Re: [virtio-comment] [PATCH v10 09/10] admin: conformance clauses

[David Edmondson <david.edmondson@oracle.com>]

"Michael S. Tsirkin" <mst@redhat.com> writes:

> On Tue, Mar 07, 2023 at 11:04:33AM +0000, David Edmondson wrote:
>> "Michael S. Tsirkin" <mst@redhat.com> writes:
>> > +The driver MAY block use of VIRTIO_ADMIN_CMD_LIST_QUERY and
>> > +VIRTIO_ADMIN_CMD_LIST_USE by issuing VIRTIO_ADMIN_CMD_LIST_USE
>> > +with respective bits cleared in \field{command_specific_data}.
>> 
>> This runs contrary to the assertion "The list of supported commands MUST
>> NOT shrink", given that a driver is told to assume that
>> VIRTIO_ADMIN_CMD_LIST_QUERY and VIRTIO_ADMIN_CMD_LIST_USE are the only
>> commands initially available.
>
> Commands are still available just disabled, the meaning of
> "MUST NOT shrink" is clarified by the following:
>
> 	> > +after reporting a given command as supported through
> 	> > +VIRTIO_ADMIN_CMD_LIST_QUERY the device MUST NOT later report it
> 	> > +as unsupported.
> I will stick an "i.e." there to make it hopefully clearer.

This puzzles me.

I can see the point of blocking LIST_USE, but not of blocking
LIST_QUERY. What's the purpose of this?
-- 
Time is waiting to explain, why refuse?