KVM: SVM: Ensure timestamp counter monotonicity

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When a vcpu is migrated from one cpu to another, its timestamp counter
may lose its monotonic property if the host has unsynced timestamp counters.
This can confuse the guest, sometimes to the point of refusing to boot.

As the rdtsc instruction is rather fast on AMD processors (7-10 cycles),
we can simply record the last host tsc when we drop the cpu, and adjust
the vcpu tsc offset when we detect that we've migrated to a different cpu.

Signed-off-by: Avi Kivity <avi@qumranet.com>

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This commit is contained in:

Avi Kivity 2007-03-25 12:07:27 +02:00

parent d28c6cfbbc

commit 0cc5064d33

2 changed files with 18 additions and 4 deletions

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1

drivers/kvm/kvm.h

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21

drivers/kvm/svm.c

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