[PATCH v3 09/21] KVM: arm64: Support SDEI_EVENT_GET_INFO hypercall

[Gavin Shan <gshan@redhat.com>]

This supports SDEI_EVENT_GET_INFO hypercall. It's used by the guest
to retrieve various information about the supported (exported) events,
including type, signaled, route mode and affinity for the shared
events.

Signed-off-by: Gavin Shan <gshan@redhat.com>
---
 arch/arm64/kvm/sdei.c | 76 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 76 insertions(+)

diff --git a/arch/arm64/kvm/sdei.c b/arch/arm64/kvm/sdei.c
index b95b8c4455e1..5dfa74b093f1 100644
--- a/arch/arm64/kvm/sdei.c
+++ b/arch/arm64/kvm/sdei.c
@@ -415,6 +415,80 @@ static unsigned long kvm_sdei_hypercall_status(struct kvm_vcpu *vcpu)
 	return ret;
 }
 
+static unsigned long kvm_sdei_hypercall_info(struct kvm_vcpu *vcpu)
+{
+	struct kvm *kvm = vcpu->kvm;
+	struct kvm_sdei_kvm *ksdei = kvm->arch.sdei;
+	struct kvm_sdei_vcpu *vsdei = vcpu->arch.sdei;
+	struct kvm_sdei_event *kse = NULL;
+	struct kvm_sdei_kvm_event *kske = NULL;
+	unsigned long event_num = smccc_get_arg1(vcpu);
+	unsigned long event_info = smccc_get_arg2(vcpu);
+	unsigned long ret = SDEI_SUCCESS;
+
+	/* Sanity check */
+	if (!(ksdei && vsdei)) {
+		ret = SDEI_NOT_SUPPORTED;
+		goto out;
+	}
+
+	if (!kvm_sdei_is_valid_event_num(event_num)) {
+		ret = SDEI_INVALID_PARAMETERS;
+		goto out;
+	}
+
+	/*
+	 * Check if the KVM event exists. The event might have been
+	 * registered, we need fetch the information from the registered
+	 * event in that case.
+	 */
+	spin_lock(&ksdei->lock);
+	kske = kvm_sdei_find_kvm_event(kvm, event_num);
+	kse = kske ? kske->kse : NULL;
+	if (!kse) {
+		kse = kvm_sdei_find_event(kvm, event_num);
+		if (!kse) {
+			ret = SDEI_INVALID_PARAMETERS;
+			goto unlock;
+		}
+	}
+
+	/* Retrieve the requested information */
+	switch (event_info) {
+	case SDEI_EVENT_INFO_EV_TYPE:
+		ret = kse->state.type;
+		break;
+	case SDEI_EVENT_INFO_EV_SIGNALED:
+		ret = kse->state.signaled;
+		break;
+	case SDEI_EVENT_INFO_EV_PRIORITY:
+		ret = kse->state.priority;
+		break;
+	case SDEI_EVENT_INFO_EV_ROUTING_MODE:
+	case SDEI_EVENT_INFO_EV_ROUTING_AFF:
+		if (kse->state.type != SDEI_EVENT_TYPE_SHARED) {
+			ret = SDEI_INVALID_PARAMETERS;
+			break;
+		}
+
+		if (event_info == SDEI_EVENT_INFO_EV_ROUTING_MODE) {
+			ret = kske ? kske->state.route_mode :
+				     SDEI_EVENT_REGISTER_RM_ANY;
+		} else {
+			ret = kske ? kske->state.route_affinity : 0;
+		}
+
+		break;
+	default:
+		ret = SDEI_INVALID_PARAMETERS;
+	}
+
+unlock:
+	spin_unlock(&ksdei->lock);
+out:
+	return ret;
+}
+
 int kvm_sdei_hypercall(struct kvm_vcpu *vcpu)
 {
 	u32 func = smccc_get_function(vcpu);
@@ -446,6 +520,8 @@ int kvm_sdei_hypercall(struct kvm_vcpu *vcpu)
 		ret = kvm_sdei_hypercall_status(vcpu);
 		break;
 	case SDEI_1_0_FN_SDEI_EVENT_GET_INFO:
+		ret = kvm_sdei_hypercall_info(vcpu);
+		break;
 	case SDEI_1_0_FN_SDEI_EVENT_ROUTING_SET:
 	case SDEI_1_0_FN_SDEI_PE_MASK:
 	case SDEI_1_0_FN_SDEI_PE_UNMASK:
-- 
2.23.0