Re: [Xen-devel] [PATCH net-next v6 8/10] xen-netback: Add stat counters for frag_list skbs

From: Konrad Rzeszutek Wilk
Date: Tue Mar 04 2014 - 21:18:07 EST



On Mar 4, 2014 5:32 PM, Zoltan Kiss <zoltan.kiss@xxxxxxxxxx> wrote:
>
> These counters help determine how often the guest sends a packet with more
> than MAX_SKB_FRAGS frags.
>
> NOTE: if bisect brought you here, you should apply the series up until #9,

s/#9/"the name of the patch.."

> otherwise malicious guests can block other guests by not releasing their sent
> packets.
>
> Signed-off-by: Zoltan Kiss <zoltan.kiss@xxxxxxxxxx>
> ---
> drivers/net/xen-netback/common.hÂÂÂ |ÂÂÂ 1 +
> drivers/net/xen-netback/interface.c |ÂÂÂ 7 +++++++
> drivers/net/xen-netback/netback.cÂÂ |ÂÂÂ 1 +
> 3 files changed, 9 insertions(+)
>
> diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h
> index eac171e..d8a2298 100644
> --- a/drivers/net/xen-netback/common.h
> +++ b/drivers/net/xen-netback/common.h
> @@ -170,6 +170,7 @@ struct xenvif {
> unsigned long tx_zerocopy_sent;
> unsigned long tx_zerocopy_success;
> unsigned long tx_zerocopy_fail;
> + unsigned long tx_frag_overflow;
>
> /* Miscellaneous private stuff. */
> struct net_device *dev;
> diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
> index adfed30..ba5be2f 100644
> --- a/drivers/net/xen-netback/interface.c
> +++ b/drivers/net/xen-netback/interface.c
> @@ -252,6 +252,13 @@ static const struct xenvif_stat {
> "tx_zerocopy_fail",
> offsetof(struct xenvif, tx_zerocopy_fail)
> },
> + /* Number of packets exceeding MAX_SKB_FRAG slots. You should use
> + * a guest with the same MAX_SKB_FRAG
> + */
> + {
> + "tx_frag_overflow",
> + offsetof(struct xenvif, tx_frag_overflow)
> + },
> };
>
> static int xenvif_get_sset_count(struct net_device *dev, int string_set)
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxx
> http://lists.xen.org/xen-devel