On Mon, Aug 31, 2015 at 02:30:06PM +0300, Michael S. Tsirkin wrote: [snip..] > > Then how about the other case: > > When startup the vhost backend, user specify 8 queues, like: > > Vhost-user ... -queues 8 # Y=8 > > When startup the guest, user specify 4 queues, like: > > Qemu-kvm ... -queues 4 # X=4 > > > > Vhost backend CAN support the queues number as much as the guest/qemu > > requires, > > And qemu don't want enable all of them(8 in the case), just part of > > them(only 4 from 8). > > Will qemu exit or go forward(of course with 4 queues)? > > I think it must go forward since guest does not have to > configure all queues anyway - and that's built in to virtio spec. > > Note that # of queues in actual use in fact changes dynamically > too, without restaring the device.
May I know how do you do that? I mean, is there a public interface, like by some commands? Or, by sending vhost messages? --yliu