3 files changed, 67 insertions, 0 deletions

diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c
index 12838b406696..ff478d826d7d 100644
--- a/drivers/crypto/ccp/psp-dev.c
+++ b/drivers/crypto/ccp/psp-dev.c
@@ -119,6 +119,7 @@ static int sev_cmd_buffer_len(int cmd)
 	case SEV_CMD_RECEIVE_UPDATE_VMSA:	return sizeof(struct sev_data_receive_update_vmsa);
 	case SEV_CMD_LAUNCH_UPDATE_SECRET:	return sizeof(struct sev_data_launch_secret);
 	case SEV_CMD_DOWNLOAD_FIRMWARE:		return sizeof(struct sev_data_download_firmware);
+	case SEV_CMD_GET_ID:			return sizeof(struct sev_data_get_id);
 	default:				return 0;
 	}
 
@@ -510,6 +511,46 @@ e_free:
 	return ret;
 }
 
+static int sev_ioctl_do_get_id(struct sev_issue_cmd *argp)
+{
+	struct sev_data_get_id *data;
+	u64 data_size, user_size;
+	void *id_blob, *mem;
+	int ret;
+
+	/* SEV GET_ID available from SEV API v0.16 and up */
+	if (!SEV_VERSION_GREATER_OR_EQUAL(0, 16))
+		return -ENOTSUPP;
+
+	/* SEV FW expects the buffer it fills with the ID to be
+	 * 8-byte aligned. Memory allocated should be enough to
+	 * hold data structure + alignment padding + memory
+	 * where SEV FW writes the ID.
+	 */
+	data_size = ALIGN(sizeof(struct sev_data_get_id), 8);
+	user_size = sizeof(struct sev_user_data_get_id);
+
+	mem = kzalloc(data_size + user_size, GFP_KERNEL);
+	if (!mem)
+		return -ENOMEM;
+
+	data = mem;
+	id_blob = mem + data_size;
+
+	data->address = __psp_pa(id_blob);
+	data->len = user_size;
+
+	ret = __sev_do_cmd_locked(SEV_CMD_GET_ID, data, &argp->error);
+	if (!ret) {
+		if (copy_to_user((void __user *)argp->data, id_blob, data->len))
+			ret = -EFAULT;
+	}
+
+	kfree(mem);
+
+	return ret;
+}
+
 static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp)
 {
 	struct sev_user_data_pdh_cert_export input;
@@ -647,6 +688,9 @@ static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg)
 	case SEV_PDH_CERT_EXPORT:
 		ret = sev_ioctl_do_pdh_export(&input);
 		break;
+	case SEV_GET_ID:
+		ret = sev_ioctl_do_get_id(&input);
+		break;
 	default:
 		ret = -EINVAL;
 		goto out;
diff --git a/include/linux/psp-sev.h b/include/linux/psp-sev.h
index 1d2496246072..827c601841c4 100644
--- a/include/linux/psp-sev.h
+++ b/include/linux/psp-sev.h
@@ -55,6 +55,7 @@ enum sev_cmd {
 	SEV_CMD_PDH_GEN			= 0x009,
 	SEV_CMD_DF_FLUSH		= 0x00A,
 	SEV_CMD_DOWNLOAD_FIRMWARE	= 0x00B,
+	SEV_CMD_GET_ID			= 0x00C,
 
 	/* Guest commands */
 	SEV_CMD_DECOMMISSION		= 0x020,
@@ -142,6 +143,16 @@ struct sev_data_download_firmware {
 } __packed;
 
 /**
+ * struct sev_data_get_id - GET_ID command parameters
+ *
+ * @address: physical address of region to place unique CPU ID(s)
+ * @len: len of the region
+ */
+struct sev_data_get_id {
+	u64 address;				/* In */
+	u32 len;				/* In/Out */
+} __packed;
+/**
  * struct sev_data_pdh_cert_export - PDH_CERT_EXPORT command parameters
  *
  * @pdh_address: PDH certificate address
diff --git a/include/uapi/linux/psp-sev.h b/include/uapi/linux/psp-sev.h
index 9008f31c7eb6..ac8c60bcc83b 100644
--- a/include/uapi/linux/psp-sev.h
+++ b/include/uapi/linux/psp-sev.h
@@ -30,6 +30,7 @@ enum {
 	SEV_PDH_GEN,
 	SEV_PDH_CERT_EXPORT,
 	SEV_PEK_CERT_IMPORT,
+	SEV_GET_ID,
 
 	SEV_MAX,
 };
@@ -124,6 +125,17 @@ struct sev_user_data_pdh_cert_export {
 } __packed;
 
 /**
+ * struct sev_user_data_get_id - GET_ID command parameters
+ *
+ * @socket1: Buffer to pass unique ID of first socket
+ * @socket2: Buffer to pass unique ID of second socket
+ */
+struct sev_user_data_get_id {
+	__u8 socket1[64];			/* Out */
+	__u8 socket2[64];			/* Out */
+} __packed;
+
+/**
  * struct sev_issue_cmd - SEV ioctl parameters
  *
  * @cmd: SEV commands to execute