Hi Michael, On Wed, Jul 8, 2015 at 4:29 PM, Michael S. Tsirkin <m...@redhat.com> wrote: > On Thu, May 28, 2015 at 09:23:06AM +0800, Ouyang Changchun wrote: >> Based on patch by Nikolay Nikolaev: >> Vhost-user will implement the multi queue support in a similar way >> to what vhost already has - a separate thread for each queue. >> To enable the multi queue functionality - a new command line parameter >> "queues" is introduced for the vhost-user netdev. >> >> Signed-off-by: Nikolay Nikolaev <n.nikol...@virtualopensystems.com> >> Signed-off-by: Changchun Ouyang <changchun.ouy...@intel.com> > > So testing turned up a significant issue with the protocol extension in this > one. Specifically, remote has no idea how many queues guest actually > wants to use (it's dynamic, guest changes this at any time). > We need support for enabling and disabling queues dynamically. > > Given we are past hard freeze, and given no one uses this yet > (dpdk upstream did not merge supporting protocol), > I think the best thing to do is to disable this functionality for 2.4. > I will send a patch to do this shortly.
You are making a wrong statement, we already use multiqueue for vhost-user and we expected to have this support officially integrated in qemu 2.4. Libvirt 1.2.17 has been released with multiqueue support for vhost-user. (http://libvirt.org/git/?p=libvirt.git;a=commit;h=366c22f2bcf1ddb8253c123f93fd18d1ba9eacd6) It checks against the version of qemu (i.e. 2.4) to know if multiqueue is supported or not by qemu. (http://libvirt.org/git/?p=libvirt.git;a=commitdiff;h=7971723b985b9adc27122a3503e7ab38ced2b57f;hp=e7f5510ef2d28ca0ae0ed5751b1fd3018130d6c1) Dynamically enabling/disabling queue between host/guest is a nice feature to have. But it's not mandatory. You can still configure manually guest and host to use the same number of queues. I think this feature can be implemented later in qemu 2.5. Regards, Maxime