On 07/29/2012 05:44 PM, Michael S. Tsirkin wrote:
On Sat, Jul 21, 2012 at 02:02:58PM +0200, Sasha Levin wrote:
quoted
On 07/20/2012 03:40 PM, Michael S. Tsirkin wrote:
quoted
quoted
- err = init_vqs(vi);
quoted
+ if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
+ vi->has_cvq = true;
+
How about we disable multiqueue if there's no cvq?
Will make logic a bit simpler, won't it?
multiqueues don't really depend on cvq. Does this added complexity really justifies adding an artificial limit?
Well !cvq support is a legacy feature: the reason we support it
in driver is to avoid breaking on old hosts. Adding more code to that
path just doesn't make much sense since old hosts won't have mq.
After some thought about this, maybe there's no need to the cvq for the negotiation if we want support only two modes ( 1 tx/rx queue pair and N tx/rx queue pairs). We can do this just through the feature bit negotiation.