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

Jan Kiszka
2013-03-12T12:52:03Z

On 2013-03-12 13:49, Gleb Natapov wrote:
> 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.

Right, but that can then easily become part of the to-be-defined nested
vcpu state (which is likely more than vmcs12).

Jan

--
Siemens AG, Corporate Technology, CT RTC ITP SDP-DE
Corporate Competence Center Embedded Linux