From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34243) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZeZVn-0008VY-OE for qemu-devel@nongnu.org; Tue, 22 Sep 2015 22:10:24 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZeZVj-0007tz-OD for qemu-devel@nongnu.org; Tue, 22 Sep 2015 22:10:23 -0400 Received: from mga02.intel.com ([134.134.136.20]:40724) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZeZVj-0007tR-Ie for qemu-devel@nongnu.org; Tue, 22 Sep 2015 22:10:19 -0400 Date: Wed, 23 Sep 2015 10:12:29 +0800 From: Yuanhan Liu Message-ID: <20150923021229.GD2339@yliu-dev.sh.intel.com> References: <1442588324-11365-1-git-send-email-yuanhan.liu@linux.intel.com> <1442588324-11365-8-git-send-email-yuanhan.liu@linux.intel.com> <560169E8.6020006@redhat.com> <20150923020502.GB2339@yliu-dev.sh.intel.com> <56020942.10701@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <56020942.10701@redhat.com> Subject: Re: [Qemu-devel] [PATCH v10 7/7] vhost-user: add a new message to disable/enable a specific virt queue. List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Blake , mst@redhat.com Cc: jasowang@redhat.com, qemu-devel@nongnu.org, Changchun.ouyang@hotmail.com, Changchun Ouyang 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 > > > > 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