From b7e60c5aedd2b63f16ef06fde4f81ca032211bc5 Mon Sep 17 00:00:00 2001 From: Marcelo Tosatti Date: Thu, 28 May 2015 20:20:41 -0300 Subject: [PATCH] KVM: x86: zero kvmclock_offset when vcpu0 initializes kvmclock system MSR Initialize kvmclock base, on kvmclock system MSR write time, so that the guest sees kvmclock counting from zero. This matches baremetal behaviour when kvmclock in guest sets sched clock stable. Signed-off-by: Marcelo Tosatti [Remove unnecessary comment. - Paolo] Signed-off-by: Paolo Bonzini --- arch/x86/kvm/x86.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 2211213a84e7..79dde1656db6 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1700,6 +1700,8 @@ static int kvm_guest_time_update(struct kvm_vcpu *v) vcpu->pvclock_set_guest_stopped_request = false; } + pvclock_flags |= PVCLOCK_COUNTS_FROM_ZERO; + /* If the host uses TSC clocksource, then it is stable */ if (use_master_clock) pvclock_flags |= PVCLOCK_TSC_STABLE_BIT; @@ -2282,6 +2284,8 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) &vcpu->requests); ka->boot_vcpu_runs_old_kvmclock = tmp; + + ka->kvmclock_offset = -get_kernel_ns(); } vcpu->arch.time = data; -- 2.34.1