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Subject[PATCH 4/5] KVM: x86: remove unnecessary sync_pir_to_irr
Date
Synchronizing PIR to IRR is not needed in most callers of
apic_find_highest_irr. Move it to the one place that matters,
interrupt acknowledgement.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kvm/lapic.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index c0928173b2e3..255b5e1658f6 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -382,8 +382,6 @@ static inline int apic_find_highest_irr(struct kvm_lapic *apic)
if (!apic->irr_pending)
return -1;

- if (apic->vcpu->arch.apicv_active)
- kvm_x86_ops->sync_pir_to_irr(apic->vcpu);
result = apic_search_irr(apic);
ASSERT(result == -1 || result >= 16);

@@ -1973,6 +1971,9 @@ int kvm_apic_has_interrupt(struct kvm_vcpu *vcpu)
return -1;

apic_update_ppr(apic);
+
+ if (apic->vcpu->arch.apicv_active)
+ kvm_x86_ops->sync_pir_to_irr(apic->vcpu);
highest_irr = apic_find_highest_irr(apic);
if ((highest_irr == -1) ||
((highest_irr & 0xF0) <= kvm_lapic_get_reg(apic, APIC_PROCPRI)))
@@ -2206,6 +2207,11 @@ void kvm_lapic_sync_to_vapic(struct kvm_vcpu *vcpu)
if (!test_bit(KVM_APIC_CHECK_VAPIC, &vcpu->arch.apic_attention))
return;

+ /* We don't get here when APICv is active, since that blocks
+ * TPR access vmexits.
+ */
+ WARN_ON_ONCE(vcpu->arch.apicv_active);
+
tpr = kvm_lapic_get_reg(apic, APIC_TASKPRI) & 0xff;
max_irr = apic_find_highest_irr(apic);
if (max_irr < 0)
--
1.8.3.1

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