[PATCH v5 05/22] KVM: arm64: Support SDEI_EVENT_{ENABLE, DISABLE} hypercall

[Gavin Shan]

This supports SDEI_EVENT_{ENABLE, DISABLE} hypercall. After SDEI
event is registered by guest, it won't be delivered to the guest
until it's enabled. For unregistration pending event, we can't
enable or disable it as the registered event is going to be
destroyed after current event is handled.

Signed-off-by: Gavin Shan <gshan@xxxxxxxxxx>
---
 arch/arm64/kvm/sdei.c | 49 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/arch/arm64/kvm/sdei.c b/arch/arm64/kvm/sdei.c
index 2458dc666445..4ab58f264992 100644
--- a/arch/arm64/kvm/sdei.c
+++ b/arch/arm64/kvm/sdei.c
@@ -252,6 +252,51 @@ static unsigned long hypercall_register(struct kvm_vcpu *vcpu)
 	return ret;
 }
 
+static unsigned long hypercall_enable(struct kvm_vcpu *vcpu, bool enable)
+{
+	struct kvm *kvm = vcpu->kvm;
+	struct kvm_sdei_kvm *ksdei = kvm->arch.sdei;
+	struct kvm_sdei_exposed_event *exposed_event;
+	struct kvm_sdei_registered_event *registered_event;
+	unsigned long event_num = smccc_get_arg1(vcpu);
+	int index;
+	unsigned long ret = SDEI_SUCCESS;
+
+	if (!kvm_sdei_is_supported(event_num)) {
+		ret = SDEI_INVALID_PARAMETERS;
+		goto out;
+	}
+
+	spin_lock(&ksdei->lock);
+
+	/* Check if the registered event exists */
+	registered_event = find_registered_event(kvm, event_num);
+	if (!registered_event) {
+		ret = SDEI_DENIED;
+		goto unlock;
+	}
+
+	/* Check if the event is registered and pending for unregistration */
+	exposed_event = registered_event->exposed_event;
+	index = kvm_sdei_vcpu_index(vcpu, exposed_event);
+	if (!kvm_sdei_is_registered(registered_event, index) ||
+	    kvm_sdei_is_unregister_pending(registered_event, index)) {
+		ret = SDEI_DENIED;
+		goto unlock;
+	}
+
+	/* Update the enablement state */
+	if (enable)
+		kvm_sdei_set_enabled(registered_event, index);
+	else
+		kvm_sdei_clear_enabled(registered_event, index);
+
+unlock:
+	spin_unlock(&ksdei->lock);
+out:
+	return ret;
+}
+
 int kvm_sdei_hypercall(struct kvm_vcpu *vcpu)
 {
 	struct kvm *kvm = vcpu->kvm;
@@ -282,7 +327,11 @@ int kvm_sdei_hypercall(struct kvm_vcpu *vcpu)
 		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;
 	case SDEI_1_0_FN_SDEI_EVENT_CONTEXT:
 	case SDEI_1_0_FN_SDEI_EVENT_COMPLETE:
 	case SDEI_1_0_FN_SDEI_EVENT_COMPLETE_AND_RESUME:
-- 
2.23.0