Граф коммитов

3564 Коммитов

Автор SHA1 Сообщение Дата
Paolo Bonzini b10d92a54d KVM: x86: fix RSM into 64-bit protected mode
In order to get into 64-bit protected mode, you need to enable
paging while EFER.LMA=1.  For this to work, CS.L must be 0.
Currently, we load the segments before CR0 and CR4, which means
that if RSM returns into 64-bit protected mode CS.L is already 1
and everything breaks.

Luckily, CS.L=0 is always the case when executing RSM, because it
is forbidden to execute RSM from 64-bit protected mode.  Hence it
is enough to load CR0 and CR4 first, and only then the segments.

Fixes: 660a5d517a
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-14 16:39:52 +02:00
Paolo Bonzini 25188b9986 KVM: x86: fix previous commit for 32-bit
Unfortunately I only noticed this after pushing.

Fixes: f0d648bdf0
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-14 16:39:25 +02:00
Paolo Bonzini 58f800d5ac Merge branch 'kvm-master' into HEAD
This merge brings in a couple important SMM fixes, which makes it
easier to test latest KVM with unrestricted_guest=0 and to test
the in-progress work on SMM support in the firmware.

Conflicts:
	arch/x86/kvm/x86.c
2015-10-13 21:32:50 +02:00
Paolo Bonzini 7391773933 KVM: x86: fix SMI to halted VCPU
An SMI to a halted VCPU must wake it up, hence a VCPU with a pending
SMI must be considered runnable.

Fixes: 64d6067057
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-13 18:29:41 +02:00
Paolo Bonzini 5d9bc648b9 KVM: x86: clean up kvm_arch_vcpu_runnable
Split the huge conditional in two functions.

Fixes: 64d6067057
Cc: stable@vger.kernel.org
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-13 18:28:59 +02:00
Paolo Bonzini f0d648bdf0 KVM: x86: map/unmap private slots in __x86_set_memory_region
Otherwise, two copies (one of them never populated and thus bogus)
are allocated for the regular and SMM address spaces.  This breaks
SMM with EPT but without unrestricted guest support, because the
SMM copy of the identity page map is all zeros.

By moving the allocation to the caller we also remove the last
vestiges of kernel-allocated memory regions (not accessible anymore
in userspace since commit b74a07beed, "KVM: Remove kernel-allocated
memory regions", 2010-06-21); that is a nice bonus.

Reported-by: Alexandre DERUMIER <aderumier@odiso.com>
Cc: stable@vger.kernel.org
Fixes: 9da0e4d5ac
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-13 18:28:58 +02:00
Paolo Bonzini 1d8007bdee KVM: x86: build kvm_userspace_memory_region in x86_set_memory_region
The next patch will make x86_set_memory_region fill the
userspace_addr.  Since the struct is not used untouched
anymore, it makes sense to build it in x86_set_memory_region
directly; it also simplifies the callers.

Reported-by: Alexandre DERUMIER <aderumier@odiso.com>
Cc: stable@vger.kernel.org
Fixes: 9da0e4d5ac
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-13 18:28:46 +02:00
Feng Wu bf9f6ac8d7 KVM: Update Posted-Interrupts Descriptor when vCPU is blocked
This patch updates the Posted-Interrupts Descriptor when vCPU
is blocked.

pre-block:
- Add the vCPU to the blocked per-CPU list
- Set 'NV' to POSTED_INTR_WAKEUP_VECTOR

post-block:
- Remove the vCPU from the per-CPU list

Signed-off-by: Feng Wu <feng.wu@intel.com>
[Concentrate invocation of pre/post-block hooks to vcpu_block. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:53 +02:00
Feng Wu 28b835d60f KVM: Update Posted-Interrupts Descriptor when vCPU is preempted
This patch updates the Posted-Interrupts Descriptor when vCPU
is preempted.

sched out:
- Set 'SN' to suppress furture non-urgent interrupts posted for
the vCPU.

sched in:
- Clear 'SN'
- Change NDST if vCPU is scheduled to a different CPU
- Set 'NV' to POSTED_INTR_VECTOR

Signed-off-by: Feng Wu <feng.wu@intel.com>
[Include asm/cpu.h to fix !CONFIG_SMP compilation. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:53 +02:00
Feng Wu 8727688006 KVM: x86: select IRQ_BYPASS_MANAGER
Select IRQ_BYPASS_MANAGER for x86 when CONFIG_KVM is set

Signed-off-by: Feng Wu <feng.wu@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:52 +02:00
Feng Wu efc644048e KVM: x86: Update IRTE for posted-interrupts
This patch adds the routine to update IRTE for posted-interrupts
when guest changes the interrupt configuration.

Signed-off-by: Feng Wu <feng.wu@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
[Squashed in automatically generated patch from the build robot
 "KVM: x86: vcpu_to_pi_desc() can be static" - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:51 +02:00
Feng Wu d84f1e0755 KVM: make kvm_set_msi_irq() public
Make kvm_set_msi_irq() public, we can use this function outside.

Signed-off-by: Feng Wu <feng.wu@intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:50 +02:00
Feng Wu 8feb4a04dc KVM: Define a new interface kvm_intr_is_single_vcpu()
This patch defines a new interface kvm_intr_is_single_vcpu(),
which can returns whether the interrupt is for single-CPU or not.

It is used by VT-d PI, since now we only support single-CPU
interrupts, For lowest-priority interrupts, if user configures
it via /proc/irq or uses irqbalance to make it single-CPU, we
can use PI to deliver the interrupts to it. Full functionality
of lowest-priority support will be added later.

Signed-off-by: Feng Wu <feng.wu@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:49 +02:00
Feng Wu ebbfc76536 KVM: Add some helper functions for Posted-Interrupts
This patch adds some helper functions to manipulate the
Posted-Interrupts Descriptor.

Signed-off-by: Feng Wu <feng.wu@intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
[Make the new functions inline. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:48 +02:00
Feng Wu 6ef1522f7e KVM: Extend struct pi_desc for VT-d Posted-Interrupts
Extend struct pi_desc for VT-d Posted-Interrupts.

Signed-off-by: Feng Wu <feng.wu@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:48 +02:00
Xiao Guangrong 1cea0ce68e KVM: VMX: drop rdtscp_enabled field
Check cpuid bit instead of it

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:41 +02:00
Xiao Guangrong 7ec362964d KVM: VMX: clean up bit operation on SECONDARY_VM_EXEC_CONTROL
Use vmcs_set_bits() and vmcs_clear_bits() to clean up the code

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:40 +02:00
Xiao Guangrong feda805fe7 KVM: VMX: unify SECONDARY_VM_EXEC_CONTROL update
Unify the update in vmx_cpuid_update()

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
[Rewrite to use vmcs_set_secondary_exec_control. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:39 +02:00
Paolo Bonzini 8b97265a15 KVM: VMX: align vmx->nested.nested_vmx_secondary_ctls_high to vmx->rdtscp_enabled
The SECONDARY_EXEC_RDTSCP must be available iff RDTSCP is enabled in the
guest.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:38 +02:00
Xiao Guangrong 29541bb8f4 KVM: VMX: simplify invpcid handling in vmx_cpuid_update()
If vmx_invpcid_supported() is true, second execution control
filed must be supported and SECONDARY_EXEC_ENABLE_INVPCID
must have already been set in current vmcs by
vmx_secondary_exec_control()

If vmx_invpcid_supported() is false, no need to clear
SECONDARY_EXEC_ENABLE_INVPCID

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:38 +02:00
Xiao Guangrong f36201e5f4 KVM: VMX: simplify rdtscp handling in vmx_cpuid_update()
if vmx_rdtscp_supported() is true SECONDARY_EXEC_RDTSCP must
have already been set in current vmcs by
vmx_secondary_exec_control()

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:37 +02:00
Xiao Guangrong e2821620c0 KVM: VMX: drop rdtscp_enabled check in prepare_vmcs02()
SECONDARY_EXEC_RDTSCP set for L2 guest comes from vmcs12

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:36 +02:00
Xiao Guangrong 8b3e34e46a KVM: x86: add pcommit support
Pass PCOMMIT CPU feature to guest to enable PCOMMIT instruction

Currently we do not catch pcommit instruction for L1 guest and
allow L1 to catch this instruction for L2 if, as required by the spec,
L1 can enumerate the PCOMMIT instruction via CPUID:
| IA32_VMX_PROCBASED_CTLS2[53] (which enumerates support for the
| 1-setting of PCOMMIT exiting) is always the same as
| CPUID.07H:EBX.PCOMMIT[bit 22]. Thus, software can set PCOMMIT exiting
| to 1 if and only if the PCOMMIT instruction is enumerated via CPUID

The spec can be found at
https://software.intel.com/sites/default/files/managed/0d/53/319433-022.pdf

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:35 +02:00
Xiao Guangrong eb1c31b468 KVM: x86: allow guest to use cflushopt and clwb
Pass these CPU features to guest to enable them in guest

They are needed by nvdimm drivers

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:35 +02:00
Paolo Bonzini d6a858d13e KVM: vmx: disable posted interrupts if no local APIC
Uniprocessor 32-bit randconfigs can disable the local APIC, and posted
interrupts require reserving a vector on the LAPIC, so they are
incompatible.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:34 +02:00
Andrey Smetanin 9eec50b8bb kvm/x86: Hyper-V HV_X64_MSR_VP_RUNTIME support
HV_X64_MSR_VP_RUNTIME msr used by guest to get
"the time the virtual processor consumes running guest code,
and the time the associated logical processor spends running
hypervisor code on behalf of that guest."

Calculation of this time is performed by task_cputime_adjusted()
for vcpu task.

Necessary to support loading of winhv.sys in guest, which in turn is
required to support Windows VMBus.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Gleb Natapov <gleb@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:33 +02:00
Andrey Smetanin 11c4b1ca71 kvm/x86: Hyper-V HV_X64_MSR_VP_INDEX export for QEMU.
Insert Hyper-V HV_X64_MSR_VP_INDEX into msr's emulated list,
so QEMU can set Hyper-V features cpuid HV_X64_MSR_VP_INDEX_AVAILABLE
bit correctly. KVM emulation part is in place already.

Necessary to support loading of winhv.sys in guest, which in turn is
required to support Windows VMBus.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Gleb Natapov <gleb@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:32 +02:00
Andrey Smetanin e516cebb4f kvm/x86: Hyper-V HV_X64_MSR_RESET msr
HV_X64_MSR_RESET msr is used by Hyper-V based Windows guest
to reset guest VM by hypervisor.

Necessary to support loading of winhv.sys in guest, which in turn is
required to support Windows VMBus.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Gleb Natapov <gleb@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:32 +02:00
Jason Wang 931c33b178 kvm: add tracepoint for fast mmio
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:30 +02:00
Steve Rutherford 1c1a9ce973 KVM: x86: Add support for local interrupt requests from userspace
In order to enable userspace PIC support, the userspace PIC needs to
be able to inject local interrupts even when the APICs are in the
kernel.

KVM_INTERRUPT now supports sending local interrupts to an APIC when
APICs are in the kernel.

The ready_for_interrupt_request flag is now only set when the CPU/APIC
will immediately accept and inject an interrupt (i.e. APIC has not
masked the PIC).

When the PIC wishes to initiate an INTA cycle with, say, CPU0, it
kicks CPU0 out of the guest, and renedezvous with CPU0 once it arrives
in userspace.

When the CPU/APIC unmasks the PIC, a KVM_EXIT_IRQ_WINDOW_OPEN is
triggered, so that userspace has a chance to inject a PIC interrupt
if it had been pending.

Overall, this design can lead to a small number of spurious userspace
renedezvous. In particular, whenever the PIC transistions from low to
high while it is masked and whenever the PIC becomes unmasked while
it is low.

Note: this does not buffer more than one local interrupt in the
kernel, so the VMM needs to enter the guest in order to complete
interrupt injection before injecting an additional interrupt.

Compiles for x86.

Can pass the KVM Unit Tests.

Signed-off-by: Steve Rutherford <srutherford@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:29 +02:00
Steve Rutherford b053b2aef2 KVM: x86: Add EOI exit bitmap inference
In order to support a userspace IOAPIC interacting with an in kernel
APIC, the EOI exit bitmaps need to be configurable.

If the IOAPIC is in userspace (i.e. the irqchip has been split), the
EOI exit bitmaps will be set whenever the GSI Routes are configured.
In particular, for the low MSI routes are reservable for userspace
IOAPICs. For these MSI routes, the EOI Exit bit corresponding to the
destination vector of the route will be set for the destination VCPU.

The intention is for the userspace IOAPICs to use the reservable MSI
routes to inject interrupts into the guest.

This is a slight abuse of the notion of an MSI Route, given that MSIs
classically bypass the IOAPIC. It might be worthwhile to add an
additional route type to improve clarity.

Compile tested for Intel x86.

Signed-off-by: Steve Rutherford <srutherford@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:28 +02:00
Steve Rutherford 7543a635aa KVM: x86: Add KVM exit for IOAPIC EOIs
Adds KVM_EXIT_IOAPIC_EOI which allows the kernel to EOI
level-triggered IOAPIC interrupts.

Uses a per VCPU exit bitmap to decide whether or not the IOAPIC needs
to be informed (which is identical to the EOI_EXIT_BITMAP field used
by modern x86 processors, but can also be used to elide kvm IOAPIC EOI
exits on older processors).

[Note: A prototype using ResampleFDs found that decoupling the EOI
from the VCPU's thread made it possible for the VCPU to not see a
recent EOI after reentering the guest. This does not match real
hardware.]

Compile tested for Intel x86.

Signed-off-by: Steve Rutherford <srutherford@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:27 +02:00
Steve Rutherford 49df6397ed KVM: x86: Split the APIC from the rest of IRQCHIP.
First patch in a series which enables the relocation of the
PIC/IOAPIC to userspace.

Adds capability KVM_CAP_SPLIT_IRQCHIP;

KVM_CAP_SPLIT_IRQCHIP enables the construction of LAPICs without the
rest of the irqchip.

Compile tested for x86.

Signed-off-by: Steve Rutherford <srutherford@google.com>
Suggested-by: Andrew Honig <ahonig@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:26 +02:00
Paolo Bonzini 4ca7dd8ce4 KVM: x86: unify handling of interrupt window
The interrupt window is currently checked twice, once in vmx.c/svm.c and
once in dm_request_for_irq_injection.  The only difference is the extra
check for kvm_arch_interrupt_allowed in dm_request_for_irq_injection,
and the different return value (EINTR/KVM_EXIT_INTR for vmx.c/svm.c vs.
0/KVM_EXIT_IRQ_WINDOW_OPEN for dm_request_for_irq_injection).

However, dm_request_for_irq_injection is basically dead code!  Revive it
by removing the checks in vmx.c and svm.c's vmexit handlers, and
fixing the returned values for the dm_request_for_irq_injection case.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:26 +02:00
Paolo Bonzini 35754c987f KVM: x86: introduce lapic_in_kernel
Avoid pointer chasing and memory barriers, and simplify the code
when split irqchip (LAPIC in kernel, IOAPIC/PIC in userspace)
is introduced.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:25 +02:00
Paolo Bonzini d50ab6c1a2 KVM: x86: replace vm_has_apicv hook with cpu_uses_apicv
This will avoid an unnecessary trip to ->kvm and from there to the VPIC.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:24 +02:00
Paolo Bonzini 3bb345f387 KVM: x86: store IOAPIC-handled vectors in each VCPU
We can reuse the algorithm that computes the EOI exit bitmap to figure
out which vectors are handled by the IOAPIC.  The only difference
between the two is for edge-triggered interrupts other than IRQ8
that have no notifiers active; however, the IOAPIC does not have to
do anything special for these interrupts anyway.

This again limits the interactions between the IOAPIC and the LAPIC,
making it easier to move the former to userspace.

Inspired by a patch from Steve Rutherford.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:23 +02:00
Paolo Bonzini bdaffe1d93 KVM: x86: set TMR when the interrupt is accepted
Do not compute TMR in advance.  Instead, set the TMR just before the interrupt
is accepted into the IRR.  This limits the coupling between IOAPIC and LAPIC.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:22 +02:00
Dirk Müller d2922422c4 Use WARN_ON_ONCE for missing X86_FEATURE_NRIPS
The cpu feature flags are not ever going to change, so warning
everytime can cause a lot of kernel log spam
(in our case more than 10GB/hour).

The warning seems to only occur when nested virtualization is
enabled, so it's probably triggered by a KVM bug.  This is a
sensible and safe change anyway, and the KVM bug fix might not
be suitable for stable releases anyway.

Cc: stable@vger.kernel.org
Signed-off-by: Dirk Mueller <dmueller@suse.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 14:59:37 +02:00
Paolo Bonzini fc07e76ac7 Revert "KVM: SVM: use NPT page attributes"
This reverts commit 3c2e7f7de3.
Initializing the mapping from MTRR to PAT values was reported to
fail nondeterministically, and it also caused extremely slow boot
(due to caching getting disabled---bug 103321) with assigned devices.

Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Reported-by: Sebastian Schuette <dracon@ewetel.net>
Cc: stable@vger.kernel.org # 4.2+
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 13:30:44 +02:00
Paolo Bonzini bcf166a994 Revert "KVM: svm: handle KVM_X86_QUIRK_CD_NW_CLEARED in svm_get_mt_mask"
This reverts commit 5492830370.
It builds on the commit that is being reverted next.

Cc: stable@vger.kernel.org # 4.2+
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 13:30:43 +02:00
Paolo Bonzini 625422f60c Revert "KVM: SVM: Sync g_pat with guest-written PAT value"
This reverts commit e098223b78,
which has a dependency on other commits being reverted.

Cc: stable@vger.kernel.org # 4.2+
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 13:30:43 +02:00
Paolo Bonzini 606decd670 Revert "KVM: x86: apply guest MTRR virtualization on host reserved pages"
This reverts commit fd717f1101.
It was reported to cause Machine Check Exceptions (bug 104091).

Reported-by: harn-solo@gmx.de
Cc: stable@vger.kernel.org # 4.2+
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 13:30:42 +02:00
Radim Krčmář 9bac175d8e Revert "KVM: x86: zero kvmclock_offset when vcpu0 initializes kvmclock system MSR"
Shifting pvclock_vcpu_time_info.system_time on write to KVM system time
MSR is a change of ABI.  Probably only 2.6.16 based SLES 10 breaks due
to its custom enhancements to kvmclock, but KVM never declared the MSR
only for one-shot initialization.  (Doc says that only one write is
needed.)

This reverts commit b7e60c5aed.
And adds a note to the definition of PVCLOCK_COUNTS_FROM_ZERO.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Acked-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-09-28 13:06:37 +02:00
Paolo Bonzini 58c95070da KVM: x86: fix off-by-one in reserved bits check
29ecd66019 ("KVM: x86: avoid uninitialized variable warning",
2015-09-06) introduced a not-so-subtle problem, which probably
escaped review because it was not part of the patch context.

Before the patch, leaf was always equal to iterator.level.  After,
it is equal to iterator.level - 1 in the call to is_shadow_zero_bits_set,
and when is_shadow_zero_bits_set does another "-1" the check on
reserved bits becomes incorrect.  Using "iterator.level" in the call
fixes this call trace:

WARNING: CPU: 2 PID: 17000 at arch/x86/kvm/mmu.c:3385 handle_mmio_page_fault.part.93+0x1a/0x20 [kvm]()
Modules linked in: tun sha256_ssse3 sha256_generic drbg binfmt_misc ipv6 vfat fat fuse dm_crypt dm_mod kvm_amd kvm crc32_pclmul aesni_intel aes_x86_64 lrw gf128mul glue_helper ablk_helper cryptd fam15h_power amd64_edac_mod k10temp edac_core amdkfd amd_iommu_v2 radeon acpi_cpufreq
[...]
Call Trace:
  dump_stack+0x4e/0x84
  warn_slowpath_common+0x95/0xe0
  warn_slowpath_null+0x1a/0x20
  handle_mmio_page_fault.part.93+0x1a/0x20 [kvm]
  tdp_page_fault+0x231/0x290 [kvm]
  ? emulator_pio_in_out+0x6e/0xf0 [kvm]
  kvm_mmu_page_fault+0x36/0x240 [kvm]
  ? svm_set_cr0+0x95/0xc0 [kvm_amd]
  pf_interception+0xde/0x1d0 [kvm_amd]
  handle_exit+0x181/0xa70 [kvm_amd]
  ? kvm_arch_vcpu_ioctl_run+0x68b/0x1730 [kvm]
  kvm_arch_vcpu_ioctl_run+0x6f6/0x1730 [kvm]
  ? kvm_arch_vcpu_ioctl_run+0x68b/0x1730 [kvm]
  ? preempt_count_sub+0x9b/0xf0
  ? mutex_lock_killable_nested+0x26f/0x490
  ? preempt_count_sub+0x9b/0xf0
  kvm_vcpu_ioctl+0x358/0x710 [kvm]
  ? __fget+0x5/0x210
  ? __fget+0x101/0x210
  do_vfs_ioctl+0x2f4/0x560
  ? __fget_light+0x29/0x90
  SyS_ioctl+0x4c/0x90
  entry_SYSCALL_64_fastpath+0x16/0x73
---[ end trace 37901c8686d84de6 ]---

Reported-by: Borislav Petkov <bp@alien8.de>
Tested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-09-25 10:31:29 +02:00
Paolo Bonzini 6fec21449a KVM: x86: use correct page table format to check nested page table reserved bits
Intel CPUID on AMD host or vice versa is a weird case, but it can
happen.  Handle it by checking the host CPU vendor instead of the
guest's in reset_tdp_shadow_zero_bits_mask.  For speed, the
check uses the fact that Intel EPT has an X (executable) bit while
AMD NPT has NX.

Reported-by: Borislav Petkov <bp@alien8.de>
Tested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-09-25 10:31:28 +02:00
Paolo Bonzini 79a8059d24 KVM: svm: do not call kvm_set_cr0 from init_vmcb
kvm_set_cr0 may want to call kvm_zap_gfn_range and thus access the
memslots array (SRCU protected).  Using a mini SRCU critical section
is ugly, and adding it to kvm_arch_vcpu_create doesn't work because
the VMX vcpu_create callback calls synchronize_srcu.

Fixes this lockdep splat:

===============================
[ INFO: suspicious RCU usage. ]
4.3.0-rc1+ #1 Not tainted
-------------------------------
include/linux/kvm_host.h:488 suspicious rcu_dereference_check() usage!

other info that might help us debug this:
rcu_scheduler_active = 1, debug_locks = 0
1 lock held by qemu-system-i38/17000:
 #0:  (&(&kvm->mmu_lock)->rlock){+.+...}, at: kvm_zap_gfn_range+0x24/0x1a0 [kvm]

[...]
Call Trace:
 dump_stack+0x4e/0x84
 lockdep_rcu_suspicious+0xfd/0x130
 kvm_zap_gfn_range+0x188/0x1a0 [kvm]
 kvm_set_cr0+0xde/0x1e0 [kvm]
 init_vmcb+0x760/0xad0 [kvm_amd]
 svm_create_vcpu+0x197/0x250 [kvm_amd]
 kvm_arch_vcpu_create+0x47/0x70 [kvm]
 kvm_vm_ioctl+0x302/0x7e0 [kvm]
 ? __lock_is_held+0x51/0x70
 ? __fget+0x101/0x210
 do_vfs_ioctl+0x2f4/0x560
 ? __fget_light+0x29/0x90
 SyS_ioctl+0x4c/0x90
 entry_SYSCALL_64_fastpath+0x16/0x73

Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-09-25 10:31:22 +02:00
Paolo Bonzini 3afb112180 KVM: x86: trap AMD MSRs for the TSeg base and mask
These have roughly the same purpose as the SMRR, which we do not need
to implement in KVM.  However, Linux accesses MSR_K8_TSEG_ADDR at
boot, which causes problems when running a Xen dom0 under KVM.
Just return 0, meaning that processor protection of SMRAM is not
in effect.

Reported-by: M A Young <m.a.young@durham.ac.uk>
Cc: stable@vger.kernel.org
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-09-21 07:41:22 +02:00
Igor Mammedov ebae871a50 kvm: svm: reset mmu on VCPU reset
When INIT/SIPI sequence is sent to VCPU which before that
was in use by OS, VMRUN might fail with:

 KVM: entry failed, hardware error 0xffffffff
 EAX=00000000 EBX=00000000 ECX=00000000 EDX=000006d3
 ESI=00000000 EDI=00000000 EBP=00000000 ESP=00000000
 EIP=00000000 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
 ES =0000 00000000 0000ffff 00009300
 CS =9a00 0009a000 0000ffff 00009a00
 [...]
 CR0=60000010 CR2=b6f3e000 CR3=01942000 CR4=000007e0
 [...]
 EFER=0000000000000000

with corresponding SVM error:
 KVM: FAILED VMRUN WITH VMCB:
 [...]
 cpl:            0                efer:         0000000000001000
 cr0:            0000000080010010 cr2:          00007fd7fe85bf90
 cr3:            0000000187d0c000 cr4:          0000000000000020
 [...]

What happens is that VCPU state right after offlinig:
CR0: 0x80050033  EFER: 0xd01  CR4: 0x7e0
  -> long mode with CR3 pointing to longmode page tables

and when VCPU gets INIT/SIPI following transition happens
CR0: 0 -> 0x60000010 EFER: 0x0  CR4: 0x7e0
  -> paging disabled with stale CR3

However SVM under the hood puts VCPU in Paged Real Mode*
which effectively translates CR0 0x60000010 -> 80010010 after

   svm_vcpu_reset()
       -> init_vmcb()
           -> kvm_set_cr0()
               -> svm_set_cr0()

but from  kvm_set_cr0() perspective CR0: 0 -> 0x60000010
only caching bits are changed and
commit d81135a57a
 ("KVM: x86: do not reset mmu if CR0.CD and CR0.NW are changed")'
regressed svm_vcpu_reset() which relied on MMU being reset.

As result VMRUN after svm_vcpu_reset() tries to run
VCPU in Paged Real Mode with stale MMU context (longmode page tables),
which causes some AMD CPUs** to bail out with VMEXIT_INVALID.

Fix issue by unconditionally resetting MMU context
at init_vmcb() time.

	* AMD64 Architecture Programmer’s Manual,
	    Volume 2: System Programming, rev: 3.25
	      15.19 Paged Real Mode
	** Opteron 1216

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Fixes: d81135a57a
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-09-18 16:49:02 +02:00
Wanpeng Li 04bb92e4b4 KVM: vmx: fix VPID is 0000H in non-root operation
Reference SDM 28.1:

The current VPID is 0000H in the following situations:
- Outside VMX operation. (This includes operation in system-management
  mode under the default treatment of SMIs and SMM with VMX operation;
  see Section 34.14.)
- In VMX root operation.
- In VMX non-root operation when the “enable VPID” VM-execution control
  is 0.

The VPID should never be 0000H in non-root operation when "enable VPID"
VM-execution control is 1. However, commit 34a1cd60 ("kvm: x86: vmx:
move some vmx setting from vmx_init() to hardware_setup()") remove the
codes which reserve 0000H for VMX root operation.

This patch fix it by again reserving 0000H for VMX root operation.

Cc: stable@vger.kernel.org # 3.19+
Fixes: 34a1cd60d1
Reported-by: Wincy Van <fanwenyi0529@gmail.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-09-16 15:17:27 +02:00
Paolo Bonzini 62bea5bff4 KVM: add halt_attempted_poll to VCPU stats
This new statistic can help diagnosing VCPUs that, for any reason,
trigger bad behavior of halt_poll_ns autotuning.

For example, say halt_poll_ns = 480000, and wakeups are spaced exactly
like 479us, 481us, 479us, 481us. Then KVM always fails polling and wastes
10+20+40+80+160+320+480 = 1110 microseconds out of every
479+481+479+481+479+481+479 = 3359 microseconds. The VCPU then
is consuming about 30% more CPU than it would use without
polling.  This would show as an abnormally high number of
attempted polling compared to the successful polls.

Acked-by: Christian Borntraeger <borntraeger@de.ibm.com<
Reviewed-by: David Matlack <dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-09-16 12:17:00 +02:00
Dave Hansen d91cab7813 x86/fpu: Rename XSAVE macros
There are two concepts that have some confusing naming:
 1. Extended State Component numbers (currently called
    XFEATURE_BIT_*)
 2. Extended State Component masks (currently called XSTATE_*)

The numbers are (currently) from 0-9.  State component 3 is the
bounds registers for MPX, for instance.

But when we want to enable "state component 3", we go set a bit
in XCR0.  The bit we set is 1<<3.  We can check to see if a
state component feature is enabled by looking at its bit.

The current 'xfeature_bit's are at best xfeature bit _numbers_.
Calling them bits is at best inconsistent with ending the enum
list with 'XFEATURES_NR_MAX'.

This patch renames the enum to be 'xfeature'.  These also
happen to be what the Intel documentation calls a "state
component".

We also want to differentiate these from the "XSTATE_*" macros.
The "XSTATE_*" macros are a mask, and we rename them to match.

These macros are reasonably widely used so this patch is a
wee bit big, but this really is just a rename.

The only non-mechanical part of this is the

	s/XSTATE_EXTEND_MASK/XFEATURE_MASK_EXTEND/

We need a better name for it, but that's another patch.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: dave@sr71.net
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/20150902233126.38653250@viggo.jf.intel.com
[ Ported to v4.3-rc1. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-09-14 12:21:46 +02:00
Linus Torvalds 33e247c7e5 Merge branch 'akpm' (patches from Andrew)
Merge third patch-bomb from Andrew Morton:

 - even more of the rest of MM

 - lib/ updates

 - checkpatch updates

 - small changes to a few scruffy filesystems

 - kmod fixes/cleanups

 - kexec updates

 - a dma-mapping cleanup series from hch

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (81 commits)
  dma-mapping: consolidate dma_set_mask
  dma-mapping: consolidate dma_supported
  dma-mapping: cosolidate dma_mapping_error
  dma-mapping: consolidate dma_{alloc,free}_noncoherent
  dma-mapping: consolidate dma_{alloc,free}_{attrs,coherent}
  mm: use vma_is_anonymous() in create_huge_pmd() and wp_huge_pmd()
  mm: make sure all file VMAs have ->vm_ops set
  mm, mpx: add "vm_flags_t vm_flags" arg to do_mmap_pgoff()
  mm: mark most vm_operations_struct const
  namei: fix warning while make xmldocs caused by namei.c
  ipc: convert invalid scenarios to use WARN_ON
  zlib_deflate/deftree: remove bi_reverse()
  lib/decompress_unlzma: Do a NULL check for pointer
  lib/decompressors: use real out buf size for gunzip with kernel
  fs/affs: make root lookup from blkdev logical size
  sysctl: fix int -> unsigned long assignments in INT_MIN case
  kexec: export KERNEL_IMAGE_SIZE to vmcoreinfo
  kexec: align crash_notes allocation to make it be inside one physical page
  kexec: remove unnecessary test in kimage_alloc_crash_control_pages()
  kexec: split kexec_load syscall from kexec core code
  ...
2015-09-10 18:19:42 -07:00
Linus Torvalds 519f526d39 ARM:
- Full debug support for arm64
 - Active state switching for timer interrupts
 - Lazy FP/SIMD save/restore for arm64
 - Generic ARMv8 target
 
 PPC:
 - Book3S: A few bug fixes
 - Book3S: Allow micro-threading on POWER8
 
 x86:
 - Compiler warnings
 
 Generic:
 - Adaptive polling for guest halt
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull more kvm updates from Paolo Bonzini:
 "ARM:
   - Full debug support for arm64
   - Active state switching for timer interrupts
   - Lazy FP/SIMD save/restore for arm64
   - Generic ARMv8 target

  PPC:
   - Book3S: A few bug fixes
   - Book3S: Allow micro-threading on POWER8

  x86:
   - Compiler warnings

  Generic:
   - Adaptive polling for guest halt"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (49 commits)
  kvm: irqchip: fix memory leak
  kvm: move new trace event outside #ifdef CONFIG_KVM_ASYNC_PF
  KVM: trace kvm_halt_poll_ns grow/shrink
  KVM: dynamic halt-polling
  KVM: make halt_poll_ns per-vCPU
  Silence compiler warning in arch/x86/kvm/emulate.c
  kvm: compile process_smi_save_seg_64() only for x86_64
  KVM: x86: avoid uninitialized variable warning
  KVM: PPC: Book3S: Fix typo in top comment about locking
  KVM: PPC: Book3S: Fix size of the PSPB register
  KVM: PPC: Book3S HV: Exit on H_DOORBELL if HOST_IPI is set
  KVM: PPC: Book3S HV: Fix race in starting secondary threads
  KVM: PPC: Book3S: correct width in XER handling
  KVM: PPC: Book3S HV: Fix preempted vcore stolen time calculation
  KVM: PPC: Book3S HV: Fix preempted vcore list locking
  KVM: PPC: Book3S HV: Implement H_CLEAR_REF and H_CLEAR_MOD
  KVM: PPC: Book3S HV: Fix bug in dirty page tracking
  KVM: PPC: Book3S HV: Fix race in reading change bit when removing HPTE
  KVM: PPC: Book3S HV: Implement dynamic micro-threading on POWER8
  KVM: PPC: Book3S HV: Make use of unused threads when running guests
  ...
2015-09-10 16:42:49 -07:00
Dave Young 2965faa5e0 kexec: split kexec_load syscall from kexec core code
There are two kexec load syscalls, kexec_load another and kexec_file_load.
 kexec_file_load has been splited as kernel/kexec_file.c.  In this patch I
split kexec_load syscall code to kernel/kexec.c.

And add a new kconfig option KEXEC_CORE, so we can disable kexec_load and
use kexec_file_load only, or vice verse.

The original requirement is from Ted Ts'o, he want kexec kernel signature
being checked with CONFIG_KEXEC_VERIFY_SIG enabled.  But kexec-tools use
kexec_load syscall can bypass the checking.

Vivek Goyal proposed to create a common kconfig option so user can compile
in only one syscall for loading kexec kernel.  KEXEC/KEXEC_FILE selects
KEXEC_CORE so that old config files still work.

Because there's general code need CONFIG_KEXEC_CORE, so I updated all the
architecture Kconfig with a new option KEXEC_CORE, and let KEXEC selects
KEXEC_CORE in arch Kconfig.  Also updated general kernel code with to
kexec_load syscall.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Dave Young <dyoung@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Petr Tesarik <ptesarik@suse.cz>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Josh Boyer <jwboyer@fedoraproject.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-10 13:29:01 -07:00
Vlastimil Babka 96db800f5d mm: rename alloc_pages_exact_node() to __alloc_pages_node()
alloc_pages_exact_node() was introduced in commit 6484eb3e2a ("page
allocator: do not check NUMA node ID when the caller knows the node is
valid") as an optimized variant of alloc_pages_node(), that doesn't
fallback to current node for nid == NUMA_NO_NODE.  Unfortunately the
name of the function can easily suggest that the allocation is
restricted to the given node and fails otherwise.  In truth, the node is
only preferred, unless __GFP_THISNODE is passed among the gfp flags.

The misleading name has lead to mistakes in the past, see for example
commits 5265047ac3 ("mm, thp: really limit transparent hugepage
allocation to local node") and b360edb43f ("mm, mempolicy:
migrate_to_node should only migrate to node").

Another issue with the name is that there's a family of
alloc_pages_exact*() functions where 'exact' means exact size (instead
of page order), which leads to more confusion.

To prevent further mistakes, this patch effectively renames
alloc_pages_exact_node() to __alloc_pages_node() to better convey that
it's an optimized variant of alloc_pages_node() not intended for general
usage.  Both functions get described in comments.

It has been also considered to really provide a convenience function for
allocations restricted to a node, but the major opinion seems to be that
__GFP_THISNODE already provides that functionality and we shouldn't
duplicate the API needlessly.  The number of users would be small
anyway.

Existing callers of alloc_pages_exact_node() are simply converted to
call __alloc_pages_node(), with the exception of sba_alloc_coherent()
which open-codes the check for NUMA_NO_NODE, so it is converted to use
alloc_pages_node() instead.  This means it no longer performs some
VM_BUG_ON checks, and since the current check for nid in
alloc_pages_node() uses a 'nid < 0' comparison (which includes
NUMA_NO_NODE), it may hide wrong values which would be previously
exposed.

Both differences will be rectified by the next patch.

To sum up, this patch makes no functional changes, except temporarily
hiding potentially buggy callers.  Restricting the checks in
alloc_pages_node() is left for the next patch which can in turn expose
more existing buggy callers.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Robin Holt <robinmholt@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mel Gorman <mgorman@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Cliff Whickman <cpw@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08 15:35:28 -07:00
Valdis Kletnieks e8dd2d2d64 Silence compiler warning in arch/x86/kvm/emulate.c
Compiler warning:

 CC [M]  arch/x86/kvm/emulate.o
arch/x86/kvm/emulate.c: In function "__do_insn_fetch_bytes":
arch/x86/kvm/emulate.c:814:9: warning: "linear" may be used uninitialized in this function [-Wmaybe-uninitialized]

GCC is smart enough to realize that the inlined __linearize may return before
setting the value of linear, but not smart enough to realize the same
X86EMU_CONTINUE blocks actual use of the value.  However, the value of
'linear' can only be set to one value, so hoisting the one line of code
upwards makes GCC happy with the code.

Reported-by: Aruna Hewapathirane <aruna.hewapathirane@gmail.com>
Tested-by: Aruna Hewapathirane <aruna.hewapathirane@gmail.com>
Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-09-06 16:26:23 +02:00
Alexander Kuleshov efbb288afc kvm: compile process_smi_save_seg_64() only for x86_64
The process_smi_save_seg_64() function called only in the
process_smi_save_state_64() if the CONFIG_X86_64 is set. This
patch adds #ifdef CONFIG_X86_64 around process_smi_save_seg_64()
to prevent following warning message:

arch/x86/kvm/x86.c:5946:13: warning: ‘process_smi_save_seg_64’ defined but not used [-Wunused-function]
 static void process_smi_save_seg_64(struct kvm_vcpu *vcpu, char *buf, int n)
             ^

Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-09-06 16:26:22 +02:00
Paolo Bonzini 29ecd66019 KVM: x86: avoid uninitialized variable warning
This does not show up on all compiler versions, so it sneaked into the
first 4.3 pull request.  The fix is to mimic the logic of the "print
sptes" loop in the "fill array" loop.  Then leaf and root can be
both initialized unconditionally.

Note that "leaf" now points to the first unused element of the array,
not the last filled element.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-09-06 16:26:21 +02:00
Linus Torvalds 5778077d03 Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 asm changes from Ingo Molnar:
 "The biggest changes in this cycle were:

   - Revamp, simplify (and in some cases fix) Time Stamp Counter (TSC)
     primitives.  (Andy Lutomirski)

   - Add new, comprehensible entry and exit handlers written in C.
     (Andy Lutomirski)

   - vm86 mode cleanups and fixes.  (Brian Gerst)

   - 32-bit compat code cleanups.  (Brian Gerst)

  The amount of simplification in low level assembly code is already
  palpable:

     arch/x86/entry/entry_32.S                          | 130 +----
     arch/x86/entry/entry_64.S                          | 197 ++-----

  but more simplifications are planned.

  There's also the usual laudry mix of low level changes - see the
  changelog for details"

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (83 commits)
  x86/asm: Drop repeated macro of X86_EFLAGS_AC definition
  x86/asm/msr: Make wrmsrl() a function
  x86/asm/delay: Introduce an MWAITX-based delay with a configurable timer
  x86/asm: Add MONITORX/MWAITX instruction support
  x86/traps: Weaken context tracking entry assertions
  x86/asm/tsc: Add rdtscll() merge helper
  selftests/x86: Add syscall_nt selftest
  selftests/x86: Disable sigreturn_64
  x86/vdso: Emit a GNU hash
  x86/entry: Remove do_notify_resume(), syscall_trace_leave(), and their TIF masks
  x86/entry/32: Migrate to C exit path
  x86/entry/32: Remove 32-bit syscall audit optimizations
  x86/vm86: Rename vm86->v86flags and v86mask
  x86/vm86: Rename vm86->vm86_info to user_vm86
  x86/vm86: Clean up vm86.h includes
  x86/vm86: Move the vm86 IRQ definitions to vm86.h
  x86/vm86: Use the normal pt_regs area for vm86
  x86/vm86: Eliminate 'struct kernel_vm86_struct'
  x86/vm86: Move fields from 'struct kernel_vm86_struct' to 'struct vm86'
  x86/vm86: Move vm86 fields out of 'thread_struct'
  ...
2015-09-01 08:40:25 -07:00
Linus Torvalds 44e98edcd1 A very small release for x86 and s390 KVM.
s390: timekeeping changes, cleanups and fixes
 
 x86: support for Hyper-V MSRs to report crashes, and a bunch of cleanups.
 
 One interesting feature that was planned for 4.3 (emulating the local
 APIC in kernel while keeping the IOAPIC and 8254 in userspace) had to
 be delayed because Intel complained about my reading of the manual.
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Merge tag 'kvm-4.3-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "A very small release for x86 and s390 KVM.

   - s390: timekeeping changes, cleanups and fixes

   - x86: support for Hyper-V MSRs to report crashes, and a bunch of
     cleanups.

  One interesting feature that was planned for 4.3 (emulating the local
  APIC in kernel while keeping the IOAPIC and 8254 in userspace) had to
  be delayed because Intel complained about my reading of the manual"

* tag 'kvm-4.3-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (42 commits)
  x86/kvm: Rename VMX's segment access rights defines
  KVM: x86/vPMU: Fix unnecessary signed extension for AMD PERFCTRn
  kvm: x86: Fix error handling in the function kvm_lapic_sync_from_vapic
  KVM: s390: Fix assumption that kvm_set_irq_routing is always run successfully
  KVM: VMX: drop ept misconfig check
  KVM: MMU: fully check zero bits for sptes
  KVM: MMU: introduce is_shadow_zero_bits_set()
  KVM: MMU: introduce the framework to check zero bits on sptes
  KVM: MMU: split reset_rsvds_bits_mask_ept
  KVM: MMU: split reset_rsvds_bits_mask
  KVM: MMU: introduce rsvd_bits_validate
  KVM: MMU: move FNAME(is_rsvd_bits_set) to mmu.c
  KVM: MMU: fix validation of mmio page fault
  KVM: MTRR: Use default type for non-MTRR-covered gfn before WARN_ON
  KVM: s390: host STP toleration for VMs
  KVM: x86: clean/fix memory barriers in irqchip_in_kernel
  KVM: document memory barriers for kvm->vcpus/kvm->online_vcpus
  KVM: x86: remove unnecessary memory barriers for shared MSRs
  KVM: move code related to KVM_SET_BOOT_CPU_ID to x86
  KVM: s390: log capability enablement and vm attribute changes
  ...
2015-08-31 08:27:44 -07:00
Ingo Molnar a5dd192496 Merge branch 'x86/urgent' into x86/asm to fix up conflicts and to pick up fixes
Conflicts:
	arch/x86/entry/entry_64_compat.S
	arch/x86/math-emu/get_address.c

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-18 09:39:47 +02:00
Andy Lutomirski 4d283ec908 x86/kvm: Rename VMX's segment access rights defines
VMX encodes access rights differently from LAR, and the latter is
most likely what x86 people think of when they think of "access
rights".

Rename them to avoid confusion.

Cc: kvm@vger.kernel.org
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-08-15 00:47:13 +02:00
Wei Huang b6bb424b40 KVM: x86/vPMU: Fix unnecessary signed extension for AMD PERFCTRn
According to AMD programmer's manual, AMD PERFCTRn is 64-bit MSR which,
unlike Intel perf counters, doesn't require signed extension. This
patch removes the unnecessary conversion in SVM vPMU code when PERFCTRn
is being updated.

Signed-off-by: Wei Huang <wei@redhat.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-08-11 15:19:41 +02:00
Nicholas Krause 603242a88a kvm: x86: Fix error handling in the function kvm_lapic_sync_from_vapic
This fixes error handling in the function kvm_lapic_sync_from_vapic
by checking if the call to kvm_read_guest_cached has returned a
error code to signal to its caller the call to this function has
failed and due to this we must immediately return to the caller
of kvm_lapic_sync_from_vapic to avoid incorrectly call apic_set_tpc
if a error has occurred here.

Signed-off-by: Nicholas Krause <xerofoify@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-08-11 15:11:05 +02:00
Haozhong Zhang d7add05458 KVM: x86: Use adjustment in guest cycles when handling MSR_IA32_TSC_ADJUST
When kvm_set_msr_common() handles a guest's write to
MSR_IA32_TSC_ADJUST, it will calcuate an adjustment based on the data
written by guest and then use it to adjust TSC offset by calling a
call-back adjust_tsc_offset(). The 3rd parameter of adjust_tsc_offset()
indicates whether the adjustment is in host TSC cycles or in guest TSC
cycles. If SVM TSC scaling is enabled, adjust_tsc_offset()
[i.e. svm_adjust_tsc_offset()] will first scale the adjustment;
otherwise, it will just use the unscaled one. As the MSR write here
comes from the guest, the adjustment is in guest TSC cycles. However,
the current kvm_set_msr_common() uses it as a value in host TSC
cycles (by using true as the 3rd parameter of adjust_tsc_offset()),
which can result in an incorrect adjustment of TSC offset if SVM TSC
scaling is enabled. This patch fixes this problem.

Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
Cc: stable@vger.linux.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-08-07 13:28:03 +02:00
Paolo Bonzini 18c3626e3d KVM: x86: zero IDT limit on entry to SMM
The recent BlackHat 2015 presentation "The Memory Sinkhole"
mentions that the IDT limit is zeroed on entry to SMM.

This is not documented, and must have changed some time after 2010
(see http://www.ssi.gouv.fr/uploads/IMG/pdf/IT_Defense_2010_final.pdf).
KVM was not doing it, but the fix is easy.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-08-07 12:46:32 +02:00
Xiao Guangrong f735d4af4b KVM: VMX: drop ept misconfig check
The logic used to check ept misconfig is completely contained in common
reserved bits check for sptes, so it can be removed

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-08-05 12:47:26 +02:00
Xiao Guangrong 47ab875169 KVM: MMU: fully check zero bits for sptes
The #PF with PFEC.RSV = 1 is designed to speed MMIO emulation, however,
it is possible that the RSV #PF is caused by real BUG by mis-configure
shadow page table entries

This patch enables full check for the zero bits on shadow page table
entries (which includes not only bits reserved by the hardware, but also
bits that will never be set in the SPTE), then dump the shadow page table
hierarchy.

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-08-05 12:47:26 +02:00
Xiao Guangrong d625b155d2 KVM: MMU: introduce is_shadow_zero_bits_set()
We have the same data struct to check reserved bits on guest page tables
and shadow page tables, split is_rsvd_bits_set() so that the logic can be
shared between these two paths

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-08-05 12:47:25 +02:00
Xiao Guangrong c258b62b26 KVM: MMU: introduce the framework to check zero bits on sptes
We have abstracted the data struct and functions which are used to check
reserved bit on guest page tables, now we extend the logic to check
zero bits on shadow page tables

The zero bits on sptes include not only reserved bits on hardware but also
the bits that SPTEs willnever use.  For example, shadow pages will never
use GB pages unless the guest uses them too.

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-08-05 12:47:24 +02:00
Xiao Guangrong 81b8eebbc3 KVM: MMU: split reset_rsvds_bits_mask_ept
Since shadow ept page tables and Intel nested guest page tables have the
same format, split reset_rsvds_bits_mask_ept so that the logic can be
reused by later patches which check zero bits on sptes

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-08-05 12:47:24 +02:00
Xiao Guangrong 6dc98b868b KVM: MMU: split reset_rsvds_bits_mask
Since softmmu & AMD nested shadow page tables and guest page tables have
the same format, split reset_rsvds_bits_mask so that the logic can be
reused by later patches which check zero bits on sptes

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-08-05 12:47:23 +02:00
Xiao Guangrong a0a64f50aa KVM: MMU: introduce rsvd_bits_validate
These two fields, rsvd_bits_mask and bad_mt_xwr, in "struct kvm_mmu" are
used to check if reserved bits set on guest ptes, move them to a data
struct so that the approach can be applied to check host shadow page
table entries as well

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-08-05 12:47:23 +02:00
Xiao Guangrong d2b0f98125 KVM: MMU: move FNAME(is_rsvd_bits_set) to mmu.c
FNAME(is_rsvd_bits_set) does not depend on guest mmu mode, move it
to mmu.c to stop being compiled multiple times

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-08-05 12:47:22 +02:00
Xiao Guangrong 6f691251c0 KVM: MMU: fix validation of mmio page fault
We got the bug that qemu complained with "KVM: unknown exit, hardware
reason 31" and KVM shown these info:
[84245.284948] EPT: Misconfiguration.
[84245.285056] EPT: GPA: 0xfeda848
[84245.285154] ept_misconfig_inspect_spte: spte 0x5eaef50107 level 4
[84245.285344] ept_misconfig_inspect_spte: spte 0x5f5fadc107 level 3
[84245.285532] ept_misconfig_inspect_spte: spte 0x5141d18107 level 2
[84245.285723] ept_misconfig_inspect_spte: spte 0x52e40dad77 level 1

This is because we got a mmio #PF and the handler see the mmio spte becomes
normal (points to the ram page)

However, this is valid after introducing fast mmio spte invalidation which
increases the generation-number instead of zapping mmio sptes, a example
is as follows:
1. QEMU drops mmio region by adding a new memslot
2. invalidate all mmio sptes
3.

        VCPU 0                        VCPU 1
    access the invalid mmio spte
                            access the region originally was MMIO before
                            set the spte to the normal ram map

    mmio #PF
    check the spte and see it becomes normal ram mapping !!!

This patch fixes the bug just by dropping the check in mmio handler, it's
good for backport. Full check will be introduced in later patches

Reported-by: Pavel Shirshov <ru.pchel@gmail.com>
Tested-by: Pavel Shirshov <ru.pchel@gmail.com>
Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-08-05 12:47:21 +02:00
Alex Williamson 9c33ae0c61 KVM: MTRR: Use default type for non-MTRR-covered gfn before WARN_ON
The patch was munged on commit to re-order these tests resulting in
excessive warnings when trying to do device assignment.  Return to
original ordering: https://lkml.org/lkml/2015/7/15/769

Fixes: 3e5d2fdced ("KVM: MTRR: simplify kvm_mtrr_get_guest_memory_type")
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-08-05 12:47:21 +02:00
Alex Williamson fc1a8126bf KVM: MTRR: Use default type for non-MTRR-covered gfn before WARN_ON
The patch was munged on commit to re-order these tests resulting in
excessive warnings when trying to do device assignment.  Return to
original ordering: https://lkml.org/lkml/2015/7/15/769

Fixes: 3e5d2fdced ("KVM: MTRR: simplify kvm_mtrr_get_guest_memory_type")
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-08-05 11:57:57 +02:00
Ingo Molnar 5b929bd11d Merge branch 'x86/urgent' into x86/asm, before applying dependent patches
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-31 10:23:35 +02:00
Paolo Bonzini 71ba994c94 KVM: x86: clean/fix memory barriers in irqchip_in_kernel
The memory barriers are trying to protect against concurrent RCU-based
interrupt injection, but the IRQ routing table is not valid at the time
kvm->arch.vpic is written.  Fix this by writing kvm->arch.vpic last.
kvm_destroy_pic then need not set kvm->arch.vpic to NULL; modify it
to take a struct kvm_pic* and reuse it if the IOAPIC creation fails.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-30 16:02:56 +02:00
Paolo Bonzini c847fe8895 KVM: x86: remove unnecessary memory barriers for shared MSRs
There is no smp_rmb matching the smp_wmb.  shared_msr_update is called from
hardware_enable, which in turn is called via on_each_cpu.  on_each_cpu
and must imply a read memory barrier (on x86 the rmb is achieved simply
through asm volatile in native_apic_mem_write).

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-29 14:27:23 +02:00
Paolo Bonzini d71ba78834 KVM: move code related to KVM_SET_BOOT_CPU_ID to x86
This is another remnant of ia64 support.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-29 14:27:21 +02:00
Paolo Bonzini 5492830370 KVM: svm: handle KVM_X86_QUIRK_CD_NW_CLEARED in svm_get_mt_mask
We can disable CD unconditionally when there is no assigned device.
KVM now forces guest PAT to all-writeback in that case, so it makes
sense to also force CR0.CD=0.

When there are assigned devices, emulate cache-disabled operation
through the page tables.  This behavior is consistent with VMX
microcode, where CD/NW are not touched by vmentry/vmexit.  However,
keep this dependent on the quirk because OVMF enables the caches
too late.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-23 08:30:27 +02:00
Mihai Donțu 5f3d45e7f2 kvm/x86: add support for MONITOR_TRAP_FLAG
Allow a nested hypervisor to single step its guests.

Signed-off-by: Mihai Donțu <mihai.dontu@gmail.com>
[Fix overlong line. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-23 08:27:07 +02:00
Andrey Smetanin 2ce7918990 kvm/x86: add sending hyper-v crash notification to user space
Sending of notification is done by exiting vcpu to user space
if KVM_REQ_HV_CRASH is enabled for vcpu. At exit to user space
the kvm_run structure contains system_event with type
KVM_SYSTEM_EVENT_CRASH to notify about guest crash occurred.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Peter Hornyack <peterhornyack@google.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Gleb Natapov <gleb@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-23 08:27:06 +02:00
Andrey Smetanin e7d9513b60 kvm/x86: added hyper-v crash msrs into kvm hyperv context
Added kvm Hyper-V context hv crash variables as storage
of Hyper-V crash msrs.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Peter Hornyack <peterhornyack@google.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Gleb Natapov <gleb@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-23 08:27:06 +02:00
Andrey Smetanin e83d58874b kvm/x86: move Hyper-V MSR's/hypercall code into hyperv.c file
This patch introduce Hyper-V related source code file - hyperv.c and
per vm and per vcpu hyperv context structures.
All Hyper-V MSR's and hypercall code moved into hyperv.c.
All Hyper-V kvm/vcpu fields moved into appropriate hyperv context
structures. Copyrights and authors information copied from x86.c
to hyperv.c.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Peter Hornyack <peterhornyack@google.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Gleb Natapov <gleb@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-23 08:27:06 +02:00
Eugene Korenevsky f9eb4af67c KVM: nVMX: VMX instructions: add checks for #GP/#SS exceptions
According to Intel SDM several checks must be applied for memory operands
of VMX instructions.

Long mode: #GP(0) or #SS(0) depending on the segment must be thrown
if the memory address is in a non-canonical form.

Protected mode, checks in chronological order:
- The segment type must be checked with access type (read or write) taken
into account.
	For write access: #GP(0) must be generated if the destination operand
		is located in a read-only data segment or any code segment.
	For read access: #GP(0) must be generated if if the source operand is
		located in an execute-only code segment.
- Usability of the segment must be checked. #GP(0) or #SS(0) depending on the
	segment must be thrown if the segment is unusable.
- Limit check. #GP(0) or #SS(0) depending on the segment must be
	thrown if the memory operand effective address is outside the segment
	limit.

Signed-off-by: Eugene Korenevsky <ekorenevsky@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-23 08:26:39 +02:00
Paolo Bonzini 0da029ed7e KVM: x86: rename quirk constants to KVM_X86_QUIRK_*
Make them clearly architecture-dependent; the capability is valid for
all architectures, but the argument is not.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-23 08:24:42 +02:00
Xiao Guangrong fb279950ba KVM: vmx: obey KVM_QUIRK_CD_NW_CLEARED
OVMF depends on WB to boot fast, because it only clears caches after
it has set up MTRRs---which is too late.

Let's do writeback if CR0.CD is set to make it happy, similar to what
SVM is already doing.

Signed-off-by: Xiao Guangrong <guangrong.xiao@intel.com>
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-23 08:23:01 +02:00
Paolo Bonzini 41dbc6bcd9 KVM: x86: introduce kvm_check_has_quirk
The logic of the disabled_quirks field usually results in a double
negation.  Wrap it in a simple function that checks the bit and
negates it.

Based on a patch from Xiao Guangrong.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-23 08:22:45 +02:00
Xiao Guangrong 3e5d2fdced KVM: MTRR: simplify kvm_mtrr_get_guest_memory_type
kvm_mtrr_get_guest_memory_type never returns -1 which is implied
in the current code since if @type = -1 (means no MTRR contains the
range), iter.partial_map must be true

Simplify the code to indicate this fact

Signed-off-by: Xiao Guangrong <guangrong.xiao@intel.com>
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-23 08:21:48 +02:00
Xiao Guangrong 10dc331ff5 KVM: MTRR: fix memory type handling if MTRR is completely disabled
Currently code uses default memory type if MTRR is fully disabled,
fix it by using UC instead.

Signed-off-by: Xiao Guangrong <guangrong.xiao@intel.com>
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-23 08:21:33 +02:00
Wanpeng Li ee4100da16 kvm: x86: fix load xsave feature warning
[   68.196974] WARNING: CPU: 1 PID: 2140 at arch/x86/kvm/x86.c:3161 kvm_arch_vcpu_ioctl+0xe88/0x1340 [kvm]()
[   68.196975] Modules linked in: snd_hda_codec_hdmi i915 rfcomm bnep bluetooth i2c_algo_bit rfkill nfsd drm_kms_helper nfs_acl nfs drm lockd grace sunrpc fscache snd_hda_codec_realtek snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_pcm snd_seq_dummy snd_seq_oss x86_pkg_temp_thermal snd_seq_midi kvm_intel snd_seq_midi_event snd_rawmidi kvm snd_seq ghash_clmulni_intel fuse snd_timer aesni_intel parport_pc ablk_helper snd_seq_device cryptd ppdev snd lp parport lrw dcdbas gf128mul i2c_core glue_helper lpc_ich video shpchp mfd_core soundcore serio_raw acpi_cpufreq ext4 mbcache jbd2 sd_mod crc32c_intel ahci libahci libata e1000e ptp pps_core
[   68.197005] CPU: 1 PID: 2140 Comm: qemu-system-x86 Not tainted 4.2.0-rc1+ #2
[   68.197006] Hardware name: Dell Inc. OptiPlex 7020/0F5C5X, BIOS A03 01/08/2015
[   68.197007]  ffffffffa03b0657 ffff8800d984bca8 ffffffff815915a2 0000000000000000
[   68.197009]  0000000000000000 ffff8800d984bce8 ffffffff81057c0a 00007ff6d0001000
[   68.197010]  0000000000000002 ffff880211c1a000 0000000000000004 ffff8800ce0288c0
[   68.197012] Call Trace:
[   68.197017]  [<ffffffff815915a2>] dump_stack+0x45/0x57
[   68.197020]  [<ffffffff81057c0a>] warn_slowpath_common+0x8a/0xc0
[   68.197022]  [<ffffffff81057cfa>] warn_slowpath_null+0x1a/0x20
[   68.197029]  [<ffffffffa037bed8>] kvm_arch_vcpu_ioctl+0xe88/0x1340 [kvm]
[   68.197035]  [<ffffffffa037aede>] ? kvm_arch_vcpu_load+0x4e/0x1c0 [kvm]
[   68.197040]  [<ffffffffa03696a6>] kvm_vcpu_ioctl+0xc6/0x5c0 [kvm]
[   68.197043]  [<ffffffff811252d2>] ? perf_pmu_enable+0x22/0x30
[   68.197044]  [<ffffffff8112663e>] ? perf_event_context_sched_in+0x7e/0xb0
[   68.197048]  [<ffffffff811a6882>] do_vfs_ioctl+0x2c2/0x4a0
[   68.197050]  [<ffffffff8107bf33>] ? finish_task_switch+0x173/0x220
[   68.197053]  [<ffffffff8123307f>] ? selinux_file_ioctl+0x4f/0xd0
[   68.197055]  [<ffffffff8122cac3>] ? security_file_ioctl+0x43/0x60
[   68.197057]  [<ffffffff811a6ad9>] SyS_ioctl+0x79/0x90
[   68.197060]  [<ffffffff81597e57>] entry_SYSCALL_64_fastpath+0x12/0x6a
[   68.197061] ---[ end trace 558a5ebf9445fc80 ]---

After commit (0c4109bec0 'x86/fpu/xstate: Fix up bad get_xsave_addr()
assumptions'), there is no assumption an xsave bit is present in the
hardware (pcntxt_mask) that it is always present in a given xsave buffer.
An enabled state to be present on 'pcntxt_mask', but *not* in 'xstate_bv'
could happen when the last 'xsave' did not request that this feature be
saved (unlikely) or because the "init optimization" caused it to not be
saved. This patch kill the assumption.

Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-10 13:26:45 +02:00
Paolo Bonzini fd717f1101 KVM: x86: apply guest MTRR virtualization on host reserved pages
Currently guest MTRR is avoided if kvm_is_reserved_pfn returns true.
However, the guest could prefer a different page type than UC for
such pages. A good example is that pass-throughed VGA frame buffer is
not always UC as host expected.

This patch enables full use of virtual guest MTRRs.

Suggested-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Tested-by: Joerg Roedel <jroedel@suse.de> (on AMD)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-10 13:25:27 +02:00
Jan Kiszka e098223b78 KVM: SVM: Sync g_pat with guest-written PAT value
When hardware supports the g_pat VMCB field, we can use it for emulating
the PAT configuration that the guest configures by writing to the
corresponding MSR.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Tested-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-10 13:25:27 +02:00
Paolo Bonzini 3c2e7f7de3 KVM: SVM: use NPT page attributes
Right now, NPT page attributes are not used, and the final page
attribute depends solely on gPAT (which however is not synced
correctly), the guest MTRRs and the guest page attributes.

However, we can do better by mimicking what is done for VMX.
In the absence of PCI passthrough, the guest PAT can be ignored
and the page attributes can be just WB.  If passthrough is being
used, instead, keep respecting the guest PAT, and emulate the guest
MTRRs through the PAT field of the nested page tables.

The only snag is that WP memory cannot be emulated correctly,
because Linux's default PAT setting only includes the other types.

Tested-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-10 13:25:26 +02:00
Paolo Bonzini 5544eb9b81 KVM: count number of assigned devices
If there are no assigned devices, the guest PAT are not providing
any useful information and can be overridden to writeback; VMX
always does this because it has the "IPAT" bit in its extended
page table entries, but SVM does not have anything similar.
Hook into VFIO and legacy device assignment so that they
provide this information to KVM.

Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-10 13:25:26 +02:00
Radim Krčmář 370777daab KVM: VMX: fix vmwrite to invalid VMCS
fpu_activate is called outside of vcpu_load(), which means it should not
touch VMCS, but fpu_activate needs to.  Avoid the call by moving it to a
point where we know that the guest needs eager FPU and VMCS is loaded.

This will get rid of the following trace

 vmwrite error: reg 6800 value 0 (err 1)
  [<ffffffff8162035b>] dump_stack+0x19/0x1b
  [<ffffffffa046c701>] vmwrite_error+0x2c/0x2e [kvm_intel]
  [<ffffffffa045f26f>] vmcs_writel+0x1f/0x30 [kvm_intel]
  [<ffffffffa04617e5>] vmx_fpu_activate.part.61+0x45/0xb0 [kvm_intel]
  [<ffffffffa0461865>] vmx_fpu_activate+0x15/0x20 [kvm_intel]
  [<ffffffffa0560b91>] kvm_arch_vcpu_create+0x51/0x70 [kvm]
  [<ffffffffa0548011>] kvm_vm_ioctl+0x1c1/0x760 [kvm]
  [<ffffffff8118b55a>] ? handle_mm_fault+0x49a/0xec0
  [<ffffffff811e47d5>] do_vfs_ioctl+0x2e5/0x4c0
  [<ffffffff8127abbe>] ? file_has_perm+0xae/0xc0
  [<ffffffff811e4a51>] SyS_ioctl+0xa1/0xc0
  [<ffffffff81630949>] system_call_fastpath+0x16/0x1b

(Note: we also unconditionally activate FPU in vmx_vcpu_reset(), so the
 removed code added nothing.)

Fixes: c447e76b4c ("kvm/fpu: Enable eager restore kvm FPU for MPX")
Cc: <stable@vger.kernel.org>
Reported-by: Vlastimil Holer <vlastimil.holer@gmail.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-10 13:25:25 +02:00
Paolo Bonzini d1fe921955 KVM: x86: reintroduce kvm_is_mmio_pfn
The call to get_mt_mask was really using kvm_is_reserved_pfn to
detect an MMIO-backed page.  In this case, we want "false" to be
returned for the zero page.

Reintroduce a separate kvm_is_mmio_pfn predicate for this use
only.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-10 13:25:24 +02:00