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References: <20230605195925.51625-1-brett.creeley@amd.com>
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From:   Jason Wang <jasowang@redhat.com>
Date:   Tue, 6 Jun 2023 09:44:05 +0800
Message-ID: <CACGkMEvbWLZHeGww5_39BDkuKE1_L5YGAF6Wxq0u1cXPgdgf5g@mail.gmail.com>
Subject: Re: [PATCH net] virtio_net: use control_buf for coalesce params
To:     Brett Creeley <brett.creeley@amd.com>
Cc:     linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
        virtualization@lists.linux-foundation.org,
        alvaro.karsz@solid-run.com, pabeni@redhat.com, kuba@kernel.org,
        edumazet@google.com, davem@davemloft.net,
        xuanzhuo@linux.alibaba.com, mst@redhat.com, shannon.nelson@amd.com,
        allen.hubbe@amd.com
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On Tue, Jun 6, 2023 at 3:59=E2=80=AFAM Brett Creeley <brett.creeley@amd.com=
> wrote:
>
> Commit 699b045a8e43 ("net: virtio_net: notifications coalescing
> support") added coalescing command support for virtio_net. However,
> the coalesce commands are using buffers on the stack, which is causing
> the device to see DMA errors. There should also be a complaint from
> check_for_stack() in debug_dma_map_xyz(). Fix this by adding and using
> coalesce params from the control_buf struct, which aligns with other
> commands.
>
> Fixes: 699b045a8e43 ("net: virtio_net: notifications coalescing support")
> Reviewed-by: Shannon Nelson <shannon.nelson@amd.com>
> Signed-off-by: Allen Hubbe <allen.hubbe@amd.com>
> Signed-off-by: Brett Creeley <brett.creeley@amd.com>
> ---
>  drivers/net/virtio_net.c | 16 ++++++++--------

The patch is needed for -stable I think.

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

Thanks

>  1 file changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 56ca1d270304..486b5849033d 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -205,6 +205,8 @@ struct control_buf {
>         __virtio16 vid;
>         __virtio64 offloads;
>         struct virtio_net_ctrl_rss rss;
> +       struct virtio_net_ctrl_coal_tx coal_tx;
> +       struct virtio_net_ctrl_coal_rx coal_rx;
>  };
>
>  struct virtnet_info {
> @@ -2934,12 +2936,10 @@ static int virtnet_send_notf_coal_cmds(struct vir=
tnet_info *vi,
>                                        struct ethtool_coalesce *ec)
>  {
>         struct scatterlist sgs_tx, sgs_rx;
> -       struct virtio_net_ctrl_coal_tx coal_tx;
> -       struct virtio_net_ctrl_coal_rx coal_rx;
>
> -       coal_tx.tx_usecs =3D cpu_to_le32(ec->tx_coalesce_usecs);
> -       coal_tx.tx_max_packets =3D cpu_to_le32(ec->tx_max_coalesced_frame=
s);
> -       sg_init_one(&sgs_tx, &coal_tx, sizeof(coal_tx));
> +       vi->ctrl->coal_tx.tx_usecs =3D cpu_to_le32(ec->tx_coalesce_usecs)=
;
> +       vi->ctrl->coal_tx.tx_max_packets =3D cpu_to_le32(ec->tx_max_coale=
sced_frames);
> +       sg_init_one(&sgs_tx, &vi->ctrl->coal_tx, sizeof(vi->ctrl->coal_tx=
));
>
>         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
>                                   VIRTIO_NET_CTRL_NOTF_COAL_TX_SET,
> @@ -2950,9 +2950,9 @@ static int virtnet_send_notf_coal_cmds(struct virtn=
et_info *vi,
>         vi->tx_usecs =3D ec->tx_coalesce_usecs;
>         vi->tx_max_packets =3D ec->tx_max_coalesced_frames;
>
> -       coal_rx.rx_usecs =3D cpu_to_le32(ec->rx_coalesce_usecs);
> -       coal_rx.rx_max_packets =3D cpu_to_le32(ec->rx_max_coalesced_frame=
s);
> -       sg_init_one(&sgs_rx, &coal_rx, sizeof(coal_rx));
> +       vi->ctrl->coal_rx.rx_usecs =3D cpu_to_le32(ec->rx_coalesce_usecs)=
;
> +       vi->ctrl->coal_rx.rx_max_packets =3D cpu_to_le32(ec->rx_max_coale=
sced_frames);
> +       sg_init_one(&sgs_rx, &vi->ctrl->coal_rx, sizeof(vi->ctrl->coal_rx=
));
>
>         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
>                                   VIRTIO_NET_CTRL_NOTF_COAL_RX_SET,
> --
> 2.17.1
>