Commit 0fdb6cc7 authored by Borislav Petkov (AMD)'s avatar Borislav Petkov (AMD)
Browse files

virt/coco/sev-guest: Carve out the request issuing logic into a helper 



This makes the code flow a lot easier to follow.

No functional changes.

  [ Tom: touchups. ]

Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: default avatarTom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230307192449.24732-6-bp@alien8.de
parent c5a33827

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

+27 −17
Original line number Diff line number Diff line
@@ -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:

		/*
@@ -401,7 +385,33 @@ static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, in 
	if (!rc && override_err == SNP_GUEST_REQ_INVALID_LEN)

		return -EIO;



	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) {

		if (rc == -EIO && *fw_err == SNP_GUEST_REQ_INVALID_LEN)

			return rc;



		dev_alert(snp_dev->dev,

			  "Detected error from ASP request. rc: %d, fw_err: %llu\n",

			  rc, *fw_err);