On 08/02/2012 06:43 PM, Marcelo Tosatti wrote: > On Thu, Aug 02, 2012 at 06:42:25PM +0300, Avi Kivity wrote: >> On 08/02/2012 06:33 PM, Marcelo Tosatti wrote: >> > >> > kvm_guest_time_update unconditionally clears hv_clock.flags field, >> > so the notification never reaches the guest. >> > >> > Fix it by allowing PVCLOCK_GUEST_STOPPED to passthrough. >> > >> > Signed-off-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx> >> > >> > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c >> > index 3a53bcc..e8ce10f 100644 >> > --- a/arch/x86/kvm/x86.c >> > +++ b/arch/x86/kvm/x86.c >> > @@ -1217,7 +1217,9 @@ static int kvm_guest_time_update(struct kvm_vcpu *v) >> > vcpu->hv_clock.system_time = kernel_ns + v->kvm->arch.kvmclock_offset; >> > vcpu->last_kernel_ns = kernel_ns; >> > vcpu->last_guest_tsc = tsc_timestamp; >> > - vcpu->hv_clock.flags = 0; >> > + /* only support PVCLOCK_GUEST_STOPPED flag ATM */ >> > + if (vcpu->hv_clock.flags != PVCLOCK_GUEST_STOPPED) >> > + vcpu->hv_clock.flags = 0; >> > >> >> Seems a little risky. Should we store the flag in a separate bool and >> mix it in instead of RMWing it? > > This is not guest memory. Its a host copy, the actual data is copied > (safely via the version mechanism) below in that function. > > Are you ok with it now? > Yeah. Though why are we writing flags at all then? We could write it one during init and leave it there (not that it matters). Anyway, patch is fine. -- error compiling committee.c: too many arguments to function -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
