Juniper · elavee · Jan 30, 2018 · Jan 30, 2018 · Jan 30, 2018 · Jan 30, 2018
diff --git a/config/common_base b/config/common_base
@@ -206,6 +206,7 @@ CONFIG_RTE_LIBRTE_FM10K_INC_VECTOR=y
 #
 CONFIG_RTE_LIBRTE_MLX4_PMD=n
 CONFIG_RTE_LIBRTE_MLX4_DEBUG=n
+CONFIG_RTE_LIBRTE_MLX4_DLOPEN_DEPS=n
 CONFIG_RTE_LIBRTE_MLX4_SGE_WR_N=4
 CONFIG_RTE_LIBRTE_MLX4_MAX_INLINE=0
 CONFIG_RTE_LIBRTE_MLX4_TX_MP_CACHE=8
@@ -216,6 +217,7 @@ CONFIG_RTE_LIBRTE_MLX4_SOFT_COUNTERS=1
 #
 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/mlx4.rst b/doc/guides/nics/mlx4.rst
@@ -110,6 +110,24 @@ 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)``.
+
+  It works by moving these dependencies to a purpose-built rdma-core "glue"
+  plug-in, which must either be installed in ``CONFIG_RTE_EAL_PMD_PATH`` if
+  set, or in a standard location for the dynamic linker (e.g. ``/lib``) if
+  left to the default empty string (``""``).
+
+  This option has no performance impact.
+
 - ``CONFIG_RTE_LIBRTE_MLX4_DEBUG`` (default **n**)
 
   Toggle debugging code and stricter compilation flags. Enabling this option
@@ -144,6 +162,15 @@ These options can be modified in the ``.config`` file.
 Environment variables
 ~~~~~~~~~~~~~~~~~~~~~
 
+- ``MLX4_GLUE_PATH``
+
+  A list of directories in which to search for the rdma-core "glue" plug-in,
+  separated by colons or semi-colons.
+
+  Only matters when compiled with ``CONFIG_RTE_LIBRTE_MLX4_DLOPEN_DEPS``
+  enabled and most useful when ``CONFIG_RTE_EAL_PMD_PATH`` is also set,
+  since ``LD_LIBRARY_PATH`` has no effect in this case.
+
 - ``MLX4_INLINE_RECV_SIZE``
 
   A nonzero value enables inline receive for packets up to that size. May

diff --git a/doc/guides/nics/mlx5.rst b/doc/guides/nics/mlx5.rst
@@ -111,6 +111,24 @@ 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)``.
+
+  It works by moving these dependencies to a purpose-built rdma-core "glue"
+  plug-in, which must either be installed in ``CONFIG_RTE_EAL_PMD_PATH`` if
+  set, or in a standard location for the dynamic linker (e.g. ``/lib``) if
+  left to the default empty string (``""``).
+
+  This option has no performance impact.
+
 - ``CONFIG_RTE_LIBRTE_MLX5_DEBUG`` (default **n**)
 
   Toggle debugging code and stricter compilation flags. Enabling this option
@@ -128,6 +146,15 @@ These options can be modified in the ``.config`` file.
 Environment variables
 ~~~~~~~~~~~~~~~~~~~~~
 
+- ``MLX5_GLUE_PATH``
+
+  A list of directories in which to search for the rdma-core "glue" plug-in,
+  separated by colons or semi-colons.
+
+  Only matters when compiled with ``CONFIG_RTE_LIBRTE_MLX5_DLOPEN_DEPS``
+  enabled and most useful when ``CONFIG_RTE_EAL_PMD_PATH`` is also set,
+  since ``LD_LIBRARY_PATH`` has no effect in this case.
+
 - ``MLX5_PMD_ENABLE_PADDING``
 
   Enables HW packet padding in PCI bus transactions.

diff --git a/drivers/net/mlx4/Makefile b/drivers/net/mlx4/Makefile
@@ -33,16 +33,26 @@ include $(RTE_SDK)/mk/rte.vars.mk
 
 # Library name.
 LIB = librte_pmd_mlx4.a
+LIB_GLUE = $(LIB_GLUE_BASE).$(LIB_GLUE_VERSION)
+LIB_GLUE_BASE = librte_pmd_mlx4_glue.so
+LIB_GLUE_VERSION = 17.02.1
 
 # Sources.
 SRCS-$(CONFIG_RTE_LIBRTE_MLX4_PMD) += mlx4.c
+ifneq ($(CONFIG_RTE_LIBRTE_MLX4_DLOPEN_DEPS),y)
+SRCS-$(CONFIG_RTE_LIBRTE_MLX4_PMD) += mlx4_glue.c
+endif
 
 # Dependencies.
 DEPDIRS-$(CONFIG_RTE_LIBRTE_MLX4_PMD) += lib/librte_ether
 DEPDIRS-$(CONFIG_RTE_LIBRTE_MLX4_PMD) += lib/librte_mbuf
 DEPDIRS-$(CONFIG_RTE_LIBRTE_MLX4_PMD) += lib/librte_eal
 DEPDIRS-$(CONFIG_RTE_LIBRTE_MLX4_PMD) += lib/librte_mempool
 
+ifeq ($(CONFIG_RTE_LIBRTE_MLX4_DLOPEN_DEPS),y)
+INSTALL-$(CONFIG_RTE_LIBRTE_MLX4_PMD)-lib += $(LIB_GLUE)
+endif
+
 # Basic CFLAGS.
 CFLAGS += -O3
 CFLAGS += -std=gnu99 -Wall -Wextra
@@ -52,7 +62,14 @@ 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='"$(LIB_GLUE)"'
+CFLAGS += -DMLX4_GLUE_VERSION='"$(LIB_GLUE_VERSION)"'
+CFLAGS_mlx4_glue.o += -fPIC
+LDLIBS += -ldl
+else
 LDLIBS += -libverbs
+endif
 
 # A few warnings cannot be avoided in external headers.
 CFLAGS += -Wno-error=cast-qual
@@ -131,7 +148,24 @@ mlx4_autoconf.h: mlx4_autoconf.h.new
 
 mlx4.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) $(EXTRA_LDFLAGS) \
+		-Wl,-h,$(LIB_GLUE) \
+		-s -shared -o $@ $< -libverbs
+
+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_BASE)*
 
 clean: clean_mlx4