[PATCH v6 05/18] KVM: arm64: Support SDEI_EVENT_{ENABLE, DISABLE}

[Gavin Shan <gshan@redhat.com>]

This supports SDEI_EVENT_{ENABLE, DISABLE} hypercall. After the
event is registered, it won't be raised and delivered to guest
until it's enabled. On other hand, the event won't be delivered
to guest if it's disabled.

Signed-off-by: Gavin Shan <gshan@redhat.com>
---
 arch/arm64/kvm/sdei.c | 45 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/arch/arm64/kvm/sdei.c b/arch/arm64/kvm/sdei.c
index 89c1b231cb60..941263578b30 100644
--- a/arch/arm64/kvm/sdei.c
+++ b/arch/arm64/kvm/sdei.c
@@ -101,6 +101,45 @@ static unsigned long hypercall_register(struct kvm_vcpu *vcpu)
 	return ret;
 }
 
+static unsigned long hypercall_enable(struct kvm_vcpu *vcpu, bool enable)
+{
+	struct kvm_sdei_vcpu *vsdei = vcpu->arch.sdei;
+	struct kvm_sdei_event *event;
+	unsigned long num = smccc_get_arg(vcpu, 1);
+	unsigned long ret = SDEI_SUCCESS;
+
+	if (!kvm_sdei_is_supported(num)) {
+		ret = SDEI_INVALID_PARAMETERS;
+		goto out;
+	}
+
+	spin_lock(&vsdei->lock);
+
+	/* Check if the event exists */
+	event = find_event(vcpu, num);
+	if (!event) {
+		ret = SDEI_DENIED;
+		goto unlock;
+	}
+
+	/* Check the event state */
+	if (!kvm_sdei_is_registered(event) ||
+	    kvm_sdei_is_unregister_pending(event)) {
+		ret = SDEI_DENIED;
+		goto unlock;
+	}
+
+	if (enable)
+		kvm_sdei_set_enabled(event);
+	else
+		kvm_sdei_clear_enabled(event);
+
+unlock:
+	spin_unlock(&vsdei->lock);
+out:
+	return ret;
+}
+
 int kvm_sdei_call(struct kvm_vcpu *vcpu)
 {
 	struct kvm_sdei_vcpu *vsdei = vcpu->arch.sdei;
@@ -125,6 +164,12 @@ int kvm_sdei_call(struct kvm_vcpu *vcpu)
 	case SDEI_1_0_FN_SDEI_EVENT_REGISTER:
 		ret = hypercall_register(vcpu);
 		break;
+	case SDEI_1_0_FN_SDEI_EVENT_ENABLE:
+		ret = hypercall_enable(vcpu, true);
+		break;
+	case SDEI_1_0_FN_SDEI_EVENT_DISABLE:
+		ret = hypercall_enable(vcpu, false);
+		break;
 	default:
 		ret = SDEI_NOT_SUPPORTED;
 	}
-- 
2.23.0