在 2023/9/22 下午12:29, Jason Wang 写道:

On Tue, Sep 19, 2023 at 3:49 PM Heng Qi [off-list ref] wrote:

quoted

According to the definition of virtqueue coalescing spec[1]:

   Upon disabling and re-enabling a transmit virtqueue, the device MUST set
   the coalescing parameters of the virtqueue to those configured through the
   VIRTIO_NET_CTRL_NOTF_COAL_TX_SET command, or, if the driver did not set
   any TX coalescing parameters, to 0.

   Upon disabling and re-enabling a receive virtqueue, the device MUST set
   the coalescing parameters of the virtqueue to those configured through the
   VIRTIO_NET_CTRL_NOTF_COAL_RX_SET command, or, if the driver did not set
   any RX coalescing parameters, to 0.

We need to add this setting for vq resize (ethtool -G) where vq_reset happens.

[1] https://lists.oasis-open.org/archives/virtio-dev/202303/msg00415.html

Fixes: 394bd87764b6 ("virtio_net: support per queue interrupt coalesce command")

I'm not sure this is a real fix as spec allows it to go zero?

The spec says that if the user has configured interrupt coalescing 
parameters,
parameters need to be restored after vq_reset, otherwise set to 0.
vi->intr_coal_tx and vi->intr_coal_rx always save the newest global 
parameters,
regardless of whether the command is sent or not. So I think we need 
this patch
it complies with the specification requirements.

Thanks!

Thanks