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  1. 11 2月, 2013 1 次提交
  3. 05 2月, 2013 2 次提交
    • T
      KVM: set_memory_region: Disallow changing read-only attribute later · 75d61fbc
      由 Takuya Yoshikawa 提交于 
      As Xiao pointed out, there are a few problems with it:
 - kvm_arch_commit_memory_region() write protects the memory slot only
   for GET_DIRTY_LOG when modifying the flags.
 - FNAME(sync_page) uses the old spte value to set a new one without
   checking KVM_MEM_READONLY flag.

Since we flush all shadow pages when creating a new slot, the simplest
fix is to disallow such problematic flag changes: this is safe because
no one is doing such things.
Reviewed-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NTakuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
      75d61fbc
    • T
      KVM: set_memory_region: Identify the requested change explicitly · f64c0398
      由 Takuya Yoshikawa 提交于 
      KVM_SET_USER_MEMORY_REGION forces __kvm_set_memory_region() to identify
what kind of change is being requested by checking the arguments.  The
current code does this checking at various points in code and each
condition being used there is not easy to understand at first glance.

This patch consolidates these checks and introduces an enum to name the
possible changes to clean up the code.

Although this does not introduce any functional changes, there is one
change which optimizes the code a bit: if we have nothing to change, the
new code returns 0 immediately.

Note that the return value for this case cannot be changed since QEMU
relies on it: we noticed this when we changed it to -EINVAL and got a
section mismatch error at the final stage of live migration.
Signed-off-by: NTakuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
      f64c0398
  5. 29 1月, 2013 2 次提交
    • R
      kvm: Handle yield_to failure return code for potential undercommit case · c45c528e
      由 Raghavendra K T 提交于 
      yield_to returns -ESRCH, When source and target of yield_to
run queue length is one. When we see three successive failures of
yield_to we assume we are in potential undercommit case and abort
from PLE handler.
The assumption is backed by low probability of wrong decision
for even worst case scenarios such as average runqueue length
between 1 and 2.

More detail on rationale behind using three tries:
if p is the probability of finding rq length one on a particular cpu,
and if we do n tries, then probability of exiting ple handler is:

 p^(n+1) [ because we would have come across one source with rq length
1 and n target cpu rqs  with length 1 ]

so
num tries:         probability of aborting ple handler (1.5x overcommit)
 1                 1/4
 2                 1/8
 3                 1/16

We can increase this probability with more tries, but the problem is
the overhead.
Also, If we have tried three times that means we would have iterated
over 3 good eligible vcpus along with many non-eligible candidates. In
worst case if we iterate all the vcpus, we reduce 1x performance and
overcommit performance get hit.

note that we do not update last boosted vcpu in failure cases.
Thank Avi for raising question on aborting after first fail from yield_to.
Reviewed-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: NRaghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Tested-by: NChegu Vinod <chegu_vinod@hp.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>
      c45c528e
    • Y
      x86, apicv: add virtual interrupt delivery support · c7c9c56c
      由 Yang Zhang 提交于 
      Virtual interrupt delivery avoids KVM to inject vAPIC interrupts
manually, which is fully taken care of by the hardware. This needs
some special awareness into existing interrupr injection path:

- for pending interrupt, instead of direct injection, we may need
  update architecture specific indicators before resuming to guest.

- A pending interrupt, which is masked by ISR, should be also
  considered in above update action, since hardware will decide
  when to inject it at right time. Current has_interrupt and
  get_interrupt only returns a valid vector from injection p.o.v.
Reviewed-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NKevin Tian <kevin.tian@intel.com>
Signed-off-by: NYang Zhang <yang.z.zhang@Intel.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>
      c7c9c56c
  7. 27 1月, 2013 1 次提交
  9. 17 1月, 2013 3 次提交
  11. 14 1月, 2013 1 次提交
  13. 24 12月, 2012 1 次提交
  15. 23 12月, 2012 1 次提交
  17. 14 12月, 2012 7 次提交
  19. 30 11月, 2012 1 次提交
    • A
      KVM: Fix user memslot overlap check · 5419369e
      由 Alex Williamson 提交于 
      Prior to memory slot sorting this loop compared all of the user memory
slots for overlap with new entries.  With memory slot sorting, we're
just checking some number of entries in the array that may or may not
be user slots.  Instead, walk all the slots with kvm_for_each_memslot,
which has the added benefit of terminating early when we hit the first
empty slot, and skip comparison to private slots.

Cc: stable@vger.kernel.org
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
      5419369e
  21. 28 11月, 2012 2 次提交
    • M
      KVM: x86: add kvm_arch_vcpu_postcreate callback, move TSC initialization · 42897d86
      由 Marcelo Tosatti 提交于 
      TSC initialization will soon make use of online_vcpus.
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
      42897d86
    • M
      KVM: x86: implement PVCLOCK_TSC_STABLE_BIT pvclock flag · d828199e
      由 Marcelo Tosatti 提交于 
      KVM added a global variable to guarantee monotonicity in the guest.
One of the reasons for that is that the time between

	1. ktime_get_ts(&timespec);
	2. rdtscll(tsc);

Is variable. That is, given a host with stable TSC, suppose that
two VCPUs read the same time via ktime_get_ts() above.

The time required to execute 2. is not the same on those two instances
executing in different VCPUS (cache misses, interrupts...).

If the TSC value that is used by the host to interpolate when
calculating the monotonic time is the same value used to calculate
the tsc_timestamp value stored in the pvclock data structure, and
a single <system_timestamp, tsc_timestamp> tuple is visible to all
vcpus simultaneously, this problem disappears. See comment on top
of pvclock_update_vm_gtod_copy for details.

Monotonicity is then guaranteed by synchronicity of the host TSCs
and guest TSCs.

Set TSC stable pvclock flag in that case, allowing the guest to read
clock from userspace.
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
      d828199e
  23. 14 11月, 2012 2 次提交
  25. 30 10月, 2012 1 次提交
  27. 23 10月, 2012 1 次提交
  29. 06 10月, 2012 1 次提交
  31. 18 9月, 2012 1 次提交
    • M
      KVM: make processes waiting on vcpu mutex killable · 9fc77441
      由 Michael S. Tsirkin 提交于 
      vcpu mutex can be held for unlimited time so
taking it with mutex_lock on an ioctl is wrong:
one process could be passed a vcpu fd and
call this ioctl on the vcpu used by another process,
it will then be unkillable until the owner exits.

Call mutex_lock_killable instead and return status.
Note: mutex_lock_interruptible would be even nicer,
but I am not sure all users are prepared to handle EINTR
from these ioctls. They might misinterpret it as an error.

Cleanup paths expect a vcpu that can't be used by
any userspace so this will always succeed - catch bugs
by calling BUG_ON.

Catch callers that don't check return state by adding
__must_check.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
      9fc77441
  33. 06 9月, 2012 3 次提交
  35. 28 8月, 2012 1 次提交
  37. 27 8月, 2012 1 次提交
  39. 22 8月, 2012 7 次提交