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

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Date:   Mon, 19 Dec 2016 10:47:15 +0100
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     rkrcmar@...hat.com, rkagan@...tuozzo.com, dplotnikov@...tuozzo.com
Subject: [PATCH 3/6] KVM: vmx: speed up TPR below threshold vmexits

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@...hat.com>
---
 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