[PATCH v6 09/18] KVM: arm64: Support SDEI_EVENT_GET_INFO hypercall

[Gavin Shan]

This supports SDEI_EVENT_GET_INFO hypercall. It's used by guest
to retrieve various information about the event: type, signaled,
priority, routing mode and affinity. SDEI_INVALID_PARAMETERS is
returned for the requests about routing mode and affinity as
they are only valid for the shared event, which isn't supported.

Signed-off-by: Gavin Shan <gshan@xxxxxxxxxx>
---
 arch/arm64/kvm/sdei.c | 54 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/arch/arm64/kvm/sdei.c b/arch/arm64/kvm/sdei.c
index b847c6028b74..9e642d01e303 100644
--- a/arch/arm64/kvm/sdei.c
+++ b/arch/arm64/kvm/sdei.c
@@ -289,6 +289,57 @@ static unsigned long hypercall_status(struct kvm_vcpu *vcpu)
 	return ret;
 }
 
+static unsigned long hypercall_info(struct kvm_vcpu *vcpu)
+{
+	struct kvm_sdei_vcpu *vsdei = vcpu->arch.sdei;
+	struct kvm_sdei_exposed_event *exposed_event;
+	struct kvm_sdei_event *event;
+	unsigned int num = smccc_get_arg(vcpu, 1);
+	unsigned long info = smccc_get_arg(vcpu, 2);
+	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_INVALID_PARAMETERS;
+		goto unlock;
+	}
+
+	/*
+	 * Retrieve the requested information. The shared events aren't
+	 * supported yet. So the requests to retrieve routing mode and
+	 * affinity should fail for now.
+	 */
+	exposed_event = event->exposed_event;
+	switch (info) {
+	case SDEI_EVENT_INFO_EV_TYPE:
+		ret = exposed_event->type;
+		break;
+	case SDEI_EVENT_INFO_EV_SIGNALED:
+		ret = exposed_event->signaled;
+		break;
+	case SDEI_EVENT_INFO_EV_PRIORITY:
+		ret = exposed_event->priority;
+		break;
+	case SDEI_EVENT_INFO_EV_ROUTING_MODE:
+	case SDEI_EVENT_INFO_EV_ROUTING_AFF:
+	default:
+		ret = SDEI_INVALID_PARAMETERS;
+	}
+
+unlock:
+	spin_unlock(&vsdei->lock);
+out:
+	return ret;
+}
+
 int kvm_sdei_call(struct kvm_vcpu *vcpu)
 {
 	struct kvm_sdei_vcpu *vsdei = vcpu->arch.sdei;
@@ -328,6 +379,9 @@ int kvm_sdei_call(struct kvm_vcpu *vcpu)
 	case SDEI_1_0_FN_SDEI_EVENT_STATUS:
 		ret = hypercall_status(vcpu);
 		break;
+	case SDEI_1_0_FN_SDEI_EVENT_GET_INFO:
+		ret = hypercall_info(vcpu);
+		break;
 	default:
 		ret = SDEI_NOT_SUPPORTED;
 	}
-- 
2.23.0