From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [PATCH] KVM: x86: Convert INIT and SIPI signals into synchronously handled events Date: Tue, 12 Mar 2013 14:13:50 +0100 Message-ID: <513F2A0E.50903@siemens.com> References: <513F1529.3040309@siemens.com> <513F1A63.9070107@redhat.com> <513F1FB1.60101@redhat.com> <513F23BD.7020903@siemens.com> <513F2904.2050905@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Gleb Natapov , Marcelo Tosatti , kvm To: Paolo Bonzini Return-path: Received: from thoth.sbs.de ([192.35.17.2]:15262 "EHLO thoth.sbs.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755278Ab3CLNNy (ORCPT ); Tue, 12 Mar 2013 09:13:54 -0400 In-Reply-To: <513F2904.2050905@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 2013-03-12 14:09, Paolo Bonzini wrote: > Il 12/03/2013 13:46, Jan Kiszka 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. > > What about persistent state such as "an INIT has been received and > caused a vmexit, but is being latched until vmxoff"? Perhaps we could > use the top 8 bits of vcpu->arch.sipi_vector for this, they are always > shifted out when sipi_vector is used, and should be zero in all cases. > It would then be possible to reuse KVM_GET/SET_VCPU_EVENTS. See my other mail. > > Migration support for nested VMX is still far far away, so perhaps we do > not care, but we still need a way to inject INIT from userspace. Ack for INIT injection. In theory, you could use the VCPU event IOCTL, it is extensible. If that is elegant is another question. Jan -- Siemens AG, Corporate Technology, CT RTC ITP SDP-DE Corporate Competence Center Embedded Linux