From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH v2] KVM: Fix simultaneous NMIs Date: Tue, 20 Sep 2011 16:56:02 +0300 Message-ID: <4E789B72.2050904@redhat.com> References: <1316515394-24762-1-git-send-email-avi@redhat.com> <20110920132537.GA27075@amt.cnet> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, Jan Kiszka To: Marcelo Tosatti Return-path: Received: from mx1.redhat.com ([209.132.183.28]:59558 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750981Ab1ITN4H (ORCPT ); Tue, 20 Sep 2011 09:56:07 -0400 In-Reply-To: <20110920132537.GA27075@amt.cnet> Sender: kvm-owner@vger.kernel.org List-ID: On 09/20/2011 04:25 PM, Marcelo Tosatti wrote: > > > > @@ -2827,6 +2828,7 @@ static int kvm_vcpu_ioctl_x86_set_mce(struct kvm_vcpu *vcpu, > > static void kvm_vcpu_ioctl_x86_get_vcpu_events(struct kvm_vcpu *vcpu, > > struct kvm_vcpu_events *events) > > { > > + process_nmi(vcpu); > > events->exception.injected = > > vcpu->arch.exception.pending&& > > !kvm_exception_is_soft(vcpu->arch.exception.nr); > > @@ -2844,7 +2846,7 @@ static void kvm_vcpu_ioctl_x86_get_vcpu_events(struct kvm_vcpu *vcpu, > > KVM_X86_SHADOW_INT_MOV_SS | KVM_X86_SHADOW_INT_STI); > > > > events->nmi.injected = vcpu->arch.nmi_injected; > > - events->nmi.pending = vcpu->arch.nmi_pending; > > + events->nmi.pending = vcpu->arch.nmi_pending != 0; > > events->nmi.masked = kvm_x86_ops->get_nmi_mask(vcpu); > > events->nmi.pad = 0; > > nmi_queued should also be saved and restored. Not sure if its necessary > though. > > Should at least reset nmi_queued somewhere (set_vcpu_events?). Did you miss the call to process_nmi()? We do have a small issue. If we exit during NMI-blocked-by-STI and nmi_pending == 2, then we lose the second interrupt. Should rarely happen, since external interrupts never exit in that condition, but it's a wart. > > > @@ -2864,6 +2866,7 @@ static int kvm_vcpu_ioctl_x86_set_vcpu_events(struct kvm_vcpu *vcpu, > > | KVM_VCPUEVENT_VALID_SHADOW)) > > return -EINVAL; > > > > + process_nmi(vcpu); > > This should be after nmi fields are set, not before? > It's actually to clear queued NMIs in case we set nmi_pending (which should never happen unless the machine is completely quiet, since it's asynchronous to the vcpu; same as the IRR). -- error compiling committee.c: too many arguments to function