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| author | Zachary Amsden <zamsden@redhat.com> | 2010-08-19 22:07:23 -1000 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2010-10-24 10:51:23 +0200 |
| commit | e48672fa25e879f7ae21785c7efd187738139593 (patch) | |
| tree | bec27bad04ba6e933e72439cc565d2c752a31928 /arch/x86/kvm/x86.c | |
| parent | 6755bae8e69093b2994b6f29cd3eaecdf610374e (diff) | |
| download | lwn-e48672fa25e879f7ae21785c7efd187738139593.tar.gz lwn-e48672fa25e879f7ae21785c7efd187738139593.zip | |
KVM: x86: Unify TSC logic
Move the TSC control logic from the vendor backends into x86.c
by adding adjust_tsc_offset to x86 ops. Now all TSC decisions
can be done in one place.
Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index a8dee58e8716..468fafaed1ae 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -973,9 +973,9 @@ static int kvm_write_guest_time(struct kvm_vcpu *v) return 1; } - if (unlikely(vcpu->hv_clock_tsc_khz != this_tsc_khz)) { + if (unlikely(vcpu->hw_tsc_khz != this_tsc_khz)) { kvm_set_time_scale(this_tsc_khz, &vcpu->hv_clock); - vcpu->hv_clock_tsc_khz = this_tsc_khz; + vcpu->hw_tsc_khz = this_tsc_khz; } /* With all the info we got, fill in the values */ @@ -1866,13 +1866,24 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) } kvm_x86_ops->vcpu_load(vcpu, cpu); - kvm_request_guest_time_update(vcpu); + if (unlikely(vcpu->cpu != cpu)) { + /* Make sure TSC doesn't go backwards */ + s64 tsc_delta = !vcpu->arch.last_host_tsc ? 0 : + native_read_tsc() - vcpu->arch.last_host_tsc; + if (tsc_delta < 0) + mark_tsc_unstable("KVM discovered backwards TSC"); + if (check_tsc_unstable()) + kvm_x86_ops->adjust_tsc_offset(vcpu, -tsc_delta); + kvm_migrate_timers(vcpu); + vcpu->cpu = cpu; + } } void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) { kvm_x86_ops->vcpu_put(vcpu); kvm_put_guest_fpu(vcpu); + vcpu->arch.last_host_tsc = native_read_tsc(); } static int is_efer_nx(void) |