diff mbox series

[2/4] ethdev: introduce protocol hdr based buffer split

Message ID 20220812181552.2908067-3-yuanx.wang@intel.com (mailing list archive)
State Superseded
Delegated to: Thomas Monjalon
Headers show
Series support protocol based buffer split | expand

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Context Check Description
ci/checkpatch warning coding style issues

Commit Message

Wang, YuanX Aug. 12, 2022, 6:15 p.m. UTC
Currently, Rx buffer split supports length based split. With Rx queue
offload RTE_ETH_RX_OFFLOAD_BUFFER_SPLIT enabled and Rx packet segment
configured, PMD will be able to split the received packets into
multiple segments.

However, length based buffer split is not suitable for NICs that do split
based on protocol headers. Given an arbitrarily variable length in Rx
packet segment, it is almost impossible to pass a fixed protocol header to
driver. Besides, the existence of tunneling results in the composition of
a packet is various, which makes the situation even worse.

This patch extends current buffer split to support protocol header based
buffer split. A new proto_hdr field is introduced in the reserved field
of rte_eth_rxseg_split structure to specify protocol header. The proto_hdr
field defines the split position of packet, splitting will always happens
after the protocol header defined in the Rx packet segment. When Rx queue
offload RTE_ETH_RX_OFFLOAD_BUFFER_SPLIT is enabled and corresponding
protocol header is configured, driver will split the ingress packets into
multiple segments.

struct rte_eth_rxseg_split {
        struct rte_mempool *mp; /* memory pools to allocate segment from */
        uint16_t length; /* segment maximal data length,
                            configures split point */
        uint16_t offset; /* data offset from beginning
                            of mbuf data buffer */
        uint32_t proto_hdr; /* supported ptype of a specific pmd,
                               configures split point.
			       It should be defined by RTE_PTYPE_*
			     */
};

If protocol header split can be supported by a PMD. The
rte_eth_buffer_split_get_supported_hdr_ptypes function can
be use to obtain a list of these protocol headers.

For example, let's suppose we configured the Rx queue with the
following segments:
        seg0 - pool0, proto_hdr0=RTE_PTYPE_L3_IPV4, off0=2B
        seg1 - pool1, proto_hdr1=RTE_PTYPE_L4_UDP, off1=128B
        seg2 - pool2, off1=0B

The packet consists of MAC_IPV4_UDP_PAYLOAD will be split like
following:
        seg0 - ipv4 header @ RTE_PKTMBUF_HEADROOM + 2 in mbuf from pool0
        seg1 - udp header @ 128 in mbuf from pool1
        seg2 - payload @ 0 in mbuf from pool2

Note: NIC will only do split when the packets exactly match all the
protocol headers in the segments. For example, if ARP packets received
with above config, the NIC won't do split for ARP packets since
it does not contains ipv4 header and udp header.

Now buffer split can be configured in two modes. For length based
buffer split, the mp, length, offset field in Rx packet segment should
be configured, while the proto_hdr field will be ignored.
For protocol header based buffer split, the mp, offset, proto_hdr field
in Rx packet segment should be configured, while the length field will
be ignored.

The split limitations imposed by underlying driver is reported in the
rte_eth_dev_info->rx_seg_capa field. The memory attributes for the split
parts may differ either, dpdk memory and external memory, respectively.

Signed-off-by: Yuan Wang <yuanx.wang@intel.com>
Signed-off-by: Xuan Ding <xuan.ding@intel.com>
Signed-off-by: Wenxuan Wu <wenxuanx.wu@intel.com>
---
 doc/guides/rel_notes/release_22_11.rst |  5 +++
 lib/ethdev/rte_ethdev.c                | 55 ++++++++++++++++++++------
 lib/ethdev/rte_ethdev.h                | 17 +++++++-
 3 files changed, 65 insertions(+), 12 deletions(-)
diff mbox series

Patch

diff --git a/doc/guides/rel_notes/release_22_11.rst b/doc/guides/rel_notes/release_22_11.rst
index 4d90514a9a..f3b58c7895 100644
--- a/doc/guides/rel_notes/release_22_11.rst
+++ b/doc/guides/rel_notes/release_22_11.rst
@@ -60,6 +60,11 @@  New Features
   Added ``rte_eth_buffer_split_get_supported_hdr_ptypes()``, to get supported
   header protocols of a PMD to split.
 
+* **Added protocol header based buffer split.**
+  Ethdev: The ``reserved`` field in the  ``rte_eth_rxseg_split`` structure is
+  replaced with ``proto_hdr`` to support protocol header based buffer split.
+  User can choose length or protocol header to configure buffer split
+  according to NIC's capability.
 
 Removed Items
 -------------
diff --git a/lib/ethdev/rte_ethdev.c b/lib/ethdev/rte_ethdev.c
index 093c577add..dfceb723ee 100644
--- a/lib/ethdev/rte_ethdev.c
+++ b/lib/ethdev/rte_ethdev.c
@@ -1635,9 +1635,10 @@  rte_eth_dev_is_removed(uint16_t port_id)
 }
 
 static int
-rte_eth_rx_queue_check_split(const struct rte_eth_rxseg_split *rx_seg,
-			     uint16_t n_seg, uint32_t *mbp_buf_size,
-			     const struct rte_eth_dev_info *dev_info)
+rte_eth_rx_queue_check_split(uint16_t port_id,
+			const struct rte_eth_rxseg_split *rx_seg,
+			uint16_t n_seg, uint32_t *mbp_buf_size,
+			const struct rte_eth_dev_info *dev_info)
 {
 	const struct rte_eth_rxseg_capa *seg_capa = &dev_info->rx_seg_capa;
 	struct rte_mempool *mp_first;
@@ -1660,6 +1661,7 @@  rte_eth_rx_queue_check_split(const struct rte_eth_rxseg_split *rx_seg,
 		struct rte_mempool *mpl = rx_seg[seg_idx].mp;
 		uint32_t length = rx_seg[seg_idx].length;
 		uint32_t offset = rx_seg[seg_idx].offset;
+		uint32_t proto_hdr = rx_seg[seg_idx].proto_hdr;
 
 		if (mpl == NULL) {
 			RTE_ETHDEV_LOG(ERR, "null mempool pointer\n");
@@ -1693,13 +1695,44 @@  rte_eth_rx_queue_check_split(const struct rte_eth_rxseg_split *rx_seg,
 		}
 		offset += seg_idx != 0 ? 0 : RTE_PKTMBUF_HEADROOM;
 		*mbp_buf_size = rte_pktmbuf_data_room_size(mpl);
-		length = length != 0 ? length : *mbp_buf_size;
-		if (*mbp_buf_size < length + offset) {
-			RTE_ETHDEV_LOG(ERR,
-				       "%s mbuf_data_room_size %u < %u (segment length=%u + segment offset=%u)\n",
-				       mpl->name, *mbp_buf_size,
-				       length + offset, length, offset);
-			return -EINVAL;
+
+		int ret = rte_eth_buffer_split_get_supported_hdr_ptypes(port_id, NULL, 0);
+		if (ret <= 0) {
+			/* Split at fixed length. */
+			length = length != 0 ? length : *mbp_buf_size;
+			if (*mbp_buf_size < length + offset) {
+				RTE_ETHDEV_LOG(ERR,
+					"%s mbuf_data_room_size %u < %u (segment length=%u + segment offset=%u)\n",
+					mpl->name, *mbp_buf_size,
+					length + offset, length, offset);
+				return -EINVAL;
+			}
+		} else {
+			/* Split after specified protocol header. */
+			uint32_t ptypes[ret];
+			int i;
+
+			ret = rte_eth_buffer_split_get_supported_hdr_ptypes(port_id, ptypes, ret);
+			for (i = 0; i < ret; i++)
+				if (ptypes[i] & proto_hdr)
+					break;
+
+			if (i == ret) {
+#define PTYPE_NAMESIZE	256
+				char ptype_name[PTYPE_NAMESIZE];
+				rte_get_ptype_name(proto_hdr, ptype_name, sizeof(ptype_name));
+				RTE_ETHDEV_LOG(ERR,
+					"Protocol header %s is not supported.\n",
+					ptype_name);
+				return -EINVAL;
+			}
+			if (*mbp_buf_size < offset) {
+				RTE_ETHDEV_LOG(ERR,
+						"%s mbuf_data_room_size %u < %u segment offset)\n",
+						mpl->name, *mbp_buf_size,
+						offset);
+				return -EINVAL;
+			}
 		}
 	}
 	return 0;
@@ -1778,7 +1811,7 @@  rte_eth_rx_queue_setup(uint16_t port_id, uint16_t rx_queue_id,
 		n_seg = rx_conf->rx_nseg;
 
 		if (rx_conf->offloads & RTE_ETH_RX_OFFLOAD_BUFFER_SPLIT) {
-			ret = rte_eth_rx_queue_check_split(rx_seg, n_seg,
+			ret = rte_eth_rx_queue_check_split(port_id, rx_seg, n_seg,
 							   &mbp_buf_size,
 							   &dev_info);
 			if (ret != 0)
diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h
index c58c908c3a..410fba5eab 100644
--- a/lib/ethdev/rte_ethdev.h
+++ b/lib/ethdev/rte_ethdev.h
@@ -1175,6 +1175,9 @@  struct rte_eth_txmode {
  *   specified in the first array element, the second buffer, from the
  *   pool in the second element, and so on.
  *
+ * - The proto_hdrs in the elements define the split position of
+ *   received packets.
+ *
  * - The offsets from the segment description elements specify
  *   the data offset from the buffer beginning except the first mbuf.
  *   The first segment offset is added with RTE_PKTMBUF_HEADROOM.
@@ -1196,12 +1199,24 @@  struct rte_eth_txmode {
  *     - pool from the last valid element
  *     - the buffer size from this pool
  *     - zero offset
+ *
+ * - Length based buffer split:
+ *     - mp, length, offset should be configured.
+ *     - The proto_hdr field will be ignored.
+ *
+ * - Protocol header based buffer split:
+ *     - mp, offset, proto_hdr should be configured.
+ *     - The length field will be ignored.
  */
 struct rte_eth_rxseg_split {
 	struct rte_mempool *mp; /**< Memory pool to allocate segment from. */
 	uint16_t length; /**< Segment data length, configures split point. */
 	uint16_t offset; /**< Data offset from beginning of mbuf data buffer. */
-	uint32_t reserved; /**< Reserved field. */
+	/**
+	 * Supported ptype of a specific pmd, configures split point.
+	 * It should be defined by RTE_PTYPE_*.
+	 */
+	uint32_t proto_hdr;
 };
 
 /**