Re: [Qemu-devel] [PATCH for-2.4 06/12] etsec: Flush queue when rx buffer is consumed

[Jason Wang <jasowang@redhat.com>]

On 07/14/2015 03:53 PM, Fam Zheng wrote:
> The BH will be scheduled when etsec->rx_buffer_len is becoming 0, which
> is the condition of queuing.
>
> Signed-off-by: Fam Zheng <famz@redhat.com>

I suggest to squash this into patch 05/12 to unbreak bisection.

And can we do this without a bh? Otherwise, we may need to stop and
restart the bh during vm stop and start?

> ---
>  hw/net/fsl_etsec/etsec.c | 9 +++++++++
>  hw/net/fsl_etsec/etsec.h | 2 ++
>  hw/net/fsl_etsec/rings.c | 1 +
>  3 files changed, 12 insertions(+)
>
> diff --git a/hw/net/fsl_etsec/etsec.c b/hw/net/fsl_etsec/etsec.c
> index f5170ae..fcde9b4 100644
> --- a/hw/net/fsl_etsec/etsec.c
> +++ b/hw/net/fsl_etsec/etsec.c
> @@ -366,6 +366,13 @@ static NetClientInfo net_etsec_info = {
>      .link_status_changed = etsec_set_link_status,
>  };
>  
> +static void etsec_flush_rx_queue(void *opaque)
> +{
> +    eTSEC *etsec = opaque;
> +
> +    qemu_flush_queued_packets(qemu_get_queue(etsec->nic));
> +}
> +
>  static void etsec_realize(DeviceState *dev, Error **errp)
>  {
>      eTSEC        *etsec = ETSEC_COMMON(dev);
> @@ -378,6 +385,8 @@ static void etsec_realize(DeviceState *dev, Error **errp)
>      etsec->bh     = qemu_bh_new(etsec_timer_hit, etsec);
>      etsec->ptimer = ptimer_init(etsec->bh);
>      ptimer_set_freq(etsec->ptimer, 100);
> +
> +    etsec->flush_bh = qemu_bh_new(etsec_flush_rx_queue, etsec);
>  }
>  
>  static void etsec_instance_init(Object *obj)
> diff --git a/hw/net/fsl_etsec/etsec.h b/hw/net/fsl_etsec/etsec.h
> index fc41773..05bb7f8 100644
> --- a/hw/net/fsl_etsec/etsec.h
> +++ b/hw/net/fsl_etsec/etsec.h
> @@ -144,6 +144,8 @@ typedef struct eTSEC {
>      QEMUBH *bh;
>      struct ptimer_state *ptimer;
>  
> +    QEMUBH *flush_bh;
> +
>  } eTSEC;
>  
>  #define TYPE_ETSEC_COMMON "eTSEC"
> diff --git a/hw/net/fsl_etsec/rings.c b/hw/net/fsl_etsec/rings.c
> index a11280b..7aae93e 100644
> --- a/hw/net/fsl_etsec/rings.c
> +++ b/hw/net/fsl_etsec/rings.c
> @@ -646,6 +646,7 @@ void etsec_walk_rx_ring(eTSEC *etsec, int ring_nbr)
>      } else {
>          etsec->rx_buffer_len = 0;
>          etsec->rx_buffer     = NULL;
> +        qemu_bh_schedule(etsec->flush_bh);
>      }
>  
>      RING_DEBUG("eTSEC End of ring_write: remaining_data:%zu\n", remaining_data);