KVM: Fix race between timer migration and vcpu migration

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A guest vcpu instance can be scheduled to a different physical CPU
between the test for KVM_REQ_MIGRATE_TIMER and local_irq_disable().

If that happens, the timer will only be migrated to the current pCPU on
the next exit, meaning that guest LAPIC timer event can be delayed until
a host interrupt is triggered.

Fix it by cancelling guest entry if any vcpu request is pending.  This
has the side effect of nicely consolidating vcpu->requests checks.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

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Marcelo Tosatti 2008-06-06 16:37:35 -03:00 • committed by Avi Kivity

parent 62786b9e81

commit d4acf7e7ab

1 changed files with 3 additions and 12 deletions

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arch/x86/kvm/x86.c

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