[PATCH v7 08/22] KVM: arm64: Support EVENT_STATUS hypercall

[Gavin Shan <gshan@redhat.com>]

This supports EVENT_STATUS hypercall. It's used to retrieve the
status about the specified event. A bitmap is returned to represent
the event status, which includes state of registration, enablement,
and running.

Signed-off-by: Gavin Shan <gshan@redhat.com>
---
 arch/arm64/kvm/sdei.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/arch/arm64/kvm/sdei.c b/arch/arm64/kvm/sdei.c
index b44ab302732d..377341f229da 100644
--- a/arch/arm64/kvm/sdei.c
+++ b/arch/arm64/kvm/sdei.c
@@ -118,6 +118,25 @@ static unsigned long event_unregister(struct kvm_vcpu *vcpu)
 	return SDEI_SUCCESS;
 }
 
+static unsigned long event_status(struct kvm_vcpu *vcpu)
+{
+	struct kvm_sdei_vcpu *vsdei = vcpu->arch.sdei;
+	unsigned int num = smccc_get_arg(vcpu, 1);
+	unsigned long ret = 0;
+
+	if (num >= KVM_NR_SDEI_EVENTS)
+		return SDEI_INVALID_PARAMETERS;
+
+	if (test_bit(num, &vsdei->registered))
+		ret |= (1UL << SDEI_EVENT_STATUS_REGISTERED);
+	if (test_bit(num, &vsdei->enabled))
+		ret |= (1UL << SDEI_EVENT_STATUS_ENABLED);
+	if (test_bit(num, &vsdei->running))
+		ret |= (1UL << SDEI_EVENT_STATUS_RUNNING);
+
+	return ret;
+}
+
 int kvm_sdei_call(struct kvm_vcpu *vcpu)
 {
 	struct kvm_sdei_vcpu *vsdei = vcpu->arch.sdei;
@@ -151,6 +170,9 @@ int kvm_sdei_call(struct kvm_vcpu *vcpu)
 	case SDEI_1_0_FN_SDEI_EVENT_UNREGISTER:
 		ret = event_unregister(vcpu);
 		break;
+	case SDEI_1_0_FN_SDEI_EVENT_STATUS:
+		ret = event_status(vcpu);
+		break;
 	default:
 		ret = SDEI_NOT_SUPPORTED;
 	}
-- 
2.23.0