On 01/09/2012 02:18 PM, Alexander Graf wrote: > > > Am 09.01.2012 um 21:00 schrieb Scott Wood <scottwood@xxxxxxxxxxxxx>: > >> On 01/09/2012 08:15 AM, Alexander Graf wrote: >>> >>> On 05.01.2012, at 10:07, Liu Yu wrote: >>> >>>> diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c >>>> index c33f6a7..1242ee1 100644 >>>> --- a/arch/powerpc/kvm/powerpc.c >>>> +++ b/arch/powerpc/kvm/powerpc.c >>>> @@ -81,6 +81,10 @@ int kvmppc_kvm_pv(struct kvm_vcpu *vcpu) >>>> >>>> /* Second return value is in r4 */ >>>> break; >>>> + case HC_VENDOR_EPAPR | HC_EV_IDLE: >>>> + r = HC_EV_SUCCESS; >>>> + kvm_vcpu_block(vcpu); >>> >>> Hrm. This will return on signal. So if the guest sends an idle hcall, >>> then user space gets a random signal, we'll continue executing the >>> guest CPU, getting us out of idle even though the guest didn't expect >>> it, since the guest really wants to get an interrupt after the idle >>> hcall. >> >> The ePAPR description of this hcall is a little vague (Stuart, put on >> list to fix in next ePAPR revision?), but this is expected. It will >> also be the case if a guest directly uses the wait instruction. Guests >> must be able to deal with spurious wakeups. > > The wait instruction does get executed in an infinite loop though, while this hcall is only executed once. Yes, I pointed that out as something that needs to be fixed in the ev_idle patch. -Scott -- 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
