Hi Jiayu,
>
> 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...@intel.com>
> Signed-off-by: Mark Kavanagh <mark.b.kavan...@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 */
Looking at the way it is used right now - there seems not much value in it...
Why not to make it a mask of ptypes for which GSO should be perfomed?
Let say for gso_ctx that supports only ip4/tcp it would be:
gso_types = (RTE_PTYPE_L2_ETHER | RTE_PTYPE_L3_IPV4 | RTE_PTYPE_L4_TCP)
and then in rte_gso_segment() we can perfom gso only on packets of requested
ptype:
if ((pkt->packet_type & gso_ctx->gso_types) == pkt->packet_type) {
/* do segmentation */
} else {
/* skip segmentation for that packet */
}
> + uint16_t gso_size;
> + /**< maximum size of a GSO segment, measured in bytes */
Is that MSS or MTU?
> +};
> +
> +/**
> + * 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.
Wouldn't it be better to return number of elems filled in pkts_out[] on success?
> + * - 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
