Linux Virtualization - Oct 2023 - [PATCH net v2 5/6] virtio-net: fix the vq coalescing setting for vq resize

On Thu, Oct 5, 2023 at 2:12?PM Heng Qi <hengqi at linux.alibaba.com>
wrote:
>
>
>
> ? 2023/10/3 ??6:41, Paolo Abeni ??:
> > On Mon, 2023-09-25 at 15:53 +0800, Heng Qi 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")
> >> Cc: Gavin Li <gavinl at nvidia.com>
> >> Signed-off-by: Heng Qi <hengqi at linux.alibaba.com>
> > @Jason, since you commented on v1, waiting for your ack.
> >
> >> ---
> >>   drivers/net/virtio_net.c | 27 +++++++++++++++++++++++++++
> >>   1 file changed, 27 insertions(+)
> >>
> >> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> >> index 12ec3ae19b60..cb19b224419b 100644
> >> --- a/drivers/net/virtio_net.c
> >> +++ b/drivers/net/virtio_net.c
> >> @@ -2855,6 +2855,9 @@ static void virtnet_get_ringparam(struct
net_device *dev,
> >>      ring->tx_pending =
virtqueue_get_vring_size(vi->sq[0].vq);
> >>   }
> >>
> >> +static int virtnet_send_ctrl_coal_vq_cmd(struct virtnet_info *vi,
> >> +                                     u16 vqn, u32 max_usecs, u32
max_packets);
> >> +
> >>   static int virtnet_set_ringparam(struct net_device *dev,
> >>                               struct ethtool_ringparam *ring,
> >>                               struct kernel_ethtool_ringparam
*kernel_ring,
> >> @@ -2890,12 +2893,36 @@ static int virtnet_set_ringparam(struct
net_device *dev,
> >>                      err = virtnet_tx_resize(vi, sq,
ring->tx_pending);
> >>                      if (err)
> >>                              return err;
> >> +
> >> +                    /* 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.
> >> +                     */
> >> +                    err = virtnet_send_ctrl_coal_vq_cmd(vi,
txq2vq(i),
> >> +                                                       
vi->intr_coal_tx.max_usecs,
> >> +                                                       
vi->intr_coal_tx.max_packets);
> >> +                    if (err)
> >> +                            return err;
> >> +                    /* Save parameters */
> > As a very minor nit, I guess the comment could be dropped here
(similar
> > to patch 4/6). @Heng Qi: please don't repost just for this,
let's wait
> > for Jason' comments.
>
> Ok. We are currently on the National Day holiday, Jason may reply in a
> few days, thanks!
With the comments removed.

Acked-by: Jason Wang <jasowang at redhat.com>

Thanks
>
> > Cheers,
> >
> > Paolo
>