From 6e24a6eff4571002cd48b99a2b92dc829ce39cb9 Mon Sep 17 00:00:00 2001 From: Marcelo Tosatti Date: Mon, 14 Dec 2009 17:37:35 -0200 Subject: KVM: LAPIC: make sure IRR bitmap is scanned after vm load The vcpus are initialized with irr_pending set to false, but loading the LAPIC registers with pending IRR fails to reset the irr_pending variable. Cc: stable@kernel.org Signed-off-by: Marcelo Tosatti Signed-off-by: Avi Kivity --- arch/x86/kvm/lapic.c | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/x86/kvm/lapic.c') diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index cd60c0bd1b32..3063a0c4858b 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -1150,6 +1150,7 @@ void kvm_apic_post_state_restore(struct kvm_vcpu *vcpu) hrtimer_cancel(&apic->lapic_timer.timer); update_divide_count(apic); start_apic_timer(apic); + apic->irr_pending = true; } void __kvm_migrate_apic_timer(struct kvm_vcpu *vcpu) -- cgit v1.2.3 From a5d36f82c4f3e852b61fdf1fee13463c8aa91b90 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Tue, 29 Dec 2009 12:42:16 +0200 Subject: KVM: Fix race between APIC TMR and IRR When we queue an interrupt to the local apic, we set the IRR before the TMR. The vcpu can pick up the IRR and inject the interrupt before setting the TMR, and perhaps even EOI it, causing incorrect behaviour. The race is really insignificant since it can only occur on the first interrupt (usually following interrupts will not change TMR), but it's better closed than open. Fixed by reordering setting the TMR vs IRR. Cc: stable@kernel.org Signed-off-by: Avi Kivity Signed-off-by: Marcelo Tosatti --- arch/x86/kvm/lapic.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) (limited to 'arch/x86/kvm/lapic.c') diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 3063a0c4858b..ba8c045da782 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -373,6 +373,12 @@ static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode, if (unlikely(!apic_enabled(apic))) break; + if (trig_mode) { + apic_debug("level trig mode for vector %d", vector); + apic_set_vector(vector, apic->regs + APIC_TMR); + } else + apic_clear_vector(vector, apic->regs + APIC_TMR); + result = !apic_test_and_set_irr(vector, apic); trace_kvm_apic_accept_irq(vcpu->vcpu_id, delivery_mode, trig_mode, vector, !result); @@ -383,11 +389,6 @@ static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode, break; } - if (trig_mode) { - apic_debug("level trig mode for vector %d", vector); - apic_set_vector(vector, apic->regs + APIC_TMR); - } else - apic_clear_vector(vector, apic->regs + APIC_TMR); kvm_vcpu_kick(vcpu); break; -- cgit v1.2.3