[3/4] fixes a bug where legacy NMI watchdog doesn't receive NMIs if a CPU that handles PIT interrupts hangs with masked interrupts. Remaining patches try to make the code nicer where necessary. ([1/4] makes you think that it fixes a bug, but that would be fixed by skipping the path in [3/4].) [3/4] only changes the discard policy. A change that allows legacy NMI watchdog with the reinject policy is below, but conscience doesn't allow me to sign it off. # diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c @@ -274,6 +274,10 @@ static void pit_do_work(struct kthread_work *work) int i; struct kvm_kpit_state *ps = &pit->pit_state; + if (atomic_read(&kvm->arch.vapics_in_nmi_mode) > 0) + kvm_for_each_vcpu(i, vcpu, kvm) + kvm_apic_nmi_wd_deliver(vcpu); + if (ps->reinject && !atomic_xchg(&ps->irq_ack, 0)) return; @@ -289,9 +293,6 @@ static void pit_do_work(struct kthread_work *work) * VCPUs and only when LVT0 is in NMI mode. The interrupt can * also be simultaneously delivered through PIC and IOAPIC. */ - if (atomic_read(&kvm->arch.vapics_in_nmi_mode) > 0) - kvm_for_each_vcpu(i, vcpu, kvm) - kvm_apic_nmi_wd_deliver(vcpu); } static enum hrtimer_restart pit_timer_fn(struct hrtimer *data) Radim Krčmář (4): KVM: x86: fix interrupt dropping race in PIT KVM: x86: refactor PIT state inject_lock KVM: x86: change PIT discard tick policy KVM: x86: remove notifiers from PIT discard policy arch/x86/kvm/i8254.c | 122 ++++++++++++++++++++++++++------------------------- arch/x86/kvm/i8254.h | 4 +- arch/x86/kvm/x86.c | 6 +-- 3 files changed, 67 insertions(+), 65 deletions(-) -- 2.7.0 -- 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
