Re: [PATCH 1/2] hw/net/net_tx_pkt: add function to check pkt->max_raw_frags

[Jason Wang <jasowang@redhat.com>]

On 2020/7/28 上午1:08, Mauro Matteo Cascella wrote:
> This patch introduces a new function in hw/net/net_tx_pkt.{c,h} to check the
> current data fragment against the maximum number of data fragments.


I wonder whether it's better to do the check in 
net_tx_pkt_add_raw_fragment() and fail there.

Btw, I find net_tx_pkt_add_raw_fragment() does not unmap dma when 
returning to true, is this a bug?

Thanks


>
> Reported-by: Ziming Zhang <ezrakiez@gmail.com>
> Signed-off-by: Mauro Matteo Cascella <mcascell@redhat.com>
> ---
>   hw/net/net_tx_pkt.c | 5 +++++
>   hw/net/net_tx_pkt.h | 8 ++++++++
>   2 files changed, 13 insertions(+)
>
> diff --git a/hw/net/net_tx_pkt.c b/hw/net/net_tx_pkt.c
> index 9560e4a49e..d035618f2c 100644
> --- a/hw/net/net_tx_pkt.c
> +++ b/hw/net/net_tx_pkt.c
> @@ -400,6 +400,11 @@ bool net_tx_pkt_add_raw_fragment(struct NetTxPkt *pkt, hwaddr pa,
>       }
>   }
>   
> +bool net_tx_pkt_exceed_max_fragments(struct NetTxPkt *pkt)
> +{
> +    return pkt->raw_frags >= pkt->max_raw_frags;
> +}
> +
>   bool net_tx_pkt_has_fragments(struct NetTxPkt *pkt)
>   {
>       return pkt->raw_frags > 0;
> diff --git a/hw/net/net_tx_pkt.h b/hw/net/net_tx_pkt.h
> index 4ec8bbe9bd..e2ee46ae03 100644
> --- a/hw/net/net_tx_pkt.h
> +++ b/hw/net/net_tx_pkt.h
> @@ -179,6 +179,14 @@ bool net_tx_pkt_send_loopback(struct NetTxPkt *pkt, NetClientState *nc);
>    */
>   bool net_tx_pkt_parse(struct NetTxPkt *pkt);
>   
> +/**
> +* indicates if the current data fragment exceeds max_raw_frags
> +*
> +* @pkt:            packet
> +*
> +*/
> +bool net_tx_pkt_exceed_max_fragments(struct NetTxPkt *pkt);
> +
>   /**
>   * indicates if there are data fragments held by this packet object.
>   *