commit af43cbbf954b50ca97d5e7bb56c2edc6ffd209ef
author Brijesh Singh <brijesh.singh@amd.com> Thu Apr 15 15:54:50 2021 +0000
committer Paolo Bonzini <pbonzini@redhat.com> Wed Apr 21 12:20:04 2021 -0400
tree 705338a58cf99493c773826d240e0d870bbd8655
parent 5569e2e7a650dfffd4df7635662b2f92162d6501

KVM: SVM: Add support for KVM_SEV_RECEIVE_START command

The command is used to create the encryption context for an incoming
SEV guest. The encryption context can be later used by the hypervisor
to import the incoming data into the SEV guest memory space.

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: 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
Reviewed-by: Steve Rutherford <srutherford@google.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
Message-Id: <c7400111ed7458eee01007c4d8d57cdf2cbb0fc2.1618498113.git.ashish.kalra@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/svm/sev.c

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 552f477..3e5064c6 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -1397,6 +1397,84 @@ static int sev_send_cancel(struct kvm *kvm, struct kvm_sev_cmd *argp)
 	return ret;
 }
 
+static int sev_receive_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
+{
+	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
+	struct sev_data_receive_start *start;
+	struct kvm_sev_receive_start params;
+	int *error = &argp->error;
+	void *session_data;
+	void *pdh_data;
+	int ret;
+
+	if (!sev_guest(kvm))
+		return -ENOTTY;
+
+	/* Get parameter from the userspace */
+	if (copy_from_user(&params, (void __user *)(uintptr_t)argp->data,
+			sizeof(struct kvm_sev_receive_start)))
+		return -EFAULT;
+
+	/* some sanity checks */
+	if (!params.pdh_uaddr || !params.pdh_len ||
+	    !params.session_uaddr || !params.session_len)
+		return -EINVAL;
+
+	pdh_data = psp_copy_user_blob(params.pdh_uaddr, params.pdh_len);
+	if (IS_ERR(pdh_data))
+		return PTR_ERR(pdh_data);
+
+	session_data = psp_copy_user_blob(params.session_uaddr,
+			params.session_len);
+	if (IS_ERR(session_data)) {
+		ret = PTR_ERR(session_data);
+		goto e_free_pdh;
+	}
+
+	ret = -ENOMEM;
+	start = kzalloc(sizeof(*start), GFP_KERNEL);
+	if (!start)
+		goto e_free_session;
+
+	start->handle = params.handle;
+	start->policy = params.policy;
+	start->pdh_cert_address = __psp_pa(pdh_data);
+	start->pdh_cert_len = params.pdh_len;
+	start->session_address = __psp_pa(session_data);
+	start->session_len = params.session_len;
+
+	/* create memory encryption context */
+	ret = __sev_issue_cmd(argp->sev_fd, SEV_CMD_RECEIVE_START, start,
+				error);
+	if (ret)
+		goto e_free;
+
+	/* Bind ASID to this guest */
+	ret = sev_bind_asid(kvm, start->handle, error);
+	if (ret)
+		goto e_free;
+
+	params.handle = start->handle;
+	if (copy_to_user((void __user *)(uintptr_t)argp->data,
+			 &params, sizeof(struct kvm_sev_receive_start))) {
+		ret = -EFAULT;
+		sev_unbind_asid(kvm, start->handle);
+		goto e_free;
+	}
+
+	sev->handle = start->handle;
+	sev->fd = argp->sev_fd;
+
+e_free:
+	kfree(start);
+e_free_session:
+	kfree(session_data);
+e_free_pdh:
+	kfree(pdh_data);
+
+	return ret;
+}
+
 int svm_mem_enc_op(struct kvm *kvm, void __user *argp)
 {
 	struct kvm_sev_cmd sev_cmd;
@@ -1471,6 +1549,9 @@ int svm_mem_enc_op(struct kvm *kvm, void __user *argp)
 	case KVM_SEV_SEND_CANCEL:
 		r = sev_send_cancel(kvm, &sev_cmd);
 		break;
+	case KVM_SEV_RECEIVE_START:
+		r = sev_receive_start(kvm, &sev_cmd);
+		break;
 	default:
 		r = -EINVAL;
 		goto out;