On Fri, Sep 22, 2023 at 5:56 PM Xuan Zhuo <xuanz...@linux.alibaba.com> wrote: > > On Fri, 22 Sep 2023 15:32:39 +0800, Jason Wang <jasow...@redhat.com> wrote: > > On Fri, Sep 22, 2023 at 1:02 PM Heng Qi <hen...@linux.alibaba.com> wrote: > > > > > > > > > > > > 在 2023/9/22 下午12:29, Jason Wang 写道: > > > > On Tue, Sep 19, 2023 at 3:49 PM Heng Qi <hen...@linux.alibaba.com> > > > > 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? > > > > > > 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. > > > > How can we make sure the old coalescing parameters still make sense > > for the new ring size? > > For the user, I don't think we should drop the config for the coalescing. > Maybe the config does not make sense for the new ring size, but when the user > just change the ring size, the config for the coalesing is missing, I think > that is not good.
How did other drivers deal with this? Thanks > > Thanks. > > > > > > > > Thanks > > > > > > > > Thanks! > > > > > > > > > > > Thanks > > > > > > _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
