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

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Mar 08, 2023 at 02:05:01PM +0100, Jiri Pirko wrote:
> Wed, Mar 08, 2023 at 01:59:10PM CET, david.edmondson@oracle.com wrote:
> >"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
> 
> What is that point, I'm curious.
> 
> 
> >LIST_QUERY. What's the purpose of this?
> 
> I think that this might be just for the sake of treating all
> commands equally.
> 

Right. There was this vague idea that blocking all commands
is good to have. E.g. if you are making some drastic
changes to the device?


> >-- 
> >Time is waiting to explain, why refuse?
> >
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