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Date: Fri, 14 Oct 2016 20:21:28 +0200
From: Paolo Bonzini <pbonzini@...hat.com>
To: linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc: rkrcmar@...hat.com, yang.zhang.wz@...il.com, feng.wu@...el.com,
mst@...hat.com
Subject: [PATCH 2/5] KVM: x86: do not scan IRR twice on APICv vmentry
Calling apic_find_highest_irr results in IRR being scanned twice,
once in vmx_sync_pir_from_irr and once in apic_search_irr. Change
sync_pir_from_irr to do the RVI write and kvm_apic_update_irr to
compute the new RVI on the fly.
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 | 24 +++++++++++++-----------
arch/x86/kvm/x86.c | 3 +--
4 files changed, 33 insertions(+), 23 deletions(-)
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 63a442aefc12..a24492a88643 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -317,7 +317,7 @@ 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;
@@ -337,27 +337,36 @@ 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 f60d01c29d51..fc72828c3782 100644
--- a/arch/x86/kvm/lapic.h
+++ b/arch/x86/kvm/lapic.h
@@ -70,8 +70,8 @@ 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);
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 7c79d6c6b6ed..c985ec8736d3 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -4856,17 +4856,6 @@ 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);
- 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.
@@ -8613,6 +8602,19 @@ 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);
+ int max_irr;
+
+ if (!pi_test_on(&vmx->pi_desc))
+ return;
+
+ pi_clear_on(&vmx->pi_desc);
+ max_irr = kvm_apic_update_irr(vcpu, vmx->pi_desc.pir);
+ vmx_hwapic_irr_update(vcpu, max_irr);
+}
+
static void vmx_load_eoi_exitmap(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap)
{
if (!kvm_vcpu_apicv_active(vcpu))
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 3ee8a91a78c3..3d29be9d9db4 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6611,8 +6611,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
* virtual interrupt delivery.
*/
if (vcpu->arch.apicv_active)
- kvm_x86_ops->hwapic_irr_update(vcpu,
- kvm_lapic_find_highest_irr(vcpu));
+ kvm_x86_ops->sync_pir_to_irr(vcpu);
}
if (kvm_check_request(KVM_REQ_EVENT, vcpu) || req_int_win) {
--
1.8.3.1
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