[PATCH v2 0/3] example/l3fwd: relax l3fwd rx RSS/Offload if needed

[PATCH v2 0/3] example/l3fwd: relax l3fwd rx RSS/Offload if needed

[Trevor Tao]

This series tries to relax l3fwd rx RSS/Offload mode requirement if they
are not supported by underlying hw or virtual devices, there is an
option named relax_rx_mode added to enable this option.

Trevor Tao (3):
  examples/l3fwd: relax RSS requirement with option
  examples/l3fwd: relax the Offload requirement
  doc: add a relax rx mode requirement option

 doc/guides/rel_notes/release_23_11.rst  |  2 ++
 doc/guides/sample_app_ug/l3_forward.rst |  4 +++-
 examples/l3fwd/l3fwd.h                  | 12 ++++++++--
 examples/l3fwd/l3fwd_em.h               |  2 +-
 examples/l3fwd/l3fwd_lpm.h              |  2 +-
 examples/l3fwd/main.c                   | 30 +++++++++++++++++++++++++
 6 files changed, 47 insertions(+), 5 deletions(-)

-- 
2.34.1

[PATCH v2 1/3] examples/l3fwd: relax RSS requirement with option

[Trevor Tao]

Now the port Rx mq_mode had been set to RTE_ETH_MQ_RX_RSS
by default, but some hw and/or virtual interface does not
support the RSS and offload mode presupposed, e.g., some
virtio interfaces in the cloud don't support
RSS and the error msg may like:

virtio_dev_configure(): RSS support requested but not supported by
the device
Port0 dev_configure = -95

So to enable the l3fwd running in that environment, the Rx mode requirement
can be relaxed to reflect the hardware feature reality here, and the l3fwd
can run smoothly then.

An option named "relax-rx-mode" is added to enable the relax action
here, and it's disabled by default.

Signed-off-by: Trevor Tao <taozj888@163.com>
---
 examples/l3fwd/main.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/examples/l3fwd/main.c b/examples/l3fwd/main.c
index 6063eb1399..89ad546a5e 100644
--- a/examples/l3fwd/main.c
+++ b/examples/l3fwd/main.c
@@ -73,6 +73,7 @@ static enum L3FWD_LOOKUP_MODE lookup_mode;
 static int numa_on = 1; /**< NUMA is enabled by default. */
 static int parse_ptype; /**< Parse packet type using rx callback, and */
 			/**< disabled by default */
+static int relax_rx_mode; /**< Relax RX mode is disabled by default */
 static int per_port_pool; /**< Use separate buffer pools per port; disabled */
 			  /**< by default */
 
@@ -678,6 +679,7 @@ static const char short_options[] =
 #define CMD_LINE_OPT_MAX_PKT_LEN "max-pkt-len"
 #define CMD_LINE_OPT_HASH_ENTRY_NUM "hash-entry-num"
 #define CMD_LINE_OPT_PARSE_PTYPE "parse-ptype"
+#define CMD_LINE_OPT_RELAX_RX_MODE "relax-rx-mode"
 #define CMD_LINE_OPT_PER_PORT_POOL "per-port-pool"
 #define CMD_LINE_OPT_MODE "mode"
 #define CMD_LINE_OPT_EVENTQ_SYNC "eventq-sched"
@@ -705,6 +707,7 @@ enum {
 	CMD_LINE_OPT_MAX_PKT_LEN_NUM,
 	CMD_LINE_OPT_HASH_ENTRY_NUM_NUM,
 	CMD_LINE_OPT_PARSE_PTYPE_NUM,
+	CMD_LINE_OPT_RELAX_RX_MODE_NUM,
 	CMD_LINE_OPT_RULE_IPV4_NUM,
 	CMD_LINE_OPT_RULE_IPV6_NUM,
 	CMD_LINE_OPT_ALG_NUM,
@@ -728,6 +731,7 @@ static const struct option lgopts[] = {
 	{CMD_LINE_OPT_MAX_PKT_LEN, 1, 0, CMD_LINE_OPT_MAX_PKT_LEN_NUM},
 	{CMD_LINE_OPT_HASH_ENTRY_NUM, 1, 0, CMD_LINE_OPT_HASH_ENTRY_NUM_NUM},
 	{CMD_LINE_OPT_PARSE_PTYPE, 0, 0, CMD_LINE_OPT_PARSE_PTYPE_NUM},
+	{CMD_LINE_OPT_RELAX_RX_MODE, 0, 0, CMD_LINE_OPT_RELAX_RX_MODE_NUM},
 	{CMD_LINE_OPT_PER_PORT_POOL, 0, 0, CMD_LINE_OPT_PARSE_PER_PORT_POOL},
 	{CMD_LINE_OPT_MODE, 1, 0, CMD_LINE_OPT_MODE_NUM},
 	{CMD_LINE_OPT_EVENTQ_SYNC, 1, 0, CMD_LINE_OPT_EVENTQ_SYNC_NUM},
@@ -853,6 +857,11 @@ parse_args(int argc, char **argv)
 			parse_ptype = 1;
 			break;
 
+		case CMD_LINE_OPT_RELAX_RX_MODE_NUM:
+			printf("Relax rx mode is enabled\n");
+			relax_rx_mode = 1;
+			break;
+
 		case CMD_LINE_OPT_PARSE_PER_PORT_POOL:
 			printf("per port buffer pool is enabled\n");
 			per_port_pool = 1;
@@ -1260,6 +1269,13 @@ l3fwd_poll_resource_setup(void)
 		if (dev_info.max_rx_queues == 1)
 			local_port_conf.rxmode.mq_mode = RTE_ETH_MQ_RX_NONE;
 
+		/* relax the rx rss requirement */
+		if (relax_rx_mode && !local_port_conf.rx_adv_conf.rss_conf.rss_hf) {
+			printf("warning: modified the rx mq_mode to RTE_ETH_MQ_RX_NONE base on"
+					" device capability\n");
+				local_port_conf.rxmode.mq_mode = RTE_ETH_MQ_RX_NONE;
+		}
+
 		if (local_port_conf.rx_adv_conf.rss_conf.rss_hf !=
 				port_conf.rx_adv_conf.rss_conf.rss_hf) {
 			printf("Port %u modified RSS hash function based on hardware support,"
-- 
2.34.1

[PATCH v2 2/3] examples/l3fwd: relax the Offload requirement

[Trevor Tao]

Now the port Rx offload mode is set to RTE_ETH_RX_OFFLOAD_CHECKSUM
by default, but some hw and/or virtual interface does not support
the offload mode presupposed, e.g., some virtio interfaces in
the cloud may only partly support RTE_ETH_RX_OFFLOAD_UDP_CKSUM/
RTE_ETH_RX_OFFLOAD_TCP_CKSUM,
but not RTE_ETH_RX_OFFLOAD_IPV4_CKSUM, and the error msg here:

Ethdev port_id=0 requested Rx offloads 0xe does not match Rx offloads
capabilities 0x201d in rte_eth_dev_configure()

So to enable the l3fwd running in that environment, the Rx mode requirement
can be relaxed to reflect the hardware feature reality here, and the l3fwd
can run smoothly then.
A warning msg would be provided to user in case it happens here.

On the other side, enabling the software cksum check in case missing the
hw support.

The relax action for rx cksum offload is just enabled when relax_rx_mode is
true which is false by default.

Signed-off-by: Trevor Tao <taozj888@163.com>
---
 examples/l3fwd/l3fwd.h     | 12 ++++++++++--
 examples/l3fwd/l3fwd_em.h  |  2 +-
 examples/l3fwd/l3fwd_lpm.h |  2 +-
 examples/l3fwd/main.c      | 14 ++++++++++++++
 4 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/examples/l3fwd/l3fwd.h b/examples/l3fwd/l3fwd.h
index b55855c932..fd98ad3373 100644
--- a/examples/l3fwd/l3fwd.h
+++ b/examples/l3fwd/l3fwd.h
@@ -159,7 +159,7 @@ send_single_packet(struct lcore_conf *qconf,
 
 #ifdef DO_RFC_1812_CHECKS
 static inline int
-is_valid_ipv4_pkt(struct rte_ipv4_hdr *pkt, uint32_t link_len)
+is_valid_ipv4_pkt(struct rte_ipv4_hdr *pkt, uint32_t link_len, uint64_t ol_flags)
 {
 	/* From http://www.rfc-editor.org/rfc/rfc1812.txt section 5.2.2 */
 	/*
@@ -170,7 +170,15 @@ is_valid_ipv4_pkt(struct rte_ipv4_hdr *pkt, uint32_t link_len)
 		return -1;
 
 	/* 2. The IP checksum must be correct. */
-	/* this is checked in H/W */
+	/* if this is not checked in H/W, check it. */
+	if ((ol_flags & RTE_ETH_RX_OFFLOAD_IPV4_CKSUM) == 0) {
+		uint16_t actual_cksum, expected_cksum;
+		actual_cksum = pkt->hdr_checksum;
+		pkt->hdr_checksum = 0;
+		expected_cksum = rte_ipv4_cksum(pkt);
+		if (actual_cksum != expected_cksum)
+			return -2;
+	}
 
 	/*
 	 * 3. The IP version number must be 4. If the version number is not 4
diff --git a/examples/l3fwd/l3fwd_em.h b/examples/l3fwd/l3fwd_em.h
index 7d051fc076..1fee2e2e6c 100644
--- a/examples/l3fwd/l3fwd_em.h
+++ b/examples/l3fwd/l3fwd_em.h
@@ -20,7 +20,7 @@ l3fwd_em_handle_ipv4(struct rte_mbuf *m, uint16_t portid,
 
 #ifdef DO_RFC_1812_CHECKS
 	/* Check to make sure the packet is valid (RFC1812) */
-	if (is_valid_ipv4_pkt(ipv4_hdr, m->pkt_len) < 0) {
+	if (is_valid_ipv4_pkt(ipv4_hdr, m->pkt_len, m->ol_flags) < 0) {
 		rte_pktmbuf_free(m);
 		return BAD_PORT;
 	}
diff --git a/examples/l3fwd/l3fwd_lpm.h b/examples/l3fwd/l3fwd_lpm.h
index c61b969584..4ee61e8d88 100644
--- a/examples/l3fwd/l3fwd_lpm.h
+++ b/examples/l3fwd/l3fwd_lpm.h
@@ -22,7 +22,7 @@ l3fwd_lpm_simple_forward(struct rte_mbuf *m, uint16_t portid,
 
 #ifdef DO_RFC_1812_CHECKS
 		/* Check to make sure the packet is valid (RFC1812) */
-		if (is_valid_ipv4_pkt(ipv4_hdr, m->pkt_len) < 0) {
+		if (is_valid_ipv4_pkt(ipv4_hdr, m->pkt_len, m->ol_flags) < 0) {
 			rte_pktmbuf_free(m);
 			return;
 		}
diff --git a/examples/l3fwd/main.c b/examples/l3fwd/main.c
index 89ad546a5e..2b815375a9 100644
--- a/examples/l3fwd/main.c
+++ b/examples/l3fwd/main.c
@@ -1285,6 +1285,20 @@ l3fwd_poll_resource_setup(void)
 				local_port_conf.rx_adv_conf.rss_conf.rss_hf);
 		}
 
+		/* relax the rx offload requirement */
+		if ((local_port_conf.rxmode.offloads & dev_info.rx_offload_capa) !=
+			local_port_conf.rxmode.offloads) {
+			printf("Port %u requested Rx offloads 0x%"PRIx64" does not"
+				" match Rx offloads capabilities 0x%"PRIx64"\n",
+				portid, local_port_conf.rxmode.offloads,
+				dev_info.rx_offload_capa);
+			if (relax_rx_mode) {
+				local_port_conf.rxmode.offloads &= dev_info.rx_offload_capa;
+				printf("warning: modified the rx offload to 0x%"PRIx64" based on device"
+				" capability\n", local_port_conf.rxmode.offloads);
+			}
+		}
+
 		ret = rte_eth_dev_configure(portid, nb_rx_queue,
 					(uint16_t)n_tx_queue, &local_port_conf);
 		if (ret < 0)
-- 
2.34.1

[PATCH v2 3/3] doc: add a relax rx mode requirement option

[Trevor Tao]

Add an option to enable the RX mode requirement relax
in release notes and l3fwd sample guide.

Signed-off-by: Trevor Tao <taozj888@163.com>
---
 doc/guides/rel_notes/release_23_11.rst  | 2 ++
 doc/guides/sample_app_ug/l3_forward.rst | 4 +++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/doc/guides/rel_notes/release_23_11.rst b/doc/guides/rel_notes/release_23_11.rst
index f09ecd50fe..2f9e4a54c8 100644
--- a/doc/guides/rel_notes/release_23_11.rst
+++ b/doc/guides/rel_notes/release_23_11.rst
@@ -84,6 +84,8 @@ New Features
   default. The implementation using C11 standard atomic operations is enabled
   via the ``enable_stdatomic`` build option.
 
+* sample: Added a command option ``--relax-rx-mode`` in l3fwd example
+  to relax the rx RSS/Offload mode requirement if needed.
 
 Removed Items
 -------------
diff --git a/doc/guides/sample_app_ug/l3_forward.rst b/doc/guides/sample_app_ug/l3_forward.rst
index 1cc2c1dd1d..00283f070c 100644
--- a/doc/guides/sample_app_ug/l3_forward.rst
+++ b/doc/guides/sample_app_ug/l3_forward.rst
@@ -126,6 +126,8 @@ Where,
 
 * ``--parse-ptype:`` Optional, set to use software to analyze packet type. Without this option, hardware will check the packet type.
 
+* ``--relax-rx-mode:`` Optional, set to enable rx mode relax when RSS/offload is not fully supported by the hardware. When the IPv4 cksum offload is relaxed, it is calculated by the software instead. Without this option, the RSS and cksum offload will be forced.
+
 * ``--per-port-pool:`` Optional, set to use independent buffer pools per port. Without this option, single buffer pool is used for all ports.
 
 * ``--mode:`` Optional, Packet transfer mode for I/O, poll or eventdev.
@@ -140,7 +142,7 @@ Where,
 
 * ``--event-vector-tmo:`` Optional, Max timeout to form vector in nanoseconds if event vectorization is enabled.
 
-* ``--alg=<val>:`` optional, ACL classify method to use, one of:
+* ``--alg=<val>:`` Optional, ACL classify method to use, one of:
   ``scalar|sse|avx2|neon|altivec|avx512x16|avx512x32``
 
 * ``-E:`` Optional, enable exact match,
-- 
2.34.1

Re: [PATCH v2 0/3] example/l3fwd: relax l3fwd rx RSS/Offload if needed

[David Marchand]

Hello,

On Fri, Oct 13, 2023 at 6:28 AM Trevor Tao <taozj888@163.com> wrote:
>
> This series tries to relax l3fwd rx RSS/Offload mode requirement if they
> are not supported by underlying hw or virtual devices, there is an
> option named relax_rx_mode added to enable this option.
>
> Trevor Tao (3):
>   examples/l3fwd: relax RSS requirement with option
>   examples/l3fwd: relax the Offload requirement
>   doc: add a relax rx mode requirement option
>
>  doc/guides/rel_notes/release_23_11.rst  | 251 +++++++++++++++++++++---
>  doc/guides/sample_app_ug/l3_forward.rst |   4 +-
>  examples/l3fwd/l3fwd.h                  |  12 +-
>  examples/l3fwd/l3fwd_em.h               |   2 +-
>  examples/l3fwd/l3fwd_lpm.h              |   2 +-
>  examples/l3fwd/main.c                   |  30 +++
>  6 files changed, 272 insertions(+), 29 deletions(-)

Thanks for the patches.
One comment on the form though.

I see 4 batches of "v2 patches" in patchwork.
https://patchwork.dpdk.org/project/dpdk/list/?submitter=3044&state=*
I marked all but the last batch as superseded.
If there is something wrong with this, please register to patchwork
with your mail address, you will then be able to update the states
yourself.


It is hard to follow what work has been done between those different
iterations of patches.
For future submissions, don't forget to version your patches with a
new revision (iirc, we should be at version 7 if I count the initial
standalone v1 patch).

In the cover letter, please provide a changelog of the differences
between revisions.
If you think it is better, you may put a more detailed changelog in
each patch commitlog (as annotations, after ---).


Thanks.

-- 
David Marchand

[PATCH v2 0/3] example/l3fwd: relax l3fwd rx RSS/Offload if needed

[Trevor Tao]

This series tries to relax l3fwd rx RSS/Offload mode requirement if they
are not supported by underlying hw or virtual devices, there is an
option named relax_rx_mode added to enable this option.

Trevor Tao (3):
  examples/l3fwd: relax RSS requirement with option
  examples/l3fwd: relax the Offload requirement
  doc: add a relax rx mode requirement option

 doc/guides/rel_notes/release_23_11.rst  | 251 +++++++++++++++++++++---
 doc/guides/sample_app_ug/l3_forward.rst |   4 +-
 examples/l3fwd/l3fwd.h                  |  12 +-
 examples/l3fwd/l3fwd_em.h               |   2 +-
 examples/l3fwd/l3fwd_lpm.h              |   2 +-
 examples/l3fwd/main.c                   |  30 +++
 6 files changed, 272 insertions(+), 29 deletions(-)

-- 
2.34.1

[PATCH v2 0/3] example/l3fwd: relax l3fwd rx RSS/Offload if needed

[Trevor Tao]

This series tries to relax l3fwd rx RSS/Offload mode requirement if they
are not supported by underlying hw or virtual devices, there is an
option named relax_rx_mode added to enable this option.

Trevor Tao (3):
  examples/l3fwd: relax RSS requirement with option
  examples/l3fwd: relax the Offload requirement
  doc: add a relax rx mode requirement option

 doc/guides/rel_notes/release_23_11.rst  |  2 ++
 doc/guides/sample_app_ug/l3_forward.rst |  4 ++-
 examples/l3fwd/l3fwd.h                  | 12 +++++++--
 examples/l3fwd/l3fwd_em.h               |  2 +-
 examples/l3fwd/l3fwd_lpm.h              |  2 +-
 examples/l3fwd/main.c                   | 33 ++++++++++++++++++++++++-
 6 files changed, 49 insertions(+), 6 deletions(-)

-- 
2.34.1