Re: [virtio-dev] Re: [PATCH v9 03/10] admin: introduce group administration commands

[Jason Wang <jasowang@redhat.com>]

å 2022/11/24 20:21, Cornelia Huck åé:
> On Thu, Nov 24 2022, Jason Wang <jasowang@redhat.com> wrote:
>
> > On Thu, Nov 24, 2022 at 5:08 AM Michael S. Tsirkin <mst@redhat.com> wrote:
> > > +All the group administration commands are of the following form:
> > > +
> > > +\begin{lstlisting}
> > > +struct virtio_admin_cmd {
> > > +        /* Device-readable part */
> > > +        le16 opcode;
> > > +        /*
> > > +         * 1 - SR-IOV
> > > +         * 2 - 65535 reserved
> > > +         */
> > > +        le16 group_type;
> > > +        /* unused, reserved for future extensions */
> > > +        u8 reserved1[12];
> > > +        le64 group_member_id;
> > > +        u8 command_specific_data[];
> > > +
> > > +        /* Device-writable part */
> > > +        le16 status;
> > > +        le16 status_qualifier;
> > > +        /* unused, reserved for future extensions */
> > > +        u8 reserved2[4];
> > > +        u8 command_specific_result[];
> > > +};
> > > +\end{lstlisting}
> > > +
> > > +For all commands, \field{opcode}, \field{group_type} and if
> > > +necessary \field{group_member_id} and \field{command_specific_data} are
> > > +set by the driver, and the owner device sets \field{status} and if
> > > +needed \field{status_qualifier} and
> > > +\field{command_specific_result}.
> > > +
> > > +As a rule, any unused device-readable fields are set to zero by the driver
> > > +and ignored by the device.  Any unused device-writeable fields are set to zero
> > > +by the device and ignored by the driver.
> > > +
> > > +\field{opcode} specifies the command. The valid
> > > +values for \field{opcode} can be found in the following table:
> > > +
> > > +\begin{tabular}{|l|l|}
> > > +\hline
> > > +opcode & Name & Command Description \\
> > > +\hline \hline
> > > +0x0000 - 0x7FFF & - &  Group administration commands    \\
> > > +\hline
> > > +0x8000 - 0xFFFF & - & Reserved    \\
> > > +\hline
> > > +\end{tabular}
> > > +
> > > +The \field{group_type} specifies the group type identifier.
> > So this means there's no way for having a group specific adminq? E.g
> > one queue for SR-IOV and another for SIOV.
> I don't see anything that prevents the device from exposing two admin
> queues... do you mean that we should provide a mechanism for the device
> to mandate that only commands for a certain group id can go on a certain
> admin queue?


Yes, and rethink about this, it seems to be possible by only returning 
the specific commands for a single type of group via query.

Thanks


> > > +The \field{group_member_id} specifies the member identifier within the group.
> > > +See section \ref{sec:Introduction / Terminology / Device group}
> > > +for the definition of the group type identifier and group member
> > > +identifier.