From 59b91bec12c602d040150973de3ce0566f47bd75 Mon Sep 17 00:00:00 2001 From: Adrien Mazarguil Date: Tue, 30 Jan 2018 16:34:58 +0100 Subject: [PATCH] net/mlx5: spawn rdma-core dependency plug-in When mlx5 is not compiled directly as an independent shared object (e.g. CONFIG_RTE_BUILD_SHARED_LIB not enabled for performance reasons), DPDK applications inherit its dependencies on libibverbs and libmlx5 through rte.app.mk. This is an issue both when DPDK is delivered as a binary package (Linux distributions) and for end users because rdma-core then propagates as a mandatory dependency for everything. Application writers relying on binary DPDK packages are not necessarily aware of this fact and may end up delivering packages with broken dependencies. This patch therefore introduces an intermediate internal plug-in hard-linked with rdma-core (to preserve symbol versioning) loaded by the PMD through dlopen(), so that a missing rdma-core does not cause unresolved symbols, allowing applications to start normally. Signed-off-by: Adrien Mazarguil --- config/common_base | 1 + doc/guides/nics/mlx5.rst | 13 +++++++++++ drivers/net/mlx5/Makefile | 31 ++++++++++++++++++++++++- drivers/net/mlx5/mlx5.c | 48 +++++++++++++++++++++++++++++++++++++++ mk/rte.app.mk | 4 ++++ 5 files changed, 96 insertions(+), 1 deletion(-) diff --git a/config/common_base b/config/common_base index b0a2d0062c..1db911276f 100644 --- a/config/common_base +++ b/config/common_base @@ -306,6 +306,7 @@ CONFIG_RTE_LIBRTE_MLX4_TX_MP_CACHE=8 # CONFIG_RTE_LIBRTE_MLX5_PMD=n CONFIG_RTE_LIBRTE_MLX5_DEBUG=n +CONFIG_RTE_LIBRTE_MLX5_DLOPEN_DEPS=n CONFIG_RTE_LIBRTE_MLX5_TX_MP_CACHE=8 # diff --git a/doc/guides/nics/mlx5.rst b/doc/guides/nics/mlx5.rst index 2e6d1e45a6..a9e4bf51a8 100644 --- a/doc/guides/nics/mlx5.rst +++ b/doc/guides/nics/mlx5.rst @@ -159,6 +159,19 @@ These options can be modified in the ``.config`` file. Toggle compilation of librte_pmd_mlx5 itself. +- ``CONFIG_RTE_LIBRTE_MLX5_DLOPEN_DEPS`` (default **n**) + + Build PMD with additional code to make it loadable without hard + dependencies on **libibverbs** nor **libmlx5**, which may not be installed + on the target system. + + In this mode, their presence is still required for it to run properly, + however their absence won't prevent a DPDK application from starting (with + ``CONFIG_RTE_BUILD_SHARED_LIB`` disabled) and they won't show up as + missing with ``ldd(1)``. + + This option has no performance impact. + - ``CONFIG_RTE_LIBRTE_MLX5_DEBUG`` (default **n**) Toggle debugging code and stricter compilation flags. Enabling this option diff --git a/drivers/net/mlx5/Makefile b/drivers/net/mlx5/Makefile index bdec30692d..4b20d718bd 100644 --- a/drivers/net/mlx5/Makefile +++ b/drivers/net/mlx5/Makefile @@ -33,9 +33,13 @@ include $(RTE_SDK)/mk/rte.vars.mk # Library name. LIB = librte_pmd_mlx5.a +LIB_GLUE = librte_pmd_mlx5_glue.so # Sources. SRCS-$(CONFIG_RTE_LIBRTE_MLX5_PMD) += mlx5.c +ifneq ($(CONFIG_RTE_LIBRTE_MLX5_DLOPEN_DEPS),y) +SRCS-$(CONFIG_RTE_LIBRTE_MLX5_PMD) += mlx5_glue.c +endif SRCS-$(CONFIG_RTE_LIBRTE_MLX5_PMD) += mlx5_rxq.c SRCS-$(CONFIG_RTE_LIBRTE_MLX5_PMD) += mlx5_txq.c SRCS-$(CONFIG_RTE_LIBRTE_MLX5_PMD) += mlx5_rxtx.c @@ -53,7 +57,10 @@ SRCS-$(CONFIG_RTE_LIBRTE_MLX5_PMD) += mlx5_rss.c SRCS-$(CONFIG_RTE_LIBRTE_MLX5_PMD) += mlx5_mr.c SRCS-$(CONFIG_RTE_LIBRTE_MLX5_PMD) += mlx5_flow.c SRCS-$(CONFIG_RTE_LIBRTE_MLX5_PMD) += mlx5_socket.c -SRCS-$(CONFIG_RTE_LIBRTE_MLX5_PMD) += mlx5_glue.c + +ifeq ($(CONFIG_RTE_LIBRTE_MLX5_DLOPEN_DEPS),y) +INSTALL-$(CONFIG_RTE_LIBRTE_MLX5_PMD)-lib += $(LIB_GLUE) +endif # Basic CFLAGS. CFLAGS += -O3 @@ -65,7 +72,13 @@ CFLAGS += -D_DEFAULT_SOURCE CFLAGS += -D_XOPEN_SOURCE=600 CFLAGS += $(WERROR_FLAGS) CFLAGS += -Wno-strict-prototypes +ifeq ($(CONFIG_RTE_LIBRTE_MLX5_DLOPEN_DEPS),y) +CFLAGS += -DMLX5_GLUE='"$(LIB_GLUE)"' +CFLAGS_mlx5_glue.o += -fPIC +LDLIBS += -ldl +else LDLIBS += -libverbs -lmlx5 +endif LDLIBS += -lrte_eal -lrte_mbuf -lrte_mempool -lrte_ring LDLIBS += -lrte_ethdev -lrte_net -lrte_kvargs LDLIBS += -lrte_bus_pci @@ -158,7 +171,23 @@ mlx5_autoconf.h: mlx5_autoconf.h.new $(SRCS-$(CONFIG_RTE_LIBRTE_MLX5_PMD):.c=.o): mlx5_autoconf.h +# Generate dependency plug-in for rdma-core when the PMD must not be linked +# directly, so that applications do not inherit this dependency. + +ifeq ($(CONFIG_RTE_LIBRTE_MLX5_DLOPEN_DEPS),y) + +$(LIB): $(LIB_GLUE) + +$(LIB_GLUE): mlx5_glue.o + $Q $(LD) $(LDFLAGS) $(EXTRA_LDFLAGS) \ + -s -shared -o $@ $< -libverbs -lmlx5 + +mlx5_glue.o: mlx5_autoconf.h + +endif + clean_mlx5: FORCE $Q rm -f -- mlx5_autoconf.h mlx5_autoconf.h.new + $Q rm -f -- mlx5_glue.o $(LIB_GLUE) clean: clean_mlx5 diff --git a/drivers/net/mlx5/mlx5.c b/drivers/net/mlx5/mlx5.c index b911d0ad42..544599b015 100644 --- a/drivers/net/mlx5/mlx5.c +++ b/drivers/net/mlx5/mlx5.c @@ -35,6 +35,7 @@ #include #include #include +#include #include #include #include @@ -57,6 +58,7 @@ #include #include #include +#include #include #include @@ -1075,6 +1077,47 @@ static struct rte_pci_driver mlx5_driver = { .drv_flags = RTE_PCI_DRV_INTR_LSC | RTE_PCI_DRV_INTR_RMV, }; +#ifdef RTE_LIBRTE_MLX5_DLOPEN_DEPS + +/** + * Initialization routine for run-time dependency on rdma-core. + */ +static int +mlx5_glue_init(void) +{ + void *handle = NULL; + void **sym; + const char *dlmsg; + + handle = dlopen(MLX5_GLUE, RTLD_LAZY); + if (!handle) { + rte_errno = EINVAL; + dlmsg = dlerror(); + if (dlmsg) + WARN("cannot load glue library: %s", dlmsg); + goto glue_error; + } + sym = dlsym(handle, "mlx5_glue"); + if (!sym || !*sym) { + rte_errno = EINVAL; + dlmsg = dlerror(); + if (dlmsg) + ERROR("cannot resolve glue symbol: %s", dlmsg); + goto glue_error; + } + mlx5_glue = *sym; + return 0; +glue_error: + if (handle) + dlclose(handle); + WARN("cannot initialize PMD due to missing run-time" + " dependency on rdma-core libraries (libibverbs," + " libmlx5)"); + return -rte_errno; +} + +#endif + /** * Driver initialization routine. */ @@ -1094,6 +1137,11 @@ rte_mlx5_pmd_init(void) /* Match the size of Rx completion entry to the size of a cacheline. */ if (RTE_CACHE_LINE_SIZE == 128) setenv("MLX5_CQE_SIZE", "128", 0); +#ifdef RTE_LIBRTE_MLX5_DLOPEN_DEPS + if (mlx5_glue_init()) + return; + assert(mlx5_glue); +#endif mlx5_glue->fork_init(); rte_pci_register(&mlx5_driver); } diff --git a/mk/rte.app.mk b/mk/rte.app.mk index 57ce8f7525..3eb41d176d 100644 --- a/mk/rte.app.mk +++ b/mk/rte.app.mk @@ -149,7 +149,11 @@ _LDLIBS-$(CONFIG_RTE_LIBRTE_MLX4_PMD) += -lrte_pmd_mlx4 -ldl else _LDLIBS-$(CONFIG_RTE_LIBRTE_MLX4_PMD) += -lrte_pmd_mlx4 -libverbs -lmlx4 endif +ifeq ($(CONFIG_RTE_LIBRTE_MLX5_DLOPEN_DEPS),y) +_LDLIBS-$(CONFIG_RTE_LIBRTE_MLX5_PMD) += -lrte_pmd_mlx5 -ldl +else _LDLIBS-$(CONFIG_RTE_LIBRTE_MLX5_PMD) += -lrte_pmd_mlx5 -libverbs -lmlx5 +endif _LDLIBS-$(CONFIG_RTE_LIBRTE_MRVL_PMD) += -lrte_pmd_mrvl -L$(LIBMUSDK_PATH)/lib -lmusdk _LDLIBS-$(CONFIG_RTE_LIBRTE_NFP_PMD) += -lrte_pmd_nfp _LDLIBS-$(CONFIG_RTE_LIBRTE_PMD_NULL) += -lrte_pmd_null -- 2.20.1