anolis: virt: csv-guest: Add support for extended attestation aware request in the CSV3 guest

ANBZ: #22214

The struct csv3_data_attestation_report is the communication structure
between the CSV3 guest and Hygon PSP. The reserved1 field in the struct
csv3_data_attestation_report has been changed to a flags field, which is
used to store the attestation extension flags. When the flags field is 0,
the firmware returns a legacy attestation report; otherwise, it returns
an extended attestation report.

The struct csv_guest_user_data_attestation is the user-space buffer for
legacy attestation, and this buffer can provide challenge data (see the
user_data and mnonce fields) to the firmware.

The struct csv_guest_user_data_attestation_ext is the user-space buffer
for extended attestation, and it can also provide challenge data (see the
user_data and mnonce fields) to the firmware. Since user space always
provides a buffer larger than the struct csv_guest_user_data_attestation,
the csv-guest module cannot determine whether the user-space request is
for extended attestation. To address this, we added a magic field to the
struct csv_guest_user_data_attestation_ext. If the magic field is
populated with the string "ATTESTATION_EXT", the csv-guest module
considers this is an extended attestation request, and the flags field in
the struct csv_guest_user_data_attestation_ext will be copied to the
struct csv3_data_attestation_report so that the firmware will serve the
attestation request as intended.

The definition of the struct csv_guest_user_data_attestation has been
moved to the csv-guest local header file.

Signed-off-by: hanliyang <hanliyang@hygon.cn>
Reviewed-by: Guixin Liu <kanie@Linux.aliabab.com>
Reviewed-by: Guixin Liu <kanie@linux.alibaba.com>
Link: https://gitee.com/anolis/cloud-kernel/pulls/5464

drivers/virt/coco/csv-guest/csv-guest.c

@@ -23,6 +23,9 @@
 /* Mutex to serialize the command handling. */
 static DEFINE_MUTEX(csv_cmd_mutex);
 
+/* The magic string is used to identify extended attestation aware requests. */
+static char csv_attestation_magic[CSV_ATTESTATION_MAGIC_LEN] = CSV_ATTESTATION_MAGIC_STRING;
+
 static int csv_get_report(unsigned long arg)
 {
 	u8	*csv_report;
@@ -68,6 +71,7 @@ static int csv3_get_report(unsigned long arg)
 	struct csv3_data_attestation_report *cmd_buff = NULL;
 	void *req_buff = NULL;
 	void *resp_buff = NULL;
+	struct csv_guest_user_data_attestation_ext *udata = NULL;
 	int ret;
 
 	if (copy_from_user(&input, (void __user *)arg, sizeof(input)))
@@ -82,6 +86,28 @@ static int csv3_get_report(unsigned long arg)
 		return -ENOMEM;
 	cmd_buff = (struct csv3_data_attestation_report *)page_address(page);
 
+	/*
+	 * If user space issues an extended attestation aware request, then sync
+	 * the flags to @cmd_buff.
+	 */
+	if (input.len >= CSV_ATTESTATION_USER_DATA_EXT_LEN) {
+		udata = kzalloc(CSV_ATTESTATION_USER_DATA_EXT_LEN, GFP_KERNEL);
+		if (!udata) {
+			ret = -ENOMEM;
+			goto err;
+		}
+
+		if (copy_from_user((void *)udata, input.report_data,
+				   CSV_ATTESTATION_USER_DATA_EXT_LEN)) {
+			ret = -EFAULT;
+			goto err;
+		}
+
+		if (!strncmp((char *)udata->magic, csv_attestation_magic,
+						CSV_ATTESTATION_MAGIC_LEN))
+			cmd_buff->flags = udata->flags;
+	}
+
 	/*
 	 * Query the firmware to get minimum length of request buffer and
 	 * respond buffer.
@@ -146,6 +172,8 @@ err:
 	if (cmd_buff)
 		free_page((unsigned long)cmd_buff);
 
+	kfree(udata);
+
 	return ret;
 }
 

drivers/virt/coco/csv-guest/csv-guest.h

@@ -20,6 +20,62 @@
 #define CSV_REPORT_INPUT_DATA_LEN	(CSV_REPORT_USER_DATA_LEN + CSV_REPORT_MNONCE_LEN \
 					+ CSV_REPORT_HASH_LEN)
 
+/**
+ * struct csv_guest_user_data_attestation - ATTESTATION command parameters.
+ *	This is used for legacy attestation.
+ *
+ *	In the legacy attestation, the size of tee info portion of the
+ *	attestation report is 0x150. The tee info does not contain rtmr.
+ *
+ * @user_data: user defined data, it's suggest that contains challenge data
+ *	       from the relying party.
+ * @mnonce: user's random nonce, just for anti-replay attack protection.
+ * @hash: the sm3 hash of the @user_data and @mnonce.
+ */
+struct csv_guest_user_data_attestation {
+	__u8 user_data[CSV_REPORT_USER_DATA_LEN];	/* In */
+	__u8 mnonce[CSV_REPORT_MNONCE_LEN];		/* In */
+	__u8 hash[CSV_REPORT_HASH_LEN];			/* In */
+} __packed;
+
+#define CSV_ATTESTATION_USER_DATA_EXT_LEN	132U
+
+#define CSV_ATTESTATION_MAGIC_LEN		16
+#define CSV_ATTESTATION_MAGIC_STRING		"ATTESTATION_EXT"
+
+#define CSV_ATTESTATION_FLAG_REPORT_EXT_BIT	0
+#define CSV_ATTESTATION_FLAG_REPORT_EXT		(1U << CSV_ATTESTATION_FLAG_REPORT_EXT)
+
+/**
+ * struct csv_guest_user_data_attestation_ext - ATTESTATION command parameters.
+ *	This is used for extended attestation.
+ *
+ *	In the extended attestation, the size of tee info portion of the
+ *	attestation report is 0x490. The tee info contains rtmr by default.
+ *
+ *	Currently, the extended attestation only supported for CSV3 guest.
+ *
+ * @user_data: user defined data, it's suggest that contains challenge data
+ *	       from the relying party.
+ * @mnonce: user's random nonce, just for anti-replay attack protection.
+ * @hash: the sm3 hash of the @user_data and @mnonce.
+ * @magic: The magic string indicates this is an extended attestation aware
+ *	   request. Due to historical reasons, users always provide a buffer
+ *	   that is much larger than the size of structure
+ *	   csv_guest_user_data_attestation_ext. The magic string will be used to
+ *	   determine whether the user space uses the extended attestation aware
+ *	   request. If the user space is using such a request, the flags field
+ *	   will be used to indicate the format of the attestation report.
+ * @flags: the bit flags used to indicate how to extend the attestation report.
+ */
+struct csv_guest_user_data_attestation_ext {
+	__u8  user_data[CSV_REPORT_USER_DATA_LEN];	/* In */
+	__u8  mnonce[CSV_REPORT_MNONCE_LEN];		/* In */
+	__u8  hash[CSV_REPORT_HASH_LEN];		/* In */
+	__u8  magic[CSV_ATTESTATION_MAGIC_LEN];		/* In */
+	__u32 flags;					/* In */
+} __packed;
+
 /**
  * struct csv_report_req - Request struct for CSV_CMD_GET_REPORT IOCTL.
  *

include/linux/psp-csv.h

@@ -198,6 +198,9 @@ struct csv_data_dbg_read_mem {
  * struct csv3_data_attestation_report - ATTESTATION secure call command parameters
  *
  * @handle: handle of the VM to process
+ * @flags: the bit flags used to indicate how to extend the attestation report.
+ *	   It's copied from user space's parameter before issuing the ATTESTATION
+ *	   secure call command.
  * @resp_gpa: guest physical address to save the generated report
  * @resp_length: length of the generated report
  * @req_gpa: guest physical address of the input for the report
@@ -206,7 +209,7 @@ struct csv_data_dbg_read_mem {
  */
 struct csv3_data_attestation_report {
 	u32 handle;				/* Out */
-	u32 reserved1;
+	u32 flags;				/* In */
 	u64 resp_gpa;				/* In */
 	u8 reserved2[16];
 	u32 resp_len;				/* In/Out */

include/uapi/linux/psp-hygon.h

@@ -13,20 +13,6 @@
 
 #include <linux/types.h>
 
-/**
- * struct csv_guest_user_data_attestation - ATTESTATION command parameters
- *
- * @user_data: user specified data for the attestation report
- * @mnonce: user's random nonce
- * @hash: sm3 hash of the @user_data and @mnonce
- */
-struct csv_guest_user_data_attestation {
-	__u8 user_data[64];			/* In */
-	__u8 monce[16];				/* In */
-	__u8 hash[32];				/* In */
-} __packed;
-
-
 /* The CSV RTMR version in the kernel */
 #define CSV_RTMR_VERSION_MAX	1U
 #define CSV_RTMR_VERSION_MIN	1U