On Thu, Mar 24, 2011 at 03:33:35PM +0200, Avi Kivity wrote: > On 03/24/2011 03:27 PM, Gleb Natapov wrote: > >On Thu, Mar 24, 2011 at 09:47:00AM -0300, Marcelo Tosatti wrote: > >> > >> Since "Fix race between nmi injection and enabling nmi window", pending NMI > >> can be represented in KVM_REQ_NMI vcpu->requests bit. > >> > >> When setting vcpu state via SET_VCPU_EVENTS, for example during reset, > >> the REQ_NMI bit should be cleared otherwise pending NMI is transferred > >> to nmi_pending upon vcpu entry. > >> > >> Also should consider requests bit on runnable conditional. > >> > >> BZ: http://bugzilla.redhat.com/show_bug.cgi?id=684719 > >> > >Looks like we need to clear request bit on cpu reset too. KVM_REQ_NMI > >start to become more complicated that it was initially. May be replaced > >it with something like this: > > > > > >diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > >index 1b8b16a..6a66d19 100644 > >--- a/arch/x86/kvm/x86.c > >+++ b/arch/x86/kvm/x86.c > >@@ -5151,6 +5151,7 @@ static void kvm_put_guest_xcr0(struct kvm_vcpu *vcpu) > > static int vcpu_enter_guest(struct kvm_vcpu *vcpu) > > { > > int r; > >+ int nmi_pending; > > bool req_int_win = !irqchip_in_kernel(vcpu->kvm)&& > > vcpu->run->request_interrupt_window; > > > >@@ -5188,19 +5189,19 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) > > r = 1; > > goto out; > > } > >- if (kvm_check_request(KVM_REQ_NMI, vcpu)) > >- vcpu->arch.nmi_pending = true; > > } > > > > r = kvm_mmu_reload(vcpu); > > if (unlikely(r)) > > goto out; > > > >+ nmi_pending = vcpu->arch.nmi_pending; > >+ > > ACCESS_ONCE() to prevent compiler cleverness > > > if (kvm_check_request(KVM_REQ_EVENT, vcpu) || req_int_win) { > > inject_pending_event(vcpu); > > This can use a newer vcpu->arch.nmi_pending. > We can do inject_pending_event(vcpu, nmi_pending); but is this a problem that newer version of vcpu->arch.nmi_pending will be used? If NMI can be injected it will - no problem. It it can't it will be delayed till the next guest entry - no problem NMI is async anyway. > > > > /* enable NMI/IRQ window open exits if needed */ > >- if (vcpu->arch.nmi_pending) > >+ if (nmi_pending) > > kvm_x86_ops->enable_nmi_window(vcpu); > > else if (kvm_cpu_has_interrupt(vcpu) || req_int_win) > > kvm_x86_ops->enable_irq_window(vcpu); > > -- > error compiling committee.c: too many arguments to function -- 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
