virt/csv-guest: Provide interface for request of CSV3 attestation report

hygon inclusion
category: feature
CVE: NA

---------------------------

This change allows user in the CSV3 guest to get attestation report.

Currently, the input from user-space for CSV3 attestation report is
same as that for CSV attestation report.

Signed-off-by: hanliyang <[email protected]>

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

@@ -12,21 +12,28 @@
 #include <linux/slab.h>
 #include <linux/cc_platform.h>
 #include <linux/cacheflush.h>
+#include <linux/psp-hygon.h>
 
 #include <uapi/linux/kvm_para.h>
 
+#include <asm/csv.h>
+
 #include "csv-guest.h"
 
-static long csv_get_report(void __user *argp)
+/* Mutex to serialize the command handling. */
+static DEFINE_MUTEX(csv_cmd_mutex);
+
+static int csv_get_report(unsigned long arg)
 {
 	u8	*csv_report;
 	long	ret;
 	struct	csv_report_req req;
 
-	if (copy_from_user(&req, argp, sizeof(struct csv_report_req)))
+	if (copy_from_user(&req, (void __user *)arg,
+			   sizeof(struct csv_report_req)))
 		return -EFAULT;
 
-	if (req.len < CSV_REPORT_INPUT_DATA_LEN)
+	if (req.len < CSV_REPORT_INPUT_DATA_LEN || !req.report_data)
 		return -EINVAL;
 
 	csv_report = kzalloc(req.len, GFP_KERNEL);
@@ -54,14 +61,124 @@ static long csv_get_report(void __user *argp)
 	return ret;
 }
 
+static int csv3_get_report(unsigned long arg)
+{
+	struct csv_report_req input;
+	struct page *page = NULL;
+	struct csv3_data_attestation_report *cmd_buff = NULL;
+	void *req_buff = NULL;
+	void *resp_buff = NULL;
+	int ret;
+
+	if (copy_from_user(&input, (void __user *)arg, sizeof(input)))
+		return -EFAULT;
+
+	if (!input.len || !input.report_data)
+		return -EINVAL;
+
+	/* Use alloc_page for alignment */
+	page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO);
+	if (!page)
+		return -ENOMEM;
+	cmd_buff = (struct csv3_data_attestation_report *)page_address(page);
+
+	/*
+	 * Query the firmware to get minimum length of request buffer and
+	 * respond buffer.
+	 */
+	ret = csv3_issue_request_report(__pa(cmd_buff), sizeof(*cmd_buff));
+
+	/*
+	 * The input.len must be the maxinum length of the req and resp buffer
+	 * at least, otherwise return with error.
+	 */
+	if (input.len < max(cmd_buff->req_len, cmd_buff->resp_len)) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	/* Use alloc_page for alignment */
+	page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO);
+	if (!page) {
+		ret = -ENOMEM;
+		goto err;
+	}
+	req_buff = page_address(page);
+
+	/* Use alloc_page for alignment */
+	page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO);
+	if (!page) {
+		ret = -ENOMEM;
+		goto err;
+	}
+	resp_buff = page_address(page);
+
+	/* Copy user's input data */
+	if (copy_from_user(req_buff, input.report_data, cmd_buff->req_len)) {
+		ret = -EFAULT;
+		goto err;
+	}
+
+	/*
+	 * The req_len and resp_len fields has already been filled by firmware
+	 * when we query the lengths from firmware.
+	 */
+	cmd_buff->req_gpa  = __pa(req_buff);
+	cmd_buff->resp_gpa = __pa(resp_buff);
+
+	ret = csv3_issue_request_report(__pa(cmd_buff), sizeof(*cmd_buff));
+	if (ret || (!ret && cmd_buff->fw_error_code)) {
+		pr_err("%s: fail to generate report, fw_error:%#x ret:%d\n",
+			__func__, cmd_buff->fw_error_code, ret);
+		ret = -EIO;
+		goto err;
+	}
+
+	/* Copy attestation report to user */
+	if (copy_to_user(input.report_data, resp_buff, cmd_buff->resp_len))
+		ret = -EFAULT;
+
+err:
+	if (resp_buff)
+		free_page((unsigned long)resp_buff);
+	if (req_buff)
+		free_page((unsigned long)req_buff);
+	if (cmd_buff)
+		free_page((unsigned long)cmd_buff);
+
+	return ret;
+}
+
+static int get_report(unsigned long arg)
+{
+	int ret = -ENOTTY;
+
+	lockdep_assert_held(&csv_cmd_mutex);
+
+	if (csv3_active())
+		ret = csv3_get_report(arg);
+	else if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
+		ret = csv_get_report(arg);
+	return ret;
+}
+
 static long csv_guest_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
+	int ret = -ENOTTY;
+
+	mutex_lock(&csv_cmd_mutex);
+
 	switch (cmd) {
 	case CSV_CMD_GET_REPORT:
-		return csv_get_report((void __user *)arg);
+		ret = get_report(arg);
+		break;
 	default:
-		return -ENOTTY;
+		break;
 	}
+
+	mutex_unlock(&csv_cmd_mutex);
+
+	return ret;
 }
 
 static const struct file_operations csv_guest_fops = {