missing one
  workqueue: make deferrable delayed_work initializer names consistent
  workqueue: cosmetic whitespace updates for macro definitions
  workqueue: deprecate system_nrt[_freezable]_wq
  workqueue: deprecate flush[_delayed]_work_sync()
  ...
2012-10-02 09:54:49 -07:00
Alex Williamson 7a84428af7 KVM: Add resampling irqfds for level triggered interrupts
To emulate level triggered interrupts, add a resample option to
KVM_IRQFD.  When specified, a new resamplefd is provided that notifies
the user when the irqchip has been resampled by the VM.  This may, for
instance, indicate an EOI.  Also in this mode, posting of an interrupt
through an irqfd only asserts the interrupt.  On resampling, the
interrupt is automatically de-asserted prior to user notification.
This enables level triggered interrupts to be posted and re-enabled
from vfio with no userspace intervention.

All resampling irqfds can make use of a single irq source ID, so we
reserve a new one for this interface.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-23 13:50:15 +02:00
Gleb Natapov 1e08ec4a13 KVM: optimize apic interrupt delivery
Most interrupt are delivered to only one vcpu. Use pre-build tables to
find interrupt destination instead of looping through all vcpus. In case
of logical mode loop only through vcpus in a logical cluster irq is sent
to.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-20 15:05:26 +03:00
Michael S. Tsirkin 9fc77441e5 KVM: make processes waiting on vcpu mutex killable
vcpu mutex can be held for unlimited time so
taking it with mutex_lock on an ioctl is wrong:
one process could be passed a vcpu fd and
call this ioctl on the vcpu used by another process,
it will then be unkillable until the owner exits.

Call mutex_lock_killable instead and return status.
Note: mutex_lock_interruptible would be even nicer,
but I am not sure all users are prepared to handle EINTR
from these ioctls. They might misinterpret it as an error.

Cleanup paths expect a vcpu that can't be used by
any userspace so this will always succeed - catch bugs
by calling BUG_ON.

Catch callers that don't check return state by adding
__must_check.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-09-17 13:46:32 -03:00
Marcelo Tosatti 3b4dc3a031 KVM: move postcommit flush to x86, as mmio sptes are x86 specific
Other arches do not need this.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

v2: fix incorrect deletion of mmio sptes on gpa move (noticed by Takuya)
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-06 16:37:30 +03:00
Marcelo Tosatti 12d6e7538e KVM: perform an invalid memslot step for gpa base change
PPC must flush all translations before the new memory slot
is visible.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-06 16:37:27 +03:00
Marcelo Tosatti 2df72e9bc4 KVM: split kvm_arch_flush_shadow
Introducing kvm_arch_flush_shadow_memslot, to invalidate the
translations of a single memory slot.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-06 16:37:25 +03:00
Gavin Shan 66a03505a7 KVM: PPC: book3s: fix build error caused by gfn_to_hva_memslot()
The build error was caused by that builtin functions are calling
the functions implemented in modules. This error was introduced by
commit 4d8b81abc4 ("KVM: introduce readonly memslot").

The patch fixes the build error by moving function __gfn_to_hva_memslot()
from kvm_main.c to kvm_host.h and making that "inline" so that the
builtin function (kvmppc_h_enter) can use that.

Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-27 16:44:20 -03:00
Alan Cox 760a9a30ad kvm: Fix nonsense handling of compat ioctl
KVM_SET_SIGNAL_MASK passed a NULL argument leaves the on stack signal
sets uninitialized. It then passes them through to
kvm_vcpu_ioctl_set_sigmask.

We should be passing a NULL in this case not translated garbage.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-26 15:11:48 -03:00
Xiao Guangrong 4d8b81abc4 KVM: introduce readonly memslot
In current code, if we map a readonly memory space from host to guest
and the page is not currently mapped in the host, we will get a fault
pfn and async is not allowed, then the vm will crash

We introduce readonly memory region to map ROM/ROMD to the guest, read access
is happy for readonly memslot, write access on readonly memslot will cause
KVM_EXIT_MMIO exit

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-22 15:09:03 +03:00
Xiao Guangrong ca3a490c7d KVM: introduce KVM_HVA_ERR_BAD
Then, remove bad_hva and inline kvm_is_error_hva

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-22 15:08:59 +03:00
Xiao Guangrong 12ce13fea9 KVM: use 'writable' as a hint to map writable pfn
In current code, we always map writable pfn for the read fault, in order
to support readonly memslot, we map writable pfn only if 'writable'
is not NULL

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-22 15:08:55 +03:00
Xiao Guangrong 2fc843117d KVM: reorganize hva_to_pfn
We do too many things in hva_to_pfn, this patch reorganize the code,
let it be better readable

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-22 15:08:54 +03:00
Xiao Guangrong 86ab8cffb4 KVM: introduce gfn_to_hva_read/kvm_read_hva/kvm_read_hva_atomic
This set of functions is only used to read data from host space, in the
later patch, we will only get a readonly hva in gfn_to_hva_read, and
the function name is a good hint to let gfn_to_hva_read to pair with
kvm_read_hva()/kvm_read_hva_atomic()

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-22 15:08:53 +03:00
Xiao Guangrong 037d92dc5d KVM: introduce gfn_to_pfn_memslot_atomic
It can instead of hva_to_pfn_atomic

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-22 15:08:52 +03:00
Xiao Guangrong a50d64d659 KVM: fix missing check for memslot flags
Check flags when memslot is registered from userspace as Avi's suggestion

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-22 15:08:50 +03:00
Tejun Heo 43829731dd workqueue: deprecate flush[_delayed]_work_sync()
flush[_delayed]_work_sync() are now spurious.  Mark them deprecated
and convert all users to flush[_delayed]_work().

If you're cc'd and wondering what's going on: Now all workqueues are
non-reentrant and the regular flushes guarantee that the work item is
not pending or running on any CPU on return, so there's no reason to
use the sync flushes at all and they're going away.

This patch doesn't make any functional difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Mattia Dongili <malattia@linux.it>
Cc: Kent Yoder <key@linux.vnet.ibm.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Bryan Wu <bryan.wu@canonical.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-wireless@vger.kernel.org
Cc: Anton Vorontsov <cbou@mail.ru>
Cc: Sangbeom Kim <sbkim73@samsung.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Petr Vandrovec <petr@vandrovec.name>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Avi Kivity <avi@redhat.com>
2012-08-20 14:51:24 -07:00
Michael S. Tsirkin 28a6fdabb3 KVM: x86: drop parameter validation in ioapic/pic
We validate irq pin number when routing is setup, so
code handling illegal irq # in pic and ioapic on each injection
is never called.
Drop it, replace with BUG_ON to catch out of bounds access bugs.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-14 22:35:22 -03:00
Xiao Guangrong 32cad84f44 KVM: do not release the error page
After commit a2766325cf, the error page is replaced by the
error code, it need not be released anymore

[ The patch has been compiling tested for powerpc ]

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-06 16:04:58 +03:00
Xiao Guangrong cb9aaa30b1 KVM: do not release the error pfn
After commit a2766325cf, the error pfn is replaced by the
error code, it need not be released anymore

[ The patch has been compiling tested for powerpc ]

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-06 16:04:57 +03:00
Xiao Guangrong 6cede2e679 KVM: introduce KVM_ERR_PTR_BAD_PAGE
It is used to eliminate the overload of function call and cleanup
the code

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-06 16:04:55 +03:00
Xiao Guangrong 83f09228d0 KVM: inline is_*_pfn functions
These functions are exported and can not inline, move them
to kvm_host.h to eliminate the overload of function call

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-06 16:04:53 +03:00
Xiao Guangrong 950e95097b KVM: introduce KVM_PFN_ERR_BAD
Then, remove get_bad_pfn

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-06 16:04:52 +03:00
Xiao Guangrong e6c1502b3f KVM: introduce KVM_PFN_ERR_HWPOISON
Then, get_hwpoison_pfn and is_hwpoison_pfn can be removed

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-06 16:04:52 +03:00
Xiao Guangrong 6c8ee57be9 KVM: introduce KVM_PFN_ERR_FAULT
After that, the exported and un-inline function, get_fault_pfn,
can be removed

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-06 16:04:50 +03:00
Xiao Guangrong 16b854c889 KVM: iommu: fix releasing unmapped page
There are two bugs:
- the 'error page' is forgot to be released
  [ it is unneeded after commit a2766325cf, for backport, we
    still do kvm_release_pfn_clean for the error pfn ]

- guest pages are always released regardless of the unmapped page
  (e,g, caused by hwpoison)

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-06 16:04:46 +03:00
Takuya Yoshikawa d89cc617b9 KVM: Push rmap into kvm_arch_memory_slot
Two reasons:
 - x86 can integrate rmap and rmap_pde and remove heuristics in
   __gfn_to_rmap().
 - Some architectures do not need rmap.

Since rmap is one of the most memory consuming stuff in KVM, ppc'd
better restrict the allocation to Book3S HV.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-06 12:47:30 +03:00
Christoffer Dall 23d43cf998 KVM: Move KVM_IRQ_LINE to arch-generic code
Handle KVM_IRQ_LINE and KVM_IRQ_LINE_STATUS in the generic
kvm_vm_ioctl() function and call into kvm_vm_ioctl_irq_line().

This is even more relevant when KVM/ARM also uses this ioctl.

Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-07-26 12:23:25 +03:00
Xiao Guangrong a2766325cf KVM: remove dummy pages
Currently, kvm allocates some pages and use them as error indicators,
it wastes memory and is not good for scalability

Base on Avi's suggestion, we use the error codes instead of these pages
to indicate the error conditions

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-07-26 11:55:34 +03:00
Xiao Guangrong 2b4b5af8f8 KVM: use kvm_release_page_clean to release the page
In kvm_async_pf_wakeup_all, it uses bad_page to generate broadcast wakeup,
and uses put_page to release bad_page, the work depends on the fact that
bad_page is the normal page. But we will use the error code instead of
bad_page, so use kvm_release_page_clean to release the page which will
release the error code properly

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-07-26 11:55:31 +03:00
Avi Kivity e9bda6f6f9 Merge branch 'queue' into next
Merge patches queued during the run-up to the merge window.

* queue: (25 commits)
  KVM: Choose better candidate for directed yield
  KVM: Note down when cpu relax intercepted or pause loop exited
  KVM: Add config to support ple or cpu relax optimzation
  KVM: switch to symbolic name for irq_states size
  KVM: x86: Fix typos in pmu.c
  KVM: x86: Fix typos in lapic.c
  KVM: x86: Fix typos in cpuid.c
  KVM: x86: Fix typos in emulate.c
  KVM: x86: Fix typos in x86.c
  KVM: SVM: Fix typos
  KVM: VMX: Fix typos
  KVM: remove the unused parameter of gfn_to_pfn_memslot
  KVM: remove is_error_hpa
  KVM: make bad_pfn static to kvm_main.c
  KVM: using get_fault_pfn to get the fault pfn
  KVM: MMU: track the refcount when unmap the page
  KVM: x86: remove unnecessary mark_page_dirty
  KVM: MMU: Avoid handling same rmap_pde in kvm_handle_hva_range()
  KVM: MMU: Push trace_kvm_age_page() into kvm_age_rmapp()
  KVM: MMU: Add memslot parameter to hva handlers
  ...

Signed-off-by: Avi Kivity <avi@redhat.com>
2012-07-26 11:54:21 +03:00
Linus Torvalds 5fecc9d8f5 KVM updates for the 3.6 merge window
-----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.12 (GNU/Linux)
 
 iQIcBAABAgAGBQJQDRDNAAoJEI7yEDeUysxlkl8P/3C2AHx2webOU8sVzhfU6ONZ
 ZoGevwBjyZIeJEmiWVpFTTEew1l0PXtpyOocXGNUXIddVnhXTQOKr/Scj4uFbmx8
 ROqgK8NSX9+xOGrBPCoN7SlJkmp+m6uYtwYkl2SGnsEVLWMKkc7J7oqmszCcTQvN
 UXMf7G47/Ul2NUSBdv4Yvizhl4kpvWxluiweDw3E/hIQKN0uyP7CY58qcAztw8nG
 csZBAnnuPFwIAWxHXW3eBBv4UP138HbNDqJ/dujjocM6GnOxmXJmcZ6b57gh+Y64
 3+w9IR4qrRWnsErb/I8inKLJ1Jdcf7yV2FmxYqR4pIXay2Yzo1BsvFd6EB+JavUv
 pJpixrFiDDFoQyXlh4tGpsjpqdXNMLqyG4YpqzSZ46C8naVv9gKE7SXqlXnjyDlb
 Llx3hb9Fop8O5ykYEGHi+gIISAK5eETiQl4yw9RUBDpxydH4qJtqGIbLiDy8y9wi
 Xyi8PBlNl+biJFsK805lxURqTp/SJTC3+Zb7A7CzYEQm5xZw3W/CKZx1ZYBfpaa/
 pWaP6tB7JwgLIVXi4HQayLWqMVwH0soZIn9yazpOEFv6qO8d5QH5RAxAW2VXE3n5
 JDlrajar/lGIdiBVWfwTJLb86gv3QDZtIWoR9mZuLKeKWE/6PRLe7HQpG1pJovsm
 2AsN5bS0BWq+aqPpZHa5
 =pECD
 -----END PGP SIGNATURE-----

Merge tag 'kvm-3.6-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Avi Kivity:
 "Highlights include
  - full big real mode emulation on pre-Westmere Intel hosts (can be
    disabled with emulate_invalid_guest_state=0)
  - relatively small ppc and s390 updates
  - PCID/INVPCID support in guests
  - EOI avoidance; 3.6 guests should perform better on 3.6 hosts on
    interrupt intensive workloads)
  - Lockless write faults during live migration
  - EPT accessed/dirty bits support for new Intel processors"

Fix up conflicts in:
 - Documentation/virtual/kvm/api.txt:

   Stupid subchapter numbering, added next to each other.

 - arch/powerpc/kvm/booke_interrupts.S:

   PPC asm changes clashing with the KVM fixes

 - arch/s390/include/asm/sigp.h, arch/s390/kvm/sigp.c:

   Duplicated commits through the kvm tree and the s390 tree, with
   subsequent edits in the KVM tree.

* tag 'kvm-3.6-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (93 commits)
  KVM: fix race with level interrupts
  x86, hyper: fix build with !CONFIG_KVM_GUEST
  Revert "apic: fix kvm build on UP without IOAPIC"
  KVM guest: switch to apic_set_eoi_write, apic_write
  apic: add apic_set_eoi_write for PV use
  KVM: VMX: Implement PCID/INVPCID for guests with EPT
  KVM: Add x86_hyper_kvm to complete detect_hypervisor_platform check
  KVM: PPC: Critical interrupt emulation support
  KVM: PPC: e500mc: Fix tlbilx emulation for 64-bit guests
  KVM: PPC64: booke: Set interrupt computation mode for 64-bit host
  KVM: PPC: bookehv: Add ESR flag to Data Storage Interrupt
  KVM: PPC: bookehv64: Add support for std/ld emulation.
  booke: Added crit/mc exception handler for e500v2
  booke/bookehv: Add host crit-watchdog exception support
  KVM: MMU: document mmu-lock and fast page fault
  KVM: MMU: fix kvm_mmu_pagetable_walk tracepoint
  KVM: MMU: trace fast page fault
  KVM: MMU: fast path of handling guest page fault
  KVM: MMU: introduce SPTE_MMU_WRITEABLE bit
  KVM: MMU: fold tlb flush judgement into mmu_spte_update
  ...
2012-07-24 12:01:20 -07:00
Raghavendra K T 06e48c510a KVM: Choose better candidate for directed yield
Currently, on a large vcpu guests, there is a high probability of
yielding to the same vcpu who had recently done a pause-loop exit or
cpu relax intercepted. Such a yield can lead to the vcpu spinning
again and hence degrade the performance.

The patchset keeps track of the pause loop exit/cpu relax interception
and gives chance to a vcpu which:
 (a) Has not done pause loop exit or cpu relax intercepted at all
     (probably he is preempted lock-holder)
 (b) Was skipped in last iteration because it did pause loop exit or
     cpu relax intercepted, and probably has become eligible now
     (next eligible lock holder)

Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> # on s390x
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-07-23 13:02:37 +03:00
Raghavendra K T 4c088493c8 KVM: Note down when cpu relax intercepted or pause loop exited
Noting pause loop exited vcpu or cpu relax intercepted helps in
filtering right candidate to yield. Wrong selection of vcpu;
i.e., a vcpu that just did a pl-exit or cpu relax intercepted may
contribute to performance degradation.

Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> # on s390x
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-07-23 13:01:52 +03:00
Raghavendra K T f2a7434731 KVM: Add config to support ple or cpu relax optimzation
Suggested-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> # on s390x
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-07-23 13:00:53 +03:00
Michael S. Tsirkin 93b6547e22 KVM: switch to symbolic name for irq_states size
Use PIC_NUM_PINS instead of hard-coded 16 for pic pins.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-07-20 16:12:16 -03:00
Michael S. Tsirkin 1a577b7247 KVM: fix race with level interrupts
When more than 1 source id is in use for the same GSI, we have the
following race related to handling irq_states race:

CPU 0 clears bit 0. CPU 0 read irq_state as 0. CPU 1 sets level to 1.
CPU 1 calls kvm_ioapic_set_irq(1). CPU 0 calls kvm_ioapic_set_irq(0).
Now ioapic thinks the level is 0 but irq_state is not 0.

Fix by performing all irq_states bitmap handling under pic/ioapic lock.
This also removes the need for atomics with irq_states handling.

Reported-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-07-20 16:12:00 -03:00
Xiao Guangrong d566104853 KVM: remove the unused parameter of gfn_to_pfn_memslot
The parameter, 'kvm', is not used in gfn_to_pfn_memslot, we can happily remove
it

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-07-19 21:25:24 -03:00
Xiao Guangrong ca0565f573 KVM: make bad_pfn static to kvm_main.c
bad_pfn is not used out of kvm_main.c, so mark it static, also move it near
hwpoison_pfn and fault_pfn

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-07-19 21:17:10 -03:00
Xiao Guangrong 903816fa4d KVM: using get_fault_pfn to get the fault pfn
Using get_fault_pfn to cleanup the code

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-07-19 21:15:25 -03:00
Takuya Yoshikawa b3ae209697 KVM: Introduce kvm_unmap_hva_range() for kvm_mmu_notifier_invalidate_range_start()
When we tested KVM under memory pressure, with THP enabled on the host,
we noticed that MMU notifier took a long time to invalidate huge pages.

Since the invalidation was done with mmu_lock held, it not only wasted
the CPU but also made the host harder to respond.

This patch mitigates this by using kvm_handle_hva_range().

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Cc: Alexander Graf <agraf@suse.de>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-07-18 16:55:04 -03:00
Alex Williamson a76beb1412 KVM: Fix device assignment threaded irq handler
The kernel no longer allows us to pass NULL for the hard handler
without also specifying IRQF_ONESHOT.  IRQF_ONESHOT imposes latency
in the exit path that we don't need for MSI interrupts.  Long term
we'd like to inject these interrupts from the hard handler when
possible.  In the short term, we can create dummy hard handlers
that return us to the previous behavior.  Credit to Michael for
original patch.

Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=43328

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-07-11 13:01:48 +03:00
Rik van Riel 5cfc2aabcb KVM: handle last_boosted_vcpu = 0 case
If last_boosted_vcpu == 0, then we fall through all test cases and
may end up with all VCPUs pouncing on vcpu 0.  With a large enough
guest, this can result in enormous runqueue lock contention, which
can prevent vcpu0 from running, leading to a livelock.

Changing < to <= makes sure we properly handle that case.

Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-07-06 14:11:18 -03:00
Xiao Guangrong f411930442 KVM: fix fault page leak
fault_page is forgot to be freed

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-07-03 17:31:50 -03:00
Alex Williamson 326cf0334b KVM: Sanitize KVM_IRQFD flags
We only know of one so far.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-07-02 21:10:30 -03:00
Alex Williamson d4db2935e4 KVM: Pass kvm_irqfd to functions
Prune this down to just the struct kvm_irqfd so we can avoid
changing function definition for every flag or field we use.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-07-02 21:10:30 -03:00
Marc Zyngier 9900b4b48b KVM: use KVM_CAP_IRQ_ROUTING to protect the routing related code
The KVM code sometimes uses CONFIG_HAVE_KVM_IRQCHIP to protect
code that is related to IRQ routing, which not all in-kernel
irqchips may support.

Use KVM_CAP_IRQ_ROUTING instead.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-06-18 16:06:35 +03:00
Jan Kiszka f961f72836 KVM: Fix PCI header check on device assignment
The masking was wrong (must have been 0x7f), and there is no need to
re-read the value as pci_setup_device already does this for us.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=43339
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-06-15 23:22:12 -03:00
Avi Kivity f2ebd422f7 KVM: Fix buffer overflow in kvm_set_irq()
kvm_set_irq() has an internal buffer of three irq routing entries, allowing
connecting a GSI to three IRQ chips or on MSI.  However setup_routing_entry()
does not properly enforce this, allowing three irqchip routes followed by
an MSI route to overflow the buffer.

Fix by ensuring that an MSI entry is added to an empty list.

Signed-off-by: Avi Kivity <avi@redhat.com>
2012-06-05 16:39:58 +03:00
Takuya Yoshikawa c1a7b32a14 KVM: Avoid wasting pages for small lpage_info arrays
lpage_info is created for each large level even when the memory slot is
not for RAM.  This means that when we add one slot for a PCI device, we
end up allocating at least KVM_NR_PAGE_SIZES - 1 pages by vmalloc().

To make things worse, there is an increasing number of devices which
would result in more pages being wasted this way.

This patch mitigates this problem by using kvm_kvzalloc().

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-06-05 16:29:49 +03:00
Takuya Yoshikawa 92eca8faad KVM: Separate out dirty_bitmap allocation code as kvm_kvzalloc()
Will be used for lpage_info allocation later.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-06-05 16:29:39 +03:00
Konstantin Weitz 41628d3343 KVM: s390: Implement the directed yield (diag 9c) hypervisor call for KVM
This patch implements the directed yield hypercall found on other
System z hypervisors. It delegates execution time to the virtual cpu
specified in the instruction's parameter.

Useful to avoid long spinlock waits in the guest.

Christian Borntraeger: moved common code in virt/kvm/

Signed-off-by: Konstantin Weitz <WEITZKON@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-04-30 21:38:31 -03:00
Jan Kiszka 07975ad3b3 KVM: Introduce direct MSI message injection for in-kernel irqchips
Currently, MSI messages can only be injected to in-kernel irqchips by
defining a corresponding IRQ route for each message. This is not only
unhandy if the MSI messages are generated "on the fly" by user space,
IRQ routes are a limited resource that user space has to manage
carefully.

By providing a direct injection path, we can both avoid using up limited
resources and simplify the necessary steps for user land.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-24 15:59:47 +03:00
Marcelo Tosatti eac0556750 Merge branch 'linus' into queue
Merge reason: development work has dependency on kvm patches merged
upstream.

Conflicts:
	Documentation/feature-removal-schedule.txt

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-04-19 17:06:26 -03:00
Alex Williamson 21a1416a1c KVM: lock slots_lock around device assignment
As pointed out by Jason Baron, when assigning a device to a guest
we first set the iommu domain pointer, which enables mapping
and unmapping of memory slots to the iommu.  This leaves a window
where this path is enabled, but we haven't synchronized the iommu
mappings to the existing memory slots.  Thus a slot being removed
at that point could send us down unexpected code paths removing
non-existent pinnings and iommu mappings.  Take the slots_lock
around creating the iommu domain and initial mappings as well as
around iommu teardown to avoid this race.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-04-19 00:04:18 -03:00
Michael S. Tsirkin a0c9a822bf KVM: dont clear TMR on EOI
Intel spec says that TMR needs to be set/cleared
when IRR is set, but kvm also clears it on  EOI.

I did some tests on a real (AMD based) system,
and I see same TMR values both before
and after EOI, so I think it's a minor bug in kvm.

This patch fixes TMR to be set/cleared on IRR set
only as per spec.

And now that we don't clear TMR, we can save
an atomic read of TMR on EOI that's not propagated
to ioapic, by checking whether ioapic needs
a specific vector first and calculating
the mode afterwards.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-04-16 20:36:38 -03:00
Alex Williamson 32f6daad46 KVM: unmap pages from the iommu when slots are removed
We've been adding new mappings, but not destroying old mappings.
This can lead to a page leak as pages are pinned using
get_user_pages, but only unpinned with put_page if they still
exist in the memslots list on vm shutdown.  A memslot that is
destroyed while an iommu domain is enabled for the guest will
therefore result in an elevated page reference count that is
never cleared.

Additionally, without this fix, the iommu is only programmed
with the first translation for a gpa.  This can result in
peer-to-peer errors if a mapping is destroyed and replaced by a
new mapping at the same gpa as the iommu will still be pointing
to the original, pinned memory address.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-04-11 22:55:25 -03:00
Takuya Yoshikawa 93474b25af KVM: Remove unused dirty_bitmap_head and nr_dirty_pages
Now that we do neither double buffering nor heuristic selection of the
write protection method these are not needed anymore.

Note: some drivers have their own implementation of set_bit_le() and
making it generic needs a bit of work; so we use test_and_set_bit_le()
and will later replace it with generic set_bit_le().

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08 12:50:01 +03:00
Marcelo Tosatti 8c84780df9 KVM: fix kvm_vcpu_kick build failure on S390
S390's kvm_vcpu_stat does not contain halt_wakeup member.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08 12:49:42 +03:00
Christoffer Dall b6d33834bd KVM: Factor out kvm_vcpu_kick to arch-generic code
The kvm_vcpu_kick function performs roughly the same funcitonality on
most all architectures, so we shouldn't have separate copies.

PowerPC keeps a pointer to interchanging waitqueues on the vcpu_arch
structure and to accomodate this special need a
__KVM_HAVE_ARCH_VCPU_GET_WQ define and accompanying function
kvm_arch_vcpu_wq have been defined. For all other architectures this
is a generic inline that just returns &vcpu->wq;

Acked-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08 12:47:47 +03:00
Amos Kong a13007160f KVM: resize kvm_io_range array dynamically
This patch makes the kvm_io_range array can be resized dynamically.

Signed-off-by: Amos Kong <akong@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08 12:46:58 +03:00
Jan Kiszka cf9eeac463 KVM: Convert intx_mask_lock to spin lock
As kvm_notify_acked_irq calls kvm_assigned_dev_ack_irq under
rcu_read_lock, we cannot use a mutex in the latter function. Switch to a
spin lock to address this.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-20 12:41:24 +02:00
Alex Shi bec87d6e34 KVM: use correct tlbs dirty type in cmpxchg
Using 'int' type is not suitable for a 'long' object. So, correct it.

Signed-off-by: Alex Shi <alex.shi@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-08 14:11:44 +02:00
Jan Kiszka 07700a94b0 KVM: Allow host IRQ sharing for assigned PCI 2.3 devices
PCI 2.3 allows to generically disable IRQ sources at device level. This
enables us to share legacy IRQs of such devices with other host devices
when passing them to a guest.

The new IRQ sharing feature introduced here is optional, user space has
to request it explicitly. Moreover, user space can inform us about its
view of PCI_COMMAND_INTX_DISABLE so that we can avoid unmasking the
interrupt and signaling it if the guest masked it via the virtualized
PCI config space.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-08 14:11:36 +02:00
Avi Kivity 3e515705a1 KVM: Ensure all vcpus are consistent with in-kernel irqchip settings
If some vcpus are created before KVM_CREATE_IRQCHIP, then
irqchip_in_kernel() and vcpu->arch.apic will be inconsistent, leading
to potential NULL pointer dereferences.

Fix by:
- ensuring that no vcpus are installed when KVM_CREATE_IRQCHIP is called
- ensuring that a vcpu has an apic if it is installed after KVM_CREATE_IRQCHIP

This is somewhat long winded because vcpu->arch.apic is created without
kvm->lock held.

Based on earlier patch by Michael Ellerman.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-08 14:10:30 +02:00
Takuya Yoshikawa 565f3be217 KVM: mmu_notifier: Flush TLBs before releasing mmu_lock
Other threads may process the same page in that small window and skip
TLB flush and then return before these functions do flush.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-08 14:10:23 +02:00
Takuya Yoshikawa db3fe4eb45 KVM: Introduce kvm_memory_slot::arch and move lpage_info into it
Some members of kvm_memory_slot are not used by every architecture.

This patch is the first step to make this difference clear by
introducing kvm_memory_slot::arch;  lpage_info is moved into it.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-08 14:10:22 +02:00
Takuya Yoshikawa 189a2f7b24 KVM: Simplify ifndef conditional usage in __kvm_set_memory_region()
Narrow down the controlled text inside the conditional so that it will
include lpage_info and rmap stuff only.

For this we change the way we check whether the slot is being created
from "if (npages && !new.rmap)" to "if (npages && !old.npages)".

We also stop checking if lpage_info is NULL when we create lpage_info
because we do it from inside the slot creation code block.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-08 14:10:21 +02:00
Takuya Yoshikawa a64f273a08 KVM: Split lpage_info creation out from __kvm_set_memory_region()
This makes it easy to make lpage_info architecture specific.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-08 14:10:20 +02:00
Takuya Yoshikawa fb03cb6f44 KVM: Introduce gfn_to_index() which returns the index for a given level
This patch cleans up the code and removes the "(void)level;" warning
suppressor.

Note that we can also use this for PT_PAGE_TABLE_LEVEL to treat every
level uniformly later.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-08 14:10:19 +02:00
Paul Mackerras 9d4cba7f93 KVM: Move gfn_to_memslot() to kvm_host.h
This moves __gfn_to_memslot() and search_memslots() from kvm_main.c to
kvm_host.h to reduce the code duplication caused by the need for
non-modular code in arch/powerpc/kvm/book3s_hv_rm_mmu.c to call
gfn_to_memslot() in real mode.

Rather than putting gfn_to_memslot() itself in a header, which would
lead to increased code size, this puts __gfn_to_memslot() in a header.
Then, the non-modular uses of gfn_to_memslot() are changed to call
__gfn_to_memslot() instead.  This way there is only one place in the
source code that needs to be changed should the gfn_to_memslot()
implementation need to be modified.

On powerpc, the Book3S HV style of KVM has code that is called from
real mode which needs to call gfn_to_memslot() and thus needs this.
(Module code is allocated in the vmalloc region, which can't be
accessed in real mode.)

With this, we can remove builtin_gfn_to_memslot() from book3s_hv_rm_mmu.c.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05 14:57:22 +02:00
Michael S. Tsirkin b93a355327 KVM: fix error handling for out of range irq
find_index_from_host_irq returns 0 on error
but callers assume < 0 on error. This should
not matter much: an out of range irq should never happen since
irq handler was registered with this irq #,
and even if it does we get a spurious msix irq in guest
and typically nothing terrible happens.

Still, better to make it consistent.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05 14:52:43 +02:00
Paul Mackerras a355aa54f1 KVM: Add barriers to allow mmu_notifier_retry to be used locklessly
This adds an smp_wmb in kvm_mmu_notifier_invalidate_range_end() and an
smp_rmb in mmu_notifier_retry() so that mmu_notifier_retry() will give
the correct answer when called without kvm->mmu_lock being held.
PowerPC Book3S HV KVM wants to use a bitlock per guest page rather than
a single global spinlock in order to improve the scalability of updates
to the guest MMU hashed page table, and so needs this.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05 14:52:38 +02:00
Carsten Otte 5b1c1493af KVM: s390: ucontrol: export SIE control block to user
This patch exports the s390 SIE hardware control block to userspace
via the mapping of the vcpu file descriptor. In order to do so,
a new arch callback named kvm_arch_vcpu_fault  is introduced for all
architectures. It allows to map architecture specific pages.

Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05 14:52:19 +02:00
Carsten Otte e08b963716 KVM: s390: add parameter for KVM_CREATE_VM
This patch introduces a new config option for user controlled kernel
virtual machines. It introduces a parameter to KVM_CREATE_VM that
allows to set bits that alter the capabilities of the newly created
virtual machine.
The parameter is passed to kvm_arch_init_vm for all architectures.
The only valid modifier bit for now is KVM_VM_S390_UCONTROL.
This requires CAP_SYS_ADMIN privileges and creates a user controlled
virtual machine on s390 architectures.

Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05 14:52:18 +02:00
Takuya Yoshikawa 50e92b3c97 KVM: Fix __set_bit() race in mark_page_dirty() during dirty logging
It is possible that the __set_bit() in mark_page_dirty() is called
simultaneously on the same region of memory, which may result in only
one bit being set, because some callers do not take mmu_lock before
mark_page_dirty().

This problem is hard to produce because when we reach mark_page_dirty()
beginning from, e.g., tdp_page_fault(), mmu_lock is being held during
__direct_map():  making kvm-unit-tests' dirty log api test write to two
pages concurrently was not useful for this reason.

So we have confirmed that there can actually be race condition by
checking if some callers really reach there without holding mmu_lock
using spin_is_locked():  probably they were from kvm_write_guest_page().

To fix this race, this patch changes the bit operation to the atomic
version:  note that nr_dirty_pages also suffers from the race but we do
not need exactly correct numbers for now.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-02-01 11:42:32 +02:00
Rusty Russell 90ab5ee941 module_param: make bool parameters really bool (drivers & misc)
module_param(bool) used to counter-intuitively take an int.  In
fddd5201 (mid-2009) we allowed bool or int/unsigned int using a messy
trick.

It's time to remove the int/unsigned int option.  For this version
it'll simply give a warning, but it'll break next kernel version.

Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-01-13 09:32:20 +10:30
Linus Torvalds 1c8106528a Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (53 commits)
  iommu/amd: Set IOTLB invalidation timeout
  iommu/amd: Init stats for iommu=pt
  iommu/amd: Remove unnecessary cache flushes in amd_iommu_resume
  iommu/amd: Add invalidate-context call-back
  iommu/amd: Add amd_iommu_device_info() function
  iommu/amd: Adapt IOMMU driver to PCI register name changes
  iommu/amd: Add invalid_ppr callback
  iommu/amd: Implement notifiers for IOMMUv2
  iommu/amd: Implement IO page-fault handler
  iommu/amd: Add routines to bind/unbind a pasid
  iommu/amd: Implement device aquisition code for IOMMUv2
  iommu/amd: Add driver stub for AMD IOMMUv2 support
  iommu/amd: Add stat counter for IOMMUv2 events
  iommu/amd: Add device errata handling
  iommu/amd: Add function to get IOMMUv2 domain for pdev
  iommu/amd: Implement function to send PPR completions
  iommu/amd: Implement functions to manage GCR3 table
  iommu/amd: Implement IOMMUv2 TLB flushing routines
  iommu/amd: Add support for IOMMUv2 domain mode
  iommu/amd: Add amd_iommu_domain_direct_map function
  ...
2012-01-10 11:08:21 -08:00
Joerg Roedel 00fb5430f5 Merge branches 'iommu/fixes', 'arm/omap' and 'x86/amd' into next
Conflicts:
	drivers/pci/hotplug/acpiphp_glue.c
2012-01-09 13:04:05 +01:00
Hamo 4f69b6805c KVM: ensure that debugfs entries have been created
by checking the return value from kvm_init_debug, we
can ensure that the entries under debugfs for KVM have
been created correctly.

Signed-off-by: Yang Bai <hamo.by@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-12-27 11:22:33 +02:00
Gleb Natapov d546cb406e KVM: drop bsp_vcpu pointer from kvm struct
Drop bsp_vcpu pointer from kvm struct since its only use is incorrect
anyway.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-12-27 11:22:32 +02:00
Sasha Levin ff5c2c0316 KVM: Use memdup_user instead of kmalloc/copy_from_user
Switch to using memdup_user when possible. This makes code more
smaller and compact, and prevents errors.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-27 11:22:21 +02:00
Sasha Levin cdfca7b346 KVM: Use kmemdup() instead of kmalloc/memcpy
Switch to kmemdup() in two places to shorten the code and avoid possible bugs.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-27 11:22:20 +02:00
Julian Stecklina d77fe6354d KVM: Allow aligned byte and word writes to IOAPIC registers.
This fixes byte accesses to IOAPIC_REG_SELECT as mandated by at least the
ICH10 and Intel Series 5 chipset specs. It also makes ioapic_mmio_write
consistent with ioapic_mmio_read, which also allows byte and word accesses.

Signed-off-by: Julian Stecklina <js@alien8.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-27 11:17:44 +02:00
Xiao Guangrong f85e2cb5db KVM: introduce a table to map slot id to index in memslots array
The operation of getting dirty log is frequent when framebuffer-based
displays are used(for example, Xwindow), so, we introduce a mapping table
to speed up id_to_memslot()

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-27 11:17:42 +02:00
Xiao Guangrong bf3e05bc1e KVM: sort memslots by its size and use line search
Sort memslots base on its size and use line search to find it, so that the
larger memslots have better fit

The idea is from Avi

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-27 11:17:40 +02:00
Xiao Guangrong 28a37544fb KVM: introduce id_to_memslot function
Introduce id_to_memslot to get memslot by slot id

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-27 11:17:39 +02:00
Xiao Guangrong be6ba0f096 KVM: introduce kvm_for_each_memslot macro
Introduce kvm_for_each_memslot to walk all valid memslot

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-27 11:17:37 +02:00
Xiao Guangrong be593d6286 KVM: introduce update_memslots function
Introduce update_memslots to update slot which will be update to
kvm->memslots

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-27 11:17:35 +02:00
Xiao Guangrong 93a5cef07d KVM: introduce KVM_MEM_SLOTS_NUM macro
Introduce KVM_MEM_SLOTS_NUM macro to instead of
KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-27 11:17:34 +02:00
Takuya Yoshikawa 7850ac5420 KVM: Count the number of dirty pages for dirty logging
Needed for the next patch which uses this number to decide how to write
protect a slot.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-27 11:17:19 +02:00
Thomas Meyer 6da64fdb8c KVM: Use kmemdup rather than duplicating its implementation
Use kmemdup rather than duplicating its implementation

 The semantic patch that makes this change is available
 in scripts/coccinelle/api/memdup.cocci.

 More information about semantic patching is available at
 http://coccinelle.lip6.fr/

Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-12-27 11:17:11 +02:00
Dan Carpenter 1a214246cb KVM: make checks stricter in coalesced_mmio_in_range()
My testing version of Smatch complains that addr and len come from
the user and they can wrap.  The path is:
  -> kvm_vm_ioctl()
     -> kvm_vm_ioctl_unregister_coalesced_mmio()
        -> coalesced_mmio_in_range()

I don't know what the implications are of wrapping here, but we may
as well fix it, if only to silence the warning.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-12-27 11:17:07 +02:00
Alex Williamson 3d27e23b17 KVM: Device assignment permission checks
Only allow KVM device assignment to attach to devices which:

 - Are not bridges
 - Have BAR resources (assume others are special devices)
 - The user has permissions to use

Assigning a bridge is a configuration error, it's not supported, and
typically doesn't result in the behavior the user is expecting anyway.
Devices without BAR resources are typically chipset components that
also don't have host drivers.  We don't want users to hold such devices
captive or cause system problems by fencing them off into an iommu
domain.  We determine "permission to use" by testing whether the user
has access to the PCI sysfs resource files.  By default a normal user
will not have access to these files, so it provides a good indication
that an administration agent has granted the user access to the device.

[Yang Bai: add missing #include]
[avi: fix comment style]

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Yang Bai <hamo.by@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-12-25 19:03:54 +02:00
Alex Williamson 423873736b KVM: Remove ability to assign a device without iommu support
This option has no users and it exposes a security hole that we
can allow devices to be assigned without iommu protection.  Make
KVM_DEV_ASSIGN_ENABLE_IOMMU a mandatory option.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-12-25 17:13:31 +02:00
Ohad Ben-Cohen 7d3002cc8c iommu/core: split mapping to page sizes as supported by the hardware
When mapping a memory region, split it to page sizes as supported
by the iommu hardware. Always prefer bigger pages, when possible,
in order to reduce the TLB pressure.

The logic to do that is now added to the IOMMU core, so neither the iommu
drivers themselves nor users of the IOMMU API have to duplicate it.

This allows a more lenient granularity of mappings; traditionally the
IOMMU API took 'order' (of a page) as a mapping size, and directly let
the low level iommu drivers handle the mapping, but now that the IOMMU
core can split arbitrary memory regions into pages, we can remove this
limitation, so users don't have to split those regions by themselves.

Currently the supported page sizes are advertised once and they then
remain static. That works well for OMAP and MSM but it would probably
not fly well with intel's hardware, where the page size capabilities
seem to have the potential to be different between several DMA
remapping devices.

register_iommu() currently sets a default pgsize behavior, so we can convert
the IOMMU drivers in subsequent patches. After all the drivers
are converted, the temporary default settings will be removed.

Mainline users of the IOMMU API (kvm and omap-iovmm) are adopted
to deal with bytes instead of page order.

Many thanks to Joerg Roedel <Joerg.Roedel@amd.com> for significant review!

Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Cc: David Brown <davidb@codeaurora.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Joerg Roedel <Joerg.Roedel@amd.com>
Cc: Stepan Moskovchenko <stepanm@codeaurora.org>
Cc: KyongHo Cho <pullip.cho@samsung.com>
Cc: Hiroshi DOYU <hdoyu@nvidia.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: kvm@vger.kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2011-11-10 11:40:37 +01:00
Paul Gortmaker 51441d434f kvm: iommu.c file requires the full module.h present.
This file has things like module_param_named() and MODULE_PARM_DESC()
so it needs the full module.h header present.  Without it, you'll get:

  CC      arch/x86/kvm/../../../virt/kvm/iommu.o
virt/kvm/iommu.c:37: error: expected ‘)’ before ‘bool’
virt/kvm/iommu.c:39: error: expected ‘)’ before string constant
make[3]: *** [arch/x86/kvm/../../../virt/kvm/iommu.o] Error 1
make[2]: *** [arch/x86/kvm] Error 2

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:32:13 -04:00
Paul Gortmaker 799fd8b239 kvm: fix implicit use of stat.h header file
This was coming in via an implicit module.h (and its sub-includes)
before, but we'll be cleaning that up shortly.  Call out the stat.h
include requirement in advance.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:32:12 -04:00
Linus Torvalds 0cfdc72439 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (33 commits)
  iommu/core: Remove global iommu_ops and register_iommu
  iommu/msm: Use bus_set_iommu instead of register_iommu
  iommu/omap: Use bus_set_iommu instead of register_iommu
  iommu/vt-d: Use bus_set_iommu instead of register_iommu
  iommu/amd: Use bus_set_iommu instead of register_iommu
  iommu/core: Use bus->iommu_ops in the iommu-api
  iommu/core: Convert iommu_found to iommu_present
  iommu/core: Add bus_type parameter to iommu_domain_alloc
  Driver core: Add iommu_ops to bus_type
  iommu/core: Define iommu_ops and register_iommu only with CONFIG_IOMMU_API
  iommu/amd: Fix wrong shift direction
  iommu/omap: always provide iommu debug code
  iommu/core: let drivers know if an iommu fault handler isn't installed
  iommu/core: export iommu_set_fault_handler()
  iommu/omap: Fix build error with !IOMMU_SUPPORT
  iommu/omap: Migrate to the generic fault report mechanism
  iommu/core: Add fault reporting mechanism
  iommu/core: Use PAGE_SIZE instead of hard-coded value
  iommu/core: use the existing IS_ALIGNED macro
  iommu/msm: ->unmap() should return order of unmapped page
  ...

Fixup trivial conflicts in drivers/iommu/Makefile: "move omap iommu to
dedicated iommu folder" vs "Rename the DMAR and INTR_REMAP config
options" just happened to touch lines next to each other.
2011-10-30 15:46:19 -07:00
Linus Torvalds 1bc87b0055 Merge branch 'kvm-updates/3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm
* 'kvm-updates/3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm: (75 commits)
  KVM: SVM: Keep intercepting task switching with NPT enabled
  KVM: s390: implement sigp external call
  KVM: s390: fix register setting
  KVM: s390: fix return value of kvm_arch_init_vm
  KVM: s390: check cpu_id prior to using it
  KVM: emulate lapic tsc deadline timer for guest
  x86: TSC deadline definitions
  KVM: Fix simultaneous NMIs
  KVM: x86 emulator: convert push %sreg/pop %sreg to direct decode
  KVM: x86 emulator: switch lds/les/lss/lfs/lgs to direct decode
  KVM: x86 emulator: streamline decode of segment registers
  KVM: x86 emulator: simplify OpMem64 decode
  KVM: x86 emulator: switch src decode to decode_operand()
  KVM: x86 emulator: qualify OpReg inhibit_byte_regs hack
  KVM: x86 emulator: switch OpImmUByte decode to decode_imm()
  KVM: x86 emulator: free up some flag bits near src, dst
  KVM: x86 emulator: switch src2 to generic decode_operand()
  KVM: x86 emulator: expand decode flags to 64 bits
  KVM: x86 emulator: split dst decode to a generic decode_operand()
  KVM: x86 emulator: move memop, memopp into emulation context
  ...
2011-10-30 15:36:45 -07:00
Joerg Roedel a1b60c1cd9 iommu/core: Convert iommu_found to iommu_present
With per-bus iommu_ops the iommu_found function needs to
work on a bus_type too. This patch adds a bus_type parameter
to that function and converts all call-places.
The function is also renamed to iommu_present because the
function now checks if an iommu is present for a given bus
and does not check for a global iommu anymore.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2011-10-21 14:37:20 +02:00
Joerg Roedel 905d66c1e5 iommu/core: Add bus_type parameter to iommu_domain_alloc
This is necessary to store a pointer to the bus-specific
iommu_ops in the iommu-domain structure. It will be used
later to call into bus-specific iommu-ops.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2011-10-21 14:37:19 +02:00
Jan Kiszka cc0793968a KVM: Split up MSI-X assigned device IRQ handler
The threaded IRQ handler for MSI-X has almost nothing in common with the
INTx/MSI handler. Move its code into a dedicated handler.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-09-25 19:52:45 +03:00
Jan Kiszka c61fa9d63b KVM: Avoid needless registrations of IRQ ack notifier for assigned devices
We only perform work in kvm_assigned_dev_ack_irq if the guest IRQ is of
INTx type. This completely avoids the callback invocation in non-INTx
cases by registering the IRQ ack notifier only for INTx.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-09-25 19:52:39 +03:00
Jan Kiszka 9f9f6b7877 KVM: Clean up unneeded void pointer casts
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-09-25 19:52:38 +03:00
Sasha Levin 743eeb0b01 KVM: Intelligent device lookup on I/O bus
Currently the method of dealing with an IO operation on a bus (PIO/MMIO)
is to call the read or write callback for each device registered
on the bus until we find a device which handles it.

Since the number of devices on a bus can be significant due to ioeventfds
and coalesced MMIO zones, this leads to a lot of overhead on each IO
operation.

Instead of registering devices, we now register ranges which points to
a device. Lookup is done using an efficient bsearch instead of a linear
search.

Performance test was conducted by comparing exit count per second with
200 ioeventfds created on one byte and the guest is trying to access a
different byte continuously (triggering usermode exits).
Before the patch the guest has achieved 259k exits per second, after the
patch the guest does 274k exits per second.

Cc: Avi Kivity <avi@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-09-25 19:17:59 +03:00
Sasha Levin 2b3c246a68 KVM: Make coalesced mmio use a device per zone
This patch changes coalesced mmio to create one mmio device per
zone instead of handling all zones in one device.

Doing so enables us to take advantage of existing locking and prevents
a race condition between coalesced mmio registration/unregistration
and lookups.

Suggested-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-09-25 19:17:57 +03:00
Sasha Levin c298125f4b KVM: MMIO: Lock coalesced device when checking for available entry
Move the check whether there are available entries to within the spinlock.
This allows working with larger amount of VCPUs and reduces premature
exits when using a large number of VCPUs.

Cc: Avi Kivity <avi@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-09-25 19:17:18 +03:00
Greg Rose 6777829cfe pci: Add flag indicating device has been assigned by KVM
Device drivers that create and destroy SR-IOV virtual functions via
calls to pci_enable_sriov() and pci_disable_sriov can cause catastrophic
failures if they attempt to destroy VFs while they are assigned to
guest virtual machines.  By adding a flag for use by the KVM module
to indicate that a device is assigned a device driver can check that
flag and avoid destroying VFs while they are assigned and avoid system
failures.

CC: Ian Campbell <ijc@hellion.org.uk>
CC: Konrad Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
2011-09-23 09:05:44 -07:00
Alex Williamson 3f68b0318b KVM: IOMMU: Disable device assignment without interrupt remapping
IOMMU interrupt remapping support provides a further layer of
isolation for device assignment by preventing arbitrary interrupt
block DMA writes by a malicious guest from reaching the host.  By
default, we should require that the platform provides interrupt
remapping support, with an opt-in mechanism for existing behavior.

Both AMD IOMMU and Intel VT-d2 hardware support interrupt
remapping, however we currently only have software support on
the Intel side.  Users wishing to re-enable device assignment
when interrupt remapping is not supported on the platform can
use the "allow_unsafe_assigned_interrupts=1" module option.

[avi: break long lines]

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-24 11:50:42 +03:00
Xiao Guangrong ce88decffd KVM: MMU: mmio page fault support
The idea is from Avi:

| We could cache the result of a miss in an spte by using a reserved bit, and
| checking the page fault error code (or seeing if we get an ept violation or
| ept misconfiguration), so if we get repeated mmio on a page, we don't need to
| search the slot list/tree.
| (https://lkml.org/lkml/2011/2/22/221)

When the page fault is caused by mmio, we cache the info in the shadow page
table, and also set the reserved bits in the shadow page table, so if the mmio
is caused again, we can quickly identify it and emulate it directly

Searching mmio gfn in memslots is heavy since we need to walk all memeslots, it
can be reduced by this feature, and also avoid walking guest page table for
soft mmu.

[jan: fix operator precedence issue]

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-24 11:50:40 +03:00
Xiao Guangrong fce92dce79 KVM: MMU: filter out the mmio pfn from the fault pfn
If the page fault is caused by mmio, the gfn can not be found in memslots, and
'bad_pfn' is returned on gfn_to_hva path, so we can use 'bad_pfn' to identify
the mmio page fault.
And, to clarify the meaning of mmio pfn, we return fault page instead of bad
page when the gfn is not allowd to prefetch

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-24 11:50:34 +03:00
Gleb Natapov e03b644fe6 KVM: introduce kvm_read_guest_cached
Introduce kvm_read_guest_cached() function in addition to write one we
already have.

[ by glauber: export function signature in kvm header ]

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Glauber Costa <glommer@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Tested-by: Eric Munson <emunson@mgebm.net>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-12 13:17:01 +03:00
Jan Kiszka 9f3191aec5 KVM: Fix off-by-one in overflow check of KVM_ASSIGN_SET_MSIX_NR
KVM_MAX_MSIX_PER_DEV implies that up to that many MSI-X entries can be
requested. But the kernel so far rejected already the upper limit.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-12 13:16:18 +03:00
Alexander Graf 1dda606c5f KVM: Add compat ioctl for KVM_SET_SIGNAL_MASK
KVM has an ioctl to define which signal mask should be used while running
inside VCPU_RUN. At least for big endian systems, this mask is different
on 32-bit and 64-bit systems (though the size is identical).

Add a compat wrapper that converts the mask to whatever the kernel accepts,
allowing 32-bit kvm user space to set signal masks.

This patch fixes qemu with --enable-io-thread on ppc64 hosts when running
32-bit user land.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-12 13:16:17 +03:00
Jan Kiszka d780592b99 KVM: Clean up error handling during VCPU creation
So far kvm_arch_vcpu_setup is responsible for freeing the vcpu struct if
it fails. Move this confusing resonsibility back into the hands of
kvm_vm_ioctl_create_vcpu. Only kvm_arch_vcpu_setup of x86 is affected,
all other archs cannot fail.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-12 11:45:08 +03:00
Xiao Guangrong 8b0cedff04 KVM: use __copy_to_user/__clear_user to write guest page
Simply use __copy_to_user/__clear_user to write guest page since we have
already verified the user address when the memslot is set

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-07-12 11:45:03 +03:00
Linus Torvalds 58a9a36b54 Merge branch 'kvm-updates/3.0' of git://git.kernel.org/pub/scm/virt/kvm/kvm
* 'kvm-updates/3.0' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: Initialize kvm before registering the mmu notifier
  KVM: x86: use proper port value when checking io instruction permission
  KVM: add missing void __user * cast to access_ok() call
2011-06-07 19:06:28 -07:00
Mike Waychison 74b5c5bfff KVM: Initialize kvm before registering the mmu notifier
It doesn't make sense to ever see a half-initialized kvm structure on
mmu notifier callbacks.  Previously, 85722cda changed the ordering to
ensure that the mmu_lock was initialized before mmu notifier
registration, but there is still a race where the mmu notifier could
come in and try accessing other portions of struct kvm before they are
intialized.

Solve this by moving the mmu notifier registration to occur after the
structure is completely initialized.

Google-Bug-Id: 452199
Signed-off-by: Mike Waychison <mikew@google.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-06-06 11:27:52 +03:00
Heiko Carstens 9e3bb6b6f6 KVM: add missing void __user * cast to access_ok() call
fa3d315a "KVM: Validate userspace_addr of memslot when registered" introduced
this new warning onn s390:

kvm_main.c: In function '__kvm_set_memory_region':
kvm_main.c:654:7: warning: passing argument 1 of '__access_ok' makes pointer from integer without a cast
arch/s390/include/asm/uaccess.h:53:19: note: expected 'const void *' but argument is of type '__u64'

Add the missing cast to get rid of it again...

Cc: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-26 02:41:44 -04:00
Linus Torvalds 5e152b4c9e Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6
* 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: (27 commits)
  PCI: Don't use dmi_name_in_vendors in quirk
  PCI: remove unused AER functions
  PCI/sysfs: move bus cpuaffinity to class dev_attrs
  PCI: add rescan to /sys/.../pci_bus/.../
  PCI: update bridge resources to get more big ranges when allocating space (again)
  KVM: Use pci_store/load_saved_state() around VM device usage
  PCI: Add interfaces to store and load the device saved state
  PCI: Track the size of each saved capability data area
  PCI/e1000e: Add and use pci_disable_link_state_locked()
  x86/PCI: derive pcibios_last_bus from ACPI MCFG
  PCI: add latency tolerance reporting enable/disable support
  PCI: add OBFF enable/disable support
  PCI: add ID-based ordering enable/disable support
  PCI hotplug: acpiphp: assume device is in state D0 after powering on a slot.
  PCI: Set PCIE maxpayload for card during hotplug insertion
  PCI/ACPI: Report _OSC control mask returned on failure to get control
  x86/PCI: irq and pci_ids patch for Intel Panther Point DeviceIDs
  PCI: handle positive error codes
  PCI: check pci_vpd_pci22_wait() return
  PCI: Use ICH6_GPIO_EN in ich6_lpc_acpi_gpio
  ...

Fix up trivial conflicts in include/linux/pci_ids.h: commit a6e5e2be44
moved the intel SMBUS ID definitons to the i2c-i801.c driver.
2011-05-23 15:39:34 -07:00
OGAWA Hirofumi 85722cda30 KVM: Fix kvm mmu_notifier initialization order
Like the following, mmu_notifier can be called after registering
immediately. So, kvm have to initialize kvm->mmu_lock before it.

BUG: spinlock bad magic on CPU#0, kswapd0/342
 lock: ffff8800af8c4000, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
Pid: 342, comm: kswapd0 Not tainted 2.6.39-rc5+ #1
Call Trace:
 [<ffffffff8118ce61>] spin_bug+0x9c/0xa3
 [<ffffffff8118ce91>] do_raw_spin_lock+0x29/0x13c
 [<ffffffff81024923>] ? flush_tlb_others_ipi+0xaf/0xfd
 [<ffffffff812e22f3>] _raw_spin_lock+0x9/0xb
 [<ffffffffa0582325>] kvm_mmu_notifier_clear_flush_young+0x2c/0x66 [kvm]
 [<ffffffff810d3ff3>] __mmu_notifier_clear_flush_young+0x2b/0x57
 [<ffffffff810c8761>] page_referenced_one+0x88/0xea
 [<ffffffff810c89bf>] page_referenced+0x1fc/0x256
 [<ffffffff810b2771>] shrink_page_list+0x187/0x53a
 [<ffffffff810b2ed7>] shrink_inactive_list+0x1e0/0x33d
 [<ffffffff810acf95>] ? determine_dirtyable_memory+0x15/0x27
 [<ffffffff812e90ee>] ? call_function_single_interrupt+0xe/0x20
 [<ffffffff810b3356>] shrink_zone+0x322/0x3de
 [<ffffffff810a9587>] ? zone_watermark_ok_safe+0xe2/0xf1
 [<ffffffff810b3928>] kswapd+0x516/0x818
 [<ffffffff810b3412>] ? shrink_zone+0x3de/0x3de
 [<ffffffff81053d17>] kthread+0x7d/0x85
 [<ffffffff812e9394>] kernel_thread_helper+0x4/0x10
 [<ffffffff81053c9a>] ? __init_kthread_worker+0x37/0x37
 [<ffffffff812e9390>] ? gs_change+0xb/0xb

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-22 08:48:12 -04:00
Takuya Yoshikawa fa3d315a4c KVM: Validate userspace_addr of memslot when registered
This way, we can avoid checking the user space address many times when
we read the guest memory.

Although we can do the same for write if we check which slots are
writable, we do not care write now: reading the guest memory happens
more often than writing.

[avi: change VERIFY_READ to VERIFY_WRITE]

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-22 08:47:56 -04:00
Liu Yuan a38f84ca8c KVM: ioapic: Fix an error field reference
Function ioapic_debug() in the ioapic_deliver() misnames
one filed by reference. This patch correct it.

Signed-off-by: Liu Yuan <tailai.ly@taobao.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-22 08:39:27 -04:00
Alex Williamson f8fcfd7755 KVM: Use pci_store/load_saved_state() around VM device usage
Store the device saved state so that we can reload the device back
to the original state when it's unassigned.  This has the benefit
that the state survives across pci_reset_function() calls via
the PCI sysfs reset interface while the VM is using the device.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-05-21 12:17:10 -07:00
Xiao Guangrong 0ee8dcb87e KVM: cleanup memslot_id function
We can get memslot id from memslot->id directly

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-11 07:56:53 -04:00
Linus Torvalds 7bc30c23c8 Merge branch 'kvm-updates/2.6.39' of git://git.kernel.org/pub/scm/virt/kvm/kvm
* 'kvm-updates/2.6.39' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: move and fix substitue search for missing CPUID entries
  KVM: fix XSAVE bit scanning
  KVM: Enable async page fault processing
  KVM: fix crash on irqfd deassign
2011-04-07 11:33:04 -07:00
Gleb Natapov 0857b9e95c KVM: Enable async page fault processing
If asynchronous hva_to_pfn() is requested call GUP with FOLL_NOWAIT to
avoid sleeping on IO. Check for hwpoison is done at the same time,
otherwise check_user_page_hwpoison() will call GUP again and will put
vcpu to sleep.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-04-06 13:15:55 +03:00
Michael S. Tsirkin 9e02fb9633 KVM: fix crash on irqfd deassign
irqfd in kvm used flush_work incorrectly: it assumed that work scheduled
previously can't run after flush_work, but since kvm uses a non-reentrant
workqueue (by means of schedule_work) we need flush_work_sync to get that
guarantee.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reported-by: Jean-Philippe Menil <jean-philippe.menil@univ-nantes.fr>
Tested-by: Jean-Philippe Menil <jean-philippe.menil@univ-nantes.fr>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-04-06 13:15:55 +03:00
Lucas De Marchi 25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Linus Torvalds 16c29dafcc Merge branch 'syscore' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6
* 'syscore' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
  Introduce ARCH_NO_SYSDEV_OPS config option (v2)
  cpufreq: Use syscore_ops for boot CPU suspend/resume (v2)
  KVM: Use syscore_ops instead of sysdev class and sysdev
  PCI / Intel IOMMU: Use syscore_ops instead of sysdev class and sysdev
  timekeeping: Use syscore_ops instead of sysdev class and sysdev
  x86: Use syscore_ops instead of sysdev classes and sysdevs
2011-03-25 21:07:59 -07:00
Akinobu Mita cd7e48c5de kvm: use little-endian bitops
As a preparation for removing ext2 non-atomic bit operations from
asm/bitops.h.  This converts ext2 non-atomic bit operations to
little-endian bit operations.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23 19:46:16 -07:00
Akinobu Mita 5140a357ea kvm: stop including asm-generic/bitops/le.h directly
asm-generic/bitops/le.h is only intended to be included directly from
asm-generic/bitops/ext2-non-atomic.h or asm-generic/bitops/minix-le.h
which implements generic ext2 or minix bit operations.

This stops including asm-generic/bitops/le.h directly and use ext2
non-atomic bit operations instead.

It seems odd to use ext2_set_bit() on kvm, but it will replaced with
__set_bit_le() after introducing little endian bit operations for all
architectures.  This indirect step is necessary to maintain bisectability
for some architectures which have their own little-endian bit operations.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23 19:46:10 -07:00
Rafael J. Wysocki fb3600cc50 KVM: Use syscore_ops instead of sysdev class and sysdev
KVM uses a sysdev class and a sysdev for executing kvm_suspend()
after interrupts have been turned off on the boot CPU (during system
suspend) and for executing kvm_resume() before turning on interrupts
on the boot CPU (during system resume).  However, since both of these
functions ignore their arguments, the entire mechanism may be
replaced with a struct syscore_ops object which is simpler.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Avi Kivity <avi@redhat.com>
2011-03-23 22:16:23 +01:00
Michael S. Tsirkin c8ce057eaf KVM: improve comment on rcu use in irqfd_deassign
The RCU use in kvm_irqfd_deassign is tricky: we have rcu_assign_pointer
but no synchronize_rcu: synchronize_rcu is done by kvm_irq_routing_update
which we share a spinlock with.

Fix up a comment in an attempt to make this clearer.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-03-17 13:08:33 -03:00
Jan Kiszka e935b8372c KVM: Convert kvm_lock to raw_spinlock
Code under this lock requires non-preemptibility. Ensure this also over
-rt by converting it to raw spinlock.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-03-17 13:08:30 -03:00
Rik van Riel 217ece6129 KVM: use yield_to instead of sleep in kvm_vcpu_on_spin
Instead of sleeping in kvm_vcpu_on_spin, which can cause gigantic
slowdowns of certain workloads, we instead use yield_to to get
another VCPU in the same KVM guest to run sooner.

This seems to give a 10-15% speedup in certain workloads.

Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-03-17 13:08:29 -03:00
Rik van Riel 34bb10b79d KVM: keep track of which task is running a KVM vcpu
Keep track of which task is running a KVM vcpu.  This helps us
figure out later what task to wake up if we want to boost a
vcpu that got preempted.

Unfortunately there are no guarantees that the same task
always keeps the same vcpu, so we can only track the task
across a single "run" of the vcpu.

Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-03-17 13:08:29 -03:00
Huang Ying fafc3dbaac KVM: Replace is_hwpoison_address with __get_user_pages
is_hwpoison_address only checks whether the page table entry is
hwpoisoned, regardless the memory page mapped.  While __get_user_pages
will check both.

QEMU will clear the poisoned page table entry (via unmap/map) to make
it possible to allocate a new memory page for the virtual address
across guest rebooting.  But it is also possible that the underlying
memory page is kept poisoned even after the corresponding page table
entry is cleared, that is, a new memory page can not be allocated.
__get_user_pages can catch these situations.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-03-17 13:08:27 -03:00
Xiao Guangrong 3cba41307a KVM: make make_all_cpus_request() lockless
Now, we have 'vcpu->mode' to judge whether need to send ipi to other
cpus, this way is very exact, so checking request bit is needless,
then we can drop the spinlock let it's collateral

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-03-17 13:08:26 -03:00
Xiao Guangrong 6b7e2d0991 KVM: Add "exiting guest mode" state
Currently we keep track of only two states: guest mode and host
mode.  This patch adds an "exiting guest mode" state that tells
us that an IPI will happen soon, so unless we need to wait for the
IPI, we can avoid it completely.

Also
1: No need atomically to read/write ->mode in vcpu's thread

2: reorganize struct kvm_vcpu to make ->mode and ->requests
   in the same cache line explicitly

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-03-17 13:08:26 -03:00
Heiko Carstens d48ead8b0b KVM: fix build warning within __kvm_set_memory_region() on s390
Get rid of this warning:

  CC      arch/s390/kvm/../../../virt/kvm/kvm_main.o
arch/s390/kvm/../../../virt/kvm/kvm_main.c:596:12: warning: 'kvm_create_dirty_bitmap' defined but not used

The only caller of the function is within a !CONFIG_S390 section, so add the
same ifdef around kvm_create_dirty_bitmap() as well.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-03-17 13:08:26 -03:00
Avi Kivity 8234b22e1c KVM: MMU: Don't flush shadow when enabling dirty tracking
Instead, drop large mappings, which were the reason we dropped shadow.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-03-17 13:08:24 -03:00
Andrea Arcangeli 22e5c47ee2 thp: add compound_trans_head() helper
Cleanup some code with common compound_trans_head helper.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Avi Kivity <avi@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 17:32:48 -08:00
Andrea Arcangeli 8ee53820ed thp: mmu_notifier_test_young
For GRU and EPT, we need gup-fast to set referenced bit too (this is why
it's correct to return 0 when shadow_access_mask is zero, it requires
gup-fast to set the referenced bit).  qemu-kvm access already sets the
young bit in the pte if it isn't zero-copy, if it's zero copy or a shadow
paging EPT minor fault we relay on gup-fast to signal the page is in
use...

We also need to check the young bits on the secondary pagetables for NPT
and not nested shadow mmu as the data may never get accessed again by the
primary pte.

Without this closer accuracy, we'd have to remove the heuristic that
avoids collapsing hugepages in hugepage virtual regions that have not even
a single subpage in use.

->test_young is full backwards compatible with GRU and other usages that
don't have young bits in pagetables set by the hardware and that should
nuke the secondary mmu mappings when ->clear_flush_young runs just like
EPT does.

Removing the heuristic that checks the young bit in
khugepaged/collapse_huge_page completely isn't so bad either probably but
I thought it was worth it and this makes it reliable.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 17:32:46 -08:00
Andrea Arcangeli 936a5fe6e6 thp: kvm mmu transparent hugepage support
This should work for both hugetlbfs and transparent hugepages.

[akpm@linux-foundation.org: bring forward PageTransCompound() addition for bisectability]
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 17:32:41 -08:00
Avi Kivity b7c4145ba2 KVM: Don't spin on virt instruction faults during reboot
Since vmx blocks INIT signals, we disable virtualization extensions during
reboot.  This leads to virtualization instructions faulting; we trap these
faults and spin while the reboot continues.

Unfortunately spinning on a non-preemptible kernel may block a task that
reboot depends on; this causes the reboot to hang.

Fix by skipping over the instruction and hoping for the best.

Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12 11:30:18 +02:00
Xiao Guangrong a4ee1ca4a3 KVM: MMU: delay flush all tlbs on sync_page path
Quote from Avi:
| I don't think we need to flush immediately; set a "tlb dirty" bit somewhere
| that is cleareded when we flush the tlb.  kvm_mmu_notifier_invalidate_page()
| can consult the bit and force a flush if set.

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:29:51 +02:00
Michael S. Tsirkin bd2b53b20f KVM: fast-path msi injection with irqfd
Store irq routing table pointer in the irqfd object,
and use that to inject MSI directly without bouncing out to
a kernel thread.

While we touch this structure, rearrange irqfd fields to make fastpath
better packed for better cache utilization.

This also adds some comments about locking rules and rcu usage in code.

Some notes on the design:
- Use pointer into the rt instead of copying an entry,
  to make it possible to use rcu, thus side-stepping
  locking complexities.  We also save some memory this way.
- Old workqueue code is still used for level irqs.
  I don't think we DTRT with level anyway, however,
  it seems easier to keep the code around as
  it has been thought through and debugged, and fix level later than
  rip out and re-instate it later.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Marcelo Tosatti <mtosatti@redhat.com>
Acked-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12 11:29:38 +02:00
Takuya Yoshikawa 75b7127c38 KVM: rename hardware_[dis|en]able() to *_nolock() and add locking wrappers
The naming convension of hardware_[dis|en]able family is little bit confusing
because only hardware_[dis|en]able_all are using _nolock suffix.

Renaming current hardware_[dis|en]able() to *_nolock() and using
hardware_[dis|en]able() as wrapper functions which take kvm_lock for them
reduces extra confusion.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:29:29 +02:00
Takuya Yoshikawa 97e91e28fa KVM: take kvm_lock for hardware_disable() during cpu hotplug
In kvm_cpu_hotplug(), only CPU_STARTING case is protected by kvm_lock.
This patch adds missing protection for CPU_DYING case.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:29:28 +02:00
Jan Kiszka 51de271d44 KVM: Clean up kvm_vm_ioctl_assigned_device
Any arch not supporting device assigment will also not build
assigned-dev.c. So testing for KVM_CAP_DEVICE_DEASSIGNMENT is pointless.
KVM_CAP_ASSIGN_DEV_IRQ is unconditinally set. Moreover, add a default
case for dispatching the ioctl.

Acked-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:29:24 +02:00
Jan Kiszka ed78661f26 KVM: Save/restore state of assigned PCI device
The guest may change states that pci_reset_function does not touch. So
we better save/restore the assigned device across guest usage.

Acked-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:29:22 +02:00
Jan Kiszka 1e001d49f9 KVM: Refactor IRQ names of assigned devices
Cosmetic change, but it helps to correlate IRQs with PCI devices.

Acked-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:29:21 +02:00
Jan Kiszka 0645211c43 KVM: Switch assigned device IRQ forwarding to threaded handler
This improves the IRQ forwarding for assigned devices: By using the
kernel's threaded IRQ scheme, we can get rid of the latency-prone work
queue and simplify the code in the same run.

Moreover, we no longer have to hold assigned_dev_lock while raising the
guest IRQ, which can be a lenghty operation as we may have to iterate
over all VCPUs. The lock is now only used for synchronizing masking vs.
unmasking of INTx-type IRQs, thus is renames to intx_lock.

Acked-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:29:20 +02:00
Jan Kiszka 0c106b5aaa KVM: Clear assigned guest IRQ on release
When we deassign a guest IRQ, clear the potentially asserted guest line.
There might be no chance for the guest to do this, specifically if we
switch from INTx to MSI mode.

Acked-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:29:19 +02:00
Jan Kiszka d89f5eff70 KVM: Clean up vm creation and release
IA64 support forces us to abstract the allocation of the kvm structure.
But instead of mixing this up with arch-specific initialization and
doing the same on destruction, split both steps. This allows to move
generic destruction calls into generic code.

It also fixes error clean-up on failures of kvm_create_vm for IA64.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12 11:29:09 +02:00
Jan Kiszka 57e7fbee1d KVM: Refactor srcu struct release on early errors
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12 11:29:05 +02:00
Xiao Guangrong 64f638c7c4 KVM: fix the race while wakeup all pv guest
In kvm_async_pf_wakeup_all(), we add a dummy apf to vcpu->async_pf.done
without holding vcpu->async_pf.lock, it will break if we are handling apfs
at this time.

Also use 'list_empty_careful()' instead of 'list_empty()'

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Acked-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:29:03 +02:00
Xiao Guangrong 15096ffcea KVM: handle more completed apfs if possible
If it's no need to inject async #PF to PV guest we can handle
more completed apfs at one time, so we can retry guest #PF
as early as possible

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Acked-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:29:01 +02:00
Takuya Yoshikawa 2653503769 KVM: replace vmalloc and memset with vzalloc
Let's use newly introduced vzalloc().

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:28:55 +02:00
Heiko Carstens aac8763697 KVM: get rid of warning within kvm_dev_ioctl_create_vm
Fixes this:

  CC      arch/s390/kvm/../../../virt/kvm/kvm_main.o
arch/s390/kvm/../../../virt/kvm/kvm_main.c: In function 'kvm_dev_ioctl_create_vm':
arch/s390/kvm/../../../virt/kvm/kvm_main.c:1828:10: warning: unused variable 'r'

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:28:50 +02:00
Heiko Carstens 3bcc8a8c6c KVM: add cast within kvm_clear_guest_page to fix warning
Fixes this:

  CC      arch/s390/kvm/../../../virt/kvm/kvm_main.o
arch/s390/kvm/../../../virt/kvm/kvm_main.c: In function 'kvm_clear_guest_page':
arch/s390/kvm/../../../virt/kvm/kvm_main.c:1224:2: warning: passing argument 3 of 'kvm_write_guest_page' makes pointer from integer without a cast
arch/s390/kvm/../../../virt/kvm/kvm_main.c:1185:5: note: expected 'const void *' but argument is of type 'long unsigned int'

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:28:49 +02:00
Takuya Yoshikawa 6f9e5c1702 KVM: use kmalloc() for small dirty bitmaps
Currently we are using vmalloc() for all dirty bitmaps even if
they are small enough, say less than K bytes.

We use kmalloc() if dirty bitmap size is less than or equal to
PAGE_SIZE so that we can avoid vmalloc area usage for VGA.

This will also make the logging start/stop faster.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:28:48 +02:00
Takuya Yoshikawa 515a01279a KVM: pre-allocate one more dirty bitmap to avoid vmalloc()
Currently x86's kvm_vm_ioctl_get_dirty_log() needs to allocate a bitmap by
vmalloc() which will be used in the next logging and this has been causing
bad effect to VGA and live-migration: vmalloc() consumes extra systime,
triggers tlb flush, etc.

This patch resolves this issue by pre-allocating one more bitmap and switching
between two bitmaps during dirty logging.

Performance improvement:
  I measured performance for the case of VGA update by trace-cmd.
  The result was 1.5 times faster than the original one.

  In the case of live migration, the improvement ratio depends on the workload
  and the guest memory size. In general, the larger the memory size is the more
  benefits we get.

Note:
  This does not change other architectures's logic but the allocation size
  becomes twice. This will increase the actual memory consumption only when
  the new size changes the number of pages allocated by vmalloc().

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:28:46 +02:00
Takuya Yoshikawa a36a57b1a1 KVM: introduce wrapper functions for creating/destroying dirty bitmaps
This makes it easy to change the way of allocating/freeing dirty bitmaps.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:28:45 +02:00
Gleb Natapov 64be500706 KVM: x86: trace "exit to userspace" event
Add tracepoint for userspace exit.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:28:44 +02:00
Marcelo Tosatti 612819c3c6 KVM: propagate fault r/w information to gup(), allow read-only memory
As suggested by Andrea, pass r/w error code to gup(), upgrading read fault
to writable if host pte allows it.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12 11:28:40 +02:00
Gleb Natapov 8030089f9e KVM: improve hva_to_pfn() readability
Improve vma handling code readability in hva_to_pfn() and fix
async pf handling code to properly check vma returned by find_vma().

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:23:23 +02:00
Gleb Natapov 7c90705bf2 KVM: Inject asynchronous page fault into a PV guest if page is swapped out.
Send async page fault to a PV guest if it accesses swapped out memory.
Guest will choose another task to run upon receiving the fault.

Allow async page fault injection only when guest is in user mode since
otherwise guest may be in non-sleepable context and will not be able
to reschedule.

Vcpu will be halted if guest will fault on the same page again or if
vcpu executes kernel code.

Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:23:17 +02:00
Gleb Natapov 344d9588a9 KVM: Add PV MSR to enable asynchronous page faults delivery.
Guest enables async PF vcpu functionality using this MSR.

Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:23:12 +02:00
Gleb Natapov 49c7754ce5 KVM: Add memory slot versioning and use it to provide fast guest write interface
Keep track of memslots changes by keeping generation number in memslots
structure. Provide kvm_write_guest_cached() function that skips
gfn_to_hva() translation if memslots was not changed since previous
invocation.

Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:23:08 +02:00
Gleb Natapov 56028d0861 KVM: Retry fault before vmentry
When page is swapped in it is mapped into guest memory only after guest
tries to access it again and generate another fault. To save this fault
we can map it immediately since we know that guest is going to access
the page. Do it only when tdp is enabled for now. Shadow paging case is
more complicated. CR[034] and EFER registers should be switched before
doing mapping and then switched back.

Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:23:06 +02:00
Gleb Natapov af585b921e KVM: Halt vcpu if page it tries to access is swapped out
If a guest accesses swapped out memory do not swap it in from vcpu thread
context. Schedule work to do swapping and put vcpu into halted state
instead.

Interrupts will still be delivered to the guest and if interrupt will
cause reschedule guest will continue to run another task.

[avi: remove call to get_user_pages_noio(), nacked by Linus; this
      makes everything synchrnous again]

Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:21:39 +02:00
Linus Torvalds 1765a1fe5d Merge branch 'kvm-updates/2.6.37' of git://git.kernel.org/pub/scm/virt/kvm/kvm
* 'kvm-updates/2.6.37' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (321 commits)
  KVM: Drop CONFIG_DMAR dependency around kvm_iommu_map_pages
  KVM: Fix signature of kvm_iommu_map_pages stub
  KVM: MCE: Send SRAR SIGBUS directly
  KVM: MCE: Add MCG_SER_P into KVM_MCE_CAP_SUPPORTED
  KVM: fix typo in copyright notice
  KVM: Disable interrupts around get_kernel_ns()
  KVM: MMU: Avoid sign extension in mmu_alloc_direct_roots() pae root address
  KVM: MMU: move access code parsing to FNAME(walk_addr) function
  KVM: MMU: audit: check whether have unsync sps after root sync
  KVM: MMU: audit: introduce audit_printk to cleanup audit code
  KVM: MMU: audit: unregister audit tracepoints before module unloaded
  KVM: MMU: audit: fix vcpu's spte walking
  KVM: MMU: set access bit for direct mapping
  KVM: MMU: cleanup for error mask set while walk guest page table
  KVM: MMU: update 'root_hpa' out of loop in PAE shadow path
  KVM: x86 emulator: Eliminate compilation warning in x86_decode_insn()
  KVM: x86: Fix constant type in kvm_get_time_scale
  KVM: VMX: Add AX to list of registers clobbered by guest switch
  KVM guest: Move a printk that's using the clock before it's ready
  KVM: x86: TSC catchup mode
  ...
2010-10-24 12:47:25 -07:00
Jan Kiszka 2a31339aa0 KVM: Drop CONFIG_DMAR dependency around kvm_iommu_map_pages
We also have to call kvm_iommu_map_pages for CONFIG_AMD_IOMMU. So drop
the dependency on Intel IOMMU, kvm_iommu_map_pages will be a nop anyway
if CONFIG_IOMMU_API is not defined.

KVM-Stable-Tag.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:53:15 +02:00
Nicolas Kaiser 9611c18777 KVM: fix typo in copyright notice
Fix typo in copyright notice.

Signed-off-by: Nicolas Kaiser <nikai@nikai.net>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:53:14 +02:00
Avi Kivity 624d84cfe6 KVM: cpu_relax() during spin waiting for reboot
It doesn't really matter, but if we spin, we should spin in a more relaxed
manner.  This way, if something goes wrong at least it won't contribute to
global warming.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:53:03 +02:00
Xiao Guangrong 365fb3fdf6 KVM: MMU: rewrite audit_mappings_page() function
There is a bugs in this function, we call gfn_to_pfn() and kvm_mmu_gva_to_gpa_read() in
atomic context(kvm_mmu_audit() is called under the spinlock(mmu_lock)'s protection).

This patch fix it by:
- introduce gfn_to_pfn_atomic instead of gfn_to_pfn
- get the mapping gfn from kvm_mmu_page_get_gfn()

And it adds 'notrap' ptes check in unsync/direct sps

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:48 +02:00
Xiao Guangrong 48987781eb KVM: MMU: introduce gfn_to_page_many_atomic() function
Introduce this function to get consecutive gfn's pages, it can reduce
gup's overload, used by later patch

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:26 +02:00
Xiao Guangrong 887c08ac19 KVM: MMU: introduce hva_to_pfn_atomic function
Introduce hva_to_pfn_atomic(), it's the fast path and can used in atomic
context, the later patch will use it

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:26 +02:00
Zachary Amsden ca84d1a24c KVM: x86: Add clock sync request to hardware enable
If there are active VCPUs which are marked as belonging to
a particular hardware CPU, request a clock sync for them when
enabling hardware; the TSC could be desynchronized on a newly
arriving CPU, and we need to recompute guests system time
relative to boot after a suspend event.

This covers both cases.

Note that it is acceptable to take the spinlock, as either
no other tasks will be running and no locks held (BSP after
resume), or other tasks will be guaranteed to drop the lock
relatively quickly (AP on CPU_STARTING).

Noting we now get clock synchronization requests for VCPUs
which are starting up (or restarting), it is tempting to
attempt to remove the arch/x86/kvm/x86.c CPU hot-notifiers
at this time, however it is not correct to do so; they are
required for systems with non-constant TSC as the frequency
may not be known immediately after the processor has started
until the cpufreq driver has had a chance to run and query
the chipset.

Updated: implement better locking semantics for hardware_enable

Removed the hack of dropping and retaking the lock by adding the
semantic that we always hold kvm_lock when hardware_enable is
called.  The one place that doesn't need to worry about it is
resume, as resuming a frozen CPU, the spinlock won't be taken.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:51:24 +02:00
Linus Torvalds 092e0e7e52 Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl
* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
  vfs: make no_llseek the default
  vfs: don't use BKL in default_llseek
  llseek: automatically add .llseek fop
  libfs: use generic_file_llseek for simple_attr
  mac80211: disallow seeks in minstrel debug code
  lirc: make chardev nonseekable
  viotape: use noop_llseek
  raw: use explicit llseek file operations
  ibmasmfs: use generic_file_llseek
  spufs: use llseek in all file operations
  arm/omap: use generic_file_llseek in iommu_debug
  lkdtm: use generic_file_llseek in debugfs
  net/wireless: use generic_file_llseek in debugfs
  drm: use noop_llseek
2010-10-22 10:52:56 -07:00
Arnd Bergmann 6038f373a3 llseek: automatically add .llseek fop
All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.

The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.

New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time.  Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.

The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.

Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.

Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.

===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
//   but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
<+...
nonseekable_open(...)
...+>
}

@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
<+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+>
}

@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
<+...
(
   *off = E
|
   *off += E
|
   func(..., off, ...)
|
   E = *off
)
...+>
}

@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}

@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
<+...
(
  *off = E
|
  *off += E
|
  func(..., off, ...)
|
  E = *off
)
...+>
}

@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}

@ fops0 @
identifier fops;
@@
struct file_operations fops = {
 ...
};

@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
 .llseek = llseek_f,
...
};

@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
 .read = read_f,
...
};

@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
 .write = write_f,
...
};

@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
 .open = open_f,
...
};

// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
...  .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};

@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
...  .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};

// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
...  .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};

// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};

// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};

@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+	.llseek = default_llseek, /* write accesses f_pos */
};

// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////

@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
 .write = write_f,
 .read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};

@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};

@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};

@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Julia Lawall <julia@diku.dk>
Cc: Christoph Hellwig <hch@infradead.org>
2010-10-15 15:53:27 +02:00
Avi Kivity ca242ac996 KVM: Fix reboot on Intel hosts
When we reboot, we disable vmx extensions or otherwise INIT gets blocked.
If a task on another cpu hits a vmx instruction, it will fault if vmx is
disabled.  We trap that to avoid a nasty oops and spin until the reboot
completes.

Problem is, we sleep with interrupts disabled.  This blocks smp_send_stop()
from running, and the reboot process halts.

Fix by enabling interrupts before spinning.

KVM-Stable-Tag.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-09-23 11:31:56 -03:00
Michael S. Tsirkin 6bbfb26531 KVM: fix irqfd assign/deassign race
I think I see the following (theoretical) race:

During irqfd assign, we drop irqfds lock before we
schedule inject work. Therefore, deassign running
on another CPU could cause shutdown and flush to run
before inject, causing user after free in inject.

A simple fix it to schedule inject under the lock.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-09-23 11:31:51 -03:00
Zachary Amsden da908f2fb4 KVM: x86: Perform hardware_enable in CPU_STARTING callback
The CPU_STARTING callback was added upstream with the intention
of being used for KVM, specifically for the hardware enablement
that must be done before we can run in hardware virt.  It had
bugs on the x86_64 architecture at the time, where it was called
after CPU_ONLINE.  The arches have since merged and the bug is
gone.

It might be noted other features should probably start making
use of this callback; microcode updates in particular which
might be fixing important erratums would be best applied before
beginning to run user tasks.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-09-09 13:48:16 -03:00
Gleb Natapov 4a994358b9 KVM: Convert mask notifiers to use irqchip/pin instead of gsi
Devices register mask notifier using gsi, but irqchip knows about
irqchip/pin, so conversion from irqchip/pin to gsi should be done before
looking for mask notifier to call.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-08-02 06:40:39 +03:00
Gleb Natapov edba23e515 KVM: Return EFAULT from kvm ioctl when guest accesses bad area
Currently if guest access address that belongs to memory slot but is not
backed up by page or page is read only KVM treats it like MMIO access.
Remove that capability. It was never part of the interface and should
not be relied upon.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-02 06:40:33 +03:00
Gleb Natapov fa7bff8f8a KVM: define hwpoison variables static
They are not used outside of the file.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-02 06:40:32 +03:00
Joerg Roedel 5689cc53fa KVM: Use u64 for frame data types
For 32bit machines where the physical address width is
larger than the virtual address width the frame number types
in KVM may overflow. Fix this by changing them to u64.

[sfr: fix build on 32-bit ppc]

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-08-02 06:39:44 +03:00
Joerg Roedel 828554136b KVM: Remove unnecessary divide operations
This patch converts unnecessary divide and modulo operations
in the KVM large page related code into logical operations.
This allows to convert gfn_t to u64 while not breaking 32
bit builds.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-08-01 10:47:30 +03:00
Sheng Yang 95c87e2b44 KVM: Fix IOMMU memslot reference warning
This patch fixes the following warning.

===================================================
[ INFO: suspicious rcu_dereference_check() usage. ]
---------------------------------------------------
include/linux/kvm_host.h:259 invoked rcu_dereference_check() without
protection!

other info that might help us debug this:

rcu_scheduler_active = 1, debug_locks = 0
no locks held by qemu-system-x86/29679.

stack backtrace:
Pid: 29679, comm: qemu-system-x86 Not tainted 2.6.35-rc3+ #200
Call Trace:
 [<ffffffff810a224e>] lockdep_rcu_dereference+0xa8/0xb1
 [<ffffffffa018a06f>] kvm_iommu_unmap_memslots+0xc9/0xde [kvm]
 [<ffffffffa018a0c4>] kvm_iommu_unmap_guest+0x40/0x4e [kvm]
 [<ffffffffa018f772>] kvm_arch_destroy_vm+0x1a/0x186 [kvm]
 [<ffffffffa01800d0>] kvm_put_kvm+0x110/0x167 [kvm]
 [<ffffffffa0180ecc>] kvm_vcpu_release+0x18/0x1c [kvm]
 [<ffffffff81156f5d>] fput+0x22a/0x3a0
 [<ffffffff81152288>] filp_close+0xb4/0xcd
 [<ffffffff8106599f>] put_files_struct+0x1b7/0x36b
 [<ffffffff81065830>] ? put_files_struct+0x48/0x36b
 [<ffffffff8131ee59>] ? do_raw_spin_unlock+0x118/0x160
 [<ffffffff81065bc0>] exit_files+0x6d/0x75
 [<ffffffff81068348>] do_exit+0x47d/0xc60
 [<ffffffff8177e7b5>] ? _raw_spin_unlock_irq+0x30/0x36
 [<ffffffff81068bfa>] do_group_exit+0xcf/0x134
 [<ffffffff81080790>] get_signal_to_deliver+0x732/0x81d
 [<ffffffff81095996>] ? cpu_clock+0x4e/0x60
 [<ffffffff81002082>] do_notify_resume+0x117/0xc43
 [<ffffffff810a2fa3>] ? trace_hardirqs_on+0xd/0xf
 [<ffffffff81080d79>] ? sys_rt_sigtimedwait+0x2b5/0x3bf
 [<ffffffff8177d9f2>] ? trace_hardirqs_off_thunk+0x3a/0x3c
 [<ffffffff81003221>] ? sysret_signal+0x5/0x3d
 [<ffffffff8100343b>] int_signal+0x12/0x17

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-08-01 10:47:29 +03:00
Huang Ying bbeb34062f KVM: Fix a race condition for usage of is_hwpoison_address()
is_hwpoison_address accesses the page table, so the caller must hold
current->mm->mmap_sem in read mode. So fix its usage in hva_to_pfn of
kvm accordingly.

Comment is_hwpoison_address to remind other users.

Reported-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:47:11 +03:00
Avi Kivity e36d96f7cf KVM: Keep slot ID in memory slot structure
May be used for distinguishing between internal and user slots, or for sorting
slots in size order.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:47:07 +03:00
Avi Kivity a8eeb04a44 KVM: Add mini-API for vcpu->requests
Makes it a little more readable and hackable.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:47:05 +03:00
Avi Kivity a1f4d39500 KVM: Remove memory alias support
As advertised in feature-removal-schedule.txt.  Equivalent support is provided
by overlapping memory regions.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:47:00 +03:00
Chris Lalancette aefd18f01e KVM: x86: In DM_LOWEST, only deliver interrupts to vcpus with enabled LAPIC's
Otherwise we might try to deliver a timer interrupt to a cpu that
can't possibly handle it.

Signed-off-by: Chris Lalancette <clalance@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-08-01 10:46:51 +03:00
Andi Kleen a24e809902 KVM: Fix unused but set warnings
No real bugs in this one.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:46:29 +03:00
Andi Kleen 376d41ff26 KVM: Fix KVM_SET_SIGNAL_MASK with arg == NULL
When the user passed in a NULL mask pass this on from the ioctl
handler.

Found by gcc 4.6's new warnings.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:46:28 +03:00
Lai Jiangshan 3bd89007ab KVM: cleanup "*new.rmap" type
The type of '*new.rmap' is not 'struct page *', fix it

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-08-01 10:39:25 +03:00
Avi Kivity 221d059d15 KVM: Update Red Hat copyrights
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:35:51 +03:00
Avi Kivity 9373662463 KVM: Consolidate arch specific vcpu ioctl locking
Now that all arch specific ioctls have centralized locking, it is easy to
move it to the central dispatcher.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:35:48 +03:00
Avi Kivity 2122ff5eab KVM: move vcpu locking to dispatcher for generic vcpu ioctls
All vcpu ioctls need to be locked, so instead of locking each one specifically
we lock at the generic dispatcher.

This patch only updates generic ioctls and leaves arch specific ioctls alone.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:35:47 +03:00
Alex Williamson 48bb09eee4 KVM: remove CAP_SYS_RAWIO requirement from kvm_vm_ioctl_assign_irq
Remove this check in an effort to allow kvm guests to run without
root privileges.  This capability check doesn't seem to add any
security since the device needs to have already been added via the
assign device ioctl and the io actually occurs through the pci
sysfs interface.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-08-01 10:35:45 +03:00
Huang Ying bf998156d2 KVM: Avoid killing userspace through guest SRAO MCE on unmapped pages
In common cases, guest SRAO MCE will cause corresponding poisoned page
be un-mapped and SIGBUS be sent to QEMU-KVM, then QEMU-KVM will relay
the MCE to guest OS.

But it is reported that if the poisoned page is accessed in guest
after unmapping and before MCE is relayed to guest OS, userspace will
be killed.

The reason is as follows. Because poisoned page has been un-mapped,
guest access will cause guest exit and kvm_mmu_page_fault will be
called. kvm_mmu_page_fault can not get the poisoned page for fault
address, so kernel and user space MMIO processing is tried in turn. In
user MMIO processing, poisoned page is accessed again, then userspace
is killed by force_sig_info.

To fix the bug, kvm_mmu_page_fault send HWPOISON signal to QEMU-KVM
and do not try kernel and user space MMIO processing for poisoned
page.

[xiao: fix warning introduced by avi]

Reported-by: Max Asbock <masbock@linux.vnet.ibm.com>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:35:26 +03:00
Marcelo Tosatti 07dc7263b9 KVM: read apic->irr with ioapic lock held
Read ioapic->irr inside ioapic->lock protected section.

KVM-Stable-Tag
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-06-10 20:29:03 +03:00
Jan Kiszka 05b782ab95 KVM: Fix order passed to iommu_unmap
This is obviously a left-over from the the old interface taking the
size. Apparently a mostly harmless issue with the current iommu_unmap
implementation.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Acked-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-06-09 18:48:38 +03:00
Linus Torvalds 98edb6ca41 Merge branch 'kvm-updates/2.6.35' of git://git.kernel.org/pub/scm/virt/kvm/kvm
* 'kvm-updates/2.6.35' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (269 commits)
  KVM: x86: Add missing locking to arch specific vcpu ioctls
  KVM: PPC: Add missing vcpu_load()/vcpu_put() in vcpu ioctls
  KVM: MMU: Segregate shadow pages with different cr0.wp
  KVM: x86: Check LMA bit before set_efer
  KVM: Don't allow lmsw to clear cr0.pe
  KVM: Add cpuid.txt file
  KVM: x86: Tell the guest we'll warn it about tsc stability
  x86, paravirt: don't compute pvclock adjustments if we trust the tsc
  x86: KVM guest: Try using new kvm clock msrs
  KVM: x86: export paravirtual cpuid flags in KVM_GET_SUPPORTED_CPUID
  KVM: x86: add new KVMCLOCK cpuid feature
  KVM: x86: change msr numbers for kvmclock
  x86, paravirt: Add a global synchronization point for pvclock
  x86, paravirt: Enable pvclock flags in vcpu_time_info structure
  KVM: x86: Inject #GP with the right rip on efer writes
  KVM: SVM: Don't allow nested guest to VMMCALL into host
  KVM: x86: Fix exception reinjection forced to true
  KVM: Fix wallclock version writing race
  KVM: MMU: Don't read pdptrs with mmu spinlock held in mmu_alloc_roots
  KVM: VMX: enable VMXON check with SMX enabled (Intel TXT)
  ...
2010-05-21 17:16:21 -07:00
Avi Kivity 0ee75bead8 KVM: Let vcpu structure alignment be determined at runtime
vmx and svm vcpus have different contents and therefore may have different
alignmment requirements.  Let each specify its required alignment.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-05-19 11:36:29 +03:00
Linus Torvalds 8123d8f17d Merge branch 'core-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86/amd-iommu: Add amd_iommu=off command line option
  iommu-api: Remove iommu_{un}map_range functions
  x86/amd-iommu: Implement ->{un}map callbacks for iommu-api
  x86/amd-iommu: Make amd_iommu_iova_to_phys aware of multiple page sizes
  x86/amd-iommu: Make iommu_unmap_page and fetch_pte aware of page sizes
  x86/amd-iommu: Make iommu_map_page and alloc_pte aware of page sizes
  kvm: Change kvm_iommu_map_pages to map large pages
  VT-d: Change {un}map_range functions to implement {un}map interface
  iommu-api: Add ->{un}map callbacks to iommu_ops
  iommu-api: Add iommu_map and iommu_unmap functions
  iommu-api: Rename ->{un}map function pointers to ->{un}map_range
2010-05-18 07:22:37 -07:00
Takuya Yoshikawa d14769377a KVM: Remove test-before-set optimization for dirty bits
As Avi pointed out, testing bit part in mark_page_dirty() was important
in the days of shadow paging, but currently EPT and NPT has already become
common and the chance of faulting a page more that once per iteration is
small. So let's remove the test bit to avoid extra access.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-05-17 12:19:13 +03:00
Lai Jiangshan 66cbff59a1 KVM: do not call hardware_disable() on CPU_UP_CANCELED
When CPU_UP_CANCELED, hardware_enable() has not been called at the CPU
which is going up because raw_notifier_call_chain(CPU_ONLINE)
has not been called for this cpu.

Drop the handling for CPU_UP_CANCELED.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-05-17 12:18:04 +03:00
Lai Jiangshan 90d83dc3d4 KVM: use the correct RCU API for PROVE_RCU=y
The RCU/SRCU API have already changed for proving RCU usage.

I got the following dmesg when PROVE_RCU=y because we used incorrect API.
This patch coverts rcu_deference() to srcu_dereference() or family API.

===================================================
[ INFO: suspicious rcu_dereference_check() usage. ]
---------------------------------------------------
arch/x86/kvm/mmu.c:3020 invoked rcu_dereference_check() without protection!

other info that might help us debug this:

rcu_scheduler_active = 1, debug_locks = 0
2 locks held by qemu-system-x86/8550:
 #0:  (&kvm->slots_lock){+.+.+.}, at: [<ffffffffa011a6ac>] kvm_set_memory_region+0x29/0x50 [kvm]
 #1:  (&(&kvm->mmu_lock)->rlock){+.+...}, at: [<ffffffffa012262d>] kvm_arch_commit_memory_region+0xa6/0xe2 [kvm]

stack backtrace:
Pid: 8550, comm: qemu-system-x86 Not tainted 2.6.34-rc4-tip-01028-g939eab1 #27
Call Trace:
 [<ffffffff8106c59e>] lockdep_rcu_dereference+0xaa/0xb3
 [<ffffffffa012f6c1>] kvm_mmu_calculate_mmu_pages+0x44/0x7d [kvm]
 [<ffffffffa012263e>] kvm_arch_commit_memory_region+0xb7/0xe2 [kvm]
 [<ffffffffa011a5d7>] __kvm_set_memory_region+0x636/0x6e2 [kvm]
 [<ffffffffa011a6ba>] kvm_set_memory_region+0x37/0x50 [kvm]
 [<ffffffffa015e956>] vmx_set_tss_addr+0x46/0x5a [kvm_intel]
 [<ffffffffa0126592>] kvm_arch_vm_ioctl+0x17a/0xcf8 [kvm]
 [<ffffffff810a8692>] ? unlock_page+0x27/0x2c
 [<ffffffff810bf879>] ? __do_fault+0x3a9/0x3e1
 [<ffffffffa011b12f>] kvm_vm_ioctl+0x364/0x38d [kvm]
 [<ffffffff81060cfa>] ? up_read+0x23/0x3d
 [<ffffffff810f3587>] vfs_ioctl+0x32/0xa6
 [<ffffffff810f3b19>] do_vfs_ioctl+0x495/0x4db
 [<ffffffff810e6b2f>] ? fget_light+0xc2/0x241
 [<ffffffff810e416c>] ? do_sys_open+0x104/0x116
 [<ffffffff81382d6d>] ? retint_swapgs+0xe/0x13
 [<ffffffff810f3ba6>] sys_ioctl+0x47/0x6a
 [<ffffffff810021db>] system_call_fastpath+0x16/0x1b

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-05-17 12:18:01 +03:00
Takuya Yoshikawa 660c22c425 KVM: limit the number of pages per memory slot
This patch limits the number of pages per memory slot to make
us free from extra care about type issues.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-05-17 12:17:41 +03:00
Takuya Yoshikawa 6ce5a090a9 KVM: coalesced_mmio: fix kvm_coalesced_mmio_init()'s error handling
kvm_coalesced_mmio_init() keeps to hold the addresses of a coalesced
mmio ring page and dev even after it has freed them.

Also, if this function fails, though it might be rare, it seems to be
suggesting the system's serious state: so we'd better stop the works
following the kvm_creat_vm().

This patch clears these problems.

  We move the coalesced mmio's initialization out of kvm_create_vm().
  This seems to be natural because it includes a registration which
  can be done only when vm is successfully created.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-05-17 12:15:53 +03:00
jing zhang d57e2c0740 KVM: fix assigned_device_enable_host_msix error handling
Free IRQ's and disable MSIX upon failure.

Cc: Avi Kivity <avi@redhat.com>
Signed-off-by: Jing Zhang <zj.barak@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-05-17 12:15:36 +03:00
Wei Yongjun a87fa35514 KVM: fix the errno of ioctl KVM_[UN]REGISTER_COALESCED_MMIO failure
This patch change the errno of ioctl KVM_[UN]REGISTER_COALESCED_MMIO
from -EINVAL to -ENXIO if no coalesced mmio dev exists.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-05-17 12:15:34 +03:00
Xiao Guangrong 2ed152afc7 KVM: cleanup kvm trace
This patch does:

 - no need call tracepoint_synchronize_unregister() when kvm module
   is unloaded since ftrace can handle it

 - cleanup ftrace's macro

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-05-17 12:15:22 +03:00
Marcelo Tosatti 46a47b1ed1 KVM: convert ioapic lock to spinlock
kvm_set_irq is used from non sleepable contexes, so convert ioapic from
mutex to spinlock.

KVM-Stable-Tag.
Tested-by: Ralf Bonenkamp <ralf.bonenkamp@swyx.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-05-13 01:23:55 -03:00
Joerg Roedel 795e74f7a6 Merge branch 'iommu/largepages' into amd-iommu/2.6.35
Conflicts:
	arch/x86/kernel/amd_iommu.c
2010-05-11 17:40:57 +02:00
Takuya Yoshikawa f5c9803173 KVM: update gfn_to_hva() to use gfn_to_hva_memslot()
Marcelo introduced gfn_to_hva_memslot() when he implemented
gfn_to_pfn_memslot(). Let's use this for gfn_to_hva() too.

Note: also remove parentheses next to return as checkpatch said to do.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-04-25 13:53:29 +03:00
Lai Jiangshan eda2beda83 KVM: Add missing srcu_read_lock() for kvm_mmu_notifier_release()
I got this dmesg due to srcu_read_lock() is missing in
kvm_mmu_notifier_release().

===================================================
[ INFO: suspicious rcu_dereference_check() usage. ]
---------------------------------------------------
arch/x86/kvm/x86.h:72 invoked rcu_dereference_check() without protection!

other info that might help us debug this:

rcu_scheduler_active = 1, debug_locks = 0
2 locks held by qemu-system-x86/3100:
 #0:  (rcu_read_lock){.+.+..}, at: [<ffffffff810d73dc>] __mmu_notifier_release+0x38/0xdf
 #1:  (&(&kvm->mmu_lock)->rlock){+.+...}, at: [<ffffffffa0130a6a>] kvm_mmu_zap_all+0x21/0x5e [kvm]

stack backtrace:
Pid: 3100, comm: qemu-system-x86 Not tainted 2.6.34-rc3-22949-gbc8a97a-dirty #2
Call Trace:
 [<ffffffff8106afd9>] lockdep_rcu_dereference+0xaa/0xb3
 [<ffffffffa0123a89>] unalias_gfn+0x56/0xab [kvm]
 [<ffffffffa0119600>] gfn_to_memslot+0x16/0x25 [kvm]
 [<ffffffffa012ffca>] gfn_to_rmap+0x17/0x6e [kvm]
 [<ffffffffa01300c1>] rmap_remove+0xa0/0x19d [kvm]
 [<ffffffffa0130649>] kvm_mmu_zap_page+0x109/0x34d [kvm]
 [<ffffffffa0130a7e>] kvm_mmu_zap_all+0x35/0x5e [kvm]
 [<ffffffffa0122870>] kvm_arch_flush_shadow+0x16/0x22 [kvm]
 [<ffffffffa01189e0>] kvm_mmu_notifier_release+0x15/0x17 [kvm]
 [<ffffffff810d742c>] __mmu_notifier_release+0x88/0xdf
 [<ffffffff810d73dc>] ? __mmu_notifier_release+0x38/0xdf
 [<ffffffff81040848>] ? exit_mm+0xe0/0x115
 [<ffffffff810c2cb0>] exit_mmap+0x2c/0x17e
 [<ffffffff8103c472>] mmput+0x2d/0xd4
 [<ffffffff81040870>] exit_mm+0x108/0x115
[...]

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-04-21 11:17:43 +03:00
Takuya Yoshikawa 87bf6e7de1 KVM: fix the handling of dirty bitmaps to avoid overflows
Int is not long enough to store the size of a dirty bitmap.

This patch fixes this problem with the introduction of a wrapper
function to calculate the sizes of dirty bitmaps.

Note: in mark_page_dirty(), we have to consider the fact that
  __set_bit() takes the offset as int, not long.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-04-20 13:06:55 +03:00
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Joerg Roedel fcd95807fb kvm: Change kvm_iommu_map_pages to map large pages
This patch changes the implementation of of
kvm_iommu_map_pages to map the pages with the host page size
into the io virtual address space.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Acked-By: Avi Kivity <avi@redhat.com>
2010-03-07 18:01:11 +01:00
Avi Kivity 70e335e168 KVM: Convert kvm->requests_lock to raw_spinlock_t
The code relies on kvm->requests_lock inhibiting preemption.

Noted by Jan Kiszka.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01 12:36:13 -03:00
Michael S. Tsirkin 8b97fb0fcb KVM: do not store wqh in irqfd
wqh is unused, so we do not need to store it in irqfd anymore

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01 12:36:10 -03:00
Wei Yongjun 72bb2fcd23 KVM: cleanup the failure path of KVM_CREATE_IRQCHIP ioctrl
If we fail to init ioapic device or the fail to setup the default irq
routing, the device register by kvm_create_pic() and kvm_ioapic_init()
remain unregister. This patch fixed to do this.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01 12:36:10 -03:00
Wei Yongjun 1ae77badc2 KVM: kvm->arch.vioapic should be NULL if kvm_ioapic_init() failure
kvm->arch.vioapic should be NULL in case of kvm_ioapic_init() failure
due to cannot register io dev.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01 12:36:09 -03:00
Jochen Maes 43db669730 KVM: Fix Codestyle in virt/kvm/coalesced_mmio.c
Fixed 2 codestyle issues in virt/kvm/coalesced_mmio.c

Signed-off-by: Jochen Maes <jochen.maes@sejo.be>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01 12:36:09 -03:00
Joerg Roedel 8f0b1ab6fb KVM: Introduce kvm_host_page_size
This patch introduces a generic function to find out the
host page size for a given gfn. This function is needed by
the kvm iommu code. This patch also simplifies the x86
host_mapping_level function.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01 12:36:08 -03:00
Zhai, Edwin ab9f4ecbb6 KVM: enable PCI multiple-segments for pass-through device
Enable optional parameter (default 0) - PCI segment (or domain) besides
BDF, when assigning PCI device to guest.

Signed-off-by: Zhai Edwin <edwin.zhai@intel.com>
Acked-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:36:06 -03:00
Sheng Yang f0f4b93090 KVM: Fix kvm_coalesced_mmio_ring duplicate allocation
The commit 0953ca73 "KVM: Simplify coalesced mmio initialization"
allocate kvm_coalesced_mmio_ring in the kvm_coalesced_mmio_init(), but
didn't discard the original allocation...

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:36:03 -03:00
Marcelo Tosatti 6474920477 KVM: fix cleanup_srcu_struct on vm destruction
cleanup_srcu_struct on VM destruction remains broken:

BUG: unable to handle kernel paging request at ffffffffffffffff
IP: [<ffffffff802533d2>] srcu_read_lock+0x16/0x21
RIP: 0010:[<ffffffff802533d2>]  [<ffffffff802533d2>] srcu_read_lock+0x16/0x21
Call Trace:
 [<ffffffffa05354c4>] kvm_arch_vcpu_uninit+0x1b/0x48 [kvm]
 [<ffffffffa05339c6>] kvm_vcpu_uninit+0x9/0x15 [kvm]
 [<ffffffffa0569f7d>] vmx_free_vcpu+0x7f/0x8f [kvm_intel]
 [<ffffffffa05357b5>] kvm_arch_destroy_vm+0x78/0x111 [kvm]
 [<ffffffffa053315b>] kvm_put_kvm+0xd4/0xfe [kvm]

Move it to kvm_arch_destroy_vm.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Reported-by: Jan Kiszka <jan.kiszka@siemens.com>
2010-03-01 12:36:01 -03:00
Avi Kivity 46a929bc15 KVM: avoid taking ioapic mutex for non-ioapic EOIs
When the guest acknowledges an interrupt, it sends an EOI message to the local
apic, which broadcasts it to the ioapic.  To handle the EOI, we need to take
the ioapic mutex.

On large guests, this causes a lot of contention on this mutex.  Since large
guests usually don't route interrupts via the ioapic (they use msi instead),
this is completely unnecessary.

Avoid taking the mutex by introducing a handled_vectors bitmap.  Before taking
the mutex, check if the ioapic was actually responsible for the acked vector.
If not, we can return early.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:35:46 -03:00
Marcelo Tosatti 79fac95ecf KVM: convert slots_lock to a mutex
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:35:45 -03:00
Marcelo Tosatti e93f8a0f82 KVM: convert io_bus to SRCU
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:35:45 -03:00
Marcelo Tosatti a983fb2387 KVM: x86: switch kvm_set_memory_alias to SRCU update
Using a similar two-step procedure as for memslots.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:35:45 -03:00
Marcelo Tosatti bc6678a33d KVM: introduce kvm->srcu and convert kvm_set_memory_region to SRCU update
Use two steps for memslot deletion: mark the slot invalid (which stops
instantiation of new shadow pages for that slot, but allows destruction),
then instantiate the new empty slot.

Also simplifies kvm_handle_hva locking.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:35:44 -03:00
Marcelo Tosatti 3ad26d8139 KVM: use gfn_to_pfn_memslot in kvm_iommu_map_pages
So its possible to iommu map a memslot before making it visible to
kvm.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:35:44 -03:00
Marcelo Tosatti 506f0d6f9c KVM: introduce gfn_to_pfn_memslot
Which takes a memslot pointer instead of using kvm->memslots.

To be used by SRCU convertion later.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:35:44 -03:00
Marcelo Tosatti f7784b8ec9 KVM: split kvm_arch_set_memory_region into prepare and commit
Required for SRCU convertion later.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:35:44 -03:00
Marcelo Tosatti 46a26bf557 KVM: modify memslots layout in struct kvm
Have a pointer to an allocated region inside struct kvm.

[alex: fix ppc book 3s]

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01 12:35:43 -03:00
Avi Kivity 980da6ce57 KVM: Simplify coalesced mmio initialization
- add destructor function
- move related allocation into constructor
- add stubs for !CONFIG_KVM_MMIO

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01 12:35:41 -03:00
Avi Kivity 50eb2a3cd0 KVM: Add KVM_MMIO kconfig item
s390 doesn't have mmio, this will simplify ifdefing it out.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01 12:35:41 -03:00
Avi Kivity 4c07b0a4b6 KVM: Remove ifdefs from mmu notifier initialization
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01 12:35:41 -03:00
Avi Kivity 3f0852e0ac KVM: Add include guards for coalesced_mmio.h
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01 12:35:41 -03:00
Avi Kivity 283d0c65e4 KVM: Disentangle mmu notifiers and coalesced_mmio registration
They aren't related.

Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01 12:35:41 -03:00
Michael S. Tsirkin b6a114d272 KVM: fix spurious interrupt with irqfd
kvm didn't clear irqfd counter on deassign, as a result we could get a
spurious interrupt when irqfd is assigned back. this leads to poor
performance and, in theory, guest crash.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-01-25 12:26:39 -02:00
Marcelo Tosatti d72118ceca KVM: properly check max PIC pin in irq route setup
Otherwise memory beyond irq_states[16] might be accessed.

Noticed by Juan Quintela.

Cc: stable@kernel.org
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Acked-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-01-25 12:26:38 -02:00
Michael S. Tsirkin f1d1c309f3 KVM: only allow one gsi per fd
Looks like repeatedly binding same fd to multiple gsi's with irqfd can
use up a ton of kernel memory for irqfd structures.

A simple fix is to allow each fd to only trigger one gsi: triggering a
storm of interrupts in guest is likely useless anyway, and we can do it
by binding a single gsi to many interrupts if we really want to.

Cc: stable@kernel.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Acked-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-01-25 12:26:37 -02:00
Heiko Carstens b4329db0d7 KVM: get rid of kvm_create_vm() unused label warning on s390
arch/s390/kvm/../../../virt/kvm/kvm_main.c: In function 'kvm_create_vm':
arch/s390/kvm/../../../virt/kvm/kvm_main.c:409: warning: label 'out_err' defined but not used

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-27 13:36:34 -02:00
Sheng Yang fae3a3536a KVM: Fix possible circular locking in kvm_vm_ioctl_assign_device()
One possible order is:

KVM_CREATE_IRQCHIP ioctl(took kvm->lock) -> kvm_iobus_register_dev() ->
down_write(kvm->slots_lock).

The other one is in kvm_vm_ioctl_assign_device(), which take kvm->slots_lock
first, then kvm->lock.

Update the comment of lock order as well.

Observe it due to kernel locking debug warnings.

Cc: stable@kernel.org
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-27 13:36:31 -02:00
Roland Dreier 628ff7c1d8 anonfd: Allow making anon files read-only
It seems a couple places such as arch/ia64/kernel/perfmon.c and
drivers/infiniband/core/uverbs_main.c could use anon_inode_getfile()
instead of a private pseudo-fs + alloc_file(), if only there were a way
to get a read-only file.  So provide this by having anon_inode_getfile()
create a read-only file if we pass O_RDONLY in flags.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-12-22 12:27:34 -05:00
Benjamin Herrenschmidt bcd6acd51f Merge commit 'origin/master' into next
Conflicts:
	include/linux/kvm.h
2009-12-09 17:14:38 +11:00
Avi Kivity a9c7399d6c KVM: Allow internal errors reported to userspace to carry extra data
Usually userspace will freeze the guest so we can inspect it, but some
internal state is not available.  Add extra data to internal error
reporting so we can expose it to the debugger.  Extra data is specific
to the suberror.

Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:24 +02:00
Marcelo Tosatti e50212bb51 KVM: only clear irq_source_id if irqchip is present
Otherwise kvm might attempt to dereference a NULL pointer.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:23 +02:00
Arnd Bergmann 6ff5894cdf KVM: Enable 32bit dirty log pointers on 64bit host
With big endian userspace, we can't quite figure out if a pointer
is 32 bit (shifted >> 32) or 64 bit when we read a 64 bit pointer.

This is what happens with dirty logging. To get the pointer interpreted
correctly, we thus need Arnd's patch to implement a compat layer for
the ioctl:

A better way to do this is to add a separate compat_ioctl() method that
converts this for you.

Based on initial patch from Arnd Bergmann.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:20 +02:00
Marcelo Tosatti cd5a2685de KVM: fix irq_source_id size verification
find_first_zero_bit works with bit numbers, not bytes.

Fixes

https://sourceforge.net/tracker/?func=detail&aid=2847560&group_id=180599&atid=893831

Reported-by: "Xu, Jiajun" <jiajun.xu@intel.com>
Cc: stable@kernel.org
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2009-12-03 09:32:19 +02:00
Zhai, Edwin d255f4f2ba KVM: introduce kvm_vcpu_on_spin
Introduce kvm_vcpu_on_spin, to be used by VMX/SVM to yield processing
once the cpu detects pause-based looping.

Signed-off-by: "Zhai, Edwin" <edwin.zhai@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2009-12-03 09:32:17 +02:00
Jiri Slaby 0c6ddcebd8 KVM: fix lock imbalance in kvm_*_irq_source_id()
Stanse found 2 lock imbalances in kvm_request_irq_source_id and
kvm_free_irq_source_id. They omit to unlock kvm->irq_lock on fail paths.

Fix that by adding unlock labels at the end of the functions and jump
there from the fail paths.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:12 +02:00
Alexander Graf 10474ae894 KVM: Activate Virtualization On Demand
X86 CPUs need to have some magic happening to enable the virtualization
extensions on them. This magic can result in unpleasant results for
users, like blocking other VMMs from working (vmx) or using invalid TLB
entries (svm).

Currently KVM activates virtualization when the respective kernel module
is loaded. This blocks us from autoloading KVM modules without breaking
other VMMs.

To circumvent this problem at least a bit, this patch introduces on
demand activation of virtualization. This means, that instead
virtualization is enabled on creation of the first virtual machine
and disabled on destruction of the last one.

So using this, KVM can be easily autoloaded, while keeping other
hypervisors usable.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:10 +02:00
Avi Kivity bfd99ff5d4 KVM: Move assigned device code to own file
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:09 +02:00
Gleb Natapov 680b3648ba KVM: Drop kvm->irq_lock lock from irq injection path
The only thing it protects now is interrupt injection into lapic and
this can work lockless. Even now with kvm->irq_lock in place access
to lapic is not entirely serialized since vcpu access doesn't take
kvm->irq_lock.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:08 +02:00
Gleb Natapov eba0226bdf KVM: Move IO APIC to its own lock
The allows removal of irq_lock from the injection path.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:08 +02:00
Gleb Natapov 280aa177dc KVM: Convert irq notifiers lists to RCU locking
Use RCU locking for mask/ack notifiers lists.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:08 +02:00
Gleb Natapov 136bdfeee7 KVM: Move irq ack notifier list to arch independent code
Mask irq notifier list is already there.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:07 +02:00
Gleb Natapov e42bba90bf KVM: Move irq routing data structure to rcu locking
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:07 +02:00
Gleb Natapov 3e71f88bc9 KVM: Maintain back mapping from irqchip/pin to gsi
Maintain back mapping from irqchip/pin to gsi to speedup
interrupt acknowledgment notifications.

[avi: build fix on non-x86/ia64]

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:07 +02:00
Gleb Natapov 46e624b95c KVM: Change irq routing table to use gsi indexed array
Use gsi indexed array instead of scanning all entries on each interrupt
injection.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:07 +02:00
Gleb Natapov 1a6e4a8c27 KVM: Move irq sharing information to irqchip level
This removes assumptions that max GSIs is smaller than number of pins.
Sharing is tracked on pin level not GSI level.

[avi: no PIC on ia64]

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:06 +02:00
Avi Kivity 45ec431c52 KVM: Don't wrap schedule() with vcpu_put()/vcpu_load()
Preemption notifiers will do that for us automatically.

Signed-off-by: Avi Kivity <avi@redhat.com>
2009-12-03 09:32:05 +02:00
Alexander Graf c8240bd6f0 Use Little Endian for Dirty Bitmap
We currently use host endian long types to store information
in the dirty bitmap.

This works reasonably well on Little Endian targets, because the
u32 after the first contains the next 32 bits. On Big Endian this
breaks completely though, forcing us to be inventive here.

So Ben suggested to always use Little Endian, which looks reasonable.

We only have dirty bitmap implemented in Little Endian targets so far
and since PowerPC would be the first Big Endian platform, we can just
as well switch to Little Endian always with little effort without
breaking existing targets.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-11-05 16:50:27 +11:00
Darrick J. Wong 0ea4ed8e94 KVM: Prevent kvm_init from corrupting debugfs structures
I'm seeing an oops condition when kvm-intel and kvm-amd are modprobe'd
during boot (say on an Intel system) and then rmmod'd:

   # modprobe kvm-intel
     kvm_init()
     kvm_init_debug()
     kvm_arch_init()  <-- stores debugfs dentries internally
     (success, etc)

   # modprobe kvm-amd
     kvm_init()
     kvm_init_debug() <-- second initialization clobbers kvm's
                          internal pointers to dentries
     kvm_arch_init()
     kvm_exit_debug() <-- and frees them

   # rmmod kvm-intel
     kvm_exit()
     kvm_exit_debug() <-- double free of debugfs files!

     *BOOM*

If execution gets to the end of kvm_init(), then the calling module has been
established as the kvm provider.  Move the debugfs initialization to the end of
the function, and remove the now-unnecessary call to kvm_exit_debug() from the
error path.  That way we avoid trampling on the debugfs entries and freeing
them twice.

Cc: stable@kernel.org
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2009-10-16 12:30:26 -03:00
Izik Eidus 3da0dd433d KVM: add support for change_pte mmu notifiers
this is needed for kvm if it want ksm to directly map pages into its
shadow page tables.

[marcelo: cast pfn assignment to u64]

Signed-off-by: Izik Eidus <ieidus@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2009-10-04 17:04:53 +02:00
Alexey Dobriyan 828c09509b const: constify remaining file_operations
[akpm@linux-foundation.org: fix KVM]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-01 16:11:11 -07:00
Alexey Dobriyan f0f37e2f77 const: mark struct vm_struct_operations
* mark struct vm_area_struct::vm_ops as const
* mark vm_ops in AGP code

But leave TTM code alone, something is fishy there with global vm_ops
being used.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-27 11:39:25 -07:00
Li Zefan 79f5599772 cpumask: use zalloc_cpumask_var() where possible
Remove open-coded zalloc_cpumask_var() and zalloc_cpumask_var_node().

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-09-24 09:34:24 +09:30
Julia Lawall 6223011fb9 KVM: correct error-handling code
This code is not executed before file has been initialized to the result of
calling eventfd_fget.  This function returns an ERR_PTR value in an error
case instead of NULL.  Thus the test that file is not NULL is always true.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@match exists@
expression x, E;
statement S1, S2;
@@

x = eventfd_fget(...)
... when != x = E
(
*  if (x == NULL || ...) S1 else S2
|
*  if (x == NULL && ...) S1 else S2
)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 18:11:12 +03:00
Heiko Carstens 28bcb11218 KVM: fix compile warnings on s390
CC      arch/s390/kvm/../../../virt/kvm/kvm_main.o
arch/s390/kvm/../../../virt/kvm/kvm_main.c: In function '__kvm_set_memory_region':
arch/s390/kvm/../../../virt/kvm/kvm_main.c:485: warning: unused variable 'j'
arch/s390/kvm/../../../virt/kvm/kvm_main.c:484: warning: unused variable 'lpages'
arch/s390/kvm/../../../virt/kvm/kvm_main.c:483: warning: unused variable 'ugfn'

Cc: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2009-09-10 18:11:11 +03:00
Gleb Natapov 65a8221163 KVM: Fix coalesced interrupt reporting in IOAPIC
This bug was introduced by b4a2f5e723.

Cc: stable@kernel.org
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 10:46:59 +03:00
Avi Kivity 6621fbc2c6 KVM: Move #endif KVM_CAP_IRQ_ROUTING to correct place
The symbol only controls irq routing, not MSI-X.

Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 10:46:42 +03:00
Xiao Guangrong aed665f7bb KVM: fix kvm_init() error handling
Remove debugfs file if kvm_arch_init() return error

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 08:33:17 +03:00
Jan Kiszka e601e3be7a KVM: Drop obsolete cpu_get/put in make_all_cpus_request
spin_lock disables preemption, so we can simply read the current cpu.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2009-09-10 08:33:16 +03:00
Gleb Natapov a1b37100d9 KVM: Reduce runnability interface with arch support code
Remove kvm_cpu_has_interrupt() and kvm_arch_interrupt_allowed() from
interface between general code and arch code. kvm_arch_vcpu_runnable()
checks for interrupts instead.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 08:33:13 +03:00
Gregory Haskins d34e6b175e KVM: add ioeventfd support
ioeventfd is a mechanism to register PIO/MMIO regions to trigger an eventfd
signal when written to by a guest.  Host userspace can register any
arbitrary IO address with a corresponding eventfd and then pass the eventfd
to a specific end-point of interest for handling.

Normal IO requires a blocking round-trip since the operation may cause
side-effects in the emulated model or may return data to the caller.
Therefore, an IO in KVM traps from the guest to the host, causes a VMX/SVM
"heavy-weight" exit back to userspace, and is ultimately serviced by qemu's
device model synchronously before returning control back to the vcpu.

However, there is a subclass of IO which acts purely as a trigger for
other IO (such as to kick off an out-of-band DMA request, etc).  For these
patterns, the synchronous call is particularly expensive since we really
only want to simply get our notification transmitted asychronously and
return as quickly as possible.  All the sychronous infrastructure to ensure
proper data-dependencies are met in the normal IO case are just unecessary
overhead for signalling.  This adds additional computational load on the
system, as well as latency to the signalling path.

Therefore, we provide a mechanism for registration of an in-kernel trigger
point that allows the VCPU to only require a very brief, lightweight
exit just long enough to signal an eventfd.  This also means that any
clients compatible with the eventfd interface (which includes userspace
and kernelspace equally well) can now register to be notified. The end
result should be a more flexible and higher performance notification API
for the backend KVM hypervisor and perhipheral components.

To test this theory, we built a test-harness called "doorbell".  This
module has a function called "doorbell_ring()" which simply increments a
counter for each time the doorbell is signaled.  It supports signalling
from either an eventfd, or an ioctl().

We then wired up two paths to the doorbell: One via QEMU via a registered
io region and through the doorbell ioctl().  The other is direct via
ioeventfd.

You can download this test harness here:

ftp://ftp.novell.com/dev/ghaskins/doorbell.tar.bz2

The measured results are as follows:

qemu-mmio:       110000 iops, 9.09us rtt
ioeventfd-mmio: 200100 iops, 5.00us rtt
ioeventfd-pio:  367300 iops, 2.72us rtt

I didn't measure qemu-pio, because I have to figure out how to register a
PIO region with qemu's device model, and I got lazy.  However, for now we
can extrapolate based on the data from the NULLIO runs of +2.56us for MMIO,
and -350ns for HC, we get:

qemu-pio:      153139 iops, 6.53us rtt
ioeventfd-hc: 412585 iops, 2.37us rtt

these are just for fun, for now, until I can gather more data.

Here is a graph for your convenience:

http://developer.novell.com/wiki/images/7/76/Iofd-chart.png

The conclusion to draw is that we save about 4us by skipping the userspace
hop.

--------------------

Signed-off-by: Gregory Haskins <ghaskins@novell.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10 08:33:12 +03:00