linux-kernel - [PATCH 3/6] KVM: x86: preparatory changes for APICv cleanups

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Date:   Mon, 19 Dec 2016 17:17:09 +0100
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Subject: [PATCH 3/6] KVM: x86: preparatory changes for APICv cleanups

Add return value to __kvm_apic_update_irr/kvm_apic_update_irr.
Move vmx_sync_pir_to_irr around.

Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
---
 arch/x86/kvm/lapic.c | 25 +++++++++++++++++--------
 arch/x86/kvm/lapic.h |  4 ++--
 arch/x86/kvm/vmx.c   | 32 ++++++++++++++++----------------
 3 files changed, 35 insertions(+), 26 deletions(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 5fa546e27b7e..4c76c602576e 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -341,7 +341,7 @@ static int find_highest_vector(void *bitmap)
 	     vec >= 0; vec -= APIC_VECTORS_PER_REG) {
 		reg = bitmap + REG_POS(vec);
 		if (*reg)
-			return fls(*reg) - 1 + vec;
+			return __fls(*reg) + vec;
 	}
 
 	return -1;
@@ -361,27 +361,36 @@ static u8 count_vectors(void *bitmap)
 	return count;
 }
 
-void __kvm_apic_update_irr(u32 *pir, void *regs)
+int __kvm_apic_update_irr(u32 *pir, void *regs)
 {
-	u32 i, pir_val;
+	u32 i, vec;
+	u32 pir_val, irr_val;
+	int max_irr = -1;
 
-	for (i = 0; i <= 7; i++) {
+	for (i = vec = 0; i <= 7; i++, vec += 32) {
 		pir_val = READ_ONCE(pir[i]);
+		irr_val = *((u32 *)(regs + APIC_IRR + i * 0x10));
 		if (pir_val) {
-			pir_val = xchg(&pir[i], 0);
-			*((u32 *)(regs + APIC_IRR + i * 0x10)) |= pir_val;
+			irr_val |= xchg(&pir[i], 0);
+			*((u32 *)(regs + APIC_IRR + i * 0x10)) = irr_val;
 		}
+		if (irr_val)
+			max_irr = __fls(irr_val) + vec;
 	}
+
+	return max_irr;
 }
 EXPORT_SYMBOL_GPL(__kvm_apic_update_irr);
 
-void kvm_apic_update_irr(struct kvm_vcpu *vcpu, u32 *pir)
+int kvm_apic_update_irr(struct kvm_vcpu *vcpu, u32 *pir)
 {
 	struct kvm_lapic *apic = vcpu->arch.apic;
+	int max_irr;
 
-	__kvm_apic_update_irr(pir, apic->regs);
+	max_irr = __kvm_apic_update_irr(pir, apic->regs);
 
 	kvm_make_request(KVM_REQ_EVENT, vcpu);
+	return max_irr;
 }
 EXPORT_SYMBOL_GPL(kvm_apic_update_irr);
 
diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
index 5b5b1ba644cb..8aa54fdc43d1 100644
--- a/arch/x86/kvm/lapic.h
+++ b/arch/x86/kvm/lapic.h
@@ -71,8 +71,8 @@ int kvm_lapic_reg_read(struct kvm_lapic *apic, u32 offset, int len,
 bool kvm_apic_match_dest(struct kvm_vcpu *vcpu, struct kvm_lapic *source,
 			   int short_hand, unsigned int dest, int dest_mode);
 
-void __kvm_apic_update_irr(u32 *pir, void *regs);
-void kvm_apic_update_irr(struct kvm_vcpu *vcpu, u32 *pir);
+int __kvm_apic_update_irr(u32 *pir, void *regs);
+int 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);
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 661956caf162..eab8ab023705 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5068,22 +5068,6 @@ static void vmx_deliver_posted_interrupt(struct kvm_vcpu *vcpu, int vector)
 		kvm_vcpu_kick(vcpu);
 }
 
-static void vmx_sync_pir_to_irr(struct kvm_vcpu *vcpu)
-{
-	struct vcpu_vmx *vmx = to_vmx(vcpu);
-
-	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);
-}
-
 /*
  * Set up the vmcs's constant host-state fields, i.e., host-state fields that
  * will not change in the lifetime of the guest.
@@ -8750,6 +8734,22 @@ static void vmx_hwapic_irr_update(struct kvm_vcpu *vcpu, int max_irr)
 	}
 }
 
+static void vmx_sync_pir_to_irr(struct kvm_vcpu *vcpu)
+{
+	struct vcpu_vmx *vmx = to_vmx(vcpu);
+
+	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);
+}
+
 static void vmx_load_eoi_exitmap(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap)
 {
 	if (!kvm_vcpu_apicv_active(vcpu))
-- 
1.8.3.1