linux-stable.git/arch/x86/kernel/kvm.c, branch linux-3.9.y Linux kernel stable tree Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-22T02:06:55+00:00 Linus Torvalds torvalds@linux-foundation.org 2013-02-22T02:06:55+00:00 2ef14f465b9e096531343f5b734cffc5f759f4a6 Pull x86 mm changes from Peter Anvin: "This is a huge set of several partly interrelated (and concurrently developed) changes, which is why the branch history is messier than one would like. The *really* big items are two humonguous patchsets mostly developed by Yinghai Lu at my request, which completely revamps the way we create initial page tables. In particular, rather than estimating how much memory we will need for page tables and then build them into that memory -- a calculation that has shown to be incredibly fragile -- we now build them (on 64 bits) with the aid of a "pseudo-linear mode" -- a #PF handler which creates temporary page tables on demand. This has several advantages: 1. It makes it much easier to support things that need access to data very early (a followon patchset uses this to load microcode way early in the kernel startup). 2. It allows the kernel and all the kernel data objects to be invoked from above the 4 GB limit. This allows kdump to work on very large systems. 3. It greatly reduces the difference between Xen and native (Xen's equivalent of the #PF handler are the temporary page tables created by the domain builder), eliminating a bunch of fragile hooks. The patch series also gets us a bit closer to W^X. Additional work in this pull is the 64-bit get_user() work which you were also involved with, and a bunch of cleanups/speedups to __phys_addr()/__pa()." * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (105 commits) x86, mm: Move reserving low memory later in initialization x86, doc: Clarify the use of asm("%edx") in uaccess.h x86, mm: Redesign get_user with a __builtin_choose_expr hack x86: Be consistent with data size in getuser.S x86, mm: Use a bitfield to mask nuisance get_user() warnings x86/kvm: Fix compile warning in kvm_register_steal_time() x86-32: Add support for 64bit get_user() x86-32, mm: Remove reference to alloc_remap() x86-32, mm: Remove reference to resume_map_numa_kva() x86-32, mm: Rip out x86_32 NUMA remapping code x86/numa: Use __pa_nodebug() instead x86: Don't panic if can not alloc buffer for swiotlb mm: Add alloc_bootmem_low_pages_nopanic() x86, 64bit, mm: hibernate use generic mapping_init x86, 64bit, mm: Mark data/bss/brk to nx x86: Merge early kernel reserve for 32bit and 64bit x86: Add Crash kernel low reservation x86, kdump: Remove crashkernel range find limit for 64bit memblock: Add memblock_mem_size() x86, boot: Not need to check setup_header version for setup_data ... 
Pull x86 mm changes from Peter Anvin:
 "This is a huge set of several partly interrelated (and concurrently
  developed) changes, which is why the branch history is messier than
  one would like.

  The *really* big items are two humonguous patchsets mostly developed
  by Yinghai Lu at my request, which completely revamps the way we
  create initial page tables.  In particular, rather than estimating how
  much memory we will need for page tables and then build them into that
  memory -- a calculation that has shown to be incredibly fragile -- we
  now build them (on 64 bits) with the aid of a "pseudo-linear mode" --
  a #PF handler which creates temporary page tables on demand.

  This has several advantages:

  1. It makes it much easier to support things that need access to data
     very early (a followon patchset uses this to load microcode way
     early in the kernel startup).

  2. It allows the kernel and all the kernel data objects to be invoked
     from above the 4 GB limit.  This allows kdump to work on very large
     systems.

  3. It greatly reduces the difference between Xen and native (Xen's
     equivalent of the #PF handler are the temporary page tables created
     by the domain builder), eliminating a bunch of fragile hooks.

  The patch series also gets us a bit closer to W^X.

  Additional work in this pull is the 64-bit get_user() work which you
  were also involved with, and a bunch of cleanups/speedups to
  __phys_addr()/__pa()."

* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (105 commits)
  x86, mm: Move reserving low memory later in initialization
  x86, doc: Clarify the use of asm("%edx") in uaccess.h
  x86, mm: Redesign get_user with a __builtin_choose_expr hack
  x86: Be consistent with data size in getuser.S
  x86, mm: Use a bitfield to mask nuisance get_user() warnings
  x86/kvm: Fix compile warning in kvm_register_steal_time()
  x86-32: Add support for 64bit get_user()
  x86-32, mm: Remove reference to alloc_remap()
  x86-32, mm: Remove reference to resume_map_numa_kva()
  x86-32, mm: Rip out x86_32 NUMA remapping code
  x86/numa: Use __pa_nodebug() instead
  x86: Don't panic if can not alloc buffer for swiotlb
  mm: Add alloc_bootmem_low_pages_nopanic()
  x86, 64bit, mm: hibernate use generic mapping_init
  x86, 64bit, mm: Mark data/bss/brk to nx
  x86: Merge early kernel reserve for 32bit and 64bit
  x86: Add Crash kernel low reservation
  x86, kdump: Remove crashkernel range find limit for 64bit
  memblock: Add memblock_mem_size()
  x86, boot: Not need to check setup_header version for setup_data
  ...
x86/kvm: Fix compile warning in kvm_register_steal_time() 2013-02-11T10:04:31+00:00 Shuah Khan shuah.khan@hp.com 2013-02-06T02:57:22+00:00 136867f517cbc3f8a91f035677911a6b503c3323 Fix the following compile warning in kvm_register_steal_time(): CC arch/x86/kernel/kvm.o arch/x86/kernel/kvm.c: In function ‘kvm_register_steal_time’: arch/x86/kernel/kvm.c:302:3: warning: format ‘%lx’ expects argument of type ‘long unsigned int’, but argument 3 has type ‘phys_addr_t’ [-Wformat] Introduced via: 5dfd486c4750 x86, kvm: Fix kvm's use of __pa() on percpu areas d76565344512 x86, mm: Create slow_virt_to_phys() f3c4fbb68e93 x86, mm: Use new pagetable helpers in try_preserve_large_page() 4cbeb51b860c x86, mm: Pagetable level size/shift/mask helpers a25b9316841c x86, mm: Make DEBUG_VIRTUAL work earlier in boot Signed-off-by: Shuah Khan <shuah.khan@hp.com> Acked-by: Gleb Natapov <gleb@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: shuahkhan@gmail.com Cc: avi@redhat.com Cc: gleb@redhat.com Cc: mst@redhat.com Link: http://lkml.kernel.org/r/1360119442.8356.8.camel@lorien2 Signed-off-by: Ingo Molnar <mingo@kernel.org> 
Fix the following compile warning in kvm_register_steal_time():

  CC      arch/x86/kernel/kvm.o
  arch/x86/kernel/kvm.c: In function ‘kvm_register_steal_time’: arch/x86/kernel/kvm.c:302:3:
  warning: format ‘%lx’ expects argument of type ‘long unsigned int’, but argument 3 has type ‘phys_addr_t’ [-Wformat]

Introduced via:

  5dfd486c4750 x86, kvm: Fix kvm's use of __pa() on percpu areas
  d76565344512 x86, mm: Create slow_virt_to_phys()
  f3c4fbb68e93 x86, mm: Use new pagetable helpers in try_preserve_large_page()
  4cbeb51b860c x86, mm: Pagetable level size/shift/mask helpers
  a25b9316841c x86, mm: Make DEBUG_VIRTUAL work earlier in boot

Signed-off-by: Shuah Khan <shuah.khan@hp.com>
Acked-by: Gleb Natapov <gleb@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: shuahkhan@gmail.com
Cc: avi@redhat.com
Cc: gleb@redhat.com
Cc: mst@redhat.com
Link: http://lkml.kernel.org/r/1360119442.8356.8.camel@lorien2
Signed-off-by: Ingo Molnar <mingo@kernel.org>
x86, kvm: Fix kvm's use of __pa() on percpu areas 2013-01-26T00:34:55+00:00 Dave Hansen dave@linux.vnet.ibm.com 2013-01-22T21:24:35+00:00 5dfd486c4750c9278c63fa96e6e85bdd2fb58e9d In short, it is illegal to call __pa() on an address holding a percpu variable. This replaces those __pa() calls with slow_virt_to_phys(). All of the cases in this patch are in boot time (or CPU hotplug time at worst) code, so the slow pagetable walking in slow_virt_to_phys() is not expected to have a performance impact. The times when this actually matters are pretty obscure (certain 32-bit NUMA systems), but it _does_ happen. It is important to keep KVM guests working on these systems because the real hardware is getting harder and harder to find. This bug manifested first by me seeing a plain hang at boot after this message: CPU 0 irqstacks, hard=f3018000 soft=f301a000 or, sometimes, it would actually make it out to the console: [ 0.000000] BUG: unable to handle kernel paging request at ffffffff I eventually traced it down to the KVM async pagefault code. This can be worked around by disabling that code either at compile-time, or on the kernel command-line. The kvm async pagefault code was injecting page faults in to the guest which the guest misinterpreted because its "reason" was not being properly sent from the host. The guest passes a physical address of an per-cpu async page fault structure via an MSR to the host. Since __pa() is broken on percpu data, the physical address it sent was bascially bogus and the host went scribbling on random data. The guest never saw the real reason for the page fault (it was injected by the host), assumed that the kernel had taken a _real_ page fault, and panic()'d. The behavior varied, though, depending on what got corrupted by the bad write. Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20130122212435.4905663F@kernel.stglabs.ibm.com Acked-by: Rik van Riel <riel@redhat.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> 
In short, it is illegal to call __pa() on an address holding
a percpu variable.  This replaces those __pa() calls with
slow_virt_to_phys().  All of the cases in this patch are
in boot time (or CPU hotplug time at worst) code, so the
slow pagetable walking in slow_virt_to_phys() is not expected
to have a performance impact.

The times when this actually matters are pretty obscure
(certain 32-bit NUMA systems), but it _does_ happen.  It is
important to keep KVM guests working on these systems because
the real hardware is getting harder and harder to find.

This bug manifested first by me seeing a plain hang at boot
after this message:

	CPU 0 irqstacks, hard=f3018000 soft=f301a000

or, sometimes, it would actually make it out to the console:

[    0.000000] BUG: unable to handle kernel paging request at ffffffff

I eventually traced it down to the KVM async pagefault code.
This can be worked around by disabling that code either at
compile-time, or on the kernel command-line.

The kvm async pagefault code was injecting page faults in
to the guest which the guest misinterpreted because its
"reason" was not being properly sent from the host.

The guest passes a physical address of an per-cpu async page
fault structure via an MSR to the host.  Since __pa() is
broken on percpu data, the physical address it sent was
bascially bogus and the host went scribbling on random data.
The guest never saw the real reason for the page fault (it
was injected by the host), assumed that the kernel had taken
a _real_ page fault, and panic()'d.  The behavior varied,
though, depending on what got corrupted by the bad write.

Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20130122212435.4905663F@kernel.stglabs.ibm.com
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
x86/apic: Allow x2apic without IR on VMware platform 2013-01-24T12:11:18+00:00 Alok N Kataria akataria@vmware.com 2013-01-17T23:44:42+00:00 4cca6ea04d31c22a7d0436949c072b27bde41f86 This patch updates x2apic initializaition code to allow x2apic on VMware platform even without interrupt remapping support. The hypervisor_x2apic_available hook was added in x2apic initialization code and used by KVM and XEN, before this. I have also cleaned up that code to export this hook through the hypervisor_x86 structure. Compile tested for KVM and XEN configs, this patch doesn't have any functional effect on those two platforms. On VMware platform, verified that x2apic is used in physical mode on products that support this. Signed-off-by: Alok N Kataria <akataria@vmware.com> Reviewed-by: Doug Covelli <dcovelli@vmware.com> Reviewed-by: Dan Hecht <dhecht@vmware.com> Acked-by: H. Peter Anvin <hpa@zytor.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Avi Kivity <avi@redhat.com> Link: http://lkml.kernel.org/r/1358466282.423.60.camel@akataria-dtop.eng.vmware.com Signed-off-by: Ingo Molnar <mingo@kernel.org> 
This patch updates x2apic initializaition code to allow x2apic
on VMware platform even without interrupt remapping support.
The hypervisor_x2apic_available hook was added in x2apic
initialization code and used by KVM and XEN, before this.
I have also cleaned up that code to export this hook through the
hypervisor_x86 structure.

Compile tested for KVM and XEN configs, this patch doesn't have
any functional effect on those two platforms.

On VMware platform, verified that x2apic is used in physical
mode on products that support this.

Signed-off-by: Alok N Kataria <akataria@vmware.com>
Reviewed-by: Doug Covelli <dcovelli@vmware.com>
Reviewed-by: Dan Hecht <dhecht@vmware.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Avi Kivity <avi@redhat.com>
Link: http://lkml.kernel.org/r/1358466282.423.60.camel@akataria-dtop.eng.vmware.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add rcu user eqs exception hooks for async page fault 2012-12-18T13:15:41+00:00 Li Zhong zhong@linux.vnet.ibm.com 2012-12-04T02:35:13+00:00 9b132fbe5419d789f1ef396bed5eb66a365dd1e9 This patch adds user eqs exception hooks for async page fault page not present code path, to exit the user eqs and re-enter it as necessary. Async page fault is different from other exceptions that it may be triggered from idle process, so we still need rcu_irq_enter() and rcu_irq_exit() to exit cpu idle eqs when needed, to protect the code that needs use rcu. As Frederic pointed out it would be safest and simplest to protect the whole kvm_async_pf_task_wait(). Otherwise, "we need to check all the code there deeply for potential RCU uses and ensure it will never be extended later to use RCU.". However, We'd better re-enter the cpu idle eqs if we get the exception in cpu idle eqs, by calling rcu_irq_exit() before native_safe_halt(). So the patch does what Frederic suggested for rcu_irq_*() API usage here, except that I moved the rcu_irq_*() pair originally in do_async_page_fault() into kvm_async_pf_task_wait(). That's because, I think it's better to have rcu_irq_*() pairs to be in one function ( rcu_irq_exit() after rcu_irq_enter() ), especially here, kvm_async_pf_task_wait() has other callers, which might cause rcu_irq_exit() be called without a matching rcu_irq_enter() before it, which is illegal if the cpu happens to be in rcu idle state. Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Signed-off-by: Gleb Natapov <gleb@redhat.com> 
This patch adds user eqs exception hooks for async page fault page not
present code path, to exit the user eqs and re-enter it as necessary.

Async page fault is different from other exceptions that it may be
triggered from idle process, so we still need rcu_irq_enter() and
rcu_irq_exit() to exit cpu idle eqs when needed, to protect the code
that needs use rcu.

As Frederic pointed out it would be safest and simplest to protect the
whole kvm_async_pf_task_wait(). Otherwise, "we need to check all the
code there deeply for potential RCU uses and ensure it will never be
extended later to use RCU.".

However, We'd better re-enter the cpu idle eqs if we get the exception
in cpu idle eqs, by calling rcu_irq_exit() before native_safe_halt().

So the patch does what Frederic suggested for rcu_irq_*() API usage
here, except that I moved the rcu_irq_*() pair originally in
do_async_page_fault() into kvm_async_pf_task_wait().

That's because, I think it's better to have rcu_irq_*() pairs to be in
one function ( rcu_irq_exit() after rcu_irq_enter() ), especially here,
kvm_async_pf_task_wait() has other callers, which might cause
rcu_irq_exit() be called without a matching rcu_irq_enter() before it,
which is illegal if the cpu happens to be in rcu idle state.

Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
KVM: use is_idle_task() instead of idle_cpu() to decide when to halt in async_pf 2012-11-28T23:30:13+00:00 Gleb Natapov gleb@redhat.com 2012-11-28T13:19:08+00:00 859f8450d8a334a7f7cb994e4676cf918deff832 As Frederic pointed idle_cpu() may return false even if async fault happened in the idle task if wake up is pending. In this case the code will try to put idle task to sleep. Fix this by using is_idle_task() to check for idle task. Reported-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> 
As Frederic pointed idle_cpu() may return false even if async fault
happened in the idle task if wake up is pending. In this case the code
will try to put idle task to sleep. Fix this by using is_idle_task() to
check for idle task.

Reported-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
x86: kvm guest: pvclock vsyscall support 2012-11-28T01:29:10+00:00 Marcelo Tosatti mtosatti@redhat.com 2012-11-28T01:28:56+00:00 3dc4f7cfb7441e5e0fed3a02fc81cdaabd28300a Hook into generic pvclock vsyscall code, with the aim to allow userspace to have visibility into pvclock data. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> 
Hook into generic pvclock vsyscall code, with the aim to
allow userspace to have visibility into pvclock data.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
KVM guest: exit idleness when handling KVM_PV_REASON_PAGE_NOT_PRESENT 2012-10-22T16:03:28+00:00 Sasha Levin sasha.levin@oracle.com 2012-10-19T16:11:55+00:00 c5e015d4949aa665c486cae6884beb00b97e3dea KVM_PV_REASON_PAGE_NOT_PRESENT kicks cpu out of idleness, but we haven't marked that spot as an exit from idleness. Not doing so can cause RCU warnings such as: [ 732.788386] =============================== [ 732.789803] [ INFO: suspicious RCU usage. ] [ 732.790032] 3.7.0-rc1-next-20121019-sasha-00002-g6d8d02d-dirty #63 Tainted: G W [ 732.790032] ------------------------------- [ 732.790032] include/linux/rcupdate.h:738 rcu_read_lock() used illegally while idle! [ 732.790032] [ 732.790032] other info that might help us debug this: [ 732.790032] [ 732.790032] [ 732.790032] RCU used illegally from idle CPU! [ 732.790032] rcu_scheduler_active = 1, debug_locks = 1 [ 732.790032] RCU used illegally from extended quiescent state! [ 732.790032] 2 locks held by trinity-child31/8252: [ 732.790032] #0: (&rq->lock){-.-.-.}, at: [<ffffffff83a67528>] __schedule+0x178/0x8f0 [ 732.790032] #1: (rcu_read_lock){.+.+..}, at: [<ffffffff81152bde>] cpuacct_charge+0xe/0x200 [ 732.790032] [ 732.790032] stack backtrace: [ 732.790032] Pid: 8252, comm: trinity-child31 Tainted: G W 3.7.0-rc1-next-20121019-sasha-00002-g6d8d02d-dirty #63 [ 732.790032] Call Trace: [ 732.790032] [<ffffffff8118266b>] lockdep_rcu_suspicious+0x10b/0x120 [ 732.790032] [<ffffffff81152c60>] cpuacct_charge+0x90/0x200 [ 732.790032] [<ffffffff81152bde>] ? cpuacct_charge+0xe/0x200 [ 732.790032] [<ffffffff81158093>] update_curr+0x1a3/0x270 [ 732.790032] [<ffffffff81158a6a>] dequeue_entity+0x2a/0x210 [ 732.790032] [<ffffffff81158ea5>] dequeue_task_fair+0x45/0x130 [ 732.790032] [<ffffffff8114ae29>] dequeue_task+0x89/0xa0 [ 732.790032] [<ffffffff8114bb9e>] deactivate_task+0x1e/0x20 [ 732.790032] [<ffffffff83a67c29>] __schedule+0x879/0x8f0 [ 732.790032] [<ffffffff8117e20d>] ? trace_hardirqs_off+0xd/0x10 [ 732.790032] [<ffffffff810a37a5>] ? kvm_async_pf_task_wait+0x1d5/0x2b0 [ 732.790032] [<ffffffff83a67cf5>] schedule+0x55/0x60 [ 732.790032] [<ffffffff810a37c4>] kvm_async_pf_task_wait+0x1f4/0x2b0 [ 732.790032] [<ffffffff81139e50>] ? abort_exclusive_wait+0xb0/0xb0 [ 732.790032] [<ffffffff81139c25>] ? prepare_to_wait+0x25/0x90 [ 732.790032] [<ffffffff810a3a66>] do_async_page_fault+0x56/0xa0 [ 732.790032] [<ffffffff83a6a6e8>] async_page_fault+0x28/0x30 Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Acked-by: Gleb Natapov <gleb@redhat.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com> 
KVM_PV_REASON_PAGE_NOT_PRESENT kicks cpu out of idleness, but we haven't
marked that spot as an exit from idleness.

Not doing so can cause RCU warnings such as:

[  732.788386] ===============================
[  732.789803] [ INFO: suspicious RCU usage. ]
[  732.790032] 3.7.0-rc1-next-20121019-sasha-00002-g6d8d02d-dirty #63 Tainted: G        W
[  732.790032] -------------------------------
[  732.790032] include/linux/rcupdate.h:738 rcu_read_lock() used illegally while idle!
[  732.790032]
[  732.790032] other info that might help us debug this:
[  732.790032]
[  732.790032]
[  732.790032] RCU used illegally from idle CPU!
[  732.790032] rcu_scheduler_active = 1, debug_locks = 1
[  732.790032] RCU used illegally from extended quiescent state!
[  732.790032] 2 locks held by trinity-child31/8252:
[  732.790032]  #0:  (&rq->lock){-.-.-.}, at: [<ffffffff83a67528>] __schedule+0x178/0x8f0
[  732.790032]  #1:  (rcu_read_lock){.+.+..}, at: [<ffffffff81152bde>] cpuacct_charge+0xe/0x200
[  732.790032]
[  732.790032] stack backtrace:
[  732.790032] Pid: 8252, comm: trinity-child31 Tainted: G        W    3.7.0-rc1-next-20121019-sasha-00002-g6d8d02d-dirty #63
[  732.790032] Call Trace:
[  732.790032]  [<ffffffff8118266b>] lockdep_rcu_suspicious+0x10b/0x120
[  732.790032]  [<ffffffff81152c60>] cpuacct_charge+0x90/0x200
[  732.790032]  [<ffffffff81152bde>] ? cpuacct_charge+0xe/0x200
[  732.790032]  [<ffffffff81158093>] update_curr+0x1a3/0x270
[  732.790032]  [<ffffffff81158a6a>] dequeue_entity+0x2a/0x210
[  732.790032]  [<ffffffff81158ea5>] dequeue_task_fair+0x45/0x130
[  732.790032]  [<ffffffff8114ae29>] dequeue_task+0x89/0xa0
[  732.790032]  [<ffffffff8114bb9e>] deactivate_task+0x1e/0x20
[  732.790032]  [<ffffffff83a67c29>] __schedule+0x879/0x8f0
[  732.790032]  [<ffffffff8117e20d>] ? trace_hardirqs_off+0xd/0x10
[  732.790032]  [<ffffffff810a37a5>] ? kvm_async_pf_task_wait+0x1d5/0x2b0
[  732.790032]  [<ffffffff83a67cf5>] schedule+0x55/0x60
[  732.790032]  [<ffffffff810a37c4>] kvm_async_pf_task_wait+0x1f4/0x2b0
[  732.790032]  [<ffffffff81139e50>] ? abort_exclusive_wait+0xb0/0xb0
[  732.790032]  [<ffffffff81139c25>] ? prepare_to_wait+0x25/0x90
[  732.790032]  [<ffffffff810a3a66>] do_async_page_fault+0x56/0xa0
[  732.790032]  [<ffffffff83a6a6e8>] async_page_fault+0x28/0x30

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Acked-by: Gleb Natapov <gleb@redhat.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
x86: KVM guest: merge CONFIG_KVM_CLOCK into CONFIG_KVM_GUEST 2012-08-23T07:57:54+00:00 Marcelo Tosatti mtosatti@redhat.com 2012-08-16T20:00:19+00:00 90993cdd1800dc6ef9587431a0c625b978584e81 The distinction between CONFIG_KVM_CLOCK and CONFIG_KVM_GUEST is not so clear anymore, as demonstrated by recent bugs caused by poor handling of on/off combinations of these options. Merge CONFIG_KVM_CLOCK into CONFIG_KVM_GUEST. Reported-By: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> 
The distinction between CONFIG_KVM_CLOCK and CONFIG_KVM_GUEST is
not so clear anymore, as demonstrated by recent bugs caused by poor
handling of on/off combinations of these options.

Merge CONFIG_KVM_CLOCK into CONFIG_KVM_GUEST.

Reported-By: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
KVM guest: disable stealtime on reboot to avoid mem corruption 2012-08-15T18:31:24+00:00 Florian Westphal fw@strlen.de 2012-08-15T14:00:40+00:00 8fbe6a541f50eeec5e3e49bd92db23ade9496673 else, host continues to update stealtime after reboot, which can corrupt e.g. initramfs area. found when tracking down initramfs unpack error on initial reboot (with qemu-kvm -smp 2, no problem with single-core). Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> 
else, host continues to update stealtime after reboot,
which can corrupt e.g. initramfs area.
found when tracking down initramfs unpack error on initial reboot
(with qemu-kvm -smp 2, no problem with single-core).

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>