Re: [RFC PATCH 03/11] virt: sev-guest: Add snp_guest_req structure

From: "Nikunj A. Dadhania" <nikunj@amd.com>
To: Dionna Amalie Glaze <dionnaglaze@google.com>
Cc: linux-kernel@vger.kernel.org, x86@kernel.org, bp@alien8.de,
	thomas.lendacky@amd.com, pgonda@google.com, jroedel@suse.de,
	mingo@redhat.com, tglx@linutronix.de,
	dave.hansen@linux.intel.com, seanjc@google.com,
	pbonzini@redhat.com, michael.roth@amd.com, ketanch@iitk.ac.in
Subject: Re: [RFC PATCH 03/11] virt: sev-guest: Add snp_guest_req structure
Date: Tue, 31 Jan 2023 08:38:31 +0530	[thread overview]
Message-ID: <a4a83fd2-b1e6-3dce-6881-8abe71c7e934@amd.com> (raw)
In-Reply-To: <CAAH4kHbJEcg9p=mXi2aQZFs1bopZgeqWKiwGWu2V4YsgmwHmmw@mail.gmail.com>

On 31/01/23 00:15, Dionna Amalie Glaze wrote:
>> +static int snp_send_guest_request(struct snp_guest_dev *snp_dev, struct snp_guest_req *req)
>>  {
>>         unsigned long err;
>>         u64 seqno;
>>         int rc;
>>
>> +       if (!snp_dev || !req)
>> +               return -ENODEV;
>> +
>>         /* Get message sequence and verify that its a non-zero */
>>         seqno = snp_get_msg_seqno(snp_dev);
>>         if (!seqno)
>> @@ -261,7 +253,7 @@ 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;
>>
>> @@ -271,7 +263,7 @@ static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, in
>>          * 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);
>>
>>         /*
>>          * If the extended guest request fails due to having too small of a
>> @@ -279,11 +271,11 @@ static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, in
>>          * extended data request in order to increment the sequence number
>>          * and thus avoid IV reuse.
>>          */
>> -       if (exit_code == SVM_VMGEXIT_EXT_GUEST_REQUEST &&
>> +       if (req->exit_code == SVM_VMGEXIT_EXT_GUEST_REQUEST &&
>>             err == SNP_GUEST_REQ_INVALID_LEN) {
>>                 const unsigned int certs_npages = snp_dev->input.data_npages;
>>
>> -               exit_code = SVM_VMGEXIT_GUEST_REQUEST;
>> +               req->exit_code = SVM_VMGEXIT_GUEST_REQUEST;
>>
>>                 /*
>>                  * If this call to the firmware succeeds, the sequence number can
>> @@ -293,7 +285,7 @@ static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, in
>>                  * of the VMPCK and the error code being propagated back to the
>>                  * user as an ioctl() return code.
>>                  */
>> -               rc = snp_issue_guest_request(exit_code, &snp_dev->input, &err);
>> +               rc = snp_issue_guest_request(req->exit_code, &snp_dev->input, &err);
>>
> 
> This is going to have a merge conflict with "[PATCH v13 1/4]
> virt/coco/sev-guest: Add throttling awareness", which is an important
> fix to ensure hosts are allowed to throttle guest requests and guests
> are able to retry instead of disabling the vmpck. I think that set of
> patches, or at least the first patch, is going to be going in before
> this series. Please be aware.

Yes, I am aware of the series. I can rebase my patches once that goes in.

Regards
Nikunj