[PATCH v7 14/22] KVM: arm64: Support EVENT_SIGNAL hypercall

[Gavin Shan <gshan@redhat.com>]

This supports EVENT_SIGNAL hypercall. It's used to inject the
software signaled event, whose number is zero. The KVM_REQ_SDEI
request is raised if the PE is unmasked and the event has been
enabled.

Signed-off-by: Gavin Shan <gshan@redhat.com>
---
 arch/arm64/kvm/sdei.c         | 28 ++++++++++++++++++++++++++++
 include/uapi/linux/arm_sdei.h |  3 +++
 2 files changed, 31 insertions(+)

diff --git a/arch/arm64/kvm/sdei.c b/arch/arm64/kvm/sdei.c
index 0bea1b2f9452..a55797fce06a 100644
--- a/arch/arm64/kvm/sdei.c
+++ b/arch/arm64/kvm/sdei.c
@@ -232,6 +232,31 @@ static unsigned long pe_mask(struct kvm_vcpu *vcpu, bool mask)
 	return SDEI_SUCCESS;
 }
 
+static unsigned long event_signal(struct kvm_vcpu *vcpu)
+{
+	struct kvm_sdei_vcpu *vsdei = vcpu->arch.sdei;
+	unsigned int num = smccc_get_arg(vcpu, 1);
+
+	if (num >= KVM_NR_SDEI_EVENTS)
+		return SDEI_INVALID_PARAMETERS;
+
+	/*
+	 * The event must be software signaled event, whose
+	 * number is zero.
+	 */
+	if (num != SDEI_SW_SIGNALED_EVENT ||
+	    !test_bit(num, &vsdei->registered))
+		return SDEI_INVALID_PARAMETERS;
+
+	if (!test_and_set_bit(num, &vsdei->pending)) {
+		if (!(vcpu->arch.flags & KVM_ARM64_SDEI_MASKED) &&
+		    test_bit(num, &vsdei->enabled))
+			kvm_make_request(KVM_REQ_SDEI, vcpu);
+	}
+
+	return SDEI_SUCCESS;
+}
+
 static unsigned long event_reset(struct kvm_vcpu *vcpu, bool private)
 {
 	struct kvm_sdei_vcpu *vsdei = vcpu->arch.sdei;
@@ -303,6 +328,9 @@ int kvm_sdei_call(struct kvm_vcpu *vcpu)
 	case SDEI_1_0_FN_SDEI_PE_UNMASK:
 		ret = pe_mask(vcpu, false);
 		break;
+	case SDEI_1_1_FN_SDEI_EVENT_SIGNAL:
+		ret = event_signal(vcpu);
+		break;
 	case SDEI_1_0_FN_SDEI_PRIVATE_RESET:
 		ret = event_reset(vcpu, true);
 		break;
diff --git a/include/uapi/linux/arm_sdei.h b/include/uapi/linux/arm_sdei.h
index af0630ba5437..72b07114bbfa 100644
--- a/include/uapi/linux/arm_sdei.h
+++ b/include/uapi/linux/arm_sdei.h
@@ -22,9 +22,12 @@
 #define SDEI_1_0_FN_SDEI_PE_UNMASK			SDEI_1_0_FN(0x0C)
 #define SDEI_1_0_FN_SDEI_INTERRUPT_BIND			SDEI_1_0_FN(0x0D)
 #define SDEI_1_0_FN_SDEI_INTERRUPT_RELEASE		SDEI_1_0_FN(0x0E)
+#define SDEI_1_1_FN_SDEI_EVENT_SIGNAL			SDEI_1_0_FN(0x0F)
 #define SDEI_1_0_FN_SDEI_PRIVATE_RESET			SDEI_1_0_FN(0x11)
 #define SDEI_1_0_FN_SDEI_SHARED_RESET			SDEI_1_0_FN(0x12)
 
+#define SDEI_SW_SIGNALED_EVENT		0
+
 #define SDEI_VERSION_MAJOR_SHIFT			48
 #define SDEI_VERSION_MAJOR_MASK				0x7fff
 #define SDEI_VERSION_MINOR_SHIFT			32
-- 
2.23.0