libibverbs: Get stable IB device index

The kernel which supports query over netlink interface returns stable IB device index as part of it. This index much better identifier than sysfs name that can be renamed and/or disappear. Up till now, this index was used internally by libibverbs, but the next patch will rely on this API in the librdmacm code. The -1 as returned value means that kernel doesn't support indexes. Reviewed-by: Yishai Hadas <yishaih@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
linux-rdma · May 13, 2020 · 307f922 · 307f922
1 parent 4ca5caf
commit 307f922
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Showing 9 changed files with 67 additions and 2 deletions.
diff --git a/debian/libibverbs1.symbols b/debian/libibverbs1.symbols
@@ -6,6 +6,7 @@ libibverbs.so.1 libibverbs1 #MINVER#
  IBVERBS_1.6@IBVERBS_1.6 24
  IBVERBS_1.7@IBVERBS_1.7 25
  IBVERBS_1.8@IBVERBS_1.8 28
+ IBVERBS_1.9@IBVERBS_1.9 30
  (symver)IBVERBS_PRIVATE_25 25
  ibv_ack_async_event@IBVERBS_1.0 1.1.6
  ibv_ack_async_event@IBVERBS_1.1 1.1.6
@@ -58,6 +59,7 @@ libibverbs.so.1 libibverbs1 #MINVER#
  ibv_get_cq_event@IBVERBS_1.1 1.1.6
  ibv_get_device_guid@IBVERBS_1.0 1.1.6
  ibv_get_device_guid@IBVERBS_1.1 1.1.6
+ ibv_get_device_index@IBVERBS_1.9 30
  ibv_get_device_list@IBVERBS_1.0 1.1.6
  ibv_get_device_list@IBVERBS_1.1 1.1.6
  ibv_get_device_name@IBVERBS_1.0 1.1.6

diff --git a/libibverbs/CMakeLists.txt b/libibverbs/CMakeLists.txt
@@ -21,7 +21,7 @@ configure_file("libibverbs.map.in"
 
 rdma_library(ibverbs "${CMAKE_CURRENT_BINARY_DIR}/libibverbs.map"
   # See Documentation/versioning.md
-  1 1.8.${PACKAGE_VERSION}
+  1 1.9.${PACKAGE_VERSION}
   all_providers.c
   cmd.c
   cmd_ah.c

diff --git a/libibverbs/device.c b/libibverbs/device.c
@@ -150,6 +150,13 @@ LATEST_SYMVER_FUNC(ibv_get_device_guid, 1_1, "IBVERBS_1.1",
 	return htobe64(guid);
 }
 
+int ibv_get_device_index(struct ibv_device *device)
+{
+	struct verbs_sysfs_dev *sysfs_dev = verbs_get_device(device)->sysfs;
+
+	return sysfs_dev->ibdev_idx;
+}
+
 int ibv_get_fw_ver(char *value, size_t len, struct verbs_sysfs_dev *sysfs_dev)
 {
 	/*

diff --git a/libibverbs/libibverbs.map.in b/libibverbs/libibverbs.map.in
@@ -126,6 +126,11 @@ IBVERBS_1.8 {
 		ibv_reg_mr_iova2;
 } IBVERBS_1.7;
 
+IBVERBS_1.9 {
+	global:
+		ibv_get_device_index;
+} IBVERBS_1.8;
+
 /* If any symbols in this stanza change ABI then the entire staza gets a new symbol
    version. See the top level CMakeLists.txt for this setting. */
 

diff --git a/libibverbs/man/CMakeLists.txt b/libibverbs/man/CMakeLists.txt
@@ -32,6 +32,7 @@ rdma_man_pages(
   ibv_get_async_event.3
   ibv_get_cq_event.3
   ibv_get_device_guid.3.md
+  ibv_get_device_index.3.md
   ibv_get_device_list.3.md
   ibv_get_device_name.3.md
   ibv_get_pkey_index.3.md

diff --git a/libibverbs/man/ibv_get_device_guid.3.md b/libibverbs/man/ibv_get_device_guid.3.md
@@ -31,7 +31,7 @@ RDMA device *device*.
 order.
 
 # SEE ALSO
-
+**ibv_get_device_index**(3),
 **ibv_get_device_list**(3),
 **ibv_get_device_name**(3),
 **ibv_open_device**(3)

diff --git a/libibverbs/man/ibv_get_device_index.3.md b/libibverbs/man/ibv_get_device_index.3.md
@@ -0,0 +1,40 @@
+---
+date: ' 2020-04-22'
+footer: libibverbs
+header: "Libibverbs Programmer's Manual"
+layout: page
+license: 'Licensed under the OpenIB.org BSD license (FreeBSD Variant) - See COPYING.md'
+section: 3
+title: IBV_GET_DEVICE_INDEX
+---
+
+# NAME
+
+ibv_get_device_index - get an RDMA device index
+
+# SYNOPSIS
+
+```c
+#include <infiniband/verbs.h>
+
+int ibv_get_device_index(struct ibv_device *device);
+```
+
+# DESCRIPTION
+
+**ibv_get_device_index()** returns stable IB device index as it is assigned by the kernel.
+
+# RETURN VALUE
+
+**ibv_get_device_index()** returns an index, or -1 if the kernel doesn't support device indexes.
+
+# SEE ALSO
+
+**ibv_get_device_name**(3),
+**ibv_get_device_guid**(3),
+**ibv_get_device_list**(3),
+**ibv_open_device**(3)
+
+# AUTHOR
+
+Leon Romanovsky <leonro@mellanox.com>
diff --git a/libibverbs/man/ibv_get_device_list.3.md b/libibverbs/man/ibv_get_device_list.3.md
@@ -88,6 +88,7 @@ recommended.
 **ibv_fork_init**(3),
 **ibv_get_device_guid**(3),
 **ibv_get_device_name**(3),
+**ibv_get_device_index**(3),
 **ibv_open_device**(3)
 
 # AUTHOR

diff --git a/libibverbs/verbs.h b/libibverbs/verbs.h
@@ -2202,6 +2202,15 @@ void ibv_free_device_list(struct ibv_device **list);
  */
 const char *ibv_get_device_name(struct ibv_device *device);
 
+/**
+ * ibv_get_device_index - Return kernel device index
+ *
+ * Available for the kernel with support of IB device query
+ * over netlink interface. For the unsupported kernels, the
+ * relevant -1 will be returned.
+ */
+int ibv_get_device_index(struct ibv_device *device);
+
 /**
  * ibv_get_device_guid - Return device's node GUID
  */