Commit Graph

242 Commits

Author SHA1 Message Date
Mike Waychison
74b5c5bfff KVM: Initialize kvm before registering the mmu notifier
It doesn't make sense to ever see a half-initialized kvm structure on
mmu notifier callbacks.  Previously, 85722cda changed the ordering to
ensure that the mmu_lock was initialized before mmu notifier
registration, but there is still a race where the mmu notifier could
come in and try accessing other portions of struct kvm before they are
intialized.

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

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

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

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

Cc: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-26 02:41:44 -04:00
OGAWA Hirofumi
85722cda30 KVM: Fix kvm mmu_notifier initialization order
Like the following, mmu_notifier can be called after registering
immediately. So, kvm have to initialize kvm->mmu_lock before it.

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

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

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

[avi: change VERIFY_READ to VERIFY_WRITE]

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-22 08:47:56 -04:00
Xiao Guangrong
0ee8dcb87e KVM: cleanup memslot_id function
We can get memslot id from memslot->id directly

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-11 07:56:53 -04:00
Gleb Natapov
0857b9e95c KVM: Enable async page fault processing
If asynchronous hva_to_pfn() is requested call GUP with FOLL_NOWAIT to
avoid sleeping on IO. Check for hwpoison is done at the same time,
otherwise check_user_page_hwpoison() will call GUP again and will put
vcpu to sleep.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-04-06 13:15:55 +03:00
Linus Torvalds
16c29dafcc Merge branch 'syscore' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6
* 'syscore' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
  Introduce ARCH_NO_SYSDEV_OPS config option (v2)
  cpufreq: Use syscore_ops for boot CPU suspend/resume (v2)
  KVM: Use syscore_ops instead of sysdev class and sysdev
  PCI / Intel IOMMU: Use syscore_ops instead of sysdev class and sysdev
  timekeeping: Use syscore_ops instead of sysdev class and sysdev
  x86: Use syscore_ops instead of sysdev classes and sysdevs
2011-03-25 21:07:59 -07:00
Akinobu Mita
cd7e48c5de kvm: use little-endian bitops
As a preparation for removing ext2 non-atomic bit operations from
asm/bitops.h.  This converts ext2 non-atomic bit operations to
little-endian bit operations.

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

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

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

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

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Avi Kivity <avi@redhat.com>
2011-03-23 22:16:23 +01:00
Jan Kiszka
e935b8372c KVM: Convert kvm_lock to raw_spinlock
Code under this lock requires non-preemptibility. Ensure this also over
-rt by converting it to raw spinlock.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:29:51 +02:00
Takuya Yoshikawa
75b7127c38 KVM: rename hardware_[dis|en]able() to *_nolock() and add locking wrappers
The naming convension of hardware_[dis|en]able family is little bit confusing
because only hardware_[dis|en]able_all are using _nolock suffix.

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

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

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:29:28 +02:00
Jan Kiszka
d89f5eff70 KVM: Clean up vm creation and release
IA64 support forces us to abstract the allocation of the kvm structure.
But instead of mixing this up with arch-specific initialization and
doing the same on destruction, split both steps. This allows to move
generic destruction calls into generic code.

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

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12 11:29:09 +02:00
Jan Kiszka
57e7fbee1d KVM: Refactor srcu struct release on early errors
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-01-12 11:29:05 +02:00
Takuya Yoshikawa
2653503769 KVM: replace vmalloc and memset with vzalloc
Let's use newly introduced vzalloc().

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

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

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

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

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

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

This will also make the logging start/stop faster.

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

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

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

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

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

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

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

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

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

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

Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-01-12 11:23:08 +02:00
Gleb Natapov
af585b921e KVM: Halt vcpu if page it tries to access is swapped out
If a guest accesses swapped out memory do not swap it in from vcpu thread
context. Schedule work to do swapping and put vcpu into halted state
instead.

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

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

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

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

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

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

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

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

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

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

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

This covers both cases.

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

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

Updated: implement better locking semantics for hardware_enable

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Fix by enabling interrupts before spinning.

KVM-Stable-Tag.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-09-23 11:31:56 -03:00
Zachary Amsden
da908f2fb4 KVM: x86: Perform hardware_enable in CPU_STARTING callback
The CPU_STARTING callback was added upstream with the intention
of being used for KVM, specifically for the hardware enablement
that must be done before we can run in hardware virt.  It had
bugs on the x86_64 architecture at the time, where it was called
after CPU_ONLINE.  The arches have since merged and the bug is
gone.

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

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-09-09 13:48:16 -03:00