[PATCH v5 08/22] KVM: arm64: Support SDEI_EVENT_STATUS hypercall

[Gavin Shan]

This supports SDEI_EVENT_STATUS hypercall. It's used by the guest
to retrieve the status about the specified SDEI event. A bitmap
is returned to indicate the corresponding status, including
registration, enablement and delivery state.

Signed-off-by: Gavin Shan <gshan@xxxxxxxxxx>
---
 arch/arm64/kvm/sdei.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/arch/arm64/kvm/sdei.c b/arch/arm64/kvm/sdei.c
index 36eda31e0392..5c43c8912ea1 100644
--- a/arch/arm64/kvm/sdei.c
+++ b/arch/arm64/kvm/sdei.c
@@ -454,6 +454,46 @@ static unsigned long hypercall_unregister(struct kvm_vcpu *vcpu)
 	return ret;
 }
 
+static unsigned long hypercall_status(struct kvm_vcpu *vcpu)
+{
+	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 = 0;
+
+	if (!kvm_sdei_is_supported(event_num)) {
+		ret = SDEI_INVALID_PARAMETERS;
+		goto out;
+	}
+
+	spin_lock(&ksdei->lock);
+
+	/*
+	 * Check if the registered event exists. None of the flags
+	 * will be set if it doesn't exist.
+	 */
+	registered_event = find_registered_event(kvm, event_num);
+	if (!registered_event)
+		goto unlock;
+
+	exposed_event = registered_event->exposed_event;
+	index = kvm_sdei_vcpu_index(vcpu, exposed_event);
+	if (kvm_sdei_is_registered(registered_event, index))
+		ret |= (1UL << SDEI_EVENT_STATUS_REGISTERED);
+	if (kvm_sdei_is_enabled(registered_event, index))
+		ret |= (1UL << SDEI_EVENT_STATUS_ENABLED);
+	if (registered_event->vcpu_event_count > 0)
+		ret |= (1UL << SDEI_EVENT_STATUS_RUNNING);
+
+unlock:
+	spin_unlock(&ksdei->lock);
+out:
+	return ret;
+}
+
 int kvm_sdei_hypercall(struct kvm_vcpu *vcpu)
 {
 	struct kvm *kvm = vcpu->kvm;
@@ -500,6 +540,8 @@ int kvm_sdei_hypercall(struct kvm_vcpu *vcpu)
 		ret = hypercall_unregister(vcpu);
 		break;
 	case SDEI_1_0_FN_SDEI_EVENT_STATUS:
+		ret = hypercall_status(vcpu);
+		break;
 	case SDEI_1_0_FN_SDEI_EVENT_GET_INFO:
 	case SDEI_1_0_FN_SDEI_EVENT_ROUTING_SET:
 	case SDEI_1_0_FN_SDEI_PE_MASK:
-- 
2.23.0