Linux Virtualization - Mar 2023 - [PATCH net] virtio-net: unify notifications coalescing structs

On Sun, Mar 5, 2023 at 11:49?PM Alvaro Karsz <alvaro.karsz at
solid-run.com> wrote:
>
> Unify virtio_net_ctrl_coal_tx and virtio_net_ctrl_coal_rx structs into a
> single struct, virtio_net_ctrl_coal, as they are identical.
>
> This patch follows the VirtIO spec patch:
> https://lists.oasis-open.org/archives/virtio-comment/202302/msg00431.html
>
> Signed-off-by: Alvaro Karsz <alvaro.karsz at solid-run.com>
> ---
>  drivers/net/virtio_net.c        | 15 +++++++--------
>  include/uapi/linux/virtio_net.h | 24 +++++++-----------------
>  2 files changed, 14 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index fb5e68ed3ec..86b6b3e0257 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -2883,12 +2883,11 @@ static int virtnet_send_notf_coal_cmds(struct
virtnet_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;
> +       struct virtio_net_ctrl_coal coal_params;
>
> -       coal_tx.tx_usecs = cpu_to_le32(ec->tx_coalesce_usecs);
> -       coal_tx.tx_max_packets =
cpu_to_le32(ec->tx_max_coalesced_frames);
> -       sg_init_one(&sgs_tx, &coal_tx, sizeof(coal_tx));
> +       coal_params.max_usecs = cpu_to_le32(ec->tx_coalesce_usecs);
> +       coal_params.max_packets =
cpu_to_le32(ec->tx_max_coalesced_frames);
> +       sg_init_one(&sgs_tx, &coal_params, sizeof(coal_params));
>
>         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
>                                   VIRTIO_NET_CTRL_NOTF_COAL_TX_SET,
> @@ -2899,9 +2898,9 @@ static int virtnet_send_notf_coal_cmds(struct
virtnet_info *vi,
>         vi->tx_usecs = ec->tx_coalesce_usecs;
>         vi->tx_max_packets = ec->tx_max_coalesced_frames;
>
> -       coal_rx.rx_usecs = cpu_to_le32(ec->rx_coalesce_usecs);
> -       coal_rx.rx_max_packets =
cpu_to_le32(ec->rx_max_coalesced_frames);
> -       sg_init_one(&sgs_rx, &coal_rx, sizeof(coal_rx));
> +       coal_params.max_usecs = cpu_to_le32(ec->rx_coalesce_usecs);
> +       coal_params.max_packets =
cpu_to_le32(ec->rx_max_coalesced_frames);
> +       sg_init_one(&sgs_rx, &coal_params, sizeof(coal_params));
>
>         if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
>                                   VIRTIO_NET_CTRL_NOTF_COAL_RX_SET,
> diff --git a/include/uapi/linux/virtio_net.h
b/include/uapi/linux/virtio_net.h
> index b4062bed186..ce044260e02 100644
> --- a/include/uapi/linux/virtio_net.h
> +++ b/include/uapi/linux/virtio_net.h
> @@ -367,28 +367,18 @@ struct virtio_net_hash_config {
>   * Available with the VIRTIO_NET_F_NOTF_COAL feature bit.
>   */
>  #define VIRTIO_NET_CTRL_NOTF_COAL              6
> -/*
> - * Set the tx-usecs/tx-max-packets parameters.
> - */
> -struct virtio_net_ctrl_coal_tx {
> -       /* Maximum number of packets to send before a TX notification */
> -       __le32 tx_max_packets;
> -       /* Maximum number of usecs to delay a TX notification */
> -       __le32 tx_usecs;
> -};
Is this too late to be changed?

Thanks
> -
> -#define VIRTIO_NET_CTRL_NOTF_COAL_TX_SET               0
>
>  /*
> - * Set the rx-usecs/rx-max-packets parameters.
> + * Set the max_usecs/max_packets coalescing parameters for all
transmit/receive virtqueues.
>   */
> -struct virtio_net_ctrl_coal_rx {
> -       /* Maximum number of packets to receive before a RX notification */
> -       __le32 rx_max_packets;
> -       /* Maximum number of usecs to delay a RX notification */
> -       __le32 rx_usecs;
> +struct virtio_net_ctrl_coal {
> +       /* Maximum number of packets to send/receive before a TX/RX
notification */
> +       __le32 max_packets;
> +       /* Maximum number of microseconds to delay a TX/RX notification */
> +       __le32 max_usecs;
>  };
>
> +#define VIRTIO_NET_CTRL_NOTF_COAL_TX_SET               0
>  #define VIRTIO_NET_CTRL_NOTF_COAL_RX_SET               1
>
>  #endif /* _UAPI_LINUX_VIRTIO_NET_H */
> --
> 2.34.1
>

> Is this too late to be changed?
> 
> Thanks
You're right.
What do you suggest, dropping the patch or adding the unified struct without
deleting the existing ones?