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* [dpdk-dev] [PATCH] net/mlx5: fix transmit descriptor with VLAN insertions
@ 2019-09-03 12:35 Viacheslav Ovsiienko
  2019-09-03 13:05 ` Matan Azrad
                   ` (2 more replies)
  0 siblings, 3 replies; 6+ messages in thread
From: Viacheslav Ovsiienko @ 2019-09-03 12:35 UTC (permalink / raw)
  To: dev; +Cc: matan, stable

If VLAN tag insertion transmit offload is engaged
(DEV_TX_OFFLOAD_VLAN_INSERT in tx queue configuration is set)
the transmit descriptor may be built with wrong format, due to
packet length is not adjusted. Also, the ring buffer wrapup
is not handled correctly.

Fixes: 18a1c20044c0 ("net/mlx5: implement Tx burst template")
Cc: stable@dpdk.org

Signed-off-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
---
 drivers/net/mlx5/mlx5_rxtx.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c
index 8ec90c3..f540977 100644
--- a/drivers/net/mlx5/mlx5_rxtx.c
+++ b/drivers/net/mlx5/mlx5_rxtx.c
@@ -2861,13 +2861,14 @@ enum mlx5_txcmp_code {
 	memcpy(pdst, buf, MLX5_DSEG_MIN_INLINE_SIZE);
 	buf += MLX5_DSEG_MIN_INLINE_SIZE;
 	pdst += MLX5_DSEG_MIN_INLINE_SIZE;
+	len -= MLX5_DSEG_MIN_INLINE_SIZE;
 	/* Insert VLAN ethertype + VLAN tag. Pointer is aligned. */
 	assert(pdst == RTE_PTR_ALIGN(pdst, MLX5_WSEG_SIZE));
+	if (unlikely(pdst >= (uint8_t *)txq->wqes_end))
+		pdst = (uint8_t *)txq->wqes;
 	*(uint32_t *)pdst = rte_cpu_to_be_32((RTE_ETHER_TYPE_VLAN << 16) |
 					      loc->mbuf->vlan_tci);
 	pdst += sizeof(struct rte_vlan_hdr);
-	if (unlikely(pdst >= (uint8_t *)txq->wqes_end))
-		pdst = (uint8_t *)txq->wqes;
 	/*
 	 * The WQEBB space availability is checked by caller.
 	 * Here we should be aware of WQE ring buffer wraparound only.
-- 
1.8.3.1


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [dpdk-dev] [PATCH] net/mlx5: fix transmit descriptor with VLAN insertions
  2019-09-03 12:35 [dpdk-dev] [PATCH] net/mlx5: fix transmit descriptor with VLAN insertions Viacheslav Ovsiienko
@ 2019-09-03 13:05 ` Matan Azrad
  2019-09-03 13:43   ` Slava Ovsiienko
  2019-09-10  7:35 ` Matan Azrad
  2019-09-10 12:08 ` Raslan Darawsheh
  2 siblings, 1 reply; 6+ messages in thread
From: Matan Azrad @ 2019-09-03 13:05 UTC (permalink / raw)
  To: Slava Ovsiienko, dev; +Cc: stable

Hi Slava

From: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
> If VLAN tag insertion transmit offload is engaged
> (DEV_TX_OFFLOAD_VLAN_INSERT in tx queue configuration is set) the
> transmit descriptor may be built with wrong format, due to packet length is
> not adjusted. Also, the ring buffer wrapup is not handled correctly.
> 
> Fixes: 18a1c20044c0 ("net/mlx5: implement Tx burst template")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
> ---
>  drivers/net/mlx5/mlx5_rxtx.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c
> index 8ec90c3..f540977 100644
> --- a/drivers/net/mlx5/mlx5_rxtx.c
> +++ b/drivers/net/mlx5/mlx5_rxtx.c
> @@ -2861,13 +2861,14 @@ enum mlx5_txcmp_code {
>  	memcpy(pdst, buf, MLX5_DSEG_MIN_INLINE_SIZE);
>  	buf += MLX5_DSEG_MIN_INLINE_SIZE;
>  	pdst += MLX5_DSEG_MIN_INLINE_SIZE;
> +	len -= MLX5_DSEG_MIN_INLINE_SIZE;
>  	/* Insert VLAN ethertype + VLAN tag. Pointer is aligned. */
>  	assert(pdst == RTE_PTR_ALIGN(pdst, MLX5_WSEG_SIZE));
> +	if (unlikely(pdst >= (uint8_t *)txq->wqes_end))

Why unlikely?
Wraparound is expected even in good cases, no?



> +		pdst = (uint8_t *)txq->wqes;
>  	*(uint32_t *)pdst = rte_cpu_to_be_32((RTE_ETHER_TYPE_VLAN <<
> 16) |
>  					      loc->mbuf->vlan_tci);
>  	pdst += sizeof(struct rte_vlan_hdr);
> -	if (unlikely(pdst >= (uint8_t *)txq->wqes_end))
> -		pdst = (uint8_t *)txq->wqes;
>  	/*
>  	 * The WQEBB space availability is checked by caller.
>  	 * Here we should be aware of WQE ring buffer wraparound only.
> --
> 1.8.3.1


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [dpdk-dev] [PATCH] net/mlx5: fix transmit descriptor with VLAN insertions
  2019-09-03 13:05 ` Matan Azrad
@ 2019-09-03 13:43   ` Slava Ovsiienko
  2019-09-04  6:17     ` Matan Azrad
  0 siblings, 1 reply; 6+ messages in thread
From: Slava Ovsiienko @ 2019-09-03 13:43 UTC (permalink / raw)
  To: Matan Azrad, dev; +Cc: stable

Hi, Matan

Please, see below.

> -----Original Message-----
> From: Matan Azrad <matan@mellanox.com>
> Sent: Tuesday, September 3, 2019 16:05
> To: Slava Ovsiienko <viacheslavo@mellanox.com>; dev@dpdk.org
> Cc: stable@dpdk.org
> Subject: RE: [PATCH] net/mlx5: fix transmit descriptor with VLAN insertions
> 
> Hi Slava
> 
> From: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
> > If VLAN tag insertion transmit offload is engaged
> > (DEV_TX_OFFLOAD_VLAN_INSERT in tx queue configuration is set) the
> > transmit descriptor may be built with wrong format, due to packet
> > length is not adjusted. Also, the ring buffer wrapup is not handled correctly.
> >
> > Fixes: 18a1c20044c0 ("net/mlx5: implement Tx burst template")
> > Cc: stable@dpdk.org
> >
> > Signed-off-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
> > ---
> >  drivers/net/mlx5/mlx5_rxtx.c | 5 +++--
> >  1 file changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/net/mlx5/mlx5_rxtx.c
> > b/drivers/net/mlx5/mlx5_rxtx.c index 8ec90c3..f540977 100644
> > --- a/drivers/net/mlx5/mlx5_rxtx.c
> > +++ b/drivers/net/mlx5/mlx5_rxtx.c
> > @@ -2861,13 +2861,14 @@ enum mlx5_txcmp_code {
> >  	memcpy(pdst, buf, MLX5_DSEG_MIN_INLINE_SIZE);
> >  	buf += MLX5_DSEG_MIN_INLINE_SIZE;
> >  	pdst += MLX5_DSEG_MIN_INLINE_SIZE;
> > +	len -= MLX5_DSEG_MIN_INLINE_SIZE;
> >  	/* Insert VLAN ethertype + VLAN tag. Pointer is aligned. */
> >  	assert(pdst == RTE_PTR_ALIGN(pdst, MLX5_WSEG_SIZE));
> > +	if (unlikely(pdst >= (uint8_t *)txq->wqes_end))
> 
> Why unlikely?
> Wraparound is expected even in good cases, no?

It is good case but supposed to be rare. Wraparound happens once on entire ring buffer fill.
At this codepoint it ever has the less chance to happen - many of wraparounds happen on
data copying (the code below in this function).

With best regards,
Slava


> 
> 
> 
> > +		pdst = (uint8_t *)txq->wqes;
> >  	*(uint32_t *)pdst = rte_cpu_to_be_32((RTE_ETHER_TYPE_VLAN <<
> > 16) |
> >  					      loc->mbuf->vlan_tci);
> >  	pdst += sizeof(struct rte_vlan_hdr);
> > -	if (unlikely(pdst >= (uint8_t *)txq->wqes_end))
> > -		pdst = (uint8_t *)txq->wqes;
> >  	/*
> >  	 * The WQEBB space availability is checked by caller.
> >  	 * Here we should be aware of WQE ring buffer wraparound only.
> > --
> > 1.8.3.1


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [dpdk-dev] [PATCH] net/mlx5: fix transmit descriptor with VLAN insertions
  2019-09-03 13:43   ` Slava Ovsiienko
@ 2019-09-04  6:17     ` Matan Azrad
  0 siblings, 0 replies; 6+ messages in thread
From: Matan Azrad @ 2019-09-04  6:17 UTC (permalink / raw)
  To: Slava Ovsiienko, dev; +Cc: stable

Hi

From: Slava Ovsiienko <viacheslavo@mellanox.com>
> Hi, Matan
> 
> Please, see below.
> 
> > -----Original Message-----
> > From: Matan Azrad <matan@mellanox.com>
> > Sent: Tuesday, September 3, 2019 16:05
> > To: Slava Ovsiienko <viacheslavo@mellanox.com>; dev@dpdk.org
> > Cc: stable@dpdk.org
> > Subject: RE: [PATCH] net/mlx5: fix transmit descriptor with VLAN
> > insertions
> >
> > Hi Slava
> >
> > From: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
> > > If VLAN tag insertion transmit offload is engaged
> > > (DEV_TX_OFFLOAD_VLAN_INSERT in tx queue configuration is set) the
> > > transmit descriptor may be built with wrong format, due to packet
> > > length is not adjusted. Also, the ring buffer wrapup is not handled
> correctly.
> > >
> > > Fixes: 18a1c20044c0 ("net/mlx5: implement Tx burst template")
> > > Cc: stable@dpdk.org
> > >
> > > Signed-off-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
> > > ---
> > >  drivers/net/mlx5/mlx5_rxtx.c | 5 +++--
> > >  1 file changed, 3 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/net/mlx5/mlx5_rxtx.c
> > > b/drivers/net/mlx5/mlx5_rxtx.c index 8ec90c3..f540977 100644
> > > --- a/drivers/net/mlx5/mlx5_rxtx.c
> > > +++ b/drivers/net/mlx5/mlx5_rxtx.c
> > > @@ -2861,13 +2861,14 @@ enum mlx5_txcmp_code {
> > >  	memcpy(pdst, buf, MLX5_DSEG_MIN_INLINE_SIZE);
> > >  	buf += MLX5_DSEG_MIN_INLINE_SIZE;
> > >  	pdst += MLX5_DSEG_MIN_INLINE_SIZE;
> > > +	len -= MLX5_DSEG_MIN_INLINE_SIZE;
> > >  	/* Insert VLAN ethertype + VLAN tag. Pointer is aligned. */
> > >  	assert(pdst == RTE_PTR_ALIGN(pdst, MLX5_WSEG_SIZE));
> > > +	if (unlikely(pdst >= (uint8_t *)txq->wqes_end))
> >
> > Why unlikely?
> > Wraparound is expected even in good cases, no?
> 
> It is good case but supposed to be rare. Wraparound happens once on entire
> ring buffer fill.

1/ring size - event - it is part of the good flow.
I think it is better to let the branch prediction to do the work in this case and in all other places when good flow may happen for both true or false.


> At this codepoint it ever has the less chance to happen - many of
> wraparounds happen on data copying (the code below in this function).
> 
> With best regards,
> Slava
> 
> 
> >
> >
> >
> > > +		pdst = (uint8_t *)txq->wqes;
> > >  	*(uint32_t *)pdst = rte_cpu_to_be_32((RTE_ETHER_TYPE_VLAN <<
> > > 16) |
> > >  					      loc->mbuf->vlan_tci);
> > >  	pdst += sizeof(struct rte_vlan_hdr);
> > > -	if (unlikely(pdst >= (uint8_t *)txq->wqes_end))
> > > -		pdst = (uint8_t *)txq->wqes;
> > >  	/*
> > >  	 * The WQEBB space availability is checked by caller.
> > >  	 * Here we should be aware of WQE ring buffer wraparound only.
> > > --
> > > 1.8.3.1


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [dpdk-dev] [PATCH] net/mlx5: fix transmit descriptor with VLAN insertions
  2019-09-03 12:35 [dpdk-dev] [PATCH] net/mlx5: fix transmit descriptor with VLAN insertions Viacheslav Ovsiienko
  2019-09-03 13:05 ` Matan Azrad
@ 2019-09-10  7:35 ` Matan Azrad
  2019-09-10 12:08 ` Raslan Darawsheh
  2 siblings, 0 replies; 6+ messages in thread
From: Matan Azrad @ 2019-09-10  7:35 UTC (permalink / raw)
  To: Slava Ovsiienko, dev; +Cc: stable



From: Viacheslav Ovsiienko
> If VLAN tag insertion transmit offload is engaged
> (DEV_TX_OFFLOAD_VLAN_INSERT in tx queue configuration is set) the
> transmit descriptor may be built with wrong format, due to packet length is
> not adjusted. Also, the ring buffer wrapup is not handled correctly.
> 
> Fixes: 18a1c20044c0 ("net/mlx5: implement Tx burst template")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
Acked-by: Matan Azrad <matan@mellanox.com>

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [dpdk-dev] [PATCH] net/mlx5: fix transmit descriptor with VLAN insertions
  2019-09-03 12:35 [dpdk-dev] [PATCH] net/mlx5: fix transmit descriptor with VLAN insertions Viacheslav Ovsiienko
  2019-09-03 13:05 ` Matan Azrad
  2019-09-10  7:35 ` Matan Azrad
@ 2019-09-10 12:08 ` Raslan Darawsheh
  2 siblings, 0 replies; 6+ messages in thread
From: Raslan Darawsheh @ 2019-09-10 12:08 UTC (permalink / raw)
  To: Slava Ovsiienko, dev; +Cc: Matan Azrad, stable

Hi,
> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Viacheslav Ovsiienko
> Sent: Tuesday, September 3, 2019 3:35 PM
> To: dev@dpdk.org
> Cc: Matan Azrad <matan@mellanox.com>; stable@dpdk.org
> Subject: [dpdk-dev] [PATCH] net/mlx5: fix transmit descriptor with VLAN
> insertions
> 
> If VLAN tag insertion transmit offload is engaged
> (DEV_TX_OFFLOAD_VLAN_INSERT in tx queue configuration is set) the
> transmit descriptor may be built with wrong format, due to packet length is
> not adjusted. Also, the ring buffer wrapup is not handled correctly.
> 
> Fixes: 18a1c20044c0 ("net/mlx5: implement Tx burst template")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>


Patch applied to next-net-mlx,

Kindest regards,
Raslan Darawsheh


^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2019-09-10 12:08 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-09-03 12:35 [dpdk-dev] [PATCH] net/mlx5: fix transmit descriptor with VLAN insertions Viacheslav Ovsiienko
2019-09-03 13:05 ` Matan Azrad
2019-09-03 13:43   ` Slava Ovsiienko
2019-09-04  6:17     ` Matan Azrad
2019-09-10  7:35 ` Matan Azrad
2019-09-10 12:08 ` Raslan Darawsheh

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