[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
