[dpdk-dev] [PATCH v2 3/3] net/vhost: fix interrupt mode

[Matan Azrad]

From: Maxime Coquelin:
> At .new_device() time, only the first vring pair is now ready, other vrings are
> consfigured later.
> 
> Problem is that when application will setup and enable interrupts, only the
> first queue pair Rx interrupt will be enabled.
> 
> This patches fixes the issue by setting the number of max interrupts to the
> number of Rx queues that will be later initialized. Then, as soon as a Rx vring
> is ready, it removes the corresponding uninitialized epoll event, and install a
> new one with the valid FD.

Doesn't it race condition to the application decision?
App may change the configuration per queue in any time by the app control thread.
The vhost PMD may change it usynchronically from the vhost control thread in the vring state callback.

I already mentioned it in other thread on this topic but didn't get reply.

> Fixes: 604052ae5395 ("net/vhost: support queue update")
> 
> Signed-off-by: Maxime Coquelin <maxime.coquelin at redhat.com>