Messages in this thread | | | Date | Mon, 30 Jul 2012 11:26:43 +0800 | From | Jason Wang <> | Subject | Re: [net-next RFC V5 4/5] virtio_net: multiqueue support |
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On 07/29/2012 05:44 PM, Michael S. Tsirkin wrote: > On Sat, Jul 21, 2012 at 02:02:58PM +0200, Sasha Levin wrote: >> On 07/20/2012 03:40 PM, Michael S. Tsirkin wrote: >>>> - err = init_vqs(vi); >>>>> + 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.
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