Re: [virtio-comment] [PATCH] vsock: add documentation about len header field

[Cornelia Huck <cohuck@redhat.com>]

On Tue, Mar 29 2022, Laura Loghin <lauralg@amazon.com> wrote:

> On 3/28/22 14:09, Stefano Garzarella wrote:
>> CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you can confirm the sender and know the content is safe.
>>
>>
>>
>> Hi Laura,
>>
>> On Tue, Mar 22, 2022 at 10:50 AM Laura Loghin<lauralg@amazon.com>  wrote:
>>> Signed-off-by: Laura Loghin<lauralg@amazon.com>
>>> ---
>>>   virtio-vsock.tex | 5 +++++
>>>   1 file changed, 5 insertions(+)
>>>
>>> diff --git a/virtio-vsock.tex b/virtio-vsock.tex
>>> index d79984d..e32cad8 100644
>>> --- a/virtio-vsock.tex
>>> +++ b/virtio-vsock.tex
>>> @@ -107,6 +107,11 @@ \subsection{Device Operation}\label{sec:Device Types / Socket Device / Device Op
>>>   #define VIRTIO_VSOCK_OP_CREDIT_REQUEST 7
>>>   \end{lstlisting}
>>>
>>> +\field{len} is the size of the payload, in bytes. However, the driver may
>>> +provide buffer(s) for the payload that have a total size longer than
>>> +\field{len}. If that is the case, only the first \field{len} bytes MUST be
>>> +used for the actual data.
>>> +
>> IIUC MUST and friends are for normative sections, so I would remove
>> the last sentence.
>
> You're right, I'll remove it. It should already be clear enough only the
> first len bytes need to be used for the payload.

Another option would be

"However, the driver may provide buffer(s) for the payload that have a
total size longer than \field{len}, in which case only the first
\field{len} bytes will be used for the actual data."