From 27cea11686ffcc64625cd321b500d6656b4720c6 Mon Sep 17 00:00:00 2001 From: Adrien Mazarguil Date: Tue, 30 Jan 2018 16:34:54 +0100 Subject: [PATCH] net/mlx4: spawn rdma-core dependency plug-in When mlx4 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 libmlx4 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/mlx4.rst | 13 +++++++++++ drivers/net/mlx4/Makefile | 29 +++++++++++++++++++++++ drivers/net/mlx4/mlx4.c | 49 +++++++++++++++++++++++++++++++++++++++ mk/rte.app.mk | 4 ++++ 5 files changed, 96 insertions(+) diff --git a/config/common_base b/config/common_base index 208b40b442..b0a2d0062c 100644 --- a/config/common_base +++ b/config/common_base @@ -298,6 +298,7 @@ CONFIG_RTE_LIBRTE_AVF_16BYTE_RX_DESC=n # CONFIG_RTE_LIBRTE_MLX4_PMD=n CONFIG_RTE_LIBRTE_MLX4_DEBUG=n +CONFIG_RTE_LIBRTE_MLX4_DLOPEN_DEPS=n CONFIG_RTE_LIBRTE_MLX4_TX_MP_CACHE=8 # diff --git a/doc/guides/nics/mlx4.rst b/doc/guides/nics/mlx4.rst index cab45dfe84..88161781c0 100644 --- a/doc/guides/nics/mlx4.rst +++ b/doc/guides/nics/mlx4.rst @@ -86,6 +86,19 @@ These options can be modified in the ``.config`` file. Toggle compilation of librte_pmd_mlx4 itself. +- ``CONFIG_RTE_LIBRTE_MLX4_DLOPEN_DEPS`` (default **n**) + + Build PMD with additional code to make it loadable without hard + dependencies on **libibverbs** nor **libmlx4**, 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_MLX4_DEBUG`` (default **n**) Toggle debugging code and stricter compilation flags. Enabling this option diff --git a/drivers/net/mlx4/Makefile b/drivers/net/mlx4/Makefile index 1d33c38ed1..c004ac71c4 100644 --- a/drivers/net/mlx4/Makefile +++ b/drivers/net/mlx4/Makefile @@ -33,12 +33,15 @@ include $(RTE_SDK)/mk/rte.vars.mk # Library name. LIB = librte_pmd_mlx4.a +LIB_GLUE = librte_pmd_mlx4_glue.so # Sources. SRCS-$(CONFIG_RTE_LIBRTE_MLX4_PMD) += mlx4.c SRCS-$(CONFIG_RTE_LIBRTE_MLX4_PMD) += mlx4_ethdev.c SRCS-$(CONFIG_RTE_LIBRTE_MLX4_PMD) += mlx4_flow.c +ifneq ($(CONFIG_RTE_LIBRTE_MLX4_DLOPEN_DEPS),y) SRCS-$(CONFIG_RTE_LIBRTE_MLX4_PMD) += mlx4_glue.c +endif SRCS-$(CONFIG_RTE_LIBRTE_MLX4_PMD) += mlx4_intr.c SRCS-$(CONFIG_RTE_LIBRTE_MLX4_PMD) += mlx4_mr.c SRCS-$(CONFIG_RTE_LIBRTE_MLX4_PMD) += mlx4_rxq.c @@ -46,6 +49,10 @@ SRCS-$(CONFIG_RTE_LIBRTE_MLX4_PMD) += mlx4_rxtx.c SRCS-$(CONFIG_RTE_LIBRTE_MLX4_PMD) += mlx4_txq.c SRCS-$(CONFIG_RTE_LIBRTE_MLX4_PMD) += mlx4_utils.c +ifeq ($(CONFIG_RTE_LIBRTE_MLX4_DLOPEN_DEPS),y) +INSTALL-$(CONFIG_RTE_LIBRTE_MLX4_PMD)-lib += $(LIB_GLUE) +endif + # Basic CFLAGS. CFLAGS += -O3 CFLAGS += -std=c11 -Wall -Wextra @@ -55,7 +62,13 @@ CFLAGS += -D_BSD_SOURCE CFLAGS += -D_DEFAULT_SOURCE CFLAGS += -D_XOPEN_SOURCE=600 CFLAGS += $(WERROR_FLAGS) +ifeq ($(CONFIG_RTE_LIBRTE_MLX4_DLOPEN_DEPS),y) +CFLAGS += -DMLX4_GLUE='"$(LIB_GLUE)"' +CFLAGS_mlx4_glue.o += -fPIC +LDLIBS += -ldl +else LDLIBS += -libverbs -lmlx4 +endif LDLIBS += -lrte_eal -lrte_mbuf -lrte_mempool -lrte_ring LDLIBS += -lrte_ethdev -lrte_net -lrte_kvargs LDLIBS += -lrte_bus_pci @@ -109,7 +122,23 @@ mlx4_autoconf.h: mlx4_autoconf.h.new $(SRCS-$(CONFIG_RTE_LIBRTE_MLX4_PMD):.c=.o): mlx4_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 ($(CONFIG_RTE_LIBRTE_MLX4_DLOPEN_DEPS),y) + +$(LIB): $(LIB_GLUE) + +$(LIB_GLUE): mlx4_glue.o + $Q $(LD) $(LDFLAGS) $(EXTRA_LDFLAGS) \ + -s -shared -o $@ $< -libverbs -lmlx4 + +mlx4_glue.o: mlx4_autoconf.h + +endif + clean_mlx4: FORCE $Q rm -f -- mlx4_autoconf.h mlx4_autoconf.h.new + $Q rm -f -- mlx4_glue.o $(LIB_GLUE) clean: clean_mlx4 diff --git a/drivers/net/mlx4/mlx4.c b/drivers/net/mlx4/mlx4.c index feabbb8828..50a55ee527 100644 --- a/drivers/net/mlx4/mlx4.c +++ b/drivers/net/mlx4/mlx4.c @@ -37,6 +37,7 @@ */ #include +#include #include #include #include @@ -44,6 +45,7 @@ #include #include #include +#include /* Verbs headers do not support -pedantic. */ #ifdef PEDANTIC @@ -55,6 +57,7 @@ #endif #include +#include #include #include #include @@ -730,6 +733,47 @@ static struct rte_pci_driver mlx4_driver = { RTE_PCI_DRV_INTR_RMV, }; +#ifdef RTE_LIBRTE_MLX4_DLOPEN_DEPS + +/** + * Initialization routine for run-time dependency on rdma-core. + */ +static int +mlx4_glue_init(void) +{ + void *handle = NULL; + void **sym; + const char *dlmsg; + + handle = dlopen(MLX4_GLUE, RTLD_LAZY); + if (!handle) { + rte_errno = EINVAL; + dlmsg = dlerror(); + if (dlmsg) + WARN("cannot load glue library: %s", dlmsg); + goto glue_error; + } + sym = dlsym(handle, "mlx4_glue"); + if (!sym || !*sym) { + rte_errno = EINVAL; + dlmsg = dlerror(); + if (dlmsg) + ERROR("cannot resolve glue symbol: %s", dlmsg); + goto glue_error; + } + mlx4_glue = *sym; + return 0; +glue_error: + if (handle) + dlclose(handle); + WARN("cannot initialize PMD due to missing run-time" + " dependency on rdma-core libraries (libibverbs," + " libmlx4)"); + return -rte_errno; +} + +#endif + /** * Driver initialization routine. */ @@ -750,6 +794,11 @@ rte_mlx4_pmd_init(void) * using this PMD, which is not supported in forked processes. */ setenv("RDMAV_HUGEPAGES_SAFE", "1", 1); +#ifdef RTE_LIBRTE_MLX4_DLOPEN_DEPS + if (mlx4_glue_init()) + return; + assert(mlx4_glue); +#endif mlx4_glue->fork_init(); rte_pci_register(&mlx4_driver); } diff --git a/mk/rte.app.mk b/mk/rte.app.mk index e683da4c9d..57ce8f7525 100644 --- a/mk/rte.app.mk +++ b/mk/rte.app.mk @@ -144,7 +144,11 @@ ifeq ($(CONFIG_RTE_LIBRTE_KNI),y) _LDLIBS-$(CONFIG_RTE_LIBRTE_PMD_KNI) += -lrte_pmd_kni endif _LDLIBS-$(CONFIG_RTE_LIBRTE_LIO_PMD) += -lrte_pmd_lio +ifeq ($(CONFIG_RTE_LIBRTE_MLX4_DLOPEN_DEPS),y) +_LDLIBS-$(CONFIG_RTE_LIBRTE_MLX4_PMD) += -lrte_pmd_mlx4 -ldl +else _LDLIBS-$(CONFIG_RTE_LIBRTE_MLX4_PMD) += -lrte_pmd_mlx4 -libverbs -lmlx4 +endif _LDLIBS-$(CONFIG_RTE_LIBRTE_MLX5_PMD) += -lrte_pmd_mlx5 -libverbs -lmlx5 _LDLIBS-$(CONFIG_RTE_LIBRTE_MRVL_PMD) += -lrte_pmd_mrvl -L$(LIBMUSDK_PATH)/lib -lmusdk _LDLIBS-$(CONFIG_RTE_LIBRTE_NFP_PMD) += -lrte_pmd_nfp -- 2.20.1