[PATCH v6 11/18] KVM: arm64: Support SDEI_{PRIVATE, SHARED}_RESET

[Gavin Shan <gshan@redhat.com>]

This supports SDEI_{PRIVATE, SHARED}_RESET. They are used by the
guest to reset the private events on the calling vCPU or the
shared events on all vCPUs.

The shared event isn't supported yet, we simply returns SDEI_SUCCESS
as the guest doesn't know it. It can't stop the guest from using
SDEI service.

Signed-off-by: Gavin Shan <gshan@redhat.com>
---
 arch/arm64/kvm/sdei.c | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/arch/arm64/kvm/sdei.c b/arch/arm64/kvm/sdei.c
index 3aca36e7e27b..6716ed020aa2 100644
--- a/arch/arm64/kvm/sdei.c
+++ b/arch/arm64/kvm/sdei.c
@@ -352,6 +352,36 @@ static unsigned long hypercall_mask(struct kvm_vcpu *vcpu, bool mask)
 	return ret;
 }
 
+static unsigned long hypercall_reset(struct kvm_vcpu *vcpu, bool private)
+{
+	struct kvm_sdei_vcpu *vsdei = vcpu->arch.sdei;
+	struct kvm_sdei_event *event;
+	unsigned int i;
+	unsigned long ret = SDEI_SUCCESS;
+
+	/*
+	 * All events, which have been registered, should be private
+	 * because the shared events aren't supported yet, so we needn't
+	 * do anything to reset the shared events.
+	 */
+	if (!private)
+		return ret;
+
+	spin_lock(&vsdei->lock);
+
+	kvm_sdei_for_each_event(vsdei, event, i) {
+		if (!kvm_sdei_is_registered(event))
+			continue;
+
+		if (reset_event(vcpu, event))
+			ret = SDEI_PENDING;
+	}
+
+	spin_unlock(&vsdei->lock);
+
+	return ret;
+}
+
 int kvm_sdei_call(struct kvm_vcpu *vcpu)
 {
 	struct kvm_sdei_vcpu *vsdei = vcpu->arch.sdei;
@@ -400,6 +430,12 @@ int kvm_sdei_call(struct kvm_vcpu *vcpu)
 	case SDEI_1_0_FN_SDEI_PE_UNMASK:
 		ret = hypercall_mask(vcpu, false);
 		break;
+	case SDEI_1_0_FN_SDEI_PRIVATE_RESET:
+		ret = hypercall_reset(vcpu, true);
+		break;
+	case SDEI_1_0_FN_SDEI_SHARED_RESET:
+		ret = hypercall_reset(vcpu, false);
+		break;
 	default:
 		ret = SDEI_NOT_SUPPORTED;
 	}
-- 
2.23.0