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

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?

Thanks