Re: [PATCH RFC 2/3] vdpa: Restore packet receive filtering state relative with _F_CTRL_RX feature

[Eugenio Perez Martin]

On Thu, Jun 22, 2023 at 5:02 AM Hawkins Jiawei <yin31149@gmail.com> wrote:
>
> This patch introduces vhost_vdpa_net_load_rx_mode()
> and vhost_vdpa_net_load_rx() to restore the packet
> receive filtering state in relation to
> VIRTIO_NET_F_CTRL_RX feature at device's startup.
>
> Signed-off-by: Hawkins Jiawei <yin31149@gmail.com>
> ---
>  net/vhost-vdpa.c | 74 ++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 74 insertions(+)
>
> diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
> index 10264d3e96..355a6aef15 100644
> --- a/net/vhost-vdpa.c
> +++ b/net/vhost-vdpa.c
> @@ -754,6 +754,76 @@ static int vhost_vdpa_net_load_offloads(VhostVDPAState 
> *s,
>      return *s->status != VIRTIO_NET_OK;
>  }
>
> +static int vhost_vdpa_net_load_rx_mode(VhostVDPAState *s,
> +                                       uint8_t cmd,
> +                                       uint8_t on)
> +{
> +    ssize_t dev_written;
> +    dev_written = vhost_vdpa_net_load_cmd(s, VIRTIO_NET_CTRL_RX,
> +                                          cmd, &on, sizeof(on));
> +    if (unlikely(dev_written < 0)) {
> +        return dev_written;
> +    }
> +    if (*s->status != VIRTIO_NET_OK) {
> +        return -EINVAL;
> +    }
> +
> +    return 0;
> +}
> +
> +static int vhost_vdpa_net_load_rx(VhostVDPAState *s,
> +                                  const VirtIONet *n)
> +{
> +    uint8_t on;
> +    int r;
> +
> +    if (virtio_vdev_has_feature(&n->parent_obj, VIRTIO_NET_F_CTRL_RX)) {
> +        /* Load the promiscous mode */
> +        if (n->mac_table.uni_overflow) {
> +            /*
> +             * According to VirtIO standard, "Since there are no guarantees,
> +             * it can use a hash filter or silently switch to
> +             * allmulti or promiscuous mode if it is given too many 
> addresses."
> +             *
> +             * QEMU ignores non-multicast(unicast) MAC addresses and
> +             * marks `uni_overflow` for the device internal state
> +             * if guest sets too many non-multicast(unicast) MAC addresses.
> +             * Therefore, we should turn promiscous mode on in this case.
> +             */
> +            on = 1;
> +        } else {
> +            on = n->promisc;
> +        }
> +        r = vhost_vdpa_net_load_rx_mode(s, VIRTIO_NET_CTRL_RX_PROMISC, on);
> +        if (r < 0) {
> +            return r;
> +        }
> +
> +        /* Load the all-multicast mode */
> +        if (n->mac_table.multi_overflow) {
> +            /*
> +             * According to VirtIO standard, "Since there are no guarantees,
> +             * it can use a hash filter or silently switch to
> +             * allmulti or promiscuous mode if it is given too many 
> addresses."
> +             *
> +             * QEMU ignores multicast MAC addresses and
> +             * marks `multi_overflow` for the device internal state
> +             * if guest sets too many multicast MAC addresses.
> +             * Therefore, we should turn all-multicast mode on in this case.
> +             */
> +            on = 1;
> +        } else {
> +            on = n->allmulti;
> +        }
> +        r = vhost_vdpa_net_load_rx_mode(s, VIRTIO_NET_CTRL_RX_ALLMULTI, on);
> +        if (r < 0) {
> +            return r;
> +        }

Can we skip the sending of the CVQ commands if the state matches the
default state?

Thanks!

> +    }
> +
> +    return 0;
> +}
> +
>  static int vhost_vdpa_net_load(NetClientState *nc)
>  {
>      VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
> @@ -780,6 +850,10 @@ static int vhost_vdpa_net_load(NetClientState *nc)
>      if (unlikely(r)) {
>          return r;
>      }
> +    r = vhost_vdpa_net_load_rx(s, n);
> +    if (unlikely(r)) {
> +        return r;
> +    }
>
>      return 0;
>  }
> --
> 2.25.1
>