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. Alex > > -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
