[PATCH 3/6] KVM: vmx: speed up TPR below threshold vmexits

From: Paolo Bonzini
Date: Mon Dec 19 2016 - 04:47:35 EST


Since we're already in VCPU context, all we have to do here is recompute
the PPR value. That will in turn generate a KVM_REQ_EVENT if necessary.

Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/kvm/lapic.c | 6 ++++++
arch/x86/kvm/lapic.h | 1 +
arch/x86/kvm/vmx.c | 2 +-
3 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 70c7428b7a57..ae59e655cd6d 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -595,6 +595,12 @@ static void apic_update_ppr(struct kvm_lapic *apic)
}
}

+void kvm_apic_update_ppr(struct kvm_vcpu *vcpu)
+{
+ apic_update_ppr(vcpu->arch.apic);
+}
+EXPORT_SYMBOL_GPL(kvm_apic_update_ppr);
+
static void apic_set_tpr(struct kvm_lapic *apic, u32 tpr)
{
kvm_lapic_set_reg(apic, APIC_TASKPRI, tpr);
diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
index cb16e6fd2330..5b5b1ba644cb 100644
--- a/arch/x86/kvm/lapic.h
+++ b/arch/x86/kvm/lapic.h
@@ -73,6 +73,7 @@ bool kvm_apic_match_dest(struct kvm_vcpu *vcpu, struct kvm_lapic *source,

void __kvm_apic_update_irr(u32 *pir, void *regs);
void kvm_apic_update_irr(struct kvm_vcpu *vcpu, u32 *pir);
+void kvm_apic_update_ppr(struct kvm_vcpu *vcpu);
int kvm_apic_set_irq(struct kvm_vcpu *vcpu, struct kvm_lapic_irq *irq,
struct dest_map *dest_map);
int kvm_apic_local_deliver(struct kvm_lapic *apic, int lvt_type);
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 24db5fb6f575..5fb54e3de061 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -6158,7 +6158,7 @@ static int handle_wrmsr(struct kvm_vcpu *vcpu)

static int handle_tpr_below_threshold(struct kvm_vcpu *vcpu)
{
- kvm_make_request(KVM_REQ_EVENT, vcpu);
+ kvm_apic_update_ppr(vcpu);
return 1;
}

--
1.8.3.1