Thread (141 messages) 141 messages, 6 authors, 2021-12-02
STALE1642d

[PATCH v2 42/43] KVM: VMX: Fold fallback path into triggering posted IRQ helper

From: Sean Christopherson <seanjc@google.com>
Date: 2021-10-09 02:17:46
Also in: kvm, kvm-riscv, kvmarm, linux-arm-kernel, linux-riscv, lkml
Subsystem: kernel virtual machine for x86 (kvm/x86), the rest, x86 architecture (32-bit and 64-bit) · Maintainers: Sean Christopherson, Paolo Bonzini, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen

Move the fallback "wake_up" path into the helper to trigger posted
interrupt helper now that the nested and non-nested paths are identical.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/kvm/vmx/vmx.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index f505fee3cf5c..b0d97cf18c34 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -3927,7 +3927,7 @@ static void vmx_msr_filter_changed(struct kvm_vcpu *vcpu)
 	pt_update_intercept_for_msr(vcpu);
 }
 
-static inline bool kvm_vcpu_trigger_posted_interrupt(struct kvm_vcpu *vcpu,
+static inline void kvm_vcpu_trigger_posted_interrupt(struct kvm_vcpu *vcpu,
 						     int pi_vec)
 {
 #ifdef CONFIG_SMP
@@ -3958,10 +3958,15 @@ static inline bool kvm_vcpu_trigger_posted_interrupt(struct kvm_vcpu *vcpu,
 		 */
 
 		apic->send_IPI_mask(get_cpu_mask(vcpu->cpu), pi_vec);
-		return true;
+		return;
 	}
 #endif
-	return false;
+	/*
+	 * The vCPU isn't in the guest; wake the vCPU in case it is blocking,
+	 * otherwise do nothing as KVM will grab the highest priority pending
+	 * IRQ via ->sync_pir_to_irr() in vcpu_enter_guest().
+	 */
+	kvm_vcpu_wake_up(vcpu);
 }
 
 static int vmx_deliver_nested_posted_interrupt(struct kvm_vcpu *vcpu,
@@ -3984,8 +3989,7 @@ static int vmx_deliver_nested_posted_interrupt(struct kvm_vcpu *vcpu,
 		 */
 		kvm_make_request(KVM_REQ_EVENT, vcpu);
 		/* the PIR and ON have been set by L1. */
-		if (!kvm_vcpu_trigger_posted_interrupt(vcpu, POSTED_INTR_NESTED_VECTOR))
-			kvm_vcpu_wake_up(vcpu);
+		kvm_vcpu_trigger_posted_interrupt(vcpu, POSTED_INTR_NESTED_VECTOR);
 		return 0;
 	}
 	return -1;
@@ -4022,9 +4026,7 @@ static int vmx_deliver_posted_interrupt(struct kvm_vcpu *vcpu, int vector)
 	 * guaranteed to see PID.ON=1 and sync the PIR to IRR if triggering a
 	 * posted interrupt "fails" because vcpu->mode != IN_GUEST_MODE.
 	 */
-	if (!kvm_vcpu_trigger_posted_interrupt(vcpu, POSTED_INTR_VECTOR))
-		kvm_vcpu_wake_up(vcpu);
-
+	kvm_vcpu_trigger_posted_interrupt(vcpu, POSTED_INTR_VECTOR);
 	return 0;
 }
 
-- 
2.33.0.882.g93a45727a2-goog
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