[PATCH 05/11] virt/coco/sev-guest: Carve out the request issuing logic into a helper

Borislav Petkov
2023-02-16T12:41:47Z

This makes the code flow a lot easier to follow.

No functional changes.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
---
drivers/virt/coco/sev-guest/sev-guest.c | 41 +++++++++++++++----------
1 file changed, 24 insertions(+), 17 deletions(-)

diff --git a/drivers/virt/coco/sev-guest/sev-guest.c b/drivers/virt/coco/sev-guest/sev-guest.c
index c0ecc5885573..e72289de2b28 100644
--- a/drivers/virt/coco/sev-guest/sev-guest.c
+++ b/drivers/virt/coco/sev-guest/sev-guest.c
@@ -318,27 +318,12 @@ static int enc_payload(struct snp_guest_dev *snp_dev, u64 seqno, int version, u8
return __enc_payload(snp_dev, req, payload, sz);
}

-static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, int msg_ver,
- u8 type, void *req_buf, size_t req_sz, void *resp_buf,
- u32 resp_sz, __u64 *fw_err)
+static int __handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, __u64 *fw_err)
{
unsigned long err, override_err = 0;
unsigned int override_npages = 0;
- u64 seqno;
int rc;

- /* Get message sequence and verify that its a non-zero */
- seqno = snp_get_msg_seqno(snp_dev);
- if (!seqno)
- return -EIO;
-
- memset(snp_dev->response, 0, sizeof(struct snp_guest_msg));
-
- /* Encrypt the userspace provided payload */
- rc = enc_payload(snp_dev, seqno, msg_ver, type, req_buf, req_sz);
- if (rc)
- return rc;
-
retry_request:
/*
* Call firmware to process the request. In this function the encrypted
@@ -347,7 +332,6 @@ static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, in
* prevent reuse of the IV.
*/
rc = snp_issue_guest_request(exit_code, &snp_dev->input, &err);
-
switch (rc) {
case -ENOSPC:
/*
@@ -384,6 +368,29 @@ static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, in
if (override_npages)
snp_dev->input.data_npages = override_npages;

+ return rc;
+}
+
+static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, int msg_ver,
+ u8 type, void *req_buf, size_t req_sz, void *resp_buf,
+ u32 resp_sz, __u64 *fw_err)
+{
+ u64 seqno;
+ int rc;
+
+ /* Get message sequence and verify that its a non-zero */
+ seqno = snp_get_msg_seqno(snp_dev);
+ if (!seqno)
+ return -EIO;
+
+ memset(snp_dev->response, 0, sizeof(struct snp_guest_msg));
+
+ /* Encrypt the userspace provided payload */
+ rc = enc_payload(snp_dev, seqno, msg_ver, type, req_buf, req_sz);
+ if (rc)
+ return rc;
+
+ rc = __handle_guest_request(snp_dev, exit_code, fw_err);
if (rc) {
dev_alert(snp_dev->dev,
"Detected error from ASP request. rc: %d, fw_err: %llu\n",
--
2.35.1