@@ -2924,14 +2924,13 @@ void kvm_inject_apic_timer_irqs(struct kvm_vcpu *vcpu)
}
}
-int kvm_get_apic_interrupt(struct kvm_vcpu *vcpu)
+void kvm_apic_ack_interrupt(struct kvm_vcpu *vcpu, int vector)
{
- int vector = kvm_apic_has_interrupt(vcpu);
struct kvm_lapic *apic = vcpu->arch.apic;
u32 ppr;
- if (vector == -1)
- return -1;
+ if (WARN_ON_ONCE(vector < 0 || !apic))
+ return;
/*
* We get here even with APIC virtualization enabled, if doing
@@ -2959,6 +2958,16 @@ int kvm_get_apic_interrupt(struct kvm_vcpu *vcpu)
__apic_update_ppr(apic, &ppr);
}
+}
+EXPORT_SYMBOL_GPL(kvm_apic_ack_interrupt);
+
+int kvm_get_apic_interrupt(struct kvm_vcpu *vcpu)
+{
+ int vector = kvm_apic_has_interrupt(vcpu);
+
+ if (vector != -1)
+ kvm_apic_ack_interrupt(vcpu, vector);
+
return vector;
}
@@ -88,6 +88,7 @@ int kvm_create_lapic(struct kvm_vcpu *vcpu);
void kvm_free_lapic(struct kvm_vcpu *vcpu);
int kvm_apic_has_interrupt(struct kvm_vcpu *vcpu);
+void kvm_apic_ack_interrupt(struct kvm_vcpu *vcpu, int vector);
int kvm_apic_accept_pic_intr(struct kvm_vcpu *vcpu);
int kvm_get_apic_interrupt(struct kvm_vcpu *vcpu);
int kvm_apic_accept_events(struct kvm_vcpu *vcpu);
Split the "ack" phase, i.e. the movement of an interrupt from IRR=>ISR, out of kvm_get_apic_interrupt() and into a separate API so that nested VMX can acknowledge a specific interrupt _after_ emulating a VM-Exit from L2 to L1. To correctly emulate nested posted interrupts while APICv is active, KVM must: 1. find the highest pending interrupt. 2. check if that IRQ is L2's notification vector 3. emulate VM-Exit if the IRQ is NOT the notification vector 4. ACK the IRQ in L1 _after_ VM-Exit When APICv is active, the process of moving the IRQ from the IRR to the ISR also requires a VMWRITE to update vmcs01.GUEST_INTERRUPT_STATUS.SVI, and so acknowledging the interrupt before switching to vmcs01 would result in marking the IRQ as in-service in the wrong VMCS. KVM currently fudges around this issue by doing kvm_get_apic_interrupt() smack dab in the middle of emulating VM-Exit, but that hack doesn't play nice with nested posted interrupts, as notification vector IRQs don't trigger a VM-Exit in the first place. Cc: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Sean Christopherson <seanjc@google.com> --- arch/x86/kvm/lapic.c | 17 +++++++++++++---- arch/x86/kvm/lapic.h | 1 + 2 files changed, 14 insertions(+), 4 deletions(-)