[dpdk-dev] [PATCH 1/5] lib: add Generic Segmentation Offload API framework

Jiayu Hu jiayu.hu at intel.com
Thu Aug 24 16:15:40 CEST 2017


Generic Segmentation Offload (GSO) is a SW technique to split large
packets into small ones. Akin to TSO, GSO enables applications to
operate on large packets, thus reducing per-packet processing overhead.

To enable more flexibility to applications, DPDK GSO is implemented
as a standalone library. Applications explicitly use the GSO library
to segment packets. This patch introduces the GSO API framework to DPDK.

The GSO library provides a segmentation API, rte_gso_segment(), for
applications. It splits an input packet into small ones in each
invocation. The GSO library refers to these small packets generated
by rte_gso_segment() as GSO segments. When all GSO segments are freed,
the input packet is freed automatically.

Signed-off-by: Jiayu Hu <jiayu.hu at intel.com>
Signed-off-by: Mark Kavanagh <mark.b.kavanagh at intel.com>
---
 config/common_base                 |   5 ++
 lib/Makefile                       |   2 +
 lib/librte_gso/Makefile            |  49 ++++++++++++++++
 lib/librte_gso/rte_gso.c           |  47 ++++++++++++++++
 lib/librte_gso/rte_gso.h           | 111 +++++++++++++++++++++++++++++++++++++
 lib/librte_gso/rte_gso_version.map |   7 +++
 mk/rte.app.mk                      |   1 +
 7 files changed, 222 insertions(+)
 create mode 100644 lib/librte_gso/Makefile
 create mode 100644 lib/librte_gso/rte_gso.c
 create mode 100644 lib/librte_gso/rte_gso.h
 create mode 100644 lib/librte_gso/rte_gso_version.map

diff --git a/config/common_base b/config/common_base
index 5e97a08..603e340 100644
--- a/config/common_base
+++ b/config/common_base
@@ -652,6 +652,11 @@ CONFIG_RTE_LIBRTE_IP_FRAG_TBL_STAT=n
 CONFIG_RTE_LIBRTE_GRO=y
 
 #
+# Compile GSO library
+#
+CONFIG_RTE_LIBRTE_GSO=y
+
+#
 # Compile librte_meter
 #
 CONFIG_RTE_LIBRTE_METER=y
diff --git a/lib/Makefile b/lib/Makefile
index 86caba1..3d123f4 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -108,6 +108,8 @@ DIRS-$(CONFIG_RTE_LIBRTE_REORDER) += librte_reorder
 DEPDIRS-librte_reorder := librte_eal librte_mempool librte_mbuf
 DIRS-$(CONFIG_RTE_LIBRTE_PDUMP) += librte_pdump
 DEPDIRS-librte_pdump := librte_eal librte_mempool librte_mbuf librte_ether
+DIRS-$(CONFIG_RTE_LIBRTE_GSO) += librte_gso
+DEPDIRS-librte_gso := librte_eal librte_mbuf librte_ether librte_net
 
 ifeq ($(CONFIG_RTE_EXEC_ENV_LINUXAPP),y)
 DIRS-$(CONFIG_RTE_LIBRTE_KNI) += librte_kni
diff --git a/lib/librte_gso/Makefile b/lib/librte_gso/Makefile
new file mode 100644
index 0000000..aeaacbc
--- /dev/null
+++ b/lib/librte_gso/Makefile
@@ -0,0 +1,49 @@
+#   BSD LICENSE
+#
+#   Copyright(c) 2017 Intel Corporation. All rights reserved.
+#   All rights reserved.
+#
+#   Redistribution and use in source and binary forms, with or without
+#   modification, are permitted provided that the following conditions
+#   are met:
+#
+#     * Redistributions of source code must retain the above copyright
+#       notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above copyright
+#       notice, this list of conditions and the following disclaimer in
+#       the documentation and/or other materials provided with the
+#       distribution.
+#     * Neither the name of Intel Corporation nor the names of its
+#       contributors may be used to endorse or promote products derived
+#       from this software without specific prior written permission.
+#
+#   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+#   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+#   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+#   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+#   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+#   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+#   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+#   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+#   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+#   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+#   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+include $(RTE_SDK)/mk/rte.vars.mk
+
+# library name
+LIB = librte_gso.a
+
+CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3
+
+EXPORT_MAP := rte_gso_version.map
+
+LIBABIVER := 1
+
+#source files
+SRCS-$(CONFIG_RTE_LIBRTE_GSO) += rte_gso.c
+
+# install this header file
+SYMLINK-$(CONFIG_RTE_LIBRTE_GSO)-include += rte_gso.h
+
+include $(RTE_SDK)/mk/rte.lib.mk
diff --git a/lib/librte_gso/rte_gso.c b/lib/librte_gso/rte_gso.c
new file mode 100644
index 0000000..b81afce
--- /dev/null
+++ b/lib/librte_gso/rte_gso.c
@@ -0,0 +1,47 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2017 Intel Corporation. All rights reserved.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "rte_gso.h"
+
+int
+rte_gso_segment(struct rte_mbuf *pkt,
+		struct rte_gso_ctx gso_ctx,
+		struct rte_mbuf **pkts_out,
+		uint16_t nb_pkts_out __rte_unused)
+{
+	if (pkt == NULL || pkts_out == NULL || gso_ctx.direct_pool ==
+			NULL || gso_ctx.indirect_pool == NULL)
+		return -EINVAL;
+
+	return 1;
+}
diff --git a/lib/librte_gso/rte_gso.h b/lib/librte_gso/rte_gso.h
new file mode 100644
index 0000000..5a8389a
--- /dev/null
+++ b/lib/librte_gso/rte_gso.h
@@ -0,0 +1,111 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2017 Intel Corporation. All rights reserved.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _RTE_GSO_H_
+#define _RTE_GSO_H_
+
+/**
+ * @file
+ * Interface to GSO library
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+#include <rte_mbuf.h>
+
+/**
+ * GSO context structure.
+ */
+struct rte_gso_ctx {
+	struct rte_mempool *direct_pool;
+	/**< MBUF pool for allocating direct buffers, which are used
+	 * to store packet headers for GSO segments.
+	 */
+	struct rte_mempool *indirect_pool;
+	/**< MBUF pool for allocating indirect buffers, which are used
+	 * to locate packet payloads for GSO segments. The indirect
+	 * buffer doesn't contain any data, but simply points to an
+	 * offset within the packet to segment.
+	 */
+	uint64_t gso_types;
+	/**< GSO types to perform */
+	uint16_t gso_size;
+	/**< maximum size of a GSO segment, measured in bytes */
+};
+
+/**
+ * Segmentation function, which supports processing of both single- and
+ * multi- segment packets. rte_gso_segment() assumes the input packet
+ * has correct checksums, and it doesn't process IP fragment packets.
+ * Additionally, it assumes that 'pkts_out' is large enough to hold all GSO
+ * segments.
+ *
+ * We refer to the packets that are segmented from the input packet as 'GSO
+ * segments'. If the input packet is GSOed, its mbuf refcnt reduces by 1.
+ * Therefore, when all GSO segments are freed, the input packet is freed
+ * automatically. If the input packet doesn't match the criteria for GSO
+ * (e.g. 'pkt's length is small and doesn't need segmentation), the packet
+ * is skipped and this function returns 1. If the available memory space
+ * in MBUF pools is insufficient, the packet is skipped and return -ENOMEM.
+ *
+ * @param pkt
+ *  The packet mbuf to segment.
+ * @param ctx
+ *  GSO context object.
+ * @param pkts_out
+ *  Pointer array used to stores the mbuf addresses of GSO segments.
+ *  Applications must ensure pkts_out is large enough to hold all GSO
+ *  segments. If the memory space in pkts_out is insufficient, the input
+ *  packet is skipped and return -EINVAL.
+ * @param nb_pkts_out
+ *  The max number of items that pkts_out can keep.
+ *
+ * @return
+ *  - The number of GSO segments created on success.
+ *  - Return 1 if no GSO is performed.
+ *  - Return -ENOMEM if run out of memory in MBUF pools.
+ *  - Return -EINVAL for invalid parameters.
+ */
+int rte_gso_segment(struct rte_mbuf *pkt,
+		struct rte_gso_ctx ctx,
+		struct rte_mbuf **pkts_out,
+		uint16_t nb_pkts_out);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _RTE_GSO_H_ */
diff --git a/lib/librte_gso/rte_gso_version.map b/lib/librte_gso/rte_gso_version.map
new file mode 100644
index 0000000..e1fd453
--- /dev/null
+++ b/lib/librte_gso/rte_gso_version.map
@@ -0,0 +1,7 @@
+DPDK_17.11 {
+	global:
+
+	rte_gso_segment;
+
+	local: *;
+};
diff --git a/mk/rte.app.mk b/mk/rte.app.mk
index c25fdd9..d4c9873 100644
--- a/mk/rte.app.mk
+++ b/mk/rte.app.mk
@@ -66,6 +66,7 @@ _LDLIBS-$(CONFIG_RTE_LIBRTE_PDUMP)          += -lrte_pdump
 _LDLIBS-$(CONFIG_RTE_LIBRTE_DISTRIBUTOR)    += -lrte_distributor
 _LDLIBS-$(CONFIG_RTE_LIBRTE_IP_FRAG)        += -lrte_ip_frag
 _LDLIBS-$(CONFIG_RTE_LIBRTE_GRO)            += -lrte_gro
+_LDLIBS-$(CONFIG_RTE_LIBRTE_GSO)            += -lrte_gso
 _LDLIBS-$(CONFIG_RTE_LIBRTE_METER)          += -lrte_meter
 _LDLIBS-$(CONFIG_RTE_LIBRTE_SCHED)          += -lrte_sched
 _LDLIBS-$(CONFIG_RTE_LIBRTE_LPM)            += -lrte_lpm
-- 
2.7.4



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