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* [PATCH 1/1] net/sfc: stop misuse of Rx ingress m-port metadata on EF100
@ 2023-03-09  4:11 Ivan Malov
  2023-03-10 14:01 ` Ferruh Yigit
                   ` (4 more replies)
  0 siblings, 5 replies; 12+ messages in thread
From: Ivan Malov @ 2023-03-09  4:11 UTC (permalink / raw)
  To: dev; +Cc: Andrew Rybchenko, Ferruh Yigit, stable, Andy Moreton

The driver supports representor functionality. In it,
packets coming from VFs to the dedicated back-end Rx
queue get demultiplexed into front-end Rx queues of
representor ethdevs as per the per-packet metadata
indicating logical HW ingress ports. On transmit,
packets are provided with symmetrical metadata
by front-end Tx queues, and the back-end queue
transforms the data into so-called Tx override
descriptors. These let the packets bypass flow
lookup and go directly to the represented VFs.

However, in the Rx part, the driver extracts
the said metadata on every HW Rx queue, that
is, not just on the one used by representors
Doing so leads to a buggy behaviour. It is
revealed by operating testpmd as follows:

dpdk-testpmd -a 0000:c6:00.0 -a 0000:c6:00.1 -- -i

testpmd> flow create 0 transfer pattern port_representor \
 port_id is 0 / end actions port_representor port_id 1 / end
Flow rule #0 created

testpmd> set fwd io
testpmd> start tx_first

testpmd> flow destroy 0 rule 0
Flow rule #0 destroyed

testpmd> stop

  ---------------------- Forward statistics for port 0  -----------------
  RX-packets: 19196498       RX-dropped: 0             RX-total: 19196498
  TX-packets: 19196535       TX-dropped: 0             TX-total: 19196535
  -----------------------------------------------------------------------

  ---------------------- Forward statistics for port 1  -----------------
  RX-packets: 19196503       RX-dropped: 0             RX-total: 19196503
  TX-packets: 19196530       TX-dropped: 0             TX-total: 19196530
  -----------------------------------------------------------------------

In this scenario, two physical functions of the adapter
do not have any corresponding "back-to-back" forwarder
on peer host. Packets transmitted from port 0 can only
be forwarded to port 1 by means of a special flow rule.

The flow rule indeed works, but destroying it does not
stop forwarding. Port statistics carry on incrementing.

Also, it is apparent that forwarding in the opposite
direction must not have worked in this case as the
flow is meant to target only one of the directions.

Because of the bug, the first 32 mbufs received
as a result of the flow rule operation have the
said metadata present. In io mode, testpmd does
not tamper with mbufs and passes them directly
to transmit path, so this data remains in them
instructing the PMD to override destinations
of the packets via Tx option descriptors.

Expected behaviour is as follows:

  ---------------------- Forward statistics for port 0  -----------------
  RX-packets: 0              RX-dropped: 0             RX-total: 0
  TX-packets: 15787496       TX-dropped: 0             TX-total: 15787496
  -----------------------------------------------------------------------

  ---------------------- Forward statistics for port 1  -----------------
  RX-packets: 15787464       RX-dropped: 0             RX-total: 15787464
  TX-packets: 32             TX-dropped: 0             TX-total: 32
  -----------------------------------------------------------------------

These figures show the rule work only for one direction.
Also, removing the flow shall cause forwarding to cease.

Provided patch fixes the bug accordingly.

Fixes: d0f981a3efd8 ("net/sfc: handle ingress mport in EF100 Rx prefix")
Cc: stable@dpdk.org

Signed-off-by: Ivan Malov <ivan.malov@arknetworks.am>
Reviewed-by: Andy Moreton <amoreton@xilinx.com>
---
 drivers/net/sfc/sfc_dp_rx.h    | 3 +++
 drivers/net/sfc/sfc_ef100_rx.c | 3 ++-
 drivers/net/sfc/sfc_rx.c       | 3 +++
 3 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/net/sfc/sfc_dp_rx.h b/drivers/net/sfc/sfc_dp_rx.h
index 246adbd87c..51a44bd034 100644
--- a/drivers/net/sfc/sfc_dp_rx.h
+++ b/drivers/net/sfc/sfc_dp_rx.h
@@ -10,6 +10,8 @@
 #ifndef _SFC_DP_RX_H
 #define _SFC_DP_RX_H
 
+#include <stdbool.h>
+
 #include <rte_mempool.h>
 #include <ethdev_driver.h>
 
@@ -27,6 +29,7 @@ extern "C" {
  */
 struct sfc_dp_rxq {
 	struct sfc_dp_queue	dpq;
+	bool			need_ingress_mport;
 };
 
 /** Datapath receive queue descriptor number limitations */
diff --git a/drivers/net/sfc/sfc_ef100_rx.c b/drivers/net/sfc/sfc_ef100_rx.c
index 16cd8524d3..c4d256b40d 100644
--- a/drivers/net/sfc/sfc_ef100_rx.c
+++ b/drivers/net/sfc/sfc_ef100_rx.c
@@ -876,7 +876,8 @@ sfc_ef100_rx_qstart(struct sfc_dp_rxq *dp_rxq, unsigned int evq_read_ptr,
 	else
 		rxq->flags &= ~SFC_EF100_RXQ_USER_MARK;
 
-	if ((unsup_rx_prefix_fields &
+	if (dp_rxq->need_ingress_mport &&
+	    (unsup_rx_prefix_fields &
 	     (1U << EFX_RX_PREFIX_FIELD_INGRESS_MPORT)) == 0)
 		rxq->flags |= SFC_EF100_RXQ_INGRESS_MPORT;
 	else
diff --git a/drivers/net/sfc/sfc_rx.c b/drivers/net/sfc/sfc_rx.c
index 5ea98187c3..3d3d7d42e3 100644
--- a/drivers/net/sfc/sfc_rx.c
+++ b/drivers/net/sfc/sfc_rx.c
@@ -1265,6 +1265,9 @@ sfc_rx_qinit(struct sfc_adapter *sa, sfc_sw_index_t sw_index,
 	if (rc != 0)
 		goto fail_dp_rx_qcreate;
 
+	rxq_info->dp->need_ingress_mport =
+		((rxq_info->type_flags & EFX_RXQ_FLAG_INGRESS_MPORT) != 0);
+
 	evq->dp_rxq = rxq_info->dp;
 
 	rxq_info->state = SFC_RXQ_INITIALIZED;
-- 
2.17.1


^ permalink raw reply	[flat|nested] 12+ messages in thread

end of thread, other threads:[~2023-04-17  9:07 UTC | newest]

Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-03-09  4:11 [PATCH 1/1] net/sfc: stop misuse of Rx ingress m-port metadata on EF100 Ivan Malov
2023-03-10 14:01 ` Ferruh Yigit
2023-03-10 14:18 ` Andrew Rybchenko
2023-03-10 14:43   ` Ferruh Yigit
2023-03-10 17:01 ` [PATCH v2] " Ivan Malov
2023-03-12  7:59   ` Andrew Rybchenko
2023-03-12 10:54 ` [PATCH v3] " Ivan Malov
2023-03-16 17:02   ` Ferruh Yigit
2023-04-09  8:00   ` Andrew Rybchenko
2023-04-12 12:04   ` Ferruh Yigit
2023-04-12 13:57 ` [PATCH v4] " Ivan Malov
2023-04-17  9:06   ` Ferruh Yigit

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