[PATCH v5 2/6] LoongArch: KVM: Check msgint feature in interrupt post

[Bibo Mao]

Interrupt AVEC is valid only if VM has msgint feature, and this feature
is checked in interrupt handling. Since interrupt handling is executing
in VM context switch, and it is hot path, here move the feature checking
in interrupt post rather than interrupt handling.

Signed-off-by: Bibo Mao <maobibo@xxxxxxxxxxx>
---
 arch/loongarch/kvm/interrupt.c |  5 -----
 arch/loongarch/kvm/vcpu.c      | 14 +++++++++-----
 2 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/arch/loongarch/kvm/interrupt.c b/arch/loongarch/kvm/interrupt.c
index a18c60dffbba..48dd56aa4dc5 100644
--- a/arch/loongarch/kvm/interrupt.c
+++ b/arch/loongarch/kvm/interrupt.c
@@ -36,8 +36,6 @@ static int kvm_irq_deliver(struct kvm_vcpu *vcpu, unsigned int priority)
 
 	switch (priority) {
 	case INT_AVEC:
-		if (!kvm_guest_has_msgint(&vcpu->arch))
-			break;
 		dmsintc_inject_irq(vcpu);
 		fallthrough;
 	case INT_TI:
@@ -75,9 +73,6 @@ static int kvm_irq_clear(struct kvm_vcpu *vcpu, unsigned int priority)
 
 	switch (priority) {
 	case INT_AVEC:
-		if (!kvm_guest_has_msgint(&vcpu->arch))
-			break;
-		fallthrough;
 	case INT_TI:
 	case INT_IPI:
 	case INT_SWI0:
diff --git a/arch/loongarch/kvm/vcpu.c b/arch/loongarch/kvm/vcpu.c
index df5be9b265e8..ebd432da3ca4 100644
--- a/arch/loongarch/kvm/vcpu.c
+++ b/arch/loongarch/kvm/vcpu.c
@@ -1493,14 +1493,18 @@ int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu, struct kvm_interrupt *irq)
 	if (vector >= EXCCODE_INT_NUM)
 		return -EINVAL;
 
-	if (intr > 0)
+	if (!kvm_guest_has_msgint(&vcpu->arch) && (vector == INT_AVEC))
+		return -EINVAL;
+
+	/*
+	 * Clear irq with INT_SWI0 (which is 0) is missing from SW side
+	 * INT_SWI0 is cleared by guest kernel with the similar instruction
+	 * clear_csr_estat(1 << INT_SWI0)
+	 */
+	if (intr >= 0)
 		kvm_queue_irq(vcpu, intr);
 	else if (intr < 0)
 		kvm_dequeue_irq(vcpu, -intr);
-	else {
-		kvm_err("%s: invalid interrupt ioctl %d\n", __func__, irq->irq);
-		return -EINVAL;
-	}
 
 	kvm_vcpu_kick(vcpu);
 
-- 
2.39.3