Messages in this thread | | | Date | Wed, 5 Apr 2023 11:01:32 +0530 | Subject | Re: [PATCH v2 03/11] virt: sev-guest: Add snp_guest_req structure | From | "Nikunj A. Dadhania" <> |
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On 4/4/2023 1:29 AM, Tom Lendacky wrote: > On 3/26/23 09:46, Nikunj A Dadhania wrote: >> Add a snp_guest_req structure to simplify the function arguments. The >> structure will be used to call the SNP Guest message request API >> instead of passing a long list of parameters. >> >> Signed-off-by: Nikunj A Dadhania <nikunj@amd.com> >> --- >> drivers/virt/coco/sev-guest/sev-guest.c | 87 ++++++++++++++----------- >> drivers/virt/coco/sev-guest/sev-guest.h | 19 ++++++ >> 2 files changed, 68 insertions(+), 38 deletions(-) >> >> diff --git a/drivers/virt/coco/sev-guest/sev-guest.c b/drivers/virt/coco/sev-guest/sev-guest.c >> index 6ae197b57644..ec93dee330f2 100644 >> --- a/drivers/virt/coco/sev-guest/sev-guest.c >> +++ b/drivers/virt/coco/sev-guest/sev-guest.c >> @@ -60,16 +60,6 @@ static inline unsigned int get_ctx_authsize(struct snp_guest_dev *snp_dev) >> return 0; >> } >> -static bool is_vmpck_empty(struct snp_guest_dev *snp_dev) >> -{ >> - char zero_key[VMPCK_KEY_LEN] = {0}; >> - >> - if (snp_dev->vmpck) >> - return !memcmp(snp_dev->vmpck, zero_key, VMPCK_KEY_LEN); >> - >> - return true; >> -} >> - > > This change seems separate from the changes for snp_guest_req.
Sure, will create a separate patch.
> >> /* >> * If an error is received from the host or AMD Secure Processor (ASP) there >> * are two options. Either retry the exact same encrypted request or discontinue >> @@ -198,8 +188,9 @@ static int verify_and_dec_payload(struct snp_guest_dev *snp_dev, void *payload, >> struct snp_guest_msg_hdr *resp_hdr = &resp->hdr; >> struct aesgcm_ctx *ctx = snp_dev->ctx; >> - dev_dbg(snp_dev->dev, "response [seqno %lld type %d version %d sz %d]\n", >> - resp_hdr->msg_seqno, resp_hdr->msg_type, resp_hdr->msg_version, resp_hdr->msg_sz); >> + pr_debug("response [seqno %lld type %d version %d sz %d]\n", >> + resp_hdr->msg_seqno, resp_hdr->msg_type, resp_hdr->msg_version, >> + resp_hdr->msg_sz); > > Again, not related to the purpose of this patch.
The idea was to get rid of dev_dbg for the movement, will do in a separate patch.
> >> /* Verify that the sequence counter is incremented by 1 */ >> if (unlikely(resp_hdr->msg_seqno != (req_hdr->msg_seqno + 1))) >> @@ -221,34 +212,34 @@ static int verify_and_dec_payload(struct snp_guest_dev *snp_dev, void *payload, >> return dec_payload(ctx, resp, payload, resp_hdr->msg_sz); >> } >> -static int enc_payload(struct snp_guest_dev *snp_dev, u64 seqno, int version, u8 type, >> - void *payload, size_t sz) >> +static int enc_payload(struct snp_guest_dev *snp_dev, u64 seqno, >> + struct snp_guest_req *req, u8 __vmpck_id) > > Can the vmpck_id be part of the snp_guest_req structure?
Sure, that should be possible.
> >> { >> - struct snp_guest_msg *req = snp_dev->request; >> - struct snp_guest_msg_hdr *hdr = &req->hdr; >> + struct snp_guest_msg *msg = snp_dev->request; >> + struct snp_guest_msg_hdr *hdr = &msg->hdr; >> - memset(req, 0, sizeof(*req)); >> + memset(msg, 0, sizeof(*msg)); >> hdr->algo = SNP_AEAD_AES_256_GCM; >> hdr->hdr_version = MSG_HDR_VER; >> hdr->hdr_sz = sizeof(*hdr); >> - hdr->msg_type = type; >> - hdr->msg_version = version; >> + hdr->msg_type = req->msg_type; >> + hdr->msg_version = req->msg_version; >> hdr->msg_seqno = seqno; >> - hdr->msg_vmpck = vmpck_id; >> - hdr->msg_sz = sz; >> + hdr->msg_vmpck = __vmpck_id; >> + hdr->msg_sz = req->req_sz; >> /* Verify the sequence number is non-zero */ >> if (!hdr->msg_seqno) >> return -ENOSR; >> - dev_dbg(snp_dev->dev, "request [seqno %lld type %d version %d sz %d]\n", >> + pr_debug("request [seqno %lld type %d version %d sz %d]\n", > > Unrelated change.
Will move to a separate patch.
> >> hdr->msg_seqno, hdr->msg_type, hdr->msg_version, hdr->msg_sz); >> - return __enc_payload(snp_dev->ctx, req, payload, sz); >> + return __enc_payload(snp_dev->ctx, msg, req->req_buf, req->req_sz); >> } >> -static int __handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, __u64 *fw_err) >> +static int __handle_guest_request(struct snp_guest_dev *snp_dev, struct snp_guest_req *req) >> { >> unsigned long err = 0xff, override_err = 0; >> unsigned long req_start = jiffies; >> @@ -262,7 +253,7 @@ static int __handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, >> * sequence number must be incremented or the VMPCK must be deleted to >> * prevent reuse of the IV. >> */ >> - rc = snp_issue_guest_request(exit_code, &snp_dev->input, &err); >> + rc = snp_issue_guest_request(req->exit_code, &snp_dev->input, &err); >> switch (rc) { >> case -ENOSPC: >> /* >> @@ -273,7 +264,7 @@ static int __handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, >> * IV reuse. >> */ >> override_npages = snp_dev->input.data_npages; >> - exit_code = SVM_VMGEXIT_GUEST_REQUEST; >> + req->exit_code = SVM_VMGEXIT_GUEST_REQUEST; >> /* >> * Override the error to inform callers the given extended >> @@ -314,8 +305,8 @@ static int __handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, >> */ >> snp_inc_msg_seqno(snp_dev); >> - if (fw_err) >> - *fw_err = override_err ?: err; >> + if (req->fw_err) >> + *req->fw_err = override_err ?: err; >> if (override_npages) >> snp_dev->input.data_npages = override_npages; >> @@ -332,13 +323,14 @@ static int __handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, >> 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) >> +static int snp_send_guest_request(struct snp_guest_dev *snp_dev, struct snp_guest_req *req) >> { >> u64 seqno; >> int rc; >> + if (!snp_dev || !req) >> + return -ENODEV; > > This seems unrelated, at least the check for snp_dev. And looking at the only caller, a guest request is always provided. So this seems unnecessary - at least at this point in the series.
Right, not necessary here, but will be needed when sev-guest driver calls this after the movement to sev.c. Otherwise, I will need to add this in the movement patch 5/11.
> >> + >> /* Get message sequence and verify that its a non-zero */ >> seqno = snp_get_msg_seqno(snp_dev); >> if (!seqno) >> @@ -347,21 +339,22 @@ static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, in >> 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); >> + rc = enc_payload(snp_dev, seqno, req, vmpck_id); >> if (rc) >> return rc; >> - rc = __handle_guest_request(snp_dev, exit_code, fw_err); >> + rc = __handle_guest_request(snp_dev, req); >> if (rc) { >> - if (rc == -EIO && *fw_err == SNP_GUEST_REQ_INVALID_LEN) >> + if (rc == -EIO && *req->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); >> + dev_alert(snp_dev->dev, "Detected error from ASP request. rc: %d, fw_err: %llu\n", >> + rc, *req->fw_err); >> snp_disable_vmpck(snp_dev); >> return rc; >> } >> - rc = verify_and_dec_payload(snp_dev, resp_buf, resp_sz); >> + rc = verify_and_dec_payload(snp_dev, req->resp_buf, req->resp_sz); > > Can't you just pass req here?
Yes, can do that.
> >> if (rc) { >> dev_alert(snp_dev->dev, "Detected unexpected decode failure from ASP. rc: %d\n", rc); >> snp_disable_vmpck(snp_dev); >> @@ -371,6 +364,24 @@ static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, in >> return 0; >> } >> + >> +static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, u8 msg_version, >> + u8 msg_type, void *req_buf, size_t req_sz, void *resp_buf, >> + u32 resp_sz, __u64 *fw_err) >> +{ >> + struct snp_guest_req guest_req = { >> + .msg_version = msg_version, >> + .msg_type = msg_type, >> + .req_buf = req_buf, >> + .req_sz = req_sz, >> + .resp_buf = resp_buf, >> + .resp_sz = resp_sz, >> + .fw_err = fw_err, >> + .exit_code = exit_code, >> + }; > > Add a blank line here.
Sure.
Regards Nikunj
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