netdev - Re: [PATCH net-next v2 1/2] virtio_net: introduce ability to get reply info from device

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CACGkMEvUT_uyLaqi533BUOqCYW1dYZTqdW_CC3-LgQXhhdJYFw@mail.gmail.com>
Date: Tue, 7 May 2024 14:24:19 +0800
From: Jason Wang <jasowang@...hat.com>
To: Heng Qi <hengqi@...ux.alibaba.com>
Cc: netdev@...r.kernel.org, virtualization@...ts.linux.dev, 
	"Michael S . Tsirkin" <mst@...hat.com>, Xuan Zhuo <xuanzhuo@...ux.alibaba.com>, 
	Eric Dumazet <edumazet@...gle.com>, "David S . Miller" <davem@...emloft.net>, 
	Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>
Subject: Re: [PATCH net-next v2 1/2] virtio_net: introduce ability to get
 reply info from device

On Fri, Apr 26, 2024 at 2:54 PM Heng Qi <hengqi@...ux.alibaba.com> wrote:
>
> From: Xuan Zhuo <xuanzhuo@...ux.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 <xuanzhuo@...ux.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
>