Re: [PATCH] KVM: x86: Convert INIT and SIPI signals into synchronously handled events

Gleb Natapov
2013-03-12T12:49:52Z

On Tue, Mar 12, 2013 at 01:46:53PM +0100, Jan Kiszka wrote:
> On 2013-03-12 13:29, Paolo Bonzini wrote:
> > Il 12/03/2013 13:06, Paolo Bonzini ha scritto:
> >>> @@ -6178,7 +6177,13 @@ int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
> >>> int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
> >>> struct kvm_mp_state *mp_state)
> >>> {
> >>> - vcpu->arch.mp_state = mp_state->mp_state;
> >>> + if (mp_state->mp_state == KVM_MP_STATE_SIPI_RECEIVED) {
> >>> + if (!kvm_vcpu_has_lapic(vcpu))
> >>> + return -EINVAL;
> >>> + vcpu->arch.mp_state = KVM_MP_STATE_INIT_RECEIVED;
> >>> + set_bit(KVM_APIC_SIPI, &vcpu->arch.apic->pending_events);
> >>> + } else
> >>> + vcpu->arch.mp_state = mp_state->mp_state;
> >>
> >> Should INIT_RECEIVED also be invalid without an in-kernel LAPIC?
> >
> > And since migration was brought up yesterday, do we need an interface to
> > retrieve and set this?
> >
> > And should KVM_GET/SET_VCPU_EVENTS use the new sipi_vector in the APIC
> > rather than the old one?
>
> I hope not. The idea is that the APIC events are processed before the
> migration completes. Translating events on get_mpstate should ensure this.
>
But when you will add nested support it will not be that simple, so as
part of migration with nested guests we will have to transfer
pending_events too instead of processing then on (set|get)_mpstate.

--
Gleb.