On Tue, Feb 16, 2010 at 11:14:45AM +0100, Jan Kiszka wrote: > Gleb Natapov wrote: > > On Tue, Feb 16, 2010 at 11:04:10AM +0100, Jan Kiszka wrote: > >> Gleb Natapov wrote: > >>> On Tue, Feb 16, 2010 at 10:16:12AM +0100, Jan Kiszka wrote: > >>>> Found while browsing Xen code: While we assume that the STI interrupt > >>>> shadow also inplies virtual NMI blocking, some processors may have a > >>>> different opinion (SDM 3: 22.3). To avoid misunderstandings that would > >>>> cause endless VM entry attempts, translate STI into MOV SS blocking when > >>>> requesting the NMI window. > >>>> > >>> Why not just remove "block by STI" check in vmx_nmi_allowed()? IIRC this > >>> is documented that on some CPUs STI does not block NMI. > >>> > >> Probably because we will stumble and fall on those CPUs that do care. > >> > > But this defines behaviour of cpu _we_ emulate. So on _our_ cpu NMI will > > not be blocked by STI. > > The host CPU decides if it accepts an NMI injections while Are you sure? I haven't found such check during VMENTRY. > blocked-by-STI is set, not we. But, of course, we could also translate > STI into MOV SS blocking unconditionally. Whatever is preferred. > -- Gleb. -- 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
