Messages in this thread | | | Date | Mon, 3 Apr 2023 14:59:00 -0500 | Subject | Re: [PATCH v2 03/11] virt: sev-guest: Add snp_guest_req structure | From | Tom Lendacky <> |
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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.
> /* > * 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.
> > /* 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?
> { > - 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.
> 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.
> + > /* 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?
> 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.
Thanks, Tom
> + return snp_send_guest_request(snp_dev, &guest_req); > +} > + > static int get_report(struct snp_guest_dev *snp_dev, struct snp_guest_request_ioctl *arg) > { > struct snp_report_resp *resp; > @@ -544,7 +555,7 @@ static long snp_guest_ioctl(struct file *file, unsigned int ioctl, unsigned long > mutex_lock(&snp_dev->cmd_mutex); > > /* Check if the VMPCK is not empty */ > - if (is_vmpck_empty(snp_dev)) { > + if (is_vmpck_empty(snp_dev->vmpck)) { > dev_err_ratelimited(snp_dev->dev, "VMPCK is disabled\n"); > mutex_unlock(&snp_dev->cmd_mutex); > return -ENOTTY; > @@ -678,7 +689,7 @@ static int __init sev_guest_probe(struct platform_device *pdev) > } > > /* Verify that VMPCK is not zero. */ > - if (is_vmpck_empty(snp_dev)) { > + if (is_vmpck_empty(snp_dev->vmpck)) { > dev_err(dev, "vmpck id %d is null\n", vmpck_id); > goto e_unmap; > } > diff --git a/drivers/virt/coco/sev-guest/sev-guest.h b/drivers/virt/coco/sev-guest/sev-guest.h > index ceb798a404d6..d245578d988e 100644 > --- a/drivers/virt/coco/sev-guest/sev-guest.h > +++ b/drivers/virt/coco/sev-guest/sev-guest.h > @@ -63,4 +63,23 @@ struct snp_guest_msg { > u8 payload[4000]; > } __packed; > > +struct snp_guest_req { > + void *req_buf, *resp_buf; > + size_t req_sz, resp_sz; > + u64 exit_code; > + u64 *fw_err; > + u8 msg_version; > + u8 msg_type; > +}; > + > +static inline bool is_vmpck_empty(u8 *vmpck) > +{ > + char zero_key[VMPCK_KEY_LEN] = {0}; > + > + if (vmpck) > + return !memcmp(vmpck, zero_key, VMPCK_KEY_LEN); > + > + return true; > +} > + > #endif /* __VIRT_SEVGUEST_H__ */
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