Re: [RFC PATCH 4/4] virtio-net: sleep instead of busy waiting for cvq command
From: Jason Wang <jasowang@redhat.com>
Date: 2022-12-23 03:01:58
Also in:
lkml, virtualization
From: Jason Wang <jasowang@redhat.com>
Date: 2022-12-23 03:01:58
Also in:
lkml, virtualization
On Thu, Dec 22, 2022 at 11:55 PM Alvaro Karsz [off-list ref] wrote:
My point is that the device may complete the control command after the timeout,
This needs to be proposed to the virtio spec first. And actually we need more than this: 1) we still need a way to deal with the device without this feature 2) driver can't depend solely on what is advertised by the device (e.g device can choose to advertise a very long timeout)
so, if I'm not mistaken, next time we send a control command and call virtqueue_wait_for_used we'll get the previous response.
In the next version, I will first put BAD_RING() to prevent future requests for cvq. Note that the patch can't fix all the issues, we need more things on top. But it's a good step and it will behave much better than the current code. Thanks