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[v2,08/12] KVM: x86: Use the correct vcpu's TSC rate to compute time scale

Message ID 1445326752-8926-9-git-send-email-haozhong.zhang@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Haozhong Zhang Oct. 20, 2015, 7:39 a.m. UTC 
This patch makes KVM use virtual_tsc_khz rather than the host TSC rate
as vcpu's TSC rate to compute the time scale if TSC scaling is enabled.

Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
---
 arch/x86/kvm/x86.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
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Patch

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index f2516bf..d5690a3 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1698,7 +1698,7 @@  static void kvm_gen_update_masterclock(struct kvm *kvm)
 
 static int kvm_guest_time_update(struct kvm_vcpu *v)
 {
-	unsigned long flags, this_tsc_khz;
+	unsigned long flags, this_tsc_khz, tgt_tsc_khz;
 	struct kvm_vcpu_arch *vcpu = &v->arch;
 	struct kvm_arch *ka = &v->kvm->arch;
 	s64 kernel_ns;
@@ -1761,7 +1761,9 @@  static int kvm_guest_time_update(struct kvm_vcpu *v)
 		return 0;
 
 	if (unlikely(vcpu->hw_tsc_khz != this_tsc_khz)) {
-		kvm_get_time_scale(NSEC_PER_SEC / 1000, this_tsc_khz,
+		tgt_tsc_khz = kvm_has_tsc_control ?
+			vcpu->virtual_tsc_khz : this_tsc_khz;
+		kvm_get_time_scale(NSEC_PER_SEC / 1000, tgt_tsc_khz,
 				   &vcpu->hv_clock.tsc_shift,
 				   &vcpu->hv_clock.tsc_to_system_mul);
 		vcpu->hw_tsc_khz = this_tsc_khz;