Граф коммитов

100 Коммитов

Автор SHA1 Сообщение Дата
Petr Mladek 36da91bdf5 KVM: x86: Handle the kthread worker using the new API
Use the new API to create and destroy the "kvm-pit" kthread
worker. The API hides some implementation details.

In particular, kthread_create_worker() allocates and initializes
struct kthread_worker. It runs the kthread the right way
and stores task_struct into the worker structure.

kthread_destroy_worker() flushes all pending works, stops
the kthread and frees the structure.

This patch does not change the existing behavior except for
dynamically allocating struct kthread_worker and storing
only the pointer of this structure.

It is compile tested only because I did not find an easy
way how to run the code. Well, it should be pretty safe
given the nature of the change.

Signed-off-by: Petr Mladek <pmladek@suse.com>
Message-Id: <1476877847-11217-1-git-send-email-pmladek@suse.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-12-08 15:31:11 +01:00
Petr Mladek 3989144f86 kthread: kthread worker API cleanup
A good practice is to prefix the names of functions by the name
of the subsystem.

The kthread worker API is a mix of classic kthreads and workqueues.  Each
worker has a dedicated kthread.  It runs a generic function that process
queued works.  It is implemented as part of the kthread subsystem.

This patch renames the existing kthread worker API to use
the corresponding name from the workqueues API prefixed by
kthread_:

__init_kthread_worker()		-> __kthread_init_worker()
init_kthread_worker()		-> kthread_init_worker()
init_kthread_work()		-> kthread_init_work()
insert_kthread_work()		-> kthread_insert_work()
queue_kthread_work()		-> kthread_queue_work()
flush_kthread_work()		-> kthread_flush_work()
flush_kthread_worker()		-> kthread_flush_worker()

Note that the names of DEFINE_KTHREAD_WORK*() macros stay
as they are. It is common that the "DEFINE_" prefix has
precedence over the subsystem names.

Note that INIT() macros and init() functions use different
naming scheme. There is no good solution. There are several
reasons for this solution:

  + "init" in the function names stands for the verb "initialize"
    aka "initialize worker". While "INIT" in the macro names
    stands for the noun "INITIALIZER" aka "worker initializer".

  + INIT() macros are used only in DEFINE() macros

  + init() functions are used close to the other kthread()
    functions. It looks much better if all the functions
    use the same scheme.

  + There will be also kthread_destroy_worker() that will
    be used close to kthread_cancel_work(). It is related
    to the init() function. Again it looks better if all
    functions use the same naming scheme.

  + there are several precedents for such init() function
    names, e.g. amd_iommu_init_device(), free_area_init_node(),
    jump_label_init_type(),  regmap_init_mmio_clk(),

  + It is not an argument but it was inconsistent even before.

[arnd@arndb.de: fix linux-next merge conflict]
 Link: http://lkml.kernel.org/r/20160908135724.1311726-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/1470754545-17632-3-git-send-email-pmladek@suse.com
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Borislav Petkov <bp@suse.de>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11 15:06:33 -07:00
Paolo Bonzini 250715a617 KVM: x86: protect KVM_CREATE_PIT/KVM_CREATE_PIT2 with kvm->lock
The syzkaller folks reported a NULL pointer dereference that seems
to be cause by a race between KVM_CREATE_IRQCHIP and KVM_CREATE_PIT2.
The former takes kvm->lock (except when registering the devices,
which needs kvm->slots_lock); the latter takes kvm->slots_lock only.
Change KVM_CREATE_PIT2 to follow the same model as KVM_CREATE_IRQCHIP.

Testcase:

    #include <pthread.h>
    #include <linux/kvm.h>
    #include <fcntl.h>
    #include <sys/ioctl.h>
    #include <stdint.h>
    #include <string.h>
    #include <stdlib.h>
    #include <sys/syscall.h>
    #include <unistd.h>

    long r[23];

    void* thr1(void* arg)
    {
        struct kvm_pit_config pitcfg = { .flags = 4 };
        switch ((long)arg) {
        case 0: r[2]  = open("/dev/kvm", O_RDONLY|O_ASYNC);    break;
        case 1: r[3]  = ioctl(r[2], KVM_CREATE_VM, 0);         break;
        case 2: r[4]  = ioctl(r[3], KVM_CREATE_IRQCHIP, 0);    break;
        case 3: r[22] = ioctl(r[3], KVM_CREATE_PIT2, &pitcfg); break;
        }
        return 0;
    }

    int main(int argc, char **argv)
    {
        long i;
        pthread_t th[4];

        memset(r, -1, sizeof(r));
        for (i = 0; i < 4; i++) {
            pthread_create(&th[i], 0, thr, (void*)i);
            if (argc > 1 && rand()%2) usleep(rand()%1000);
        }
        usleep(20000);
        return 0;
    }

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-06-03 15:28:19 +02:00
Paolo Bonzini 0e4d44151a KVM: i8254: drop local copy of mul_u64_u32_div
A function that does the same as i8254.c's muldiv64 has been added
(for KVM's own use, in fact!) in include/linux/math64.h.  Use it
instead of muldiv64.

Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-04 22:39:17 +01:00
Radim Krčmář a0aace5ac0 KVM: i8254: turn kvm_kpit_state.reinject into atomic_t
Document possible races between readers and concurrent update to the
ioctl.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-04 09:30:25 +01:00
Radim Krčmář ab4c14763b KVM: i8254: move PIT timer function initialization
We can do it just once.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-04 09:30:22 +01:00
Radim Krčmář 4a2095df8a KVM: i8254: remove pointless dereference of PIT
PIT is known at that point.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-04 09:30:15 +01:00
Radim Krčmář a3e1311549 KVM: i8254: remove pit and kvm from kvm_kpit_state
kvm isn't ever used and pit can be accessed with container_of.
If you *really* need kvm, pit_state_to_pit(ps)->kvm.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-04 09:30:12 +01:00
Radim Krčmář 08e5ccf3ae KVM: i8254: refactor kvm_free_pit
Could be easier to read, but git history will become deeper.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-04 09:30:07 +01:00
Radim Krčmář 10d2482126 KVM: i8254: refactor kvm_create_pit
Locks are gone, so we don't need to duplicate error paths.
Use goto everywhere.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-04 09:30:04 +01:00
Radim Krčmář 71474e2f0f KVM: i8254: remove notifiers from PIT discard policy
Discard policy doesn't rely on information from notifiers, so we don't
need to register notifiers unconditionally.  We kept correct counts in
case userspace switched between policies during runtime, but that can be
avoided by reseting the state.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-04 09:30:01 +01:00
Radim Krčmář b39c90b656 KVM: i8254: remove unnecessary uses of PIT state lock
- kvm_create_pit had to lock only because it exposed kvm->arch.vpit very
  early, but initialization doesn't use kvm->arch.vpit since the last
  patch, so we can drop locking.
- kvm_free_pit is only run after there are no users of KVM and therefore
  is the sole actor.
- Locking in kvm_vm_ioctl_reinject doesn't do anything, because reinject
  is only protected at that place.
- kvm_pit_reset isn't used anywhere and its locking can be dropped if we
  hide it.

Removing useless locking allows to see what actually is being protected
by PIT state lock (values accessible from the guest).

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-04 09:29:58 +01:00
Radim Krčmář 09edea72b7 KVM: i8254: pass struct kvm_pit instead of kvm in PIT
This patch passes struct kvm_pit into internal PIT functions.
Those functions used to get PIT through kvm->arch.vpit, even though most
of them never used *kvm for other purposes.  Another benefit is that we
don't need to set kvm->arch.vpit during initialization.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-04 09:29:55 +01:00
Radim Krčmář b69d920f68 KVM: i8254: tone down WARN_ON pit.state_lock
If the guest could hit this, it would hang the host kernel, bacause of
sheer number of those reports.  Internal callers have to be sensible
anyway, so we now only check for it in an API function.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-04 09:29:51 +01:00
Radim Krčmář ddf54503e2 KVM: i8254: use atomic_t instead of pit.inject_lock
The lock was an overkill, the same can be done with atomics.

A mb() was added in kvm_pit_ack_irq, to pair with implicit barrier
between pit_timer_fn and pit_do_work.  The mb() prevents a race that
could happen if pending == 0 and irq_ack == 0:

  kvm_pit_ack_irq:                | pit_timer_fn:
   p = atomic_read(&ps->pending); |
                                  |  atomic_inc(&ps->pending);
                                  |  queue_work(pit_do_work);
                                  | pit_do_work:
                                  |  atomic_xchg(&ps->irq_ack, 0);
                                  |  return;
   atomic_set(&ps->irq_ack, 1);   |
   if (p == 0) return;            |

where the interrupt would not be delivered in this tick of pit_timer_fn.
PIT would have eventually delivered the interrupt, but we sacrifice
perofmance to make sure that interrupts are not needlessly delayed.

sfence isn't enough: atomic_dec_if_positive does atomic_read first and
x86 can reorder loads before stores.  lfence isn't enough: store can
pass lfence, turning it into a nop.  A compiler barrier would be more
than enough as CPU needs to stall for unbelievably long to use fences.

This patch doesn't do anything in kvm_pit_reset_reinject, because any
order of resets can race, but the result differs by at most one
interrupt, which is ok, because it's the same result as if the reset
happened at a slightly different time.  (Original code didn't protect
the reset path with a proper lock, so users have to be robust.)

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-04 09:29:47 +01:00
Radim Krčmář fd700a00dc KVM: i8254: add kvm_pit_reset_reinject
pit_state.pending and pit_state.irq_ack are always reset at the same
time.  Create a function for them.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-04 09:29:43 +01:00
Radim Krčmář f6e0a0c113 KVM: i8254: simplify atomics in kvm_pit_ack_irq
We already have a helper that does the same thing.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-04 09:29:37 +01:00
Radim Krčmář 7dd0fdff14 KVM: i8254: change PIT discard tick policy
Discard policy uses ack_notifiers to prevent injection of PIT interrupts
before EOI from the last one.

This patch changes the policy to always try to deliver the interrupt,
which makes a difference when its vector is in ISR.
Old implementation would drop the interrupt, but proposed one injects to
IRR, like real hardware would.

The old policy breaks legacy NMI watchdogs, where PIT is used through
virtual wire (LVT0): PIT never sends an interrupt before receiving EOI,
thus a guest deadlock with disabled interrupts will stop NMIs.

Note that NMI doesn't do EOI, so PIT also had to send a normal interrupt
through IOAPIC.  (KVM's PIT is deeply rotten and luckily not used much
in modern systems.)

Even though there is a chance of regressions, I think we can fix the
LVT0 NMI bug without introducing a new tick policy.

Cc: <stable@vger.kernel.org>
Reported-by: Yuki Shibuya <shibuya.yk@ncos.nec.co.jp>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-04 09:29:31 +01:00
Paolo Bonzini e5e57e7a03 kvm: x86: only channel 0 of the i8254 is linked to the HPET
While setting the KVM PIT counters in 'kvm_pit_load_count', if
'hpet_legacy_start' is set, the function disables the timer on
channel[0], instead of the respective index 'channel'. This is
because channels 1-3 are not linked to the HPET.  Fix the caller
to only activate the special HPET processing for channel 0.

Reported-by: P J P <pjp@fedoraproject.org>
Fixes: 0185604c2d
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-01-07 13:50:38 +01:00
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
Radim Krčmář 42720138b0 KVM: x86: make vapics_in_nmi_mode atomic
Writes were a bit racy, but hard to turn into a bug at the same time.
(Particularly because modern Linux doesn't use this feature anymore.)

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
[Actually the next patch makes it much, much easier to trigger the race
 so I'm including this one for stable@ as well. - Paolo]
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-03 18:55:17 +02:00
Nikolay Nikolaev e32edf4fd0 KVM: Redesign kvm_io_bus_ API to pass VCPU structure to the callbacks.
This is needed in e.g. ARM vGIC emulation, where the MMIO handling
depends on the VCPU that does the access.

Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-03-26 21:43:11 +00:00
Andy Honig 2febc83913 KVM: x86: Improve thread safety in pit
There's a race condition in the PIT emulation code in KVM.  In
__kvm_migrate_pit_timer the pit_timer object is accessed without
synchronization.  If the race condition occurs at the wrong time this
can crash the host kernel.

This fixes CVE-2014-3611.

Cc: stable@vger.kernel.org
Signed-off-by: Andrew Honig <ahonig@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-10-24 13:21:14 +02:00
Marcelo Tosatti 9ed96e87c5 KVM: x86: limit PIT timer frequency
Limit PIT timer frequency similarly to the limit applied by
LAPIC timer.

Cc: stable@kernel.org
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-01-15 12:43:54 +01:00
Yang Zhang aa2fbe6d44 KVM: Let ioapic know the irq line status
Userspace may deliver RTC interrupt without query the status. So we
want to track RTC EOI for this case.

Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-04-15 23:20:34 -03:00
Nickolai Zeldovich d4b06c2d4c kvm: fix i8254 counter 0 wraparound
The kvm i8254 emulation for counter 0 (but not for counters 1 and 2)
has at least two bugs in mode 0:

1. The OUT bit, computed by pit_get_out(), is never set high.

2. The counter value, computed by pit_get_count(), wraps back around to
   the initial counter value, rather than wrapping back to 0xFFFF
   (which is the behavior described in the comment in __kpit_elapsed,
   the behavior implemented by qemu, and the behavior observed on AMD
   hardware).

The bug stems from __kpit_elapsed computing the elapsed time mod the
initial counter value (stored as nanoseconds in ps->period).  This is both
unnecessary (none of the callers of kpit_elapsed expect the value to be
at most the initial counter value) and incorrect (it causes pit_get_count
to appear to wrap around to the initial counter value rather than 0xFFFF).
Removing this mod from __kpit_elapsed fixes both of the above bugs.

Signed-off-by: Nickolai Zeldovich <nickolai@csail.mit.edu>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
2012-12-18 11:12:38 +02:00
Avi Kivity 26ef19242f KVM: fold kvm_pit_timer into kvm_kpit_state
One structure nests inside the other, providing no value at all.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-01 00:21:07 -03:00
Avi Kivity 9d9d2239bd KVM: Simplify kvm_pit_timer
'timer_mode_mask' is unused
'tscdeadline' is unused
't_ops' only adds needless indirection
'vcpu' is unused

Remove.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-01 00:21:07 -03:00
Avi Kivity e9d90d472d KVM: Remove internal timer abstraction
kvm_timer_fn(), the sole inhabitant of timer.c, is only used by lapic.c. Move
it there to make it easier to hack on it.

struct kvm_timer is a thin wrapper around hrtimer, and only adds obfuscation.
Move near its two users (with different names) to prepare for simplification.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-01 00:21:06 -03:00
Jan Kiszka b6ddf05ff6 KVM: x86: Run PIT work in own kthread
We can't run PIT IRQ injection work in the interrupt context of the host
timer. This would allow the user to influence the handler complexity by
asking for a broadcast to a large number of VCPUs. Therefore, this work
was pushed into workqueue context in 9d244caf2e. However, this prevents
prioritizing the PIT injection over other task as workqueues share
kernel threads.

This replaces the workqueue with a kthread worker and gives that thread
a name in the format "kvm-pit/<owner-process-pid>". That allows to
identify and adjust the kthread priority according to the VM process
parameters.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-04-27 19:40:29 -03:00
Jan Kiszka a647795efb KVM: x86: Consolidate PIT legacy test
Move the test for KVM_PIT_FLAGS_HPET_LEGACY into create_pit_timer
instead of replicating it on the caller site.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-12-27 11:22:30 +02:00
Jan Kiszka 0924ab2cfa KVM: x86: Prevent starting PIT timers in the absence of irqchip support
User space may create the PIT and forgets about setting up the irqchips.
In that case, firing PIT IRQs will crash the host:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000128
IP: [<ffffffffa10f6280>] kvm_set_irq+0x30/0x170 [kvm]
...
Call Trace:
 [<ffffffffa11228c1>] pit_do_work+0x51/0xd0 [kvm]
 [<ffffffff81071431>] process_one_work+0x111/0x4d0
 [<ffffffff81071bb2>] worker_thread+0x152/0x340
 [<ffffffff81075c8e>] kthread+0x7e/0x90
 [<ffffffff815a4474>] kernel_thread_helper+0x4/0x10

Prevent this by checking the irqchip mode before starting a timer. We
can't deny creating the PIT if the irqchips aren't set up yet as
current user land expects this order to work.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-12-25 17:13:18 +02:00
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
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
Jason Wang 23e7a7944f KVM: pit: Do not check pending pit timer in vcpu thread
Pit interrupt injection was done by workqueue, so no need to check
pending pit timer in vcpu thread which could lead unnecessary
unblocking of vcpu.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-10-24 10:51:45 +02:00
Xiao Guangrong 6b5d7a9f6f KVM: PIT: free irq source id in handling error path
Free irq source id if create pit workqueue fail

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-17 12:04:23 +03:00
Xiaotian Feng 3185bf8c23 KVM: destroy workqueue on kvm_create_pit() failures
kernel needs to destroy workqueue if kvm_create_pit() fails, otherwise
after pit is freed, the workqueue is leaked.

Signed-off-by: Xiaotian Feng <dfeng@redhat.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-15 14:17:35 +03:00
Xiao Guangrong aea924f606 KVM: PIT: stop vpit before freeing irq_routing
Fix:
general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
......
Call Trace:
 [<ffffffffa0159bd1>] ? kvm_set_irq+0xdd/0x24b [kvm]
 [<ffffffff8106ea8b>] ? trace_hardirqs_off_caller+0x1f/0x10e
 [<ffffffff813ad17f>] ? sub_preempt_count+0xe/0xb6
 [<ffffffff8106d273>] ? put_lock_stats+0xe/0x27
...
RIP  [<ffffffffa0159c72>] kvm_set_irq+0x17e/0x24b [kvm]

This bug is triggered when guest is shutdown, is because we freed
irq_routing before pit thread stopped

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-08-02 06:40:35 +03:00
Jiri Slaby 673813e81d KVM: fix lock imbalance in kvm_create_pit()
Stanse found that there is an omitted unlock in kvm_create_pit in one fail
path. Add proper unlock there.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: Gleb Natapov <gleb@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Gregory Haskins <ghaskins@novell.com>
Cc: kvm@vger.kernel.org
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-02 06:40:31 +03:00
Chris Lalancette 33572ac0ad KVM: x86: Introduce a workqueue to deliver PIT timer interrupts
We really want to "kvm_set_irq" during the hrtimer callback,
but that is risky because that is during interrupt context.
Instead, offload the work to a workqueue, which is a bit safer
and should provide most of the same functionality.

Signed-off-by: Chris Lalancette <clalance@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-08-01 10:46:49 +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
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
Thomas Gleixner fa8273e954 KVM: Convert i8254/i8259 locks to raw_spinlocks
The i8254/i8259 locks need to be real spinlocks on preempt-rt. Convert
them to raw_spinlock. No change for !RT kernels.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01 12:36:12 -03:00
Wei Yongjun d225f53b76 KVM: PIT: unregister kvm irq notifier if fail to create pit
If fail to create pit, we should unregister kvm irq notifier
which register in kvm_create_pit().

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Acked-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-03-01 12:36:09 -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 ee73f656a6 KVM: PIT: control word is write-only
PIT control word (address 0x43) is write-only, reads are undefined.

Cc: stable@kernel.org
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-02-09 19:20:15 +02:00
Joe Perches a78d9626f4 x86: i8254.c: Add pr_fmt(fmt)
- Add pr_fmt(fmt) "pit: " fmt
 - Strip pit: prefixes from pr_debug

Signed-off-by: Joe Perches <joe@perches.com>
LKML-Reference: <bbd4de532f18bb7c11f64ba20d224c08291cb126.1260383912.git.joe@perches.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-10 08:57:50 +01:00
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
Marcelo Tosatti ace1546487 KVM: use proper hrtimer function to retrieve expiration time
hrtimer->base can be temporarily NULL due to racing hrtimer_start.
See switch_hrtimer_base/lock_hrtimer_base.

Use hrtimer_get_remaining which is robust against it.

CC: stable@kernel.org
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-10-16 12:30:25 -03:00