Hi,
Doc building failed, it seems the rte_mbuf_dynfield_copy() description should
be fixed:
./lib/librte_mbuf/rte_mbuf.h:1694: warning: argument 'm_dst' of command @param
is not found in the argument list of rte_mbuf_dynfield_copy(struct rte_mbuf
*mdst, const struct rte_mbuf *msrc)
./lib/librte_mbuf/rte_mbuf.h:1694: warning: argument 'm_src' of command @param
is not found in the argument list of rte_mbuf_dynfield_copy(struct rte_mbuf
*mdst, const struct rte_mbuf *msrc)
./lib/librte_mbuf/rte_mbuf.h:1694: warning: The following parameters of
rte_mbuf_dynfield_copy(struct rte_mbuf *mdst, const struct rte_mbuf *msrc) are
not documented
With best regards,
Slava
> -----Original Message-----
> From: dev <dev-boun...@dpdk.org> On Behalf Of Olivier Matz
> Sent: Thursday, October 17, 2019 17:42
> To: dev@dpdk.org
> Cc: Andrew Rybchenko <arybche...@solarflare.com>; Bruce Richardson
> <bruce.richard...@intel.com>; Wang, Haiyue <haiyue.w...@intel.com>;
> Jerin Jacob Kollanukkaran <jer...@marvell.com>; Wiles, Keith
> <keith.wi...@intel.com>; Ananyev, Konstantin
> <konstantin.anan...@intel.com>; Morten Brørup
> <m...@smartsharesystems.com>; Stephen Hemminger
> <step...@networkplumber.org>; Thomas Monjalon
> <tho...@monjalon.net>
> Subject: [dpdk-dev] [PATCH v2] mbuf: support dynamic fields and flags
>
> Many features require to store data inside the mbuf. As the room in mbuf
> structure is limited, it is not possible to have a field for each feature.
> Also,
> changing fields in the mbuf structure can break the API or ABI.
>
> This commit addresses these issues, by enabling the dynamic registration of
> fields or flags:
>
> - a dynamic field is a named area in the rte_mbuf structure, with a
> given size (>= 1 byte) and alignment constraint.
> - a dynamic flag is a named bit in the rte_mbuf structure.
>
> The typical use case is a PMD that registers space for an offload feature,
> when the application requests to enable this feature. As the space in mbuf is
> limited, the space should only be reserved if it is going to be used (i.e when
> the application explicitly asks for it).
>
> The registration can be done at any moment, but it is not possible to
> unregister fields or flags for now.
>
> Signed-off-by: Olivier Matz <olivier.m...@6wind.com>
> Acked-by: Thomas Monjalon <tho...@monjalon.net>
> ---
>
> v2
>
> * Rebase on top of master: solve conflict with Stephen's patchset
> (packet copy)
> * Add new apis to register a dynamic field/flag at a specific place
> * Add a dump function (sugg by David)
> * Enhance field registration function to select the best offset, keeping
> large aligned zones as much as possible (sugg by Konstantin)
> * Use a size_t and unsigned int instead of int when relevant
> (sugg by Konstantin)
> * Use "uint64_t dynfield1[2]" in mbuf instead of 2 uint64_t fields
> (sugg by Konstantin)
> * Remove unused argument in private function (sugg by Konstantin)
> * Fix and simplify locking (sugg by Konstantin)
> * Fix minor typo
>
> rfc -> v1
>
> * Rebase on top of master
> * Change registration API to use a structure instead of
> variables, getting rid of #defines (Stephen's comment)
> * Update flag registration to use a similar API as fields.
> * Change max name length from 32 to 64 (sugg. by Thomas)
> * Enhance API documentation (Haiyue's and Andrew's comments)
> * Add a debug log at registration
> * Add some words in release note
> * Did some performance tests (sugg. by Andrew):
> On my platform, reading a dynamic field takes ~3 cycles more
> than a static field, and ~2 cycles more for writing.
>
> app/test/test_mbuf.c | 145 ++++++-
> doc/guides/rel_notes/release_19_11.rst | 7 +
> lib/librte_mbuf/Makefile | 2 +
> lib/librte_mbuf/meson.build | 6 +-
> lib/librte_mbuf/rte_mbuf.h | 23 +-
> lib/librte_mbuf/rte_mbuf_dyn.c | 548 +++++++++++++++++++++++++
> lib/librte_mbuf/rte_mbuf_dyn.h | 226 ++++++++++
> lib/librte_mbuf/rte_mbuf_version.map | 7 +
> 8 files changed, 959 insertions(+), 5 deletions(-) create mode 100644
> lib/librte_mbuf/rte_mbuf_dyn.c create mode 100644
> lib/librte_mbuf/rte_mbuf_dyn.h
>
> diff --git a/app/test/test_mbuf.c b/app/test/test_mbuf.c index
> b9c2b2500..01cafad59 100644
> --- a/app/test/test_mbuf.c
> +++ b/app/test/test_mbuf.c
> @@ -28,6 +28,7 @@
> #include <rte_random.h>
> #include <rte_cycles.h>
> #include <rte_malloc.h>
> +#include <rte_mbuf_dyn.h>
>
> #include "test.h"
>
> @@ -657,7 +658,6 @@ test_attach_from_different_pool(struct
> rte_mempool *pktmbuf_pool,
> rte_pktmbuf_free(clone2);
> return -1;
> }
> -#undef GOTO_FAIL
>
> /*
> * test allocation and free of mbufs
> @@ -1276,6 +1276,143 @@ test_tx_offload(void)
> return (v1 == v2) ? 0 : -EINVAL;
> }
>
> +static int
> +test_mbuf_dyn(struct rte_mempool *pktmbuf_pool) {
> + const struct rte_mbuf_dynfield dynfield = {
> + .name = "test-dynfield",
> + .size = sizeof(uint8_t),
> + .align = __alignof__(uint8_t),
> + .flags = 0,
> + };
> + const struct rte_mbuf_dynfield dynfield2 = {
> + .name = "test-dynfield2",
> + .size = sizeof(uint16_t),
> + .align = __alignof__(uint16_t),
> + .flags = 0,
> + };
> + const struct rte_mbuf_dynfield dynfield3 = {
> + .name = "test-dynfield3",
> + .size = sizeof(uint8_t),
> + .align = __alignof__(uint8_t),
> + .flags = 0,
> + };
> + const struct rte_mbuf_dynfield dynfield_fail_big = {
> + .name = "test-dynfield-fail-big",
> + .size = 256,
> + .align = 1,
> + .flags = 0,
> + };
> + const struct rte_mbuf_dynfield dynfield_fail_align = {
> + .name = "test-dynfield-fail-align",
> + .size = 1,
> + .align = 3,
> + .flags = 0,
> + };
> + const struct rte_mbuf_dynflag dynflag = {
> + .name = "test-dynflag",
> + .flags = 0,
> + };
> + const struct rte_mbuf_dynflag dynflag2 = {
> + .name = "test-dynflag2",
> + .flags = 0,
> + };
> + const struct rte_mbuf_dynflag dynflag3 = {
> + .name = "test-dynflag3",
> + .flags = 0,
> + };
> + struct rte_mbuf *m = NULL;
> + int offset, offset2, offset3;
> + int flag, flag2, flag3;
> + int ret;
> +
> + printf("Test mbuf dynamic fields and flags\n");
> + rte_mbuf_dyn_dump(stdout);
> +
> + offset = rte_mbuf_dynfield_register(&dynfield);
> + if (offset == -1)
> + GOTO_FAIL("failed to register dynamic field, offset=%d: %s",
> + offset, strerror(errno));
> +
> + ret = rte_mbuf_dynfield_register(&dynfield);
> + if (ret != offset)
> + GOTO_FAIL("failed to lookup dynamic field, ret=%d: %s",
> + ret, strerror(errno));
> +
> + offset2 = rte_mbuf_dynfield_register(&dynfield2);
> + if (offset2 == -1 || offset2 == offset || (offset2 & 1))
> + GOTO_FAIL("failed to register dynamic field 2, offset2=%d:
> %s",
> + offset2, strerror(errno));
> +
> + offset3 = rte_mbuf_dynfield_register_offset(&dynfield3,
> + offsetof(struct rte_mbuf, dynfield1[1]));
> + if (offset3 != offsetof(struct rte_mbuf, dynfield1[1]))
> + GOTO_FAIL("failed to register dynamic field 3, offset=%d:
> %s",
> + offset3, strerror(errno));
> +
> + printf("dynfield: offset=%d, offset2=%d, offset3=%d\n",
> + offset, offset2, offset3);
> +
> + ret = rte_mbuf_dynfield_register(&dynfield_fail_big);
> + if (ret != -1)
> + GOTO_FAIL("dynamic field creation should fail (too big)");
> +
> + ret = rte_mbuf_dynfield_register(&dynfield_fail_align);
> + if (ret != -1)
> + GOTO_FAIL("dynamic field creation should fail (bad
> alignment)");
> +
> + ret = rte_mbuf_dynfield_register_offset(&dynfield_fail_align,
> + offsetof(struct rte_mbuf, ol_flags));
> + if (ret != -1)
> + GOTO_FAIL("dynamic field creation should fail (not avail)");
> +
> + flag = rte_mbuf_dynflag_register(&dynflag);
> + if (flag == -1)
> + GOTO_FAIL("failed to register dynamic flag, flag=%d: %s",
> + flag, strerror(errno));
> +
> + ret = rte_mbuf_dynflag_register(&dynflag);
> + if (ret != flag)
> + GOTO_FAIL("failed to lookup dynamic flag, ret=%d: %s",
> + ret, strerror(errno));
> +
> + flag2 = rte_mbuf_dynflag_register(&dynflag2);
> + if (flag2 == -1 || flag2 == flag)
> + GOTO_FAIL("failed to register dynamic flag 2, flag2=%d: %s",
> + flag2, strerror(errno));
> +
> + flag3 = rte_mbuf_dynflag_register_bitnum(&dynflag3,
> + rte_bsf64(PKT_LAST_FREE));
> + if (flag3 != rte_bsf64(PKT_LAST_FREE))
> + GOTO_FAIL("failed to register dynamic flag 3, flag2=%d: %s",
> + flag3, strerror(errno));
> +
> + printf("dynflag: flag=%d, flag2=%d, flag3=%d\n", flag, flag2, flag3);
> +
> + /* set, get dynamic field */
> + m = rte_pktmbuf_alloc(pktmbuf_pool);
> + if (m == NULL)
> + GOTO_FAIL("Cannot allocate mbuf");
> +
> + *RTE_MBUF_DYNFIELD(m, offset, uint8_t *) = 1;
> + if (*RTE_MBUF_DYNFIELD(m, offset, uint8_t *) != 1)
> + GOTO_FAIL("failed to read dynamic field");
> + *RTE_MBUF_DYNFIELD(m, offset2, uint16_t *) = 1000;
> + if (*RTE_MBUF_DYNFIELD(m, offset2, uint16_t *) != 1000)
> + GOTO_FAIL("failed to read dynamic field");
> +
> + /* set a dynamic flag */
> + m->ol_flags |= (1ULL << flag);
> +
> + rte_mbuf_dyn_dump(stdout);
> + rte_pktmbuf_free(m);
> + return 0;
> +fail:
> + rte_pktmbuf_free(m);
> + return -1;
> +}
> +#undef GOTO_FAIL
> +
> static int
> test_mbuf(void)
> {
> @@ -1295,6 +1432,12 @@ test_mbuf(void)
> goto err;
> }
>
> + /* test registration of dynamic fields and flags */
> + if (test_mbuf_dyn(pktmbuf_pool) < 0) {
> + printf("mbuf dynflag test failed\n");
> + goto err;
> + }
> +
> /* create a specific pktmbuf pool with a priv_size != 0 and no data
> * room size */
> pktmbuf_pool2 = rte_pktmbuf_pool_create("test_pktmbuf_pool2",
> diff --git a/doc/guides/rel_notes/release_19_11.rst
> b/doc/guides/rel_notes/release_19_11.rst
> index 85953b962..9e9c94554 100644
> --- a/doc/guides/rel_notes/release_19_11.rst
> +++ b/doc/guides/rel_notes/release_19_11.rst
> @@ -21,6 +21,13 @@ DPDK Release 19.11
>
> xdg-open build/doc/html/guides/rel_notes/release_19_11.html
>
> +* **Add support of support dynamic fields and flags in mbuf.**
> +
> + This new feature adds the ability to dynamically register some room
> + for a field or a flag in the mbuf structure. This is typically used
> + for specific offload features, where adding a static field or flag in
> + the mbuf is not justified.
> +
>
> New Features
> ------------
> diff --git a/lib/librte_mbuf/Makefile b/lib/librte_mbuf/Makefile index
> c8f6d2689..5a9bcee73 100644
> --- a/lib/librte_mbuf/Makefile
> +++ b/lib/librte_mbuf/Makefile
> @@ -17,8 +17,10 @@ LIBABIVER := 5
>
> # all source are stored in SRCS-y
> SRCS-$(CONFIG_RTE_LIBRTE_MBUF) := rte_mbuf.c rte_mbuf_ptype.c
> rte_mbuf_pool_ops.c
> +SRCS-$(CONFIG_RTE_LIBRTE_MBUF) += rte_mbuf_dyn.c
>
> # install includes
> SYMLINK-$(CONFIG_RTE_LIBRTE_MBUF)-include := rte_mbuf.h
> rte_mbuf_ptype.h rte_mbuf_pool_ops.h
> +SYMLINK-$(CONFIG_RTE_LIBRTE_MBUF)-include += rte_mbuf_dyn.h
>
> include $(RTE_SDK)/mk/rte.lib.mk
> diff --git a/lib/librte_mbuf/meson.build b/lib/librte_mbuf/meson.build index
> 6cc11ebb4..9137e8f26 100644
> --- a/lib/librte_mbuf/meson.build
> +++ b/lib/librte_mbuf/meson.build
> @@ -2,8 +2,10 @@
> # Copyright(c) 2017 Intel Corporation
>
> version = 5
> -sources = files('rte_mbuf.c', 'rte_mbuf_ptype.c', 'rte_mbuf_pool_ops.c') -
> headers = files('rte_mbuf.h', 'rte_mbuf_ptype.h', 'rte_mbuf_pool_ops.h')
> +sources = files('rte_mbuf.c', 'rte_mbuf_ptype.c', 'rte_mbuf_pool_ops.c',
> + 'rte_mbuf_dyn.c')
> +headers = files('rte_mbuf.h', 'rte_mbuf_ptype.h', 'rte_mbuf_pool_ops.h',
> + 'rte_mbuf_dyn.h')
> deps += ['mempool']
>
> allow_experimental_apis = true
> diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h index
> fb0849ac1..5740b1e93 100644
> --- a/lib/librte_mbuf/rte_mbuf.h
> +++ b/lib/librte_mbuf/rte_mbuf.h
> @@ -198,9 +198,12 @@ extern "C" {
> #define PKT_RX_OUTER_L4_CKSUM_GOOD (1ULL << 22)
> #define PKT_RX_OUTER_L4_CKSUM_INVALID ((1ULL << 21) | (1ULL << 22))
>
> -/* add new RX flags here */
> +/* add new RX flags here, don't forget to update PKT_FIRST_FREE */
>
> -/* add new TX flags here */
> +#define PKT_FIRST_FREE (1ULL << 23)
> +#define PKT_LAST_FREE (1ULL << 39)
> +
> +/* add new TX flags here, don't forget to update PKT_LAST_FREE */
>
> /**
> * Indicate that the metadata field in the mbuf is in use.
> @@ -738,6 +741,7 @@ struct rte_mbuf {
> */
> struct rte_mbuf_ext_shared_info *shinfo;
>
> + uint64_t dynfield1[2]; /**< Reserved for dynamic fields. */
> } __rte_cache_aligned;
>
> /**
> @@ -1684,6 +1688,20 @@ rte_pktmbuf_attach_extbuf(struct rte_mbuf *m,
> void *buf_addr,
> */
> #define rte_pktmbuf_detach_extbuf(m) rte_pktmbuf_detach(m)
>
> +/**
> + * Copy dynamic fields from m_src to m_dst.
> + *
> + * @param m_dst
> + * The destination mbuf.
> + * @param m_src
> + * The source mbuf.
> + */
> +static inline void
> +rte_mbuf_dynfield_copy(struct rte_mbuf *mdst, const struct rte_mbuf
> +*msrc) {
> + memcpy(&mdst->dynfield1, msrc->dynfield1, sizeof(mdst-
> >dynfield1)); }
> +
> /* internal */
> static inline void
> __rte_pktmbuf_copy_hdr(struct rte_mbuf *mdst, const struct rte_mbuf
> *msrc) @@ -1695,6 +1713,7 @@ __rte_pktmbuf_copy_hdr(struct rte_mbuf
> *mdst, const struct rte_mbuf *msrc)
> mdst->hash = msrc->hash;
> mdst->packet_type = msrc->packet_type;
> mdst->timestamp = msrc->timestamp;
> + rte_mbuf_dynfield_copy(mdst, msrc);
> }
>
> /**
> diff --git a/lib/librte_mbuf/rte_mbuf_dyn.c
> b/lib/librte_mbuf/rte_mbuf_dyn.c new file mode 100644 index
> 000000000..9ef235483
> --- /dev/null
> +++ b/lib/librte_mbuf/rte_mbuf_dyn.c
> @@ -0,0 +1,548 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright 2019 6WIND S.A.
> + */
> +
> +#include <sys/queue.h>
> +#include <stdint.h>
> +#include <limits.h>
> +
> +#include <rte_common.h>
> +#include <rte_eal.h>
> +#include <rte_eal_memconfig.h>
> +#include <rte_tailq.h>
> +#include <rte_errno.h>
> +#include <rte_malloc.h>
> +#include <rte_string_fns.h>
> +#include <rte_mbuf.h>
> +#include <rte_mbuf_dyn.h>
> +
> +#define RTE_MBUF_DYN_MZNAME "rte_mbuf_dyn"
> +
> +struct mbuf_dynfield_elt {
> + TAILQ_ENTRY(mbuf_dynfield_elt) next;
> + struct rte_mbuf_dynfield params;
> + size_t offset;
> +};
> +TAILQ_HEAD(mbuf_dynfield_list, rte_tailq_entry);
> +
> +static struct rte_tailq_elem mbuf_dynfield_tailq = {
> + .name = "RTE_MBUF_DYNFIELD",
> +};
> +EAL_REGISTER_TAILQ(mbuf_dynfield_tailq);
> +
> +struct mbuf_dynflag_elt {
> + TAILQ_ENTRY(mbuf_dynflag_elt) next;
> + struct rte_mbuf_dynflag params;
> + unsigned int bitnum;
> +};
> +TAILQ_HEAD(mbuf_dynflag_list, rte_tailq_entry);
> +
> +static struct rte_tailq_elem mbuf_dynflag_tailq = {
> + .name = "RTE_MBUF_DYNFLAG",
> +};
> +EAL_REGISTER_TAILQ(mbuf_dynflag_tailq);
> +
> +struct mbuf_dyn_shm {
> + /**
> + * For each mbuf byte, free_space[i] != 0 if space is free.
> + * The value is the size of the biggest aligned element that
> + * can fit in the zone.
> + */
> + uint8_t free_space[sizeof(struct rte_mbuf)];
> + /** Bitfield of available flags. */
> + uint64_t free_flags;
> +};
> +static struct mbuf_dyn_shm *shm;
> +
> +/* Set the value of free_space[] according to the size and alignment of
> + * the free areas. This helps to select the best place when reserving a
> + * dynamic field. Assume tailq is locked.
> + */
> +static void
> +process_score(void)
> +{
> + size_t off, align, size, i;
> +
> + /* first, erase previous info */
> + for (i = 0; i < sizeof(struct rte_mbuf); i++) {
> + if (shm->free_space[i])
> + shm->free_space[i] = 1;
> + }
> +
> + for (off = 0; off < sizeof(struct rte_mbuf); off++) {
> + /* get the size of the free zone */
> + for (size = 0; shm->free_space[off + size]; size++)
> + ;
> + if (size == 0)
> + continue;
> +
> + /* get the alignment of biggest object that can fit in
> + * the zone at this offset.
> + */
> + for (align = 1;
> + (off % (align << 1)) == 0 && (align << 1) <= size;
> + align <<= 1)
> + ;
> +
> + /* save it in free_space[] */
> + for (i = off; i < off + size; i++)
> + shm->free_space[i] = RTE_MAX(align, shm-
> >free_space[i]);
> + }
> +}
> +
> +/* Allocate and initialize the shared memory. Assume tailq is locked */
> +static int
> +init_shared_mem(void)
> +{
> + const struct rte_memzone *mz;
> + uint64_t mask;
> +
> + if (rte_eal_process_type() == RTE_PROC_PRIMARY) {
> + mz =
> rte_memzone_reserve_aligned(RTE_MBUF_DYN_MZNAME,
> + sizeof(struct
> mbuf_dyn_shm),
> + SOCKET_ID_ANY, 0,
> + RTE_CACHE_LINE_SIZE);
> + } else {
> + mz = rte_memzone_lookup(RTE_MBUF_DYN_MZNAME);
> + }
> + if (mz == NULL)
> + return -1;
> +
> + shm = mz->addr;
> +
> +#define mark_free(field) \
> + memset(&shm->free_space[offsetof(struct rte_mbuf, field)], \
> + 1, sizeof(((struct rte_mbuf *)0)->field))
> +
> + if (rte_eal_process_type() == RTE_PROC_PRIMARY) {
> + /* init free_space, keep it sync'd with
> + * rte_mbuf_dynfield_copy().
> + */
> + memset(shm, 0, sizeof(*shm));
> + mark_free(dynfield1);
> +
> + /* init free_flags */
> + for (mask = PKT_FIRST_FREE; mask <= PKT_LAST_FREE; mask
> <<= 1)
> + shm->free_flags |= mask;
> +
> + process_score();
> + }
> +#undef mark_free
> +
> + return 0;
> +}
> +
> +/* check if this offset can be used */
> +static int
> +check_offset(size_t offset, size_t size, size_t align) {
> + size_t i;
> +
> + if ((offset & (align - 1)) != 0)
> + return -1;
> + if (offset + size > sizeof(struct rte_mbuf))
> + return -1;
> +
> + for (i = 0; i < size; i++) {
> + if (!shm->free_space[i + offset])
> + return -1;
> + }
> +
> + return 0;
> +}
> +
> +/* assume tailq is locked */
> +static struct mbuf_dynfield_elt *
> +__mbuf_dynfield_lookup(const char *name) {
> + struct mbuf_dynfield_list *mbuf_dynfield_list;
> + struct mbuf_dynfield_elt *mbuf_dynfield;
> + struct rte_tailq_entry *te;
> +
> + mbuf_dynfield_list = RTE_TAILQ_CAST(
> + mbuf_dynfield_tailq.head, mbuf_dynfield_list);
> +
> + TAILQ_FOREACH(te, mbuf_dynfield_list, next) {
> + mbuf_dynfield = (struct mbuf_dynfield_elt *)te->data;
> + if (strcmp(name, mbuf_dynfield->params.name) == 0)
> + break;
> + }
> +
> + if (te == NULL) {
> + rte_errno = ENOENT;
> + return NULL;
> + }
> +
> + return mbuf_dynfield;
> +}
> +
> +int
> +rte_mbuf_dynfield_lookup(const char *name, struct rte_mbuf_dynfield
> +*params) {
> + struct mbuf_dynfield_elt *mbuf_dynfield;
> +
> + if (shm == NULL) {
> + rte_errno = ENOENT;
> + return -1;
> + }
> +
> + rte_mcfg_tailq_read_lock();
> + mbuf_dynfield = __mbuf_dynfield_lookup(name);
> + rte_mcfg_tailq_read_unlock();
> +
> + if (mbuf_dynfield == NULL) {
> + rte_errno = ENOENT;
> + return -1;
> + }
> +
> + if (params != NULL)
> + memcpy(params, &mbuf_dynfield->params,
> sizeof(*params));
> +
> + return mbuf_dynfield->offset;
> +}
> +
> +static int mbuf_dynfield_cmp(const struct rte_mbuf_dynfield *params1,
> + const struct rte_mbuf_dynfield *params2) {
> + if (strcmp(params1->name, params2->name))
> + return -1;
> + if (params1->size != params2->size)
> + return -1;
> + if (params1->align != params2->align)
> + return -1;
> + if (params1->flags != params2->flags)
> + return -1;
> + return 0;
> +}
> +
> +/* assume tailq is locked */
> +static int
> +__rte_mbuf_dynfield_register_offset(const struct rte_mbuf_dynfield
> *params,
> + size_t req)
> +{
> + struct mbuf_dynfield_list *mbuf_dynfield_list;
> + struct mbuf_dynfield_elt *mbuf_dynfield = NULL;
> + struct rte_tailq_entry *te = NULL;
> + unsigned int best_zone = UINT_MAX;
> + size_t i, offset;
> + int ret;
> +
> + if (shm == NULL && init_shared_mem() < 0)
> + return -1;
> +
> + mbuf_dynfield = __mbuf_dynfield_lookup(params->name);
> + if (mbuf_dynfield != NULL) {
> + if (req != SIZE_MAX && req != mbuf_dynfield->offset) {
> + rte_errno = EEXIST;
> + return -1;
> + }
> + if (mbuf_dynfield_cmp(params, &mbuf_dynfield->params) <
> 0) {
> + rte_errno = EEXIST;
> + return -1;
> + }
> + return mbuf_dynfield->offset;
> + }
> +
> + if (rte_eal_process_type() != RTE_PROC_PRIMARY) {
> + rte_errno = EPERM;
> + return -1;
> + }
> +
> + if (req == SIZE_MAX) {
> + for (offset = 0;
> + offset < sizeof(struct rte_mbuf);
> + offset++) {
> + if (check_offset(offset, params->size,
> + params->align) == 0 &&
> + shm->free_space[offset] <
> best_zone) {
> + best_zone = shm->free_space[offset];
> + req = offset;
> + }
> + }
> + if (req == SIZE_MAX) {
> + rte_errno = ENOENT;
> + return -1;
> + }
> + } else {
> + if (check_offset(req, params->size, params->align) < 0) {
> + rte_errno = EBUSY;
> + return -1;
> + }
> + }
> +
> + offset = req;
> + mbuf_dynfield_list = RTE_TAILQ_CAST(
> + mbuf_dynfield_tailq.head, mbuf_dynfield_list);
> +
> + te = rte_zmalloc("MBUF_DYNFIELD_TAILQ_ENTRY", sizeof(*te), 0);
> + if (te == NULL)
> + return -1;
> +
> + mbuf_dynfield = rte_zmalloc("mbuf_dynfield",
> sizeof(*mbuf_dynfield), 0);
> + if (mbuf_dynfield == NULL) {
> + rte_free(te);
> + return -1;
> + }
> +
> + ret = strlcpy(mbuf_dynfield->params.name, params->name,
> + sizeof(mbuf_dynfield->params.name));
> + if (ret < 0 || ret >= (int)sizeof(mbuf_dynfield->params.name)) {
> + rte_errno = ENAMETOOLONG;
> + rte_free(mbuf_dynfield);
> + rte_free(te);
> + return -1;
> + }
> + memcpy(&mbuf_dynfield->params, params, sizeof(mbuf_dynfield-
> >params));
> + mbuf_dynfield->offset = offset;
> + te->data = mbuf_dynfield;
> +
> + TAILQ_INSERT_TAIL(mbuf_dynfield_list, te, next);
> +
> + for (i = offset; i < offset + params->size; i++)
> + shm->free_space[i] = 0;
> + process_score();
> +
> + RTE_LOG(DEBUG, MBUF, "Registered dynamic field %s (sz=%zu,
> al=%zu, fl=0x%x) -> %zd\n",
> + params->name, params->size, params->align, params->flags,
> + offset);
> +
> + return offset;
> +}
> +
> +int
> +rte_mbuf_dynfield_register_offset(const struct rte_mbuf_dynfield
> *params,
> + size_t req)
> +{
> + int ret;
> +
> + if (params->size >= sizeof(struct rte_mbuf)) {
> + rte_errno = EINVAL;
> + return -1;
> + }
> + if (!rte_is_power_of_2(params->align)) {
> + rte_errno = EINVAL;
> + return -1;
> + }
> + if (params->flags != 0) {
> + rte_errno = EINVAL;
> + return -1;
> + }
> +
> + rte_mcfg_tailq_write_lock();
> + ret = __rte_mbuf_dynfield_register_offset(params, req);
> + rte_mcfg_tailq_write_unlock();
> +
> + return ret;
> +}
> +
> +int
> +rte_mbuf_dynfield_register(const struct rte_mbuf_dynfield *params) {
> + return rte_mbuf_dynfield_register_offset(params, SIZE_MAX); }
> +
> +/* assume tailq is locked */
> +static struct mbuf_dynflag_elt *
> +__mbuf_dynflag_lookup(const char *name) {
> + struct mbuf_dynflag_list *mbuf_dynflag_list;
> + struct mbuf_dynflag_elt *mbuf_dynflag;
> + struct rte_tailq_entry *te;
> +
> + mbuf_dynflag_list = RTE_TAILQ_CAST(
> + mbuf_dynflag_tailq.head, mbuf_dynflag_list);
> +
> + TAILQ_FOREACH(te, mbuf_dynflag_list, next) {
> + mbuf_dynflag = (struct mbuf_dynflag_elt *)te->data;
> + if (strncmp(name, mbuf_dynflag->params.name,
> + RTE_MBUF_DYN_NAMESIZE) == 0)
> + break;
> + }
> +
> + if (te == NULL) {
> + rte_errno = ENOENT;
> + return NULL;
> + }
> +
> + return mbuf_dynflag;
> +}
> +
> +int
> +rte_mbuf_dynflag_lookup(const char *name,
> + struct rte_mbuf_dynflag *params)
> +{
> + struct mbuf_dynflag_elt *mbuf_dynflag;
> +
> + if (shm == NULL) {
> + rte_errno = ENOENT;
> + return -1;
> + }
> +
> + rte_mcfg_tailq_read_lock();
> + mbuf_dynflag = __mbuf_dynflag_lookup(name);
> + rte_mcfg_tailq_read_unlock();
> +
> + if (mbuf_dynflag == NULL) {
> + rte_errno = ENOENT;
> + return -1;
> + }
> +
> + if (params != NULL)
> + memcpy(params, &mbuf_dynflag->params, sizeof(*params));
> +
> + return mbuf_dynflag->bitnum;
> +}
> +
> +static int mbuf_dynflag_cmp(const struct rte_mbuf_dynflag *params1,
> + const struct rte_mbuf_dynflag *params2) {
> + if (strcmp(params1->name, params2->name))
> + return -1;
> + if (params1->flags != params2->flags)
> + return -1;
> + return 0;
> +}
> +
> +/* assume tailq is locked */
> +static int
> +__rte_mbuf_dynflag_register_bitnum(const struct rte_mbuf_dynflag
> *params,
> + unsigned int req)
> +{
> + struct mbuf_dynflag_list *mbuf_dynflag_list;
> + struct mbuf_dynflag_elt *mbuf_dynflag = NULL;
> + struct rte_tailq_entry *te = NULL;
> + unsigned int bitnum;
> + int ret;
> +
> + if (shm == NULL && init_shared_mem() < 0)
> + return -1;
> +
> + mbuf_dynflag = __mbuf_dynflag_lookup(params->name);
> + if (mbuf_dynflag != NULL) {
> + if (req != UINT_MAX && req != mbuf_dynflag->bitnum) {
> + rte_errno = EEXIST;
> + return -1;
> + }
> + if (mbuf_dynflag_cmp(params, &mbuf_dynflag->params) < 0)
> {
> + rte_errno = EEXIST;
> + return -1;
> + }
> + return mbuf_dynflag->bitnum;
> + }
> +
> + if (rte_eal_process_type() != RTE_PROC_PRIMARY) {
> + rte_errno = EPERM;
> + return -1;
> + }
> +
> + if (req == UINT_MAX) {
> + if (shm->free_flags == 0) {
> + rte_errno = ENOENT;
> + return -1;
> + }
> + bitnum = rte_bsf64(shm->free_flags);
> + } else {
> + if ((shm->free_flags & (1ULL << req)) == 0) {
> + rte_errno = EBUSY;
> + return -1;
> + }
> + bitnum = req;
> + }
> +
> + mbuf_dynflag_list = RTE_TAILQ_CAST(
> + mbuf_dynflag_tailq.head, mbuf_dynflag_list);
> +
> + te = rte_zmalloc("MBUF_DYNFLAG_TAILQ_ENTRY", sizeof(*te), 0);
> + if (te == NULL)
> + return -1;
> +
> + mbuf_dynflag = rte_zmalloc("mbuf_dynflag", sizeof(*mbuf_dynflag),
> 0);
> + if (mbuf_dynflag == NULL) {
> + rte_free(te);
> + return -1;
> + }
> +
> + ret = strlcpy(mbuf_dynflag->params.name, params->name,
> + sizeof(mbuf_dynflag->params.name));
> + if (ret < 0 || ret >= (int)sizeof(mbuf_dynflag->params.name)) {
> + rte_free(mbuf_dynflag);
> + rte_free(te);
> + rte_errno = ENAMETOOLONG;
> + return -1;
> + }
> + mbuf_dynflag->bitnum = bitnum;
> + te->data = mbuf_dynflag;
> +
> + TAILQ_INSERT_TAIL(mbuf_dynflag_list, te, next);
> +
> + shm->free_flags &= ~(1ULL << bitnum);
> +
> + RTE_LOG(DEBUG, MBUF, "Registered dynamic flag %s (fl=0x%x) ->
> %u\n",
> + params->name, params->flags, bitnum);
> +
> + return bitnum;
> +}
> +
> +int
> +rte_mbuf_dynflag_register_bitnum(const struct rte_mbuf_dynflag *params,
> + unsigned int req)
> +{
> + int ret;
> +
> + if (req != UINT_MAX && req >= 64) {
> + rte_errno = EINVAL;
> + return -1;
> + }
> +
> + rte_mcfg_tailq_write_lock();
> + ret = __rte_mbuf_dynflag_register_bitnum(params, req);
> + rte_mcfg_tailq_write_unlock();
> +
> + return ret;
> +}
> +
> +int
> +rte_mbuf_dynflag_register(const struct rte_mbuf_dynflag *params) {
> + return rte_mbuf_dynflag_register_bitnum(params, UINT_MAX); }
> +
> +void rte_mbuf_dyn_dump(FILE *out)
> +{
> + struct mbuf_dynfield_list *mbuf_dynfield_list;
> + struct mbuf_dynfield_elt *dynfield;
> + struct mbuf_dynflag_list *mbuf_dynflag_list;
> + struct mbuf_dynflag_elt *dynflag;
> + struct rte_tailq_entry *te;
> + size_t i;
> +
> + rte_mcfg_tailq_write_lock();
> + init_shared_mem();
> + fprintf(out, "Reserved fields:\n");
> + mbuf_dynfield_list = RTE_TAILQ_CAST(
> + mbuf_dynfield_tailq.head, mbuf_dynfield_list);
> + TAILQ_FOREACH(te, mbuf_dynfield_list, next) {
> + dynfield = (struct mbuf_dynfield_elt *)te->data;
> + fprintf(out, " name=%s offset=%zd size=%zd align=%zd
> flags=%x\n",
> + dynfield->params.name, dynfield->offset,
> + dynfield->params.size, dynfield->params.align,
> + dynfield->params.flags);
> + }
> + fprintf(out, "Reserved flags:\n");
> + mbuf_dynflag_list = RTE_TAILQ_CAST(
> + mbuf_dynflag_tailq.head, mbuf_dynflag_list);
> + TAILQ_FOREACH(te, mbuf_dynflag_list, next) {
> + dynflag = (struct mbuf_dynflag_elt *)te->data;
> + fprintf(out, " name=%s bitnum=%u flags=%x\n",
> + dynflag->params.name, dynflag->bitnum,
> + dynflag->params.flags);
> + }
> + fprintf(out, "Free space in mbuf (0 = free, value = zone
> alignment):\n");
> + for (i = 0; i < sizeof(struct rte_mbuf); i++) {
> + if ((i % 8) == 0)
> + fprintf(out, " %4.4zx: ", i);
> + fprintf(out, "%2.2x%s", shm->free_space[i],
> + (i % 8 != 7) ? " " : "\n");
> + }
> + rte_mcfg_tailq_write_unlock();
> +}
> diff --git a/lib/librte_mbuf/rte_mbuf_dyn.h
> b/lib/librte_mbuf/rte_mbuf_dyn.h new file mode 100644 index
> 000000000..307613c96
> --- /dev/null
> +++ b/lib/librte_mbuf/rte_mbuf_dyn.h
> @@ -0,0 +1,226 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright 2019 6WIND S.A.
> + */
> +
> +#ifndef _RTE_MBUF_DYN_H_
> +#define _RTE_MBUF_DYN_H_
> +
> +/**
> + * @file
> + * RTE Mbuf dynamic fields and flags
> + *
> + * Many features require to store data inside the mbuf. As the room in
> + * mbuf structure is limited, it is not possible to have a field for
> + * each feature. Also, changing fields in the mbuf structure can break
> + * the API or ABI.
> + *
> + * This module addresses this issue, by enabling the dynamic
> + * registration of fields or flags:
> + *
> + * - a dynamic field is a named area in the rte_mbuf structure, with a
> + * given size (>= 1 byte) and alignment constraint.
> + * - a dynamic flag is a named bit in the rte_mbuf structure, stored
> + * in mbuf->ol_flags.
> + *
> + * The typical use case is when a specific offload feature requires to
> + * register a dedicated offload field in the mbuf structure, and adding
> + * a static field or flag is not justified.
> + *
> + * Example of use:
> + *
> + * - A rte_mbuf_dynfield structure is defined, containing the parameters
> + * of the dynamic field to be registered:
> + * const struct rte_mbuf_dynfield rte_dynfield_my_feature = { ... };
> + * - The application initializes the PMD, and asks for this feature
> + * at port initialization by passing DEV_RX_OFFLOAD_MY_FEATURE in
> + * rxconf. This will make the PMD to register the field by calling
> + * rte_mbuf_dynfield_register(&rte_dynfield_my_feature). The PMD
> + * stores the returned offset.
> + * - The application that uses the offload feature also registers
> + * the field to retrieve the same offset.
> + * - When the PMD receives a packet, it can set the field:
> + * *RTE_MBUF_DYNFIELD(m, offset, <type *>) = value;
> + * - In the main loop, the application can retrieve the value with
> + * the same macro.
> + *
> + * To avoid wasting space, the dynamic fields or flags must only be
> + * reserved on demand, when an application asks for the related feature.
> + *
> + * The registration can be done at any moment, but it is not possible
> + * to unregister fields or flags for now.
> + *
> + * A dynamic field can be reserved and used by an application only.
> + * It can for instance be a packet mark.
> + */
> +
> +#include <sys/types.h>
> +/**
> + * Maximum length of the dynamic field or flag string.
> + */
> +#define RTE_MBUF_DYN_NAMESIZE 64
> +
> +/**
> + * Structure describing the parameters of a mbuf dynamic field.
> + */
> +struct rte_mbuf_dynfield {
> + char name[RTE_MBUF_DYN_NAMESIZE]; /**< Name of the field. */
> + size_t size; /**< The number of bytes to reserve. */
> + size_t align; /**< The alignment constraint (power of 2). */
> + unsigned int flags; /**< Reserved for future use, must be 0. */ };
> +
> +/**
> + * Structure describing the parameters of a mbuf dynamic flag.
> + */
> +struct rte_mbuf_dynflag {
> + char name[RTE_MBUF_DYN_NAMESIZE]; /**< Name of the dynamic
> flag. */
> + unsigned int flags; /**< Reserved for future use, must be 0. */ };
> +
> +/**
> + * Register space for a dynamic field in the mbuf structure.
> + *
> + * If the field is already registered (same name and parameters), its
> + * offset is returned.
> + *
> + * @param params
> + * A structure containing the requested parameters (name, size,
> + * alignment constraint and flags).
> + * @return
> + * The offset in the mbuf structure, or -1 on error.
> + * Possible values for rte_errno:
> + * - EINVAL: invalid parameters (size, align, or flags).
> + * - EEXIST: this name is already register with different parameters.
> + * - EPERM: called from a secondary process.
> + * - ENOENT: not enough room in mbuf.
> + * - ENOMEM: allocation failure.
> + * - ENAMETOOLONG: name does not ends with \0.
> + */
> +__rte_experimental
> +int rte_mbuf_dynfield_register(const struct rte_mbuf_dynfield *params);
> +
> +/**
> + * Register space for a dynamic field in the mbuf structure at offset.
> + *
> + * If the field is already registered (same name, parameters and
> +offset),
> + * the offset is returned.
> + *
> + * @param params
> + * A structure containing the requested parameters (name, size,
> + * alignment constraint and flags).
> + * @param offset
> + * The requested offset. Ignored if SIZE_MAX is passed.
> + * @return
> + * The offset in the mbuf structure, or -1 on error.
> + * Possible values for rte_errno:
> + * - EINVAL: invalid parameters (size, align, flags, or offset).
> + * - EEXIST: this name is already register with different parameters.
> + * - EBUSY: the requested offset cannot be used.
> + * - EPERM: called from a secondary process.
> + * - ENOENT: not enough room in mbuf.
> + * - ENOMEM: allocation failure.
> + * - ENAMETOOLONG: name does not ends with \0.
> + */
> +__rte_experimental
> +int rte_mbuf_dynfield_register_offset(const struct rte_mbuf_dynfield
> *params,
> + size_t offset);
> +
> +/**
> + * Lookup for a registered dynamic mbuf field.
> + *
> + * @param name
> + * A string identifying the dynamic field.
> + * @param params
> + * If not NULL, and if the lookup is successful, the structure is
> + * filled with the parameters of the dynamic field.
> + * @return
> + * The offset of this field in the mbuf structure, or -1 on error.
> + * Possible values for rte_errno:
> + * - ENOENT: no dynamic field matches this name.
> + */
> +__rte_experimental
> +int rte_mbuf_dynfield_lookup(const char *name,
> + struct rte_mbuf_dynfield *params);
> +
> +/**
> + * Register a dynamic flag in the mbuf structure.
> + *
> + * If the flag is already registered (same name and parameters), its
> + * bitnum is returned.
> + *
> + * @param params
> + * A structure containing the requested parameters of the dynamic
> + * flag (name and options).
> + * @return
> + * The number of the reserved bit, or -1 on error.
> + * Possible values for rte_errno:
> + * - EINVAL: invalid parameters (size, align, or flags).
> + * - EEXIST: this name is already register with different parameters.
> + * - EPERM: called from a secondary process.
> + * - ENOENT: no more flag available.
> + * - ENOMEM: allocation failure.
> + * - ENAMETOOLONG: name is longer than RTE_MBUF_DYN_NAMESIZE -
> 1.
> + */
> +__rte_experimental
> +int rte_mbuf_dynflag_register(const struct rte_mbuf_dynflag *params);
> +
> +/**
> + * Register a dynamic flag in the mbuf structure specifying bitnum.
> + *
> + * If the flag is already registered (same name, parameters and
> +bitnum),
> + * the bitnum is returned.
> + *
> + * @param params
> + * A structure containing the requested parameters of the dynamic
> + * flag (name and options).
> + * @param bitnum
> + * The requested bitnum. Ignored if UINT_MAX is passed.
> + * @return
> + * The number of the reserved bit, or -1 on error.
> + * Possible values for rte_errno:
> + * - EINVAL: invalid parameters (size, align, or flags).
> + * - EEXIST: this name is already register with different parameters.
> + * - EBUSY: the requested bitnum cannot be used.
> + * - EPERM: called from a secondary process.
> + * - ENOENT: no more flag available.
> + * - ENOMEM: allocation failure.
> + * - ENAMETOOLONG: name is longer than RTE_MBUF_DYN_NAMESIZE -
> 1.
> + */
> +__rte_experimental
> +int rte_mbuf_dynflag_register_bitnum(const struct rte_mbuf_dynflag
> *params,
> + unsigned int bitnum);
> +
> +/**
> + * Lookup for a registered dynamic mbuf flag.
> + *
> + * @param name
> + * A string identifying the dynamic flag.
> + * @param params
> + * If not NULL, and if the lookup is successful, the structure is
> + * filled with the parameters of the dynamic flag.
> + * @return
> + * The offset of this flag in the mbuf structure, or -1 on error.
> + * Possible values for rte_errno:
> + * - ENOENT: no dynamic flag matches this name.
> + */
> +__rte_experimental
> +int rte_mbuf_dynflag_lookup(const char *name,
> + struct rte_mbuf_dynflag *params);
> +
> +/**
> + * Helper macro to access to a dynamic field.
> + */
> +#define RTE_MBUF_DYNFIELD(m, offset, type) ((type)((uintptr_t)(m) +
> +(offset)))
> +
> +/**
> + * Dump the status of dynamic fields and flags.
> + *
> + * @param out
> + * The stream where the status is displayed.
> + */
> +__rte_experimental
> +void rte_mbuf_dyn_dump(FILE *out);
> +
> +/* Placeholder for dynamic fields and flags declarations. */
> +
> +#endif
> diff --git a/lib/librte_mbuf/rte_mbuf_version.map
> b/lib/librte_mbuf/rte_mbuf_version.map
> index 519fead35..9bf5ca37a 100644
> --- a/lib/librte_mbuf/rte_mbuf_version.map
> +++ b/lib/librte_mbuf/rte_mbuf_version.map
> @@ -58,6 +58,13 @@ EXPERIMENTAL {
> global:
>
> rte_mbuf_check;
> + rte_mbuf_dynfield_lookup;
> + rte_mbuf_dynfield_register;
> + rte_mbuf_dynfield_register_offset;
> + rte_mbuf_dynflag_lookup;
> + rte_mbuf_dynflag_register;
> + rte_mbuf_dynflag_register_bitnum;
> + rte_mbuf_dyn_dump;
> rte_pktmbuf_copy;
>
> } DPDK_18.08;
> --
> 2.20.1
