[PATCH v4 08/21] KVM: arm64: Support SDEI_EVENT_STATUS hypercall

[Gavin Shan <gshan@redhat.com>]

This supports SDEI_EVENT_STATUS hypercall. It's used by the guest
to retrieve a bitmap to indicate the SDEI event states, including
registration, enablement and delivery state.

Signed-off-by: Gavin Shan <gshan@redhat.com>
---
 arch/arm64/kvm/sdei.c | 50 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/arch/arm64/kvm/sdei.c b/arch/arm64/kvm/sdei.c
index a3ba69dc91cb..b95b8c4455e1 100644
--- a/arch/arm64/kvm/sdei.c
+++ b/arch/arm64/kvm/sdei.c
@@ -367,6 +367,54 @@ static unsigned long kvm_sdei_hypercall_unregister(struct kvm_vcpu *vcpu)
 	return ret;
 }
 
+static unsigned long kvm_sdei_hypercall_status(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);
+	int index = 0;
+	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. None of the flags
+	 * will be set if it doesn't exist.
+	 */
+	spin_lock(&ksdei->lock);
+	kske = kvm_sdei_find_kvm_event(kvm, event_num);
+	if (!kske) {
+		ret = 0;
+		goto unlock;
+	}
+
+	index = (kse->state.type == SDEI_EVENT_TYPE_PRIVATE) ?
+		vcpu->vcpu_idx : 0;
+	if (kvm_sdei_is_registered(kske, index))
+		ret |= (1UL << SDEI_EVENT_STATUS_REGISTERED);
+	if (kvm_sdei_is_enabled(kske, index))
+		ret |= (1UL << SDEI_EVENT_STATUS_ENABLED);
+	if (kske->state.refcount)
+		ret |= (1UL << SDEI_EVENT_STATUS_RUNNING);
+
+unlock:
+	spin_unlock(&ksdei->lock);
+out:
+	return ret;
+}
+
 int kvm_sdei_hypercall(struct kvm_vcpu *vcpu)
 {
 	u32 func = smccc_get_function(vcpu);
@@ -395,6 +443,8 @@ int kvm_sdei_hypercall(struct kvm_vcpu *vcpu)
 		ret = kvm_sdei_hypercall_unregister(vcpu);
 		break;
 	case SDEI_1_0_FN_SDEI_EVENT_STATUS:
+		ret = kvm_sdei_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