Re: [patch 3/3] KVM: x86: zero kvmclock_offset when vcpu0 initializes kvmclock system MSR
On 28/05/2015 03:47, Marcelo Tosatti wrote: > 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 > > --- > arch/x86/kvm/x86.c |5 + > 1 file changed, 5 insertions(+) > > Index: kvm/arch/x86/kvm/x86.c > === > --- kvm.orig/arch/x86/kvm/x86.c 2015-05-27 17:40:46.948189811 -0300 > +++ kvm/arch/x86/kvm/x86.c2015-05-27 22:43:47.340413347 -0300 > @@ -1703,6 +1703,8 @@ > /* If the host uses TSC clocksource, then it is stable */ > if (use_master_clock) > pvclock_flags |= PVCLOCK_TSC_STABLE_BIT; > + if (ka->kvmclk_counts_from_zero) Not defined anywhere. > + pvclock_flags |= PVCLOCK_COUNTS_FROM_ZERO; Why can't this be unconditional? Paolo > vcpu->hv_clock.flags = pvclock_flags; > > @@ -2282,6 +2284,9 @@ > &vcpu->requests); > > ka->boot_vcpu_runs_old_kvmclock = tmp; > + > + ka->kvmclock_offset = -get_kernel_ns(); > + ka->kvmclk_counts_from_zero = true; > } > > vcpu->arch.time = data; > > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
[patch 3/3] 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 --- arch/x86/kvm/x86.c |5 + 1 file changed, 5 insertions(+) Index: kvm/arch/x86/kvm/x86.c === --- kvm.orig/arch/x86/kvm/x86.c 2015-05-27 17:40:46.948189811 -0300 +++ kvm/arch/x86/kvm/x86.c 2015-05-27 22:43:47.340413347 -0300 @@ -1703,6 +1703,8 @@ /* If the host uses TSC clocksource, then it is stable */ if (use_master_clock) pvclock_flags |= PVCLOCK_TSC_STABLE_BIT; + if (ka->kvmclk_counts_from_zero) + pvclock_flags |= PVCLOCK_COUNTS_FROM_ZERO; vcpu->hv_clock.flags = pvclock_flags; @@ -2282,6 +2284,9 @@ &vcpu->requests); ka->boot_vcpu_runs_old_kvmclock = tmp; + + ka->kvmclock_offset = -get_kernel_ns(); + ka->kvmclk_counts_from_zero = true; } vcpu->arch.time = data; -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html