Commit Graph

736 Commits

Author SHA1 Message Date
Marcelo Tosatti 2df72e9bc4 KVM: split kvm_arch_flush_shadow
Introducing kvm_arch_flush_shadow_memslot, to invalidate the
translations of a single memory slot.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-06 16:37:25 +03:00
Mathias Krause f1d248315a KVM: x86: more constification
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-05 12:42:02 +03:00
Mathias Krause 0fbe9b0b19 KVM: x86: constify read_write_emulator_ops
We never change those, make them r/o.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-05 12:41:54 +03:00
Mathias Krause 0225fb509d KVM: x86 emulator: constify emulate_ops
We never change emulate_ops[] at runtime so it should be r/o.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-05 12:41:48 +03:00
Marcelo Tosatti 9a7819774e KVM: x86: remove unused variable from kvm_task_switch()
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-30 17:45:54 -03:00
Avi Kivity dd856efafe KVM: x86 emulator: access GPRs on demand
Instead of populating the entire register file, read in registers
as they are accessed, and write back only the modified ones.  This
saves a VMREAD and VMWRITE on Intel (for rsp, since it is not usually
used during emulation), and a two 128-byte copies for the registers.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-27 18:38:55 -03:00
Xiao Guangrong 4d8b81abc4 KVM: introduce readonly memslot
In current code, if we map a readonly memory space from host to guest
and the page is not currently mapped in the host, we will get a fault
pfn and async is not allowed, then the vm will crash

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

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-22 15:09:03 +03:00
Xiao Guangrong 8e3d9d061b KVM: x86: fix possible infinite loop caused by reexecute_instruction
Currently, we reexecute all unhandleable instructions if they do not
access on the mmio, however, it can not work if host map the readonly
memory to guest. If the instruction try to write this kind of memory,
it will fault again when guest retry it, then we will goto a infinite
loop: retry instruction -> write #PF -> emulation fail ->
retry instruction -> ...

Fix it by retrying the instruction only when it faults on the writable
memory

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-22 15:08:49 +03:00
Marcelo Tosatti 51d59c6b42 KVM: x86: fix pvclock guest stopped flag reporting
kvm_guest_time_update unconditionally clears hv_clock.flags field,
so the notification never reaches the guest.

Fix it by allowing PVCLOCK_GUEST_STOPPED to passthrough.

Reviewed-by: Eric B Munson <emunson@mgebm.net>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-13 16:10:45 -03:00
Gleb Natapov 64eb062029 KVM: correctly detect APIC SW state in kvm_apic_post_state_restore()
For apic_set_spiv() to track APIC SW state correctly it needs to see
previous and next values of the spurious vector register, but currently
memset() overwrite the old value before apic_set_spiv() get a chance to
do tracking. Fix it by calling apic_set_spiv() before overwriting old
value.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-09 12:44:46 +03:00
Gleb Natapov 54e9818f39 KVM: use jump label to optimize checking for in kernel local apic presence
Usually all vcpus have local apic pointer initialized, so the check may
be completely skipped.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-06 19:00:44 +03:00
Gleb Natapov c5cc421ba3 KVM: use jump label to optimize checking for HW enabled APIC in APIC_BASE MSR
Usually all APICs are HW enabled so the check can be optimized out.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-06 19:00:43 +03:00
Gleb Natapov 8a5a87d9b7 KVM: clean up kvm_(set|get)_apic_base
kvm_get_apic_base() needlessly checks irqchip_in_kernel although it does
the same no matter what result of the check is. kvm_set_apic_base() also
checks for irqchip_in_kernel, but kvm_lapic_set_base() can handle this
case.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-06 16:20:03 +03:00
Xiao Guangrong 32cad84f44 KVM: do not release the error page
After commit a2766325cf, the error page is replaced by the
error code, it need not be released anymore

[ The patch has been compiling tested for powerpc ]

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-06 16:04:58 +03:00
Takuya Yoshikawa d89cc617b9 KVM: Push rmap into kvm_arch_memory_slot
Two reasons:
 - x86 can integrate rmap and rmap_pde and remove heuristics in
   __gfn_to_rmap().
 - Some architectures do not need rmap.

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

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-06 12:47:30 +03:00
Takuya Yoshikawa aab2eb7a38 KVM: Stop checking rmap to see if slot is being created
Instead, check npages consistently.  This helps to make rmap
architecture specific in a later patch.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-06 12:47:02 +03:00
Avi Kivity fe56097b23 Merge remote-tracking branch 'upstream' into next
- bring back critical fixes (esp. aa67f6096c)
 - provide an updated base for development

* upstream: (4334 commits)
  missed mnt_drop_write() in do_dentry_open()
  UBIFS: nuke pdflush from comments
  gfs2: nuke pdflush from comments
  drbd: nuke pdflush from comments
  nilfs2: nuke write_super from comments
  hfs: nuke write_super from comments
  vfs: nuke pdflush from comments
  jbd/jbd2: nuke write_super from comments
  btrfs: nuke pdflush from comments
  btrfs: nuke write_super from comments
  ext4: nuke pdflush from comments
  ext4: nuke write_super from comments
  ext3: nuke write_super from comments
  Documentation: fix the VM knobs descritpion WRT pdflush
  Documentation: get rid of write_super
  vfs: kill write_super and sync_supers
  ACPI processor: Fix tick_broadcast_mask online/offline regression
  ACPI: Only count valid srat memory structures
  ACPI: Untangle a return statement for better readability
  Linux 3.6-rc1
  ...

Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-05 13:25:10 +03:00
Gleb Natapov e115676e04 KVM: x86: update KVM_SAVE_MSRS_BEGIN to correct value
When MSR_KVM_PV_EOI_EN was added to msrs_to_save array
KVM_SAVE_MSRS_BEGIN was not updated accordingly.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-03 15:08:22 -03:00
Bruce Rogers 4b6486659a KVM: x86: apply kvmclock offset to guest wall clock time
When a guest migrates to a new host, the system time difference from the
previous host is used in the updates to the kvmclock system time visible
to the guest, resulting in a continuation of correct kvmclock based guest
timekeeping.

The wall clock component of the kvmclock provided time is currently not
updated with this same time offset. Since the Linux guest caches the
wall clock based time, this discrepency is not noticed until the guest is
rebooted. After reboot the guest's time calculations are off.

This patch adjusts the wall clock by the kvmclock_offset, resulting in
correct guest time after a reboot.

Cc: Zachary Amsden <zamsden@gmail.com>
Signed-off-by: Bruce Rogers <brogers@suse.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-01 17:23:50 -03:00
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
Christoffer Dall 23d43cf998 KVM: Move KVM_IRQ_LINE to arch-generic code
Handle KVM_IRQ_LINE and KVM_IRQ_LINE_STATUS in the generic
kvm_vm_ioctl() function and call into kvm_vm_ioctl_irq_line().

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

Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-07-26 12:23:25 +03:00
Guo Chao 4a9699807c KVM: x86: Fix typos in x86.c
Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-07-20 15:26:36 -03:00
Xiao Guangrong 9d3c92af47 KVM: x86: remove unnecessary mark_page_dirty
fix:
[  132.474633] 3.5.0-rc1+ #50 Not tainted
[  132.474634] -------------------------------
[  132.474635] include/linux/kvm_host.h:369 suspicious rcu_dereference_check() usage!
[  132.474636]
[  132.474636] other info that might help us debug this:
[  132.474636]
[  132.474638]
[  132.474638] rcu_scheduler_active = 1, debug_locks = 1
[  132.474640] 1 lock held by qemu-kvm/2832:
[  132.474657]  #0:  (&vcpu->mutex){+.+.+.}, at: [<ffffffffa01e1636>] vcpu_load+0x1e/0x91 [kvm]
[  132.474658]
[  132.474658] stack backtrace:
[  132.474660] Pid: 2832, comm: qemu-kvm Not tainted 3.5.0-rc1+ #50
[  132.474661] Call Trace:
[  132.474665]  [<ffffffff81092f40>] lockdep_rcu_suspicious+0xfc/0x105
[  132.474675]  [<ffffffffa01e0c85>] kvm_memslots+0x6d/0x75 [kvm]
[  132.474683]  [<ffffffffa01e0ca1>] gfn_to_memslot+0x14/0x4c [kvm]
[  132.474693]  [<ffffffffa01e3575>] mark_page_dirty+0x17/0x2a [kvm]
[  132.474706]  [<ffffffffa01f21ea>] kvm_arch_vcpu_ioctl+0xbcf/0xc07 [kvm]

Actually, we do not write vcpu->arch.time at this time, mark_page_dirty
should be removed.

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-07-19 21:00:20 -03:00
Takuya Yoshikawa 77d11309b3 KVM: Separate rmap_pde from kvm_lpage_info->write_count
This makes it possible to loop over rmap_pde arrays in the same way as
we do over rmap so that we can optimize kvm_handle_hva_range() easily in
the following patch.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-07-18 16:55:04 -03:00
Mao, Junjie ad756a1603 KVM: VMX: Implement PCID/INVPCID for guests with EPT
This patch handles PCID/INVPCID for guests.

Process-context identifiers (PCIDs) are a facility by which a logical processor
may cache information for multiple linear-address spaces so that the processor
may retain cached information when software switches to a different linear
address space. Refer to section 4.10.1 in IA32 Intel Software Developer's Manual
Volume 3A for details.

For guests with EPT, the PCID feature is enabled and INVPCID behaves as running
natively.
For guests without EPT, the PCID feature is disabled and INVPCID triggers #UD.

Signed-off-by: Junjie Mao <junjie.mao@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-07-12 13:07:34 +03:00
Avi Kivity 0017f93a27 KVM: x86 emulator: change ->get_cpuid() accessor to use the x86 semantics
Instead of getting an exact leaf, follow the spec and fall back to the last
main leaf instead.  This lets us easily emulate the cpuid instruction in the
emulator.

Signed-off-by: Avi Kivity <avi@redhat.com>
2012-07-09 14:19:00 +03:00
Michael S. Tsirkin ae7a2a3fb6 KVM: host side for eoi optimization
Implementation of PV EOI using shared memory.
This reduces the number of exits an interrupt
causes as much as by half.

The idea is simple: there's a bit, per APIC, in guest memory,
that tells the guest that it does not need EOI.
We set it before injecting an interrupt and clear
before injecting a nested one. Guest tests it using
a test and clear operation - this is necessary
so that host can detect interrupt nesting -
and if set, it can skip the EOI MSR.

There's a new MSR to set the address of said register
in guest memory. Otherwise not much changed:
- Guest EOI is not required
- Register is tested & ISR is automatically cleared on exit

For testing results see description of previous patch
'kvm_para: guest side for eoi avoidance'.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-06-25 12:40:55 +03:00
Michael S. Tsirkin d905c06935 KVM: rearrange injection cancelling code
Each time we need to cancel injection we invoke same code
(cancel_injection callback).  Move it towards the end of function using
the familiar goto on error pattern.

Will make it easier to do more cleanups for PV EOI.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-06-25 12:40:50 +03:00
Michael S. Tsirkin 5cfb1d5a65 KVM: only sync when attention bits set
Commit eb0dc6d0368072236dcd086d7fdc17fd3c4574d4 introduced apic
attention bitmask but kvm still syncs lapic unconditionally.
As that commit suggested and in anticipation of adding more attention
bits, only sync lapic if(apic_attention).

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-06-25 12:40:40 +03:00
Takuya Yoshikawa 9e40b67bf2 KVM: Use kvm_kvfree() to free memory allocated by kvm_kvzalloc()
The following commit did not care about the error handling path:

  commit c1a7b32a14
  KVM: Avoid wasting pages for small lpage_info arrays

If memory allocation fails, vfree() will be called with the address
returned by kzalloc().  This patch fixes this issue.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-06-19 16:10:25 +03:00
Christoffer Dall a737f256bf KVM: Cleanup the kvm_print functions and introduce pr_XX wrappers
Introduces a couple of print functions, which are essentially wrappers
around standard printk functions, with a KVM: prefix.

Functions introduced or modified are:
 - kvm_err(fmt, ...)
 - kvm_info(fmt, ...)
 - kvm_debug(fmt, ...)
 - kvm_pr_unimpl(fmt, ...)
 - pr_unimpl(vcpu, fmt, ...) -> vcpu_unimpl(vcpu, fmt, ...)

Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-06-06 15:24:00 +03:00
Takuya Yoshikawa c1a7b32a14 KVM: Avoid wasting pages for small lpage_info arrays
lpage_info is created for each large level even when the memory slot is
not for RAM.  This means that when we add one slot for a PCI device, we
end up allocating at least KVM_NR_PAGE_SIZES - 1 pages by vmalloc().

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

This patch mitigates this problem by using kvm_kvzalloc().

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-06-05 16:29:49 +03:00
Linus Torvalds 07acfc2a93 Merge branch 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM changes from Avi Kivity:
 "Changes include additional instruction emulation, page-crossing MMIO,
  faster dirty logging, preventing the watchdog from killing a stopped
  guest, module autoload, a new MSI ABI, and some minor optimizations
  and fixes.  Outside x86 we have a small s390 and a very large ppc
  update.

  Regarding the new (for kvm) rebaseless workflow, some of the patches
  that were merged before we switch trees had to be rebased, while
  others are true pulls.  In either case the signoffs should be correct
  now."

Fix up trivial conflicts in Documentation/feature-removal-schedule.txt
arch/powerpc/kvm/book3s_segment.S and arch/x86/include/asm/kvm_para.h.

I suspect the kvm_para.h resolution ends up doing the "do I have cpuid"
check effectively twice (it was done differently in two different
commits), but better safe than sorry ;)

* 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (125 commits)
  KVM: make asm-generic/kvm_para.h have an ifdef __KERNEL__ block
  KVM: s390: onereg for timer related registers
  KVM: s390: epoch difference and TOD programmable field
  KVM: s390: KVM_GET/SET_ONEREG for s390
  KVM: s390: add capability indicating COW support
  KVM: Fix mmu_reload() clash with nested vmx event injection
  KVM: MMU: Don't use RCU for lockless shadow walking
  KVM: VMX: Optimize %ds, %es reload
  KVM: VMX: Fix %ds/%es clobber
  KVM: x86 emulator: convert bsf/bsr instructions to emulate_2op_SrcV_nobyte()
  KVM: VMX: unlike vmcs on fail path
  KVM: PPC: Emulator: clean up SPR reads and writes
  KVM: PPC: Emulator: clean up instruction parsing
  kvm/powerpc: Add new ioctl to retreive server MMU infos
  kvm/book3s: Make kernel emulated H_PUT_TCE available for "PR" KVM
  KVM: PPC: bookehv: Fix r8/r13 storing in level exception handler
  KVM: PPC: Book3S: Enable IRQs during exit handling
  KVM: PPC: Fix PR KVM on POWER7 bare metal
  KVM: PPC: Fix stbux emulation
  KVM: PPC: bookehv: Use lwz/stw instead of PPC_LL/PPC_STL for 32-bit fields
  ...
2012-05-24 16:17:30 -07:00
Avi Kivity d8368af8b4 KVM: Fix mmu_reload() clash with nested vmx event injection
Currently the inject_pending_event() call during guest entry happens after
kvm_mmu_reload().  This is for historical reasons - we used to
inject_pending_event() in atomic context, while kvm_mmu_reload() needs task
context.

A problem is that nested vmx can cause the mmu context to be reset, if event
injection is intercepted and causes a #VMEXIT instead (the #VMEXIT resets
CR0/CR3/CR4).  If this happens, we end up with invalid root_hpa, and since
kvm_mmu_reload() has already run, no one will fix it and we end up entering
the guest this way.

Fix by reordering event injection to be before kvm_mmu_reload().  Use
->cancel_injection() to undo if kvm_mmu_reload() fails.

https://bugzilla.kernel.org/show_bug.cgi?id=42980

Reported-by: Luke-Jr <luke-jr+linuxbugs@utopios.org>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-05-16 18:09:26 -03:00
Gleb Natapov a4fa163531 KVM: ensure async PF event wakes up vcpu from halt
If vcpu executes hlt instruction while async PF is waiting to be delivered
vcpu can block and deliver async PF only after another even wakes it
up. This happens because kvm_check_async_pf_completion() will remove
completion event from vcpu->async_pf.done before entering kvm_vcpu_block()
and this will make kvm_arch_vcpu_runnable() return false. The solution
is to make vcpu runnable when processing completion.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-05-06 14:56:54 +03:00
Al Viro bfce281c28 kill mm argument of vm_munmap()
it's always current->mm

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-04-21 01:58:20 -04:00
Linus Torvalds 6be5ceb02e VM: add "vm_mmap()" helper function
This continues the theme started with vm_brk() and vm_munmap():
vm_mmap() does the same thing as do_mmap(), but additionally does the
required VM locking.

This uninlines (and rewrites it to be clearer) do_mmap(), which sadly
duplicates it in mm/mmap.c and mm/nommu.c.  But that way we don't have
to export our internal do_mmap_pgoff() function.

Some day we hopefully don't have to export do_mmap() either, if all
modular users can become the simpler vm_mmap() instead.  We're actually
very close to that already, with the notable exception of the (broken)
use in i810, and a couple of stragglers in binfmt_elf.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-04-20 17:29:13 -07:00
Linus Torvalds a46ef99d80 VM: add "vm_munmap()" helper function
Like the vm_brk() function, this is the same as "do_munmap()", except it
does the VM locking for the caller.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-04-20 17:29:13 -07:00
Avi Kivity f78146b0f9 KVM: Fix page-crossing MMIO
MMIO that are split across a page boundary are currently broken - the
code does not expect to be aborted by the exit to userspace for the
first MMIO fragment.

This patch fixes the problem by generalizing the current code for handling
16-byte MMIOs to handle a number of "fragments", and changes the MMIO
code to create those fragments.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-04-19 20:35:07 -03:00
Takuya Yoshikawa 60c34612b7 KVM: Switch to srcu-less get_dirty_log()
We have seen some problems of the current implementation of
get_dirty_log() which uses synchronize_srcu_expedited() for updating
dirty bitmaps; e.g. it is noticeable that this sometimes gives us ms
order of latency when we use VGA displays.

Furthermore the recent discussion on the following thread
    "srcu: Implement call_srcu()"
    http://lkml.org/lkml/2012/1/31/211
also motivated us to implement get_dirty_log() without SRCU.

This patch achieves this goal without sacrificing the performance of
both VGA and live migration: in practice the new code is much faster
than the old one unless we have too many dirty pages.

Implementation:

The key part of the implementation is the use of xchg() operation for
clearing dirty bits atomically.  Since this allows us to update only
BITS_PER_LONG pages at once, we need to iterate over the dirty bitmap
until every dirty bit is cleared again for the next call.

Although some people may worry about the problem of using the atomic
memory instruction many times to the concurrently accessible bitmap,
it is usually accessed with mmu_lock held and we rarely see concurrent
accesses: so what we need to care about is the pure xchg() overheads.

Another point to note is that we do not use for_each_set_bit() to check
which ones in each BITS_PER_LONG pages are actually dirty.  Instead we
simply use __ffs() in a loop.  This is much faster than repeatedly call
find_next_bit().

Performance:

The dirty-log-perf unit test showed nice improvements, some times faster
than before, except for some extreme cases; for such cases the speed of
getting dirty page information is much faster than we process it in the
userspace.

For real workloads, both VGA and live migration, we have observed pure
improvements: when the guest was reading a file during live migration,
we originally saw a few ms of latency, but with the new method the
latency was less than 200us.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08 12:50:00 +03:00
Takuya Yoshikawa 5dc99b2380 KVM: Avoid checking huge page mappings in get_dirty_log()
Dropped such mappings when we enabled dirty logging and we will never
create new ones until we stop the logging.

For this we introduce a new function which can be used to write protect
a range of PT level pages: although we do not need to care about a range
of pages at this point, the following patch will need this feature to
optimize the write protection of many pages.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08 12:49:58 +03:00
Eric B Munson 1c0b28c2a4 KVM: x86: Add ioctl for KVM_KVMCLOCK_CTRL
Now that we have a flag that will tell the guest it was suspended, create an
interface for that communication using a KVM ioctl.

Signed-off-by: Eric B Munson <emunson@mgebm.net>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08 12:49:01 +03:00
Christoffer Dall b6d33834bd KVM: Factor out kvm_vcpu_kick to arch-generic code
The kvm_vcpu_kick function performs roughly the same funcitonality on
most all architectures, so we shouldn't have separate copies.

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

Acked-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08 12:47:47 +03:00
Linus Torvalds 2e7580b0e7 Merge branch 'kvm-updates/3.4' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm updates from Avi Kivity:
 "Changes include timekeeping improvements, support for assigning host
  PCI devices that share interrupt lines, s390 user-controlled guests, a
  large ppc update, and random fixes."

This is with the sign-off's fixed, hopefully next merge window we won't
have rebased commits.

* 'kvm-updates/3.4' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (130 commits)
  KVM: Convert intx_mask_lock to spin lock
  KVM: x86: fix kvm_write_tsc() TSC matching thinko
  x86: kvmclock: abstract save/restore sched_clock_state
  KVM: nVMX: Fix erroneous exception bitmap check
  KVM: Ignore the writes to MSR_K7_HWCR(3)
  KVM: MMU: make use of ->root_level in reset_rsvds_bits_mask
  KVM: PMU: add proper support for fixed counter 2
  KVM: PMU: Fix raw event check
  KVM: PMU: warn when pin control is set in eventsel msr
  KVM: VMX: Fix delayed load of shared MSRs
  KVM: use correct tlbs dirty type in cmpxchg
  KVM: Allow host IRQ sharing for assigned PCI 2.3 devices
  KVM: Ensure all vcpus are consistent with in-kernel irqchip settings
  KVM: x86 emulator: Allow PM/VM86 switch during task switch
  KVM: SVM: Fix CPL updates
  KVM: x86 emulator: VM86 segments must have DPL 3
  KVM: x86 emulator: Fix task switch privilege checks
  arch/powerpc/kvm/book3s_hv.c: included linux/sched.h twice
  KVM: x86 emulator: correctly mask pmc index bits in RDPMC instruction emulation
  KVM: mmu_notifier: Flush TLBs before releasing mmu_lock
  ...
2012-03-28 14:35:31 -07:00
Linus Torvalds 35cb8d9e18 Merge branch 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86/fpu changes from Ingo Molnar.

* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  i387: Split up <asm/i387.h> into exported and internal interfaces
  i387: Uninline the generic FP helpers that we expose to kernel modules
2012-03-22 09:41:22 -07:00
Cong Wang 8fd75e1216 x86: remove the second argument of k[un]map_atomic()
Acked-by: Avi Kivity <avi@redhat.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Cong Wang <amwang@redhat.com>
2012-03-20 21:48:15 +08:00
Marcelo Tosatti 02626b6af5 KVM: x86: fix kvm_write_tsc() TSC matching thinko
kvm_write_tsc() converts from guest TSC to microseconds, not nanoseconds
as intended. The result is that the window for matching is 1000 seconds,
not 1 second.

Microsecond precision is enough for checking whether the TSC write delta
is within the heuristic values, so use it instead of nanoseconds.

Noted by Avi Kivity.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-20 12:40:36 +02:00
Nicolae Mogoreanu a223c313cb KVM: Ignore the writes to MSR_K7_HWCR(3)
When CPUID Fn8000_0001_EAX reports 0x00100f22 Windows 7 x64 guest
tries to set bit 3 in MSRC001_0015 in nt!KiDisableCacheErrataSource
and fails. This patch will ignore this step and allow things to move
on without having to fake CPUID value.

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

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

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

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

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

Based on earlier patch by Michael Ellerman.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-08 14:10:30 +02:00