KVM: SVM: Add support for SEV GUEST_STATUS command

The command is used for querying the SEV guest information.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: x86@kernel.org
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Reviewed-by: Borislav Petkov <bp@suse.de>

arch/x86/kvm/svm.c

@@ -6133,6 +6133,36 @@ static int sev_launch_finish(struct kvm *kvm, struct kvm_sev_cmd *argp)
 	return ret;
 }
 
+static int sev_guest_status(struct kvm *kvm, struct kvm_sev_cmd *argp)
+{
+	struct kvm_sev_info *sev = &kvm->arch.sev_info;
+	struct kvm_sev_guest_status params;
+	struct sev_data_guest_status *data;
+	int ret;
+
+	if (!sev_guest(kvm))
+		return -ENOTTY;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->handle = sev->handle;
+	ret = sev_issue_cmd(kvm, SEV_CMD_GUEST_STATUS, data, &argp->error);
+	if (ret)
+		goto e_free;
+
+	params.policy = data->policy;
+	params.state = data->state;
+	params.handle = data->handle;
+
+	if (copy_to_user((void __user *)(uintptr_t)argp->data, &params, sizeof(params)))
+		ret = -EFAULT;
+e_free:
+	kfree(data);
+	return ret;
+}
+
 static int svm_mem_enc_op(struct kvm *kvm, void __user *argp)
 {
 	struct kvm_sev_cmd sev_cmd;
@@ -6162,6 +6192,9 @@ static int svm_mem_enc_op(struct kvm *kvm, void __user *argp)
 	case KVM_SEV_LAUNCH_FINISH:
 		r = sev_launch_finish(kvm, &sev_cmd);
 		break;
+	case KVM_SEV_GUEST_STATUS:
+		r = sev_guest_status(kvm, &sev_cmd);
+		break;
 	default:
 		r = -EINVAL;
 		goto out;