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From: Paolo Bonzini <pbonzini@redhat.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Subject: [PATCH 5/6] KVM: x86: do not scan IRR twice on APICv vmentry
Date: Mon, 19 Dec 2016 17:17:11 +0100	[thread overview]
Message-ID: <1482164232-130035-6-git-send-email-pbonzini@redhat.com> (raw)
In-Reply-To: <1482164232-130035-1-git-send-email-pbonzini@redhat.com>

Calls to apic_find_highest_irr are scanning IRR twice, once
in vmx_sync_pir_from_irr and once in apic_search_irr.  Change
sync_pir_from_irr to get the new maximum IRR from kvm_apic_update_irr;
now that it does the computation, it can also do the RVI write.

In order to avoid complications in svm.c, make the callback optional.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/include/asm/kvm_host.h |  2 +-
 arch/x86/kvm/lapic.c            |  8 +++++---
 arch/x86/kvm/svm.c              |  6 ------
 arch/x86/kvm/vmx.c              | 30 ++++++++++++++++++------------
 arch/x86/kvm/x86.c              |  7 ++-----
 5 files changed, 26 insertions(+), 27 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 4b820b2b6bfa..b182b0ee0997 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -965,7 +965,7 @@ struct kvm_x86_ops {
 	void (*set_virtual_x2apic_mode)(struct kvm_vcpu *vcpu, bool set);
 	void (*set_apic_access_page_addr)(struct kvm_vcpu *vcpu, hpa_t hpa);
 	void (*deliver_posted_interrupt)(struct kvm_vcpu *vcpu, int vector);
-	void (*sync_pir_to_irr)(struct kvm_vcpu *vcpu);
+	int (*sync_pir_to_irr)(struct kvm_vcpu *vcpu);
 	int (*set_tss_addr)(struct kvm *kvm, unsigned int addr);
 	int (*get_tdp_level)(void);
 	u64 (*get_mt_mask)(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio);
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 4af0e105caad..f644dd1dbe71 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -515,6 +515,7 @@ int kvm_lapic_find_highest_irr(struct kvm_vcpu *vcpu)
 	 */
 	return apic_find_highest_irr(vcpu->arch.apic);
 }
+EXPORT_SYMBOL_GPL(kvm_lapic_find_highest_irr);
 
 static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
 			     int vector, int level, int trig_mode,
@@ -580,9 +581,10 @@ static void pv_eoi_clr_pending(struct kvm_vcpu *vcpu)
 static int apic_has_interrupt_for_ppr(struct kvm_lapic *apic, u32 ppr)
 {
 	int highest_irr;
-	if (apic->vcpu->arch.apicv_active)
-		kvm_x86_ops->sync_pir_to_irr(apic->vcpu);
-	highest_irr = apic_find_highest_irr(apic);
+	if (kvm_x86_ops->sync_pir_to_irr)
+		highest_irr = kvm_x86_ops->sync_pir_to_irr(apic->vcpu);
+	else
+		highest_irr = apic_find_highest_irr(apic);
 	if (highest_irr == -1 || (highest_irr & 0xF0) <= ppr)
 		return -1;
 	return highest_irr;
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 08a4d3ab3455..dc4b8834caee 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -4357,11 +4357,6 @@ static void svm_load_eoi_exitmap(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap)
 	return;
 }
 
-static void svm_sync_pir_to_irr(struct kvm_vcpu *vcpu)
-{
-	return;
-}
-
 static void svm_deliver_avic_intr(struct kvm_vcpu *vcpu, int vec)
 {
 	kvm_lapic_set_irr(vec, vcpu->arch.apic);
@@ -5371,7 +5366,6 @@ static inline void avic_post_state_restore(struct kvm_vcpu *vcpu)
 	.get_enable_apicv = svm_get_enable_apicv,
 	.refresh_apicv_exec_ctrl = svm_refresh_apicv_exec_ctrl,
 	.load_eoi_exitmap = svm_load_eoi_exitmap,
-	.sync_pir_to_irr = svm_sync_pir_to_irr,
 	.hwapic_irr_update = svm_hwapic_irr_update,
 	.hwapic_isr_update = svm_hwapic_isr_update,
 	.apicv_post_state_restore = avic_post_state_restore,
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index eab8ab023705..27e40b180242 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -6660,8 +6660,10 @@ static __init int hardware_setup(void)
 	if (!cpu_has_vmx_ple())
 		ple_gap = 0;
 
-	if (!cpu_has_vmx_apicv())
+	if (!cpu_has_vmx_apicv()) {
 		enable_apicv = 0;
+		kvm_x86_ops->sync_pir_to_irr = NULL;
+	}
 
 	if (cpu_has_vmx_tsc_scaling()) {
 		kvm_has_tsc_control = true;
@@ -8734,20 +8736,24 @@ static void vmx_hwapic_irr_update(struct kvm_vcpu *vcpu, int max_irr)
 	}
 }
 
-static void vmx_sync_pir_to_irr(struct kvm_vcpu *vcpu)
+static int vmx_sync_pir_to_irr(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
+	int max_irr;
 
-	if (!pi_test_on(&vmx->pi_desc))
-		return;
-
-	pi_clear_on(&vmx->pi_desc);
-	/*
-	 * IOMMU can write to PIR.ON, so the barrier matters even on UP.
-	 * But on x86 this is just a compiler barrier anyway.
-	 */
-	smp_mb__after_atomic();
-	kvm_apic_update_irr(vcpu, vmx->pi_desc.pir);
+	if (vcpu->arch.apicv_active && pi_test_on(&vmx->pi_desc)) {
+		pi_clear_on(&vmx->pi_desc);
+		/*
+		 * IOMMU can write to PIR.ON, so the barrier matters even on UP.
+		 * But on x86 this is just a compiler barrier anyway.
+		 */
+		smp_mb__after_atomic();
+		max_irr = kvm_apic_update_irr(vcpu, vmx->pi_desc.pir);
+	} else {
+		max_irr = kvm_lapic_find_highest_irr(vcpu);
+	}
+	vmx_hwapic_irr_update(vcpu, max_irr);
+	return max_irr;
 }
 
 static void vmx_load_eoi_exitmap(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 641e9309ee08..c666414adc1d 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2871,7 +2871,7 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
 static int kvm_vcpu_ioctl_get_lapic(struct kvm_vcpu *vcpu,
 				    struct kvm_lapic_state *s)
 {
-	if (vcpu->arch.apicv_active)
+	if (kvm_x86_ops->sync_pir_to_irr)
 		kvm_x86_ops->sync_pir_to_irr(vcpu);
 
 	return kvm_apic_get_state(vcpu, s);
@@ -6719,11 +6719,8 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
 		 * Update architecture specific hints for APIC
 		 * virtual interrupt delivery.
 		 */
-		if (vcpu->arch.apicv_active) {
+		if (kvm_x86_ops->sync_pir_to_irr)
 			kvm_x86_ops->sync_pir_to_irr(vcpu);
-			kvm_x86_ops->hwapic_irr_update(vcpu,
-				kvm_lapic_find_highest_irr(vcpu));
-		}
 	}
 
 	if (kvm_check_request(KVM_REQ_EVENT, vcpu) || req_int_win) {
-- 
1.8.3.1

  parent reply	other threads:[~2016-12-19 16:17 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-12-19 16:17 [PATCH v2 0/6] KVM: x86: cleanup and speedup for APICv Paolo Bonzini
2016-12-19 16:17 ` [PATCH 1/6] KVM: vmx: clear pending interrupts on KVM_SET_LAPIC Paolo Bonzini
2017-02-07 17:42   ` Radim Krčmář
2016-12-19 16:17 ` [PATCH 2/6] kvm: nVMX: move nested events check to kvm_vcpu_running Paolo Bonzini
2017-02-07 18:16   ` Radim Krčmář
2016-12-19 16:17 ` [PATCH 3/6] KVM: x86: preparatory changes for APICv cleanups Paolo Bonzini
2017-02-07 18:20   ` Radim Krčmář
2016-12-19 16:17 ` [PATCH 4/6] KVM: vmx: move sync_pir_to_irr from apic_find_highest_irr to callers Paolo Bonzini
2016-12-19 16:17 ` Paolo Bonzini [this message]
2017-02-07 20:19   ` [PATCH 5/6] KVM: x86: do not scan IRR twice on APICv vmentry Radim Krčmář
2017-02-07 21:49     ` Radim Krčmář
2017-02-08 14:10     ` Paolo Bonzini
2017-02-08 14:24       ` Radim Krčmář
2016-12-19 16:17 ` [PATCH 6/6] kvm: x86: do not use KVM_REQ_EVENT for APICv interrupt injection Paolo Bonzini
2017-02-07 19:58   ` Radim Krčmář
2017-02-08 16:23     ` Paolo Bonzini
2017-02-09 15:11       ` Radim Krčmář
2017-03-09  1:23   ` Wanpeng Li
2017-03-09  9:40     ` Wanpeng Li
2017-03-09 10:03       ` Paolo Bonzini
2017-02-07 17:23 ` [PATCH v2 0/6] KVM: x86: cleanup and speedup for APICv Paolo Bonzini
2017-02-07 21:52   ` Radim Krčmář
2017-02-08 10:04     ` Paolo Bonzini
2017-02-08 13:33       ` Radim Krčmář
2017-02-08 15:01         ` Paolo Bonzini

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