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. -Scott -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
