On Fri, Apr 26, 2024 at 2:54 PM Heng Qi <hen...@linux.alibaba.com> wrote:
>
> From: Xuan Zhuo <xuanz...@linux.alibaba.com>
>
> As the spec
> https://github.com/oasis-tcs/virtio-spec/commit/42f389989823039724f95bbbd243291ab0064f82
>
> Based on the description provided in the above specification, we have
> enabled the virtio-net driver to support acquiring some response
> information from the device via the CVQ (Control Virtqueue).
>
> Signed-off-by: Xuan Zhuo <xuanz...@linux.alibaba.com>
I wonder if we need to tweak the spec as it has:
"""
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.
"""
So for reset, this patch tells us the device would have a non-zero
default value.
But spec tolds us after vq reset, it has a zero default value ...
Thanks
> ---
> drivers/net/virtio_net.c | 24 +++++++++++++++++-------
> 1 file changed, 17 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 7176b956460b..3bc9b1e621db 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -2527,11 +2527,12 @@ static int virtnet_tx_resize(struct virtnet_info *vi,
> * supported by the hypervisor, as indicated by feature bits, should
> * never fail unless improperly formatted.
> */
> -static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
> - struct scatterlist *out)
> +static bool virtnet_send_command_reply(struct virtnet_info *vi, u8 class, u8
> cmd,
> + struct scatterlist *out,
> + struct scatterlist *in)
> {
> - struct scatterlist *sgs[4], hdr, stat;
> - unsigned out_num = 0, tmp;
> + struct scatterlist *sgs[5], hdr, stat;
> + u32 out_num = 0, tmp, in_num = 0;
> int ret;
>
> /* Caller should know better */
> @@ -2549,10 +2550,13 @@ static bool virtnet_send_command(struct virtnet_info
> *vi, u8 class, u8 cmd,
>
> /* Add return status. */
> sg_init_one(&stat, &vi->ctrl->status, sizeof(vi->ctrl->status));
> - sgs[out_num] = &stat;
> + sgs[out_num + in_num++] = &stat;
>
> - BUG_ON(out_num + 1 > ARRAY_SIZE(sgs));
> - ret = virtqueue_add_sgs(vi->cvq, sgs, out_num, 1, vi, GFP_ATOMIC);
> + if (in)
> + sgs[out_num + in_num++] = in;
> +
> + BUG_ON(out_num + in_num > ARRAY_SIZE(sgs));
> + ret = virtqueue_add_sgs(vi->cvq, sgs, out_num, in_num, vi,
> GFP_ATOMIC);
> if (ret < 0) {
> dev_warn(&vi->vdev->dev,
> "Failed to add sgs for command vq: %d\n.", ret);
> @@ -2574,6 +2578,12 @@ static bool virtnet_send_command(struct virtnet_info
> *vi, u8 class, u8 cmd,
> return vi->ctrl->status == VIRTIO_NET_OK;
> }
>
> +static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
> + struct scatterlist *out)
> +{
> + return virtnet_send_command_reply(vi, class, cmd, out, NULL);
> +}
> +
> static int virtnet_set_mac_address(struct net_device *dev, void *p)
> {
> struct virtnet_info *vi = netdev_priv(dev);
> --
> 2.32.0.3.g01195cf9f
>
