Since rdma-core glue libraries are intrinsically tied to their respective
PMDs and used as internal plug-ins, their presence in the default search
path among other system libraries for the dynamic linker is not necessarily
desired.
This commit enables their installation and subsequent look-up at run time
in RTE_EAL_PMD_PATH if configured to a nonempty string. This path can also
be overridden by environment variables MLX[45]_GLUE_PATH.
Signed-off-by: Adrien Mazarguil <adrien.mazarg...@6wind.com>
---
doc/guides/nics/mlx4.rst | 17 +++++++++++++++++
doc/guides/nics/mlx5.rst | 14 ++++++++++++++
drivers/net/mlx4/mlx4.c | 43 ++++++++++++++++++++++++++++++++++++++++++-
drivers/net/mlx5/mlx5.c | 43 ++++++++++++++++++++++++++++++++++++++++++-
4 files changed, 115 insertions(+), 2 deletions(-)
diff --git a/doc/guides/nics/mlx4.rst b/doc/guides/nics/mlx4.rst
index 88161781c..9e4fbf692 100644
--- a/doc/guides/nics/mlx4.rst
+++ b/doc/guides/nics/mlx4.rst
@@ -97,6 +97,11 @@ These options can be modified in the ``.config`` file.
``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**)
@@ -113,6 +118,18 @@ These options can be modified in the ``.config`` file.
This value is always 1 for RX queues since they use a single MP.
+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.
+
Run-time configuration
~~~~~~~~~~~~~~~~~~~~~~
diff --git a/doc/guides/nics/mlx5.rst b/doc/guides/nics/mlx5.rst
index a9e4bf51a..1635dff2b 100644
--- a/doc/guides/nics/mlx5.rst
+++ b/doc/guides/nics/mlx5.rst
@@ -170,6 +170,11 @@ These options can be modified in the ``.config`` file.
``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**)
@@ -189,6 +194,15 @@ 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/mlx4.c b/drivers/net/mlx4/mlx4.c
index 61a852fb9..4266cb1bb 100644
--- a/drivers/net/mlx4/mlx4.c
+++ b/drivers/net/mlx4/mlx4.c
@@ -741,11 +741,52 @@ static struct rte_pci_driver mlx4_driver = {
static int
mlx4_glue_init(void)
{
+ const char *path[] = {
+ /*
+ * A basic security check is necessary before trusting
+ * MLX4_GLUE_PATH, which may override RTE_EAL_PMD_PATH.
+ */
+ (geteuid() == getuid() && getegid() == getgid() ?
+ getenv("MLX4_GLUE_PATH") : NULL),
+ RTE_EAL_PMD_PATH,
+ };
+ unsigned int i = 0;
void *handle = NULL;
void **sym;
const char *dlmsg;
- handle = dlopen(MLX4_GLUE, RTLD_LAZY);
+ while (!handle && i != RTE_DIM(path)) {
+ const char *end;
+ size_t len;
+ int ret;
+
+ if (!path[i]) {
+ ++i;
+ continue;
+ }
+ end = strpbrk(path[i], ":;");
+ if (!end)
+ end = path[i] + strlen(path[i]);
+ len = end - path[i];
+ ret = 0;
+ do {
+ char name[ret + 1];
+
+ ret = snprintf(name, ret, "%.*s%s" MLX4_GLUE "\n",
+ (int)len, path[i],
+ (!len || *(end - 1) == '/') ? "" : "/");
+ if (ret == -1)
+ break;
+ if (sizeof(name) != (size_t)ret + 1)
+ continue;
+ DEBUG("looking for rdma-core glue as \"%s\"", name);
+ handle = dlopen(name, RTLD_LAZY);
+ break;
+ } while (1);
+ path[i] = end + 1;
+ if (!*end)
+ ++i;
+ }
if (!handle) {
rte_errno = EINVAL;
dlmsg = dlerror();
diff --git a/drivers/net/mlx5/mlx5.c b/drivers/net/mlx5/mlx5.c
index 341230d2b..caa60339e 100644
--- a/drivers/net/mlx5/mlx5.c
+++ b/drivers/net/mlx5/mlx5.c
@@ -1085,11 +1085,52 @@ static struct rte_pci_driver mlx5_driver = {
static int
mlx5_glue_init(void)
{
+ const char *path[] = {
+ /*
+ * A basic security check is necessary before trusting
+ * MLX5_GLUE_PATH, which may override RTE_EAL_PMD_PATH.
+ */
+ (geteuid() == getuid() && getegid() == getgid() ?
+ getenv("MLX5_GLUE_PATH") : NULL),
+ RTE_EAL_PMD_PATH,
+ };
+ unsigned int i = 0;
void *handle = NULL;
void **sym;
const char *dlmsg;
- handle = dlopen(MLX5_GLUE, RTLD_LAZY);
+ while (!handle && i != RTE_DIM(path)) {
+ const char *end;
+ size_t len;
+ int ret;
+
+ if (!path[i]) {
+ ++i;
+ continue;
+ }
+ end = strpbrk(path[i], ":;");
+ if (!end)
+ end = path[i] + strlen(path[i]);
+ len = end - path[i];
+ ret = 0;
+ do {
+ char name[ret + 1];
+
+ ret = snprintf(name, ret, "%.*s%s" MLX5_GLUE "\n",
+ (int)len, path[i],
+ (!len || *(end - 1) == '/') ? "" : "/");
+ if (ret == -1)
+ break;
+ if (sizeof(name) != (size_t)ret + 1)
+ continue;
+ DEBUG("looking for rdma-core glue as \"%s\"", name);
+ handle = dlopen(name, RTLD_LAZY);
+ break;
+ } while (1);
+ path[i] = end + 1;
+ if (!*end)
+ ++i;
+ }
if (!handle) {
rte_errno = EINVAL;
dlmsg = dlerror();
--
2.11.0
