[PATCH v6 16/18] KVM: arm64: Support SDEI_VERSION hypercall

[Gavin Shan <gshan@redhat.com>]

This supports SDEI_VERSION hypercall by returning v1.1, which is
the specification version we're following. The vendor is set to
one of the values returned from ARM_SMCCC_VENDOR_HYP_CALL_UID
hypercall.

Signed-off-by: Gavin Shan <gshan@redhat.com>
---
 arch/arm64/include/asm/kvm_sdei.h |  3 +++
 arch/arm64/kvm/sdei.c             | 11 +++++++++++
 2 files changed, 14 insertions(+)

diff --git a/arch/arm64/include/asm/kvm_sdei.h b/arch/arm64/include/asm/kvm_sdei.h
index f946d4ebdc14..32dfd5595f15 100644
--- a/arch/arm64/include/asm/kvm_sdei.h
+++ b/arch/arm64/include/asm/kvm_sdei.h
@@ -71,6 +71,9 @@ struct kvm_sdei_vcpu {
 	struct kvm_sdei_vcpu_context	context[SDEI_EVENT_PRIORITY_CRITICAL + 1];
 };
 
+/* Returned as vendor through SDEI_VERSION hypercall */
+#define KVM_SDEI_VENDOR	ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_2
+
 /*
  * According to SDEI specification (v1.1), the event number spans 32-bits
  * and the lower 24-bits are used as the (real) event number. I don't
diff --git a/arch/arm64/kvm/sdei.c b/arch/arm64/kvm/sdei.c
index ab0b7b5e3191..5d9b49a4355c 100644
--- a/arch/arm64/kvm/sdei.c
+++ b/arch/arm64/kvm/sdei.c
@@ -117,6 +117,14 @@ static int inject_event(struct kvm_vcpu *vcpu,
 	return 0;
 }
 
+static unsigned long hypercall_version(struct kvm_vcpu *vcpu)
+{
+	/* v1.1 and vendor ID */
+	return (1UL << SDEI_VERSION_MAJOR_SHIFT) |
+	       (1UL << SDEI_VERSION_MINOR_SHIFT) |
+	       KVM_SDEI_VENDOR;
+}
+
 static unsigned long hypercall_register(struct kvm_vcpu *vcpu)
 {
 	struct kvm_sdei_vcpu *vsdei = vcpu->arch.sdei;
@@ -565,6 +573,9 @@ int kvm_sdei_call(struct kvm_vcpu *vcpu)
 	}
 
 	switch (func) {
+	case SDEI_1_0_FN_SDEI_VERSION:
+		ret = hypercall_version(vcpu);
+		break;
 	case SDEI_1_0_FN_SDEI_EVENT_REGISTER:
 		ret = hypercall_register(vcpu);
 		break;
-- 
2.23.0