On Tue, Sep 22, 2015 at 08:06:58PM -0600, Eric Blake wrote:
> On 09/22/2015 08:05 PM, Yuanhan Liu wrote:
>
> >>> + * VHOST_USER_SET_VRING_ENABLE
> >>> +
> >>> + Id: 18
> >>> + Equivalent ioctl: N/A
> >>> + Master payload: vring state description
> >>> +
> >>> + Signal slave to enable or disable corresponding vring.
> >>
> >> Does there need to be any QMP control to manually change a given queue,
> >> or is it all used under the hood with no need for management apps to
> >> care other than their initial request of max queues?
> >
> > TBH, I don't know. As far as I know, there is only one queue pair will
> > be enabled by default, and it's user's job to enable (or disable) more
> > queue pairs, say, by ethtool:
> >
> > # ethtool -L eth0 combined <queue pair number>
> >
> > Which ends up sending the VHOST_USER_SET_VRING_ENABLE to actually enable
> > (or disable) a specific queue pairs.
>
> So if I'm understanding, it is ethtool, not qemu, that is used to turn
> on additional queues, and therefore we don't need a QMP command in qemu
> to control things.
I guess so, and that's what Michael told me before.
> > Does that answer your question?
>
> I think so, but I'll let other reviewers more familiar with this area of
> code give a final say.
Michael?
--yliu
