[RFC PATCH] net/af_xdp: use libxdp if available

[RFC PATCH] net/af_xdp: use libxdp if available

[Ciara Loftus]

AF_XDP support is deprecated in libbpf since v0.7.0 [1]. The
libxdp library now provides the functionality which once was in
libbpf and which the AF_XDP PMD relies on. This commit updates the
AF_XDP meson build to use the libxdp library if available. If it
is not available, only versions of libbpf prior to v0.7.0 are
allowed, as they still contain the required AF_XDP functionality.

libbpf still remains a dependency even if libxdp is present, as we
use libbpf APIs for program loading.

[1] https://github.com/libbpf/libbpf/commit/277846bc6c15

Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
---
 doc/guides/nics/af_xdp.rst             |  4 +--
 doc/guides/rel_notes/release_22_03.rst |  4 +++
 drivers/net/af_xdp/compat.h            |  4 +++
 drivers/net/af_xdp/meson.build         | 45 +++++++++++++++++++++-----
 drivers/net/af_xdp/rte_eth_af_xdp.c    |  1 -
 5 files changed, 46 insertions(+), 12 deletions(-)

diff --git a/doc/guides/nics/af_xdp.rst b/doc/guides/nics/af_xdp.rst
index c9d0e1ad6c..966f713c11 100644
--- a/doc/guides/nics/af_xdp.rst
+++ b/doc/guides/nics/af_xdp.rst
@@ -43,9 +43,7 @@ Prerequisites
 This is a Linux-specific PMD, thus the following prerequisites apply:
 
 *  A Linux Kernel (version > v4.18) with XDP sockets configuration enabled;
-*  libbpf (within kernel version > v5.1-rc4) with latest af_xdp support installed,
-   User can install libbpf via `make install_lib` && `make install_headers` in
-   <kernel src tree>/tools/lib/bpf;
+*  Both libxdp and libbpf libraries installed, or, libbpf <=v0.6.0
 *  A Kernel bound interface to attach to;
 *  For need_wakeup feature, it requires kernel version later than v5.3-rc1;
 *  For PMD zero copy, it requires kernel version later than v5.4-rc1;
diff --git a/doc/guides/rel_notes/release_22_03.rst b/doc/guides/rel_notes/release_22_03.rst
index 6d99d1eaa9..acf0f66fa8 100644
--- a/doc/guides/rel_notes/release_22_03.rst
+++ b/doc/guides/rel_notes/release_22_03.rst
@@ -55,6 +55,10 @@ New Features
      Also, make sure to start the actual text at the margin.
      =======================================================
 
+* **Update AF_XDP PMD**
+
+  * Added libxdp support.
+
 
 Removed Items
 -------------
diff --git a/drivers/net/af_xdp/compat.h b/drivers/net/af_xdp/compat.h
index 3880dc7dd7..245df1b109 100644
--- a/drivers/net/af_xdp/compat.h
+++ b/drivers/net/af_xdp/compat.h
@@ -2,7 +2,11 @@
  * Copyright(c) 2020 Intel Corporation.
  */
 
+#ifdef RTE_LIBRTE_AF_XDP_PMD_LIBXDP
+#include <xdp/xsk.h>
+#else
 #include <bpf/xsk.h>
+#endif
 #include <linux/version.h>
 #include <poll.h>
 
diff --git a/drivers/net/af_xdp/meson.build b/drivers/net/af_xdp/meson.build
index 3ed2b29784..dc4f53352e 100644
--- a/drivers/net/af_xdp/meson.build
+++ b/drivers/net/af_xdp/meson.build
@@ -9,19 +9,48 @@ endif
 
 sources = files('rte_eth_af_xdp.c')
 
+xdp_dep = dependency('libxdp', required: false, method: 'pkg-config')
+if not xdp_dep.found()
+    xdp_dep = cc.find_library('xdp', required: false)
+endif
+
 bpf_dep = dependency('libbpf', required: false, method: 'pkg-config')
 if not bpf_dep.found()
     bpf_dep = cc.find_library('bpf', required: false)
 endif
 
-if bpf_dep.found() and cc.has_header('bpf/xsk.h') and cc.has_header('linux/if_xdp.h')
-    ext_deps += bpf_dep
-    bpf_ver_dep = dependency('libbpf', version : '>=0.2.0',
-            required: false, method: 'pkg-config')
-    if bpf_ver_dep.found()
-        dpdk_conf.set('RTE_LIBRTE_AF_XDP_PMD_SHARED_UMEM', 1)
+if cc.has_header('linux/if_xdp.h')
+    if xdp_dep.found() and cc.has_header('xdp/xsk.h')
+        if bpf_dep.found() and cc.has_header('bpf/bpf.h')
+            dpdk_conf.set('RTE_LIBRTE_AF_XDP_PMD_LIBXDP', 1)
+            dpdk_conf.set('RTE_LIBRTE_AF_XDP_PMD_SHARED_UMEM', 1)
+            ext_deps += xdp_dep
+            ext_deps += bpf_dep
+        else
+            build = false
+            reason = 'missing dependency, libbpf'
+        endif
+    elif bpf_dep.found() and cc.has_header('bpf/xsk.h') and cc.has_header('bpf/bpf.h')
+        # libxdp not found. Rely solely on libbpf for xsk functionality
+        # which is only available in versions <= v0.6.0.
+        bpf_ver_dep = dependency('libbpf', version : '<=0.6.0',
+                                 required: false, method: 'pkg-config')
+        if bpf_ver_dep.found()
+            ext_deps += bpf_dep
+            bpf_shumem_ver_dep = dependency('libbpf', version : '>=0.2.0',
+                            required: false, method: 'pkg-config')
+            if bpf_shumem_ver_dep.found()
+                dpdk_conf.set('RTE_LIBRTE_AF_XDP_PMD_SHARED_UMEM', 1)
+            endif
+        else
+            build = false
+            reason = 'missing dependency, "libxdp" or "libbpf <= v0.6.0"'
+        endif
+    else
+        build = false
+        reason = 'missing dependency, "libxdp" and "libbpf"'
     endif
 else
     build = false
-    reason = 'missing dependency, "libbpf"'
-endif
+    reason = 'missing header, "linux/if_xdp.h"'
+endif
\ No newline at end of file
diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c b/drivers/net/af_xdp/rte_eth_af_xdp.c
index 96c2c9d939..5d89bebb01 100644
--- a/drivers/net/af_xdp/rte_eth_af_xdp.c
+++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
@@ -16,7 +16,6 @@
 #include <linux/sockios.h>
 #include "af_xdp_deps.h"
 #include <bpf/bpf.h>
-#include <bpf/xsk.h>
 
 #include <rte_ethdev.h>
 #include <ethdev_driver.h>
-- 
2.17.1

[PATCH] net/af_xdp: use libxdp if available

[Ciara Loftus]

AF_XDP support is deprecated in libbpf since v0.7.0 [1]. The
libxdp library now provides the functionality which once was in
libbpf and which the AF_XDP PMD relies on. This commit updates the
AF_XDP meson build to use the libxdp library if a version >= v1.3.0 is
available. If it is not available, only versions of libbpf prior to v0.7.0
are allowed, as they still contain the required AF_XDP functionality.

libbpf still remains a dependency even if libxdp is present, as we
use libbpf APIs for program loading.

The minimum required kernel version for libxdp for use with AF_XDP is v5.3.
For the library to be fully-featured, a kernel v5.10 or newer is
recommended. The full compatibility information can be found in the libxdp
README.

v1.3.0 of libxdp includes an important fix required for linking with
DPDK which is why this version or greater is required. Meson uses
pkg-config to verify the version of libxdp on the system, so it is
necessary that the library is discoverable using pkg-config in order for
the PMD to use it. To verify this, you can run:
pkg-config --modversion libxdp

[1] https://github.com/libbpf/libbpf/commit/277846bc6c15

Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
---
RFC -> v1:
* Set minimum libxdp version at v1.3.0
* Don't provide alternative to discovery via pkg-config
* Add missing newline to end of file
---
 doc/guides/nics/af_xdp.rst             |  6 ++--
 doc/guides/rel_notes/release_22_03.rst |  4 +++
 drivers/net/af_xdp/compat.h            |  4 +++
 drivers/net/af_xdp/meson.build         | 39 +++++++++++++++++++++-----
 drivers/net/af_xdp/rte_eth_af_xdp.c    |  1 -
 5 files changed, 42 insertions(+), 12 deletions(-)

diff --git a/doc/guides/nics/af_xdp.rst b/doc/guides/nics/af_xdp.rst
index c9d0e1ad6c..60f4536ac5 100644
--- a/doc/guides/nics/af_xdp.rst
+++ b/doc/guides/nics/af_xdp.rst
@@ -43,9 +43,7 @@ Prerequisites
 This is a Linux-specific PMD, thus the following prerequisites apply:
 
 *  A Linux Kernel (version > v4.18) with XDP sockets configuration enabled;
-*  libbpf (within kernel version > v5.1-rc4) with latest af_xdp support installed,
-   User can install libbpf via `make install_lib` && `make install_headers` in
-   <kernel src tree>/tools/lib/bpf;
+*  Both libxdp >=v1.3.0 and libbpf libraries installed, or, libbpf <=v0.6.0
 *  A Kernel bound interface to attach to;
 *  For need_wakeup feature, it requires kernel version later than v5.3-rc1;
 *  For PMD zero copy, it requires kernel version later than v5.4-rc1;
@@ -143,4 +141,4 @@ Limitations
   NAPI context from a watchdog timer instead of from softirqs. More information
   on this feature can be found at [1].
 
-  [1] https://lwn.net/Articles/837010/
\ No newline at end of file
+  [1] https://lwn.net/Articles/837010/
diff --git a/doc/guides/rel_notes/release_22_03.rst b/doc/guides/rel_notes/release_22_03.rst
index 6d99d1eaa9..1258bdac61 100644
--- a/doc/guides/rel_notes/release_22_03.rst
+++ b/doc/guides/rel_notes/release_22_03.rst
@@ -55,6 +55,10 @@ New Features
      Also, make sure to start the actual text at the margin.
      =======================================================
 
+* **Update AF_XDP PMD**
+
+  * Added support for libxdp >=v1.3.0.
+
 
 Removed Items
 -------------
diff --git a/drivers/net/af_xdp/compat.h b/drivers/net/af_xdp/compat.h
index 3880dc7dd7..245df1b109 100644
--- a/drivers/net/af_xdp/compat.h
+++ b/drivers/net/af_xdp/compat.h
@@ -2,7 +2,11 @@
  * Copyright(c) 2020 Intel Corporation.
  */
 
+#ifdef RTE_LIBRTE_AF_XDP_PMD_LIBXDP
+#include <xdp/xsk.h>
+#else
 #include <bpf/xsk.h>
+#endif
 #include <linux/version.h>
 #include <poll.h>
 
diff --git a/drivers/net/af_xdp/meson.build b/drivers/net/af_xdp/meson.build
index 3ed2b29784..cdc4c1ca06 100644
--- a/drivers/net/af_xdp/meson.build
+++ b/drivers/net/af_xdp/meson.build
@@ -9,19 +9,44 @@ endif
 
 sources = files('rte_eth_af_xdp.c')
 
+xdp_dep = dependency('libxdp', version : '>=1.3.0', required: false, method: 'pkg-config')
 bpf_dep = dependency('libbpf', required: false, method: 'pkg-config')
 if not bpf_dep.found()
     bpf_dep = cc.find_library('bpf', required: false)
 endif
 
-if bpf_dep.found() and cc.has_header('bpf/xsk.h') and cc.has_header('linux/if_xdp.h')
-    ext_deps += bpf_dep
-    bpf_ver_dep = dependency('libbpf', version : '>=0.2.0',
-            required: false, method: 'pkg-config')
-    if bpf_ver_dep.found()
-        dpdk_conf.set('RTE_LIBRTE_AF_XDP_PMD_SHARED_UMEM', 1)
+if cc.has_header('linux/if_xdp.h')
+    if xdp_dep.found() and cc.has_header('xdp/xsk.h')
+        if bpf_dep.found() and cc.has_header('bpf/bpf.h')
+            dpdk_conf.set('RTE_LIBRTE_AF_XDP_PMD_LIBXDP', 1)
+            dpdk_conf.set('RTE_LIBRTE_AF_XDP_PMD_SHARED_UMEM', 1)
+            ext_deps += xdp_dep
+            ext_deps += bpf_dep
+        else
+            build = false
+            reason = 'missing dependency, libbpf'
+        endif
+    elif bpf_dep.found() and cc.has_header('bpf/xsk.h') and cc.has_header('bpf/bpf.h')
+        # libxdp not found. Rely solely on libbpf for xsk functionality
+        # which is only available in versions <= v0.6.0.
+        bpf_ver_dep = dependency('libbpf', version : '<=0.6.0',
+                                 required: false, method: 'pkg-config')
+        if bpf_ver_dep.found()
+            ext_deps += bpf_dep
+            bpf_shumem_ver_dep = dependency('libbpf', version : '>=0.2.0',
+                            required: false, method: 'pkg-config')
+            if bpf_shumem_ver_dep.found()
+                dpdk_conf.set('RTE_LIBRTE_AF_XDP_PMD_SHARED_UMEM', 1)
+            endif
+        else
+            build = false
+            reason = 'missing dependency, "libxdp" or "libbpf <= v0.6.0"'
+        endif
+    else
+        build = false
+        reason = 'missing dependency, "libxdp" and "libbpf"'
     endif
 else
     build = false
-    reason = 'missing dependency, "libbpf"'
+    reason = 'missing header, "linux/if_xdp.h"'
 endif
diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c b/drivers/net/af_xdp/rte_eth_af_xdp.c
index 96c2c9d939..5d89bebb01 100644
--- a/drivers/net/af_xdp/rte_eth_af_xdp.c
+++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
@@ -16,7 +16,6 @@
 #include <linux/sockios.h>
 #include "af_xdp_deps.h"
 #include <bpf/bpf.h>
-#include <bpf/xsk.h>
 
 #include <rte_ethdev.h>
 #include <ethdev_driver.h>
-- 
2.17.1

[PATCH v2] net/af_xdp: use libxdp if available

[Ciara Loftus]

AF_XDP support is deprecated in libbpf since v0.7.0 [1]. The
libxdp library now provides the functionality which once was in
libbpf and which the AF_XDP PMD relies on. This commit updates the
AF_XDP meson build to use the libxdp library if a version >= v1.2.2 is
available. If it is not available, only versions of libbpf prior to v0.7.0
are allowed, as they still contain the required AF_XDP functionality.

libbpf still remains a dependency even if libxdp is present, as we
use libbpf APIs for program loading.

The minimum required kernel version for libxdp for use with AF_XDP is v5.3.
For the library to be fully-featured, a kernel v5.10 or newer is
recommended. The full compatibility information can be found in the libxdp
README.

v1.2.2 of libxdp includes an important fix required for linking with
DPDK which is why this version or greater is required. Meson uses
pkg-config to verify the version of libxdp on the system, so it is
necessary that the library is discoverable using pkg-config in order for
the PMD to use it. To verify this, you can run:
pkg-config --modversion libxdp

[1] https://github.com/libbpf/libbpf/commit/277846bc6c15

Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
---
v2:
* Set minimum libxdp version at v1.2.2

RFC -> v1:
* Set minimum libxdp version at v1.3.0
* Don't provide alternative to discovery via pkg-config
* Add missing newline to end of file
---
 doc/guides/nics/af_xdp.rst             |  6 ++--
 doc/guides/rel_notes/release_22_03.rst |  4 +++
 drivers/net/af_xdp/compat.h            |  4 +++
 drivers/net/af_xdp/meson.build         | 39 +++++++++++++++++++++-----
 drivers/net/af_xdp/rte_eth_af_xdp.c    |  1 -
 5 files changed, 42 insertions(+), 12 deletions(-)

diff --git a/doc/guides/nics/af_xdp.rst b/doc/guides/nics/af_xdp.rst
index c9d0e1ad6c..db02ea1984 100644
--- a/doc/guides/nics/af_xdp.rst
+++ b/doc/guides/nics/af_xdp.rst
@@ -43,9 +43,7 @@ Prerequisites
 This is a Linux-specific PMD, thus the following prerequisites apply:
 
 *  A Linux Kernel (version > v4.18) with XDP sockets configuration enabled;
-*  libbpf (within kernel version > v5.1-rc4) with latest af_xdp support installed,
-   User can install libbpf via `make install_lib` && `make install_headers` in
-   <kernel src tree>/tools/lib/bpf;
+*  Both libxdp >=v1.2.2 and libbpf libraries installed, or, libbpf <=v0.6.0
 *  A Kernel bound interface to attach to;
 *  For need_wakeup feature, it requires kernel version later than v5.3-rc1;
 *  For PMD zero copy, it requires kernel version later than v5.4-rc1;
@@ -143,4 +141,4 @@ Limitations
   NAPI context from a watchdog timer instead of from softirqs. More information
   on this feature can be found at [1].
 
-  [1] https://lwn.net/Articles/837010/
\ No newline at end of file
+  [1] https://lwn.net/Articles/837010/
diff --git a/doc/guides/rel_notes/release_22_03.rst b/doc/guides/rel_notes/release_22_03.rst
index 8a202ec4f4..ad7283df65 100644
--- a/doc/guides/rel_notes/release_22_03.rst
+++ b/doc/guides/rel_notes/release_22_03.rst
@@ -55,6 +55,10 @@ New Features
      Also, make sure to start the actual text at the margin.
      =======================================================
 
+* **Update AF_XDP PMD**
+
+  * Added support for libxdp >=v1.2.2.
+
 
 Removed Items
 -------------
diff --git a/drivers/net/af_xdp/compat.h b/drivers/net/af_xdp/compat.h
index 3880dc7dd7..245df1b109 100644
--- a/drivers/net/af_xdp/compat.h
+++ b/drivers/net/af_xdp/compat.h
@@ -2,7 +2,11 @@
  * Copyright(c) 2020 Intel Corporation.
  */
 
+#ifdef RTE_LIBRTE_AF_XDP_PMD_LIBXDP
+#include <xdp/xsk.h>
+#else
 #include <bpf/xsk.h>
+#endif
 #include <linux/version.h>
 #include <poll.h>
 
diff --git a/drivers/net/af_xdp/meson.build b/drivers/net/af_xdp/meson.build
index 3ed2b29784..981d4c6087 100644
--- a/drivers/net/af_xdp/meson.build
+++ b/drivers/net/af_xdp/meson.build
@@ -9,19 +9,44 @@ endif
 
 sources = files('rte_eth_af_xdp.c')
 
+xdp_dep = dependency('libxdp', version : '>=1.2.2', required: false, method: 'pkg-config')
 bpf_dep = dependency('libbpf', required: false, method: 'pkg-config')
 if not bpf_dep.found()
     bpf_dep = cc.find_library('bpf', required: false)
 endif
 
-if bpf_dep.found() and cc.has_header('bpf/xsk.h') and cc.has_header('linux/if_xdp.h')
-    ext_deps += bpf_dep
-    bpf_ver_dep = dependency('libbpf', version : '>=0.2.0',
-            required: false, method: 'pkg-config')
-    if bpf_ver_dep.found()
-        dpdk_conf.set('RTE_LIBRTE_AF_XDP_PMD_SHARED_UMEM', 1)
+if cc.has_header('linux/if_xdp.h')
+    if xdp_dep.found() and cc.has_header('xdp/xsk.h')
+        if bpf_dep.found() and cc.has_header('bpf/bpf.h')
+            dpdk_conf.set('RTE_LIBRTE_AF_XDP_PMD_LIBXDP', 1)
+            dpdk_conf.set('RTE_LIBRTE_AF_XDP_PMD_SHARED_UMEM', 1)
+            ext_deps += xdp_dep
+            ext_deps += bpf_dep
+        else
+            build = false
+            reason = 'missing dependency, libbpf'
+        endif
+    elif bpf_dep.found() and cc.has_header('bpf/xsk.h') and cc.has_header('bpf/bpf.h')
+        # libxdp not found. Rely solely on libbpf for xsk functionality
+        # which is only available in versions <= v0.6.0.
+        bpf_ver_dep = dependency('libbpf', version : '<=0.6.0',
+                                 required: false, method: 'pkg-config')
+        if bpf_ver_dep.found()
+            ext_deps += bpf_dep
+            bpf_shumem_ver_dep = dependency('libbpf', version : '>=0.2.0',
+                            required: false, method: 'pkg-config')
+            if bpf_shumem_ver_dep.found()
+                dpdk_conf.set('RTE_LIBRTE_AF_XDP_PMD_SHARED_UMEM', 1)
+            endif
+        else
+            build = false
+            reason = 'missing dependency, "libxdp" or "libbpf <= v0.6.0"'
+        endif
+    else
+        build = false
+        reason = 'missing dependency, "libxdp" and "libbpf"'
     endif
 else
     build = false
-    reason = 'missing dependency, "libbpf"'
+    reason = 'missing header, "linux/if_xdp.h"'
 endif
diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c b/drivers/net/af_xdp/rte_eth_af_xdp.c
index 96c2c9d939..5d89bebb01 100644
--- a/drivers/net/af_xdp/rte_eth_af_xdp.c
+++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
@@ -16,7 +16,6 @@
 #include <linux/sockios.h>
 #include "af_xdp_deps.h"
 #include <bpf/bpf.h>
-#include <bpf/xsk.h>
 
 #include <rte_ethdev.h>
 #include <ethdev_driver.h>
-- 
2.17.1

Re: [PATCH v2] net/af_xdp: use libxdp if available

[Bruce Richardson]

On Tue, Jan 25, 2022 at 07:20:43AM +0000, Ciara Loftus wrote:
> AF_XDP support is deprecated in libbpf since v0.7.0 [1]. The
> libxdp library now provides the functionality which once was in
> libbpf and which the AF_XDP PMD relies on. This commit updates the
> AF_XDP meson build to use the libxdp library if a version >= v1.2.2 is
> available. If it is not available, only versions of libbpf prior to v0.7.0
> are allowed, as they still contain the required AF_XDP functionality.
> 
> libbpf still remains a dependency even if libxdp is present, as we
> use libbpf APIs for program loading.
> 
> The minimum required kernel version for libxdp for use with AF_XDP is v5.3.
> For the library to be fully-featured, a kernel v5.10 or newer is
> recommended. The full compatibility information can be found in the libxdp
> README.
> 
> v1.2.2 of libxdp includes an important fix required for linking with
> DPDK which is why this version or greater is required. Meson uses
> pkg-config to verify the version of libxdp on the system, so it is
> necessary that the library is discoverable using pkg-config in order for
> the PMD to use it. To verify this, you can run:
> pkg-config --modversion libxdp
> 
> [1] https://github.com/libbpf/libbpf/commit/277846bc6c15
> 
> Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>

Hi Ciara,

couple of comments inline below.

/Bruce

> ---
> v2:
> * Set minimum libxdp version at v1.2.2
> 
> RFC -> v1:
> * Set minimum libxdp version at v1.3.0
> * Don't provide alternative to discovery via pkg-config
> * Add missing newline to end of file
> ---
>  doc/guides/nics/af_xdp.rst             |  6 ++--
>  doc/guides/rel_notes/release_22_03.rst |  4 +++
>  drivers/net/af_xdp/compat.h            |  4 +++
>  drivers/net/af_xdp/meson.build         | 39 +++++++++++++++++++++-----
>  drivers/net/af_xdp/rte_eth_af_xdp.c    |  1 -
>  5 files changed, 42 insertions(+), 12 deletions(-)
> 
> diff --git a/doc/guides/nics/af_xdp.rst b/doc/guides/nics/af_xdp.rst
> index c9d0e1ad6c..db02ea1984 100644
> --- a/doc/guides/nics/af_xdp.rst
> +++ b/doc/guides/nics/af_xdp.rst
> @@ -43,9 +43,7 @@ Prerequisites
>  This is a Linux-specific PMD, thus the following prerequisites apply:
>  
>  *  A Linux Kernel (version > v4.18) with XDP sockets configuration enabled;
> -*  libbpf (within kernel version > v5.1-rc4) with latest af_xdp support installed,
> -   User can install libbpf via `make install_lib` && `make install_headers` in
> -   <kernel src tree>/tools/lib/bpf;
> +*  Both libxdp >=v1.2.2 and libbpf libraries installed, or, libbpf <=v0.6.0
>  *  A Kernel bound interface to attach to;
>  *  For need_wakeup feature, it requires kernel version later than v5.3-rc1;
>  *  For PMD zero copy, it requires kernel version later than v5.4-rc1;
> @@ -143,4 +141,4 @@ Limitations
>    NAPI context from a watchdog timer instead of from softirqs. More information
>    on this feature can be found at [1].
>  
> -  [1] https://lwn.net/Articles/837010/
> \ No newline at end of file
> +  [1] https://lwn.net/Articles/837010/
> diff --git a/doc/guides/rel_notes/release_22_03.rst b/doc/guides/rel_notes/release_22_03.rst
> index 8a202ec4f4..ad7283df65 100644
> --- a/doc/guides/rel_notes/release_22_03.rst
> +++ b/doc/guides/rel_notes/release_22_03.rst
> @@ -55,6 +55,10 @@ New Features
>       Also, make sure to start the actual text at the margin.
>       =======================================================
>  
> +* **Update AF_XDP PMD**
> +
> +  * Added support for libxdp >=v1.2.2.
> +
>  
>  Removed Items
>  -------------
> diff --git a/drivers/net/af_xdp/compat.h b/drivers/net/af_xdp/compat.h
> index 3880dc7dd7..245df1b109 100644
> --- a/drivers/net/af_xdp/compat.h
> +++ b/drivers/net/af_xdp/compat.h
> @@ -2,7 +2,11 @@
>   * Copyright(c) 2020 Intel Corporation.
>   */
>  
> +#ifdef RTE_LIBRTE_AF_XDP_PMD_LIBXDP

This is a really long macro name. With meson builds we have largely moved
away from using "RTE_LIBRTE_" as a prefix, and also have dropped "PMD" from
names too. The global enable macro for AF_XDP driver is now
"RTE_NET_AF_XDP" so I'd suggest this macro could be shortened to
"RTE_NET_AF_XDP_LIBXDP".

> +#include <xdp/xsk.h>
> +#else
>  #include <bpf/xsk.h>
> +#endif
>  #include <linux/version.h>
>  #include <poll.h>
>  
> diff --git a/drivers/net/af_xdp/meson.build b/drivers/net/af_xdp/meson.build
> index 3ed2b29784..981d4c6087 100644
> --- a/drivers/net/af_xdp/meson.build
> +++ b/drivers/net/af_xdp/meson.build
> @@ -9,19 +9,44 @@ endif
>  
>  sources = files('rte_eth_af_xdp.c')
>  
> +xdp_dep = dependency('libxdp', version : '>=1.2.2', required: false, method: 'pkg-config')
>  bpf_dep = dependency('libbpf', required: false, method: 'pkg-config')
>  if not bpf_dep.found()
>      bpf_dep = cc.find_library('bpf', required: false)
>  endif
>  
> -if bpf_dep.found() and cc.has_header('bpf/xsk.h') and cc.has_header('linux/if_xdp.h')
> -    ext_deps += bpf_dep
> -    bpf_ver_dep = dependency('libbpf', version : '>=0.2.0',
> -            required: false, method: 'pkg-config')
> -    if bpf_ver_dep.found()
> -        dpdk_conf.set('RTE_LIBRTE_AF_XDP_PMD_SHARED_UMEM', 1)
> +if cc.has_header('linux/if_xdp.h')
> +    if xdp_dep.found() and cc.has_header('xdp/xsk.h')
> +        if bpf_dep.found() and cc.has_header('bpf/bpf.h')
> +            dpdk_conf.set('RTE_LIBRTE_AF_XDP_PMD_LIBXDP', 1)
> +            dpdk_conf.set('RTE_LIBRTE_AF_XDP_PMD_SHARED_UMEM', 1)

Do these defines need to be exposed to the end user, or are they for
internal use only? If they don't need to be exposed to the user, I'd
suggest changing them to cflags, rather than writing them to the build
config. As well as reducing the info we show to the end user, not having
them in the build config means that if they change, only this driver needs
a rebuild, rather than the whole of DPDK. [Every DPDK file includes the
build config, so a change there requires everything rebuild]

> +            ext_deps += xdp_dep
> +            ext_deps += bpf_dep
> +        else
> +            build = false
> +            reason = 'missing dependency, libbpf'
> +        endif
<snip>

RE: [PATCH v2] net/af_xdp: use libxdp if available

[Loftus, Ciara]

> 
> On Tue, Jan 25, 2022 at 07:20:43AM +0000, Ciara Loftus wrote:
> > AF_XDP support is deprecated in libbpf since v0.7.0 [1]. The
> > libxdp library now provides the functionality which once was in
> > libbpf and which the AF_XDP PMD relies on. This commit updates the
> > AF_XDP meson build to use the libxdp library if a version >= v1.2.2 is
> > available. If it is not available, only versions of libbpf prior to v0.7.0
> > are allowed, as they still contain the required AF_XDP functionality.
> >
> > libbpf still remains a dependency even if libxdp is present, as we
> > use libbpf APIs for program loading.
> >
> > The minimum required kernel version for libxdp for use with AF_XDP is
> v5.3.
> > For the library to be fully-featured, a kernel v5.10 or newer is
> > recommended. The full compatibility information can be found in the
> libxdp
> > README.
> >
> > v1.2.2 of libxdp includes an important fix required for linking with
> > DPDK which is why this version or greater is required. Meson uses
> > pkg-config to verify the version of libxdp on the system, so it is
> > necessary that the library is discoverable using pkg-config in order for
> > the PMD to use it. To verify this, you can run:
> > pkg-config --modversion libxdp
> >
> > [1] https://github.com/libbpf/libbpf/commit/277846bc6c15
> >
> > Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
> 
> Hi Ciara,
> 
> couple of comments inline below.
> 
> /Bruce
> 
> > ---
> > v2:
> > * Set minimum libxdp version at v1.2.2
> >
> > RFC -> v1:
> > * Set minimum libxdp version at v1.3.0
> > * Don't provide alternative to discovery via pkg-config
> > * Add missing newline to end of file
> > ---
> >  doc/guides/nics/af_xdp.rst             |  6 ++--
> >  doc/guides/rel_notes/release_22_03.rst |  4 +++
> >  drivers/net/af_xdp/compat.h            |  4 +++
> >  drivers/net/af_xdp/meson.build         | 39 +++++++++++++++++++++-----
> >  drivers/net/af_xdp/rte_eth_af_xdp.c    |  1 -
> >  5 files changed, 42 insertions(+), 12 deletions(-)
> >
> > diff --git a/doc/guides/nics/af_xdp.rst b/doc/guides/nics/af_xdp.rst
> > index c9d0e1ad6c..db02ea1984 100644
> > --- a/doc/guides/nics/af_xdp.rst
> > +++ b/doc/guides/nics/af_xdp.rst
> > @@ -43,9 +43,7 @@ Prerequisites
> >  This is a Linux-specific PMD, thus the following prerequisites apply:
> >
> >  *  A Linux Kernel (version > v4.18) with XDP sockets configuration enabled;
> > -*  libbpf (within kernel version > v5.1-rc4) with latest af_xdp support
> installed,
> > -   User can install libbpf via `make install_lib` && `make install_headers` in
> > -   <kernel src tree>/tools/lib/bpf;
> > +*  Both libxdp >=v1.2.2 and libbpf libraries installed, or, libbpf <=v0.6.0
> >  *  A Kernel bound interface to attach to;
> >  *  For need_wakeup feature, it requires kernel version later than v5.3-rc1;
> >  *  For PMD zero copy, it requires kernel version later than v5.4-rc1;
> > @@ -143,4 +141,4 @@ Limitations
> >    NAPI context from a watchdog timer instead of from softirqs. More
> information
> >    on this feature can be found at [1].
> >
> > -  [1] https://lwn.net/Articles/837010/
> > \ No newline at end of file
> > +  [1] https://lwn.net/Articles/837010/
> > diff --git a/doc/guides/rel_notes/release_22_03.rst
> b/doc/guides/rel_notes/release_22_03.rst
> > index 8a202ec4f4..ad7283df65 100644
> > --- a/doc/guides/rel_notes/release_22_03.rst
> > +++ b/doc/guides/rel_notes/release_22_03.rst
> > @@ -55,6 +55,10 @@ New Features
> >       Also, make sure to start the actual text at the margin.
> >       =======================================================
> >
> > +* **Update AF_XDP PMD**
> > +
> > +  * Added support for libxdp >=v1.2.2.
> > +
> >
> >  Removed Items
> >  -------------
> > diff --git a/drivers/net/af_xdp/compat.h b/drivers/net/af_xdp/compat.h
> > index 3880dc7dd7..245df1b109 100644
> > --- a/drivers/net/af_xdp/compat.h
> > +++ b/drivers/net/af_xdp/compat.h
> > @@ -2,7 +2,11 @@
> >   * Copyright(c) 2020 Intel Corporation.
> >   */
> >
> > +#ifdef RTE_LIBRTE_AF_XDP_PMD_LIBXDP
> 
> This is a really long macro name. With meson builds we have largely moved
> away from using "RTE_LIBRTE_" as a prefix, and also have dropped "PMD"
> from
> names too. The global enable macro for AF_XDP driver is now
> "RTE_NET_AF_XDP" so I'd suggest this macro could be shortened to
> "RTE_NET_AF_XDP_LIBXDP".

+1

> 
> > +#include <xdp/xsk.h>
> > +#else
> >  #include <bpf/xsk.h>
> > +#endif
> >  #include <linux/version.h>
> >  #include <poll.h>
> >
> > diff --git a/drivers/net/af_xdp/meson.build
> b/drivers/net/af_xdp/meson.build
> > index 3ed2b29784..981d4c6087 100644
> > --- a/drivers/net/af_xdp/meson.build
> > +++ b/drivers/net/af_xdp/meson.build
> > @@ -9,19 +9,44 @@ endif
> >
> >  sources = files('rte_eth_af_xdp.c')
> >
> > +xdp_dep = dependency('libxdp', version : '>=1.2.2', required: false,
> method: 'pkg-config')
> >  bpf_dep = dependency('libbpf', required: false, method: 'pkg-config')
> >  if not bpf_dep.found()
> >      bpf_dep = cc.find_library('bpf', required: false)
> >  endif
> >
> > -if bpf_dep.found() and cc.has_header('bpf/xsk.h') and
> cc.has_header('linux/if_xdp.h')
> > -    ext_deps += bpf_dep
> > -    bpf_ver_dep = dependency('libbpf', version : '>=0.2.0',
> > -            required: false, method: 'pkg-config')
> > -    if bpf_ver_dep.found()
> > -        dpdk_conf.set('RTE_LIBRTE_AF_XDP_PMD_SHARED_UMEM', 1)
> > +if cc.has_header('linux/if_xdp.h')
> > +    if xdp_dep.found() and cc.has_header('xdp/xsk.h')
> > +        if bpf_dep.found() and cc.has_header('bpf/bpf.h')
> > +            dpdk_conf.set('RTE_LIBRTE_AF_XDP_PMD_LIBXDP', 1)
> > +            dpdk_conf.set('RTE_LIBRTE_AF_XDP_PMD_SHARED_UMEM', 1)
> 
> Do these defines need to be exposed to the end user, or are they for
> internal use only? If they don't need to be exposed to the user, I'd
> suggest changing them to cflags, rather than writing them to the build
> config. As well as reducing the info we show to the end user, not having
> them in the build config means that if they change, only this driver needs
> a rebuild, rather than the whole of DPDK. [Every DPDK file includes the
> build config, so a change there requires everything rebuild]

These don't need to be exposed to the end user. Thanks for the suggestion,
it definitely makes more sense to use cflags instead. I'll add that in the v3.

Thanks,
Ciara

> 
> > +            ext_deps += xdp_dep
> > +            ext_deps += bpf_dep
> > +        else
> > +            build = false
> > +            reason = 'missing dependency, libbpf'
> > +        endif
> <snip>

[PATCH v3] net/af_xdp: use libxdp if available

[Ciara Loftus]

AF_XDP support is deprecated in libbpf since v0.7.0 [1]. The libxdp library
now provides the functionality which once was in libbpf and which the
AF_XDP PMD relies on. This commit updates the AF_XDP meson build to use the
libxdp library if a version >= v1.2.2 is available. If it is not available,
only versions of libbpf prior to v0.7.0 are allowed, as they still contain
the required AF_XDP functionality.

libbpf still remains a dependency even if libxdp is present, as we use
libbpf APIs for program loading.

The minimum required kernel version for libxdp for use with AF_XDP is v5.3.
For the library to be fully-featured, a kernel v5.10 or newer is
recommended. The full compatibility information can be found in the libxdp
README.

v1.2.2 of libxdp includes an important fix required for linking with DPDK
which is why this version or greater is required. Meson uses pkg-config to
verify the version of libxdp on the system, so it is necessary that the
library is discoverable using pkg-config in order for the PMD to use it. To
verify this, you can run: pkg-config --modversion libxdp

[1] https://github.com/libbpf/libbpf/commit/277846bc6c15

Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
---
v3:
* Use cflags instead of writing to the build config
* Change flag names to suit convention.

v2:
* Set minimum libxdp version at v1.2.2

RFC -> v1:
* Set minimum libxdp version at v1.3.0
* Don't provide alternative to discovery via pkg-config
* Add missing newline to end of file
---
 doc/guides/nics/af_xdp.rst             |  6 ++--
 doc/guides/rel_notes/release_22_03.rst |  4 +++
 drivers/net/af_xdp/compat.h            |  6 +++-
 drivers/net/af_xdp/meson.build         | 39 +++++++++++++++++++++-----
 drivers/net/af_xdp/rte_eth_af_xdp.c    |  1 -
 5 files changed, 43 insertions(+), 13 deletions(-)

diff --git a/doc/guides/nics/af_xdp.rst b/doc/guides/nics/af_xdp.rst
index c9d0e1ad6c..db02ea1984 100644
--- a/doc/guides/nics/af_xdp.rst
+++ b/doc/guides/nics/af_xdp.rst
@@ -43,9 +43,7 @@ Prerequisites
 This is a Linux-specific PMD, thus the following prerequisites apply:
 
 *  A Linux Kernel (version > v4.18) with XDP sockets configuration enabled;
-*  libbpf (within kernel version > v5.1-rc4) with latest af_xdp support installed,
-   User can install libbpf via `make install_lib` && `make install_headers` in
-   <kernel src tree>/tools/lib/bpf;
+*  Both libxdp >=v1.2.2 and libbpf libraries installed, or, libbpf <=v0.6.0
 *  A Kernel bound interface to attach to;
 *  For need_wakeup feature, it requires kernel version later than v5.3-rc1;
 *  For PMD zero copy, it requires kernel version later than v5.4-rc1;
@@ -143,4 +141,4 @@ Limitations
   NAPI context from a watchdog timer instead of from softirqs. More information
   on this feature can be found at [1].
 
-  [1] https://lwn.net/Articles/837010/
\ No newline at end of file
+  [1] https://lwn.net/Articles/837010/
diff --git a/doc/guides/rel_notes/release_22_03.rst b/doc/guides/rel_notes/release_22_03.rst
index 3bc0630c7c..68ef02cb54 100644
--- a/doc/guides/rel_notes/release_22_03.rst
+++ b/doc/guides/rel_notes/release_22_03.rst
@@ -69,6 +69,10 @@ New Features
 
   The new API ``rte_event_eth_rx_adapter_event_port_get()`` was added.
 
+* **Update AF_XDP PMD**
+
+  * Added support for libxdp >=v1.2.2.
+
 
 Removed Items
 -------------
diff --git a/drivers/net/af_xdp/compat.h b/drivers/net/af_xdp/compat.h
index 3880dc7dd7..bf40c6572e 100644
--- a/drivers/net/af_xdp/compat.h
+++ b/drivers/net/af_xdp/compat.h
@@ -2,12 +2,16 @@
  * Copyright(c) 2020 Intel Corporation.
  */
 
+#ifdef RTE_NET_AF_XDP_LIBXDP
+#include <xdp/xsk.h>
+#else
 #include <bpf/xsk.h>
+#endif
 #include <linux/version.h>
 #include <poll.h>
 
 #if KERNEL_VERSION(5, 10, 0) <= LINUX_VERSION_CODE && \
-	defined(RTE_LIBRTE_AF_XDP_PMD_SHARED_UMEM)
+	defined(RTE_NET_AF_XDP_SHARED_UMEM)
 #define ETH_AF_XDP_SHARED_UMEM 1
 #endif
 
diff --git a/drivers/net/af_xdp/meson.build b/drivers/net/af_xdp/meson.build
index 3ed2b29784..93e895eab9 100644
--- a/drivers/net/af_xdp/meson.build
+++ b/drivers/net/af_xdp/meson.build
@@ -9,19 +9,44 @@ endif
 
 sources = files('rte_eth_af_xdp.c')
 
+xdp_dep = dependency('libxdp', version : '>=1.2.2', required: false, method: 'pkg-config')
 bpf_dep = dependency('libbpf', required: false, method: 'pkg-config')
 if not bpf_dep.found()
     bpf_dep = cc.find_library('bpf', required: false)
 endif
 
-if bpf_dep.found() and cc.has_header('bpf/xsk.h') and cc.has_header('linux/if_xdp.h')
-    ext_deps += bpf_dep
-    bpf_ver_dep = dependency('libbpf', version : '>=0.2.0',
-            required: false, method: 'pkg-config')
-    if bpf_ver_dep.found()
-        dpdk_conf.set('RTE_LIBRTE_AF_XDP_PMD_SHARED_UMEM', 1)
+if cc.has_header('linux/if_xdp.h')
+    if xdp_dep.found() and cc.has_header('xdp/xsk.h')
+        if bpf_dep.found() and cc.has_header('bpf/bpf.h')
+            cflags += ['-DRTE_NET_AF_XDP_LIBXDP']
+            cflags += ['-DRTE_NET_AF_XDP_SHARED_UMEM']
+            ext_deps += xdp_dep
+            ext_deps += bpf_dep
+        else
+            build = false
+            reason = 'missing dependency, libbpf'
+        endif
+    elif bpf_dep.found() and cc.has_header('bpf/xsk.h') and cc.has_header('bpf/bpf.h')
+        # libxdp not found. Rely solely on libbpf for xsk functionality
+        # which is only available in versions <= v0.6.0.
+        bpf_ver_dep = dependency('libbpf', version : '<=0.6.0',
+                                 required: false, method: 'pkg-config')
+        if bpf_ver_dep.found()
+            ext_deps += bpf_dep
+            bpf_shumem_ver_dep = dependency('libbpf', version : '>=0.2.0',
+                            required: false, method: 'pkg-config')
+            if bpf_shumem_ver_dep.found()
+                cflags += ['-DRTE_NET_AF_XDP_SHARED_UMEM']
+            endif
+        else
+            build = false
+            reason = 'missing dependency, "libxdp" or "libbpf <= v0.6.0"'
+        endif
+    else
+        build = false
+        reason = 'missing dependency, "libxdp" and "libbpf"'
     endif
 else
     build = false
-    reason = 'missing dependency, "libbpf"'
+    reason = 'missing header, "linux/if_xdp.h"'
 endif
diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c b/drivers/net/af_xdp/rte_eth_af_xdp.c
index 96c2c9d939..5d89bebb01 100644
--- a/drivers/net/af_xdp/rte_eth_af_xdp.c
+++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
@@ -16,7 +16,6 @@
 #include <linux/sockios.h>
 #include "af_xdp_deps.h"
 #include <bpf/bpf.h>
-#include <bpf/xsk.h>
 
 #include <rte_ethdev.h>
 #include <ethdev_driver.h>
-- 
2.17.1

Re: [PATCH v3] net/af_xdp: use libxdp if available

[Ferruh Yigit]

On 1/28/2022 9:50 AM, Ciara Loftus wrote:
> AF_XDP support is deprecated in libbpf since v0.7.0 [1]. The libxdp library
> now provides the functionality which once was in libbpf and which the
> AF_XDP PMD relies on. This commit updates the AF_XDP meson build to use the
> libxdp library if a version >= v1.2.2 is available. If it is not available,
> only versions of libbpf prior to v0.7.0 are allowed, as they still contain
> the required AF_XDP functionality.
> 
> libbpf still remains a dependency even if libxdp is present, as we use
> libbpf APIs for program loading.
> 
> The minimum required kernel version for libxdp for use with AF_XDP is v5.3.
> For the library to be fully-featured, a kernel v5.10 or newer is
> recommended. The full compatibility information can be found in the libxdp
> README.
> 
> v1.2.2 of libxdp includes an important fix required for linking with DPDK
> which is why this version or greater is required. Meson uses pkg-config to
> verify the version of libxdp on the system, so it is necessary that the
> library is discoverable using pkg-config in order for the PMD to use it. To
> verify this, you can run: pkg-config --modversion libxdp
> 
> [1] https://github.com/libbpf/libbpf/commit/277846bc6c15
> 
> Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>

Tested build with combination of following, build looks good
libxdp 1.2.0, libxdp 1.2.2
libbpf 0.7.0, libbpf 0.4.0


But while running testpmd can't find the libxdp.so by default [1], although
setting 'LD_LIBRARY_PATH' works (LD_LIBRARY_PATH=/usr/local/lib64/ for my case),
this wasn't required for libbpf, just checking if this is expected?

Similarly for 'build/drivers/librte_net_af_xdp.so', ldd can find 'libbpf' but
not libxdp.so (although they are in same folder):
$ ldd build/drivers/librte_net_af_xdp.so
         libxdp.so.1 => not found
         libbpf.so.0 => /usr/local/lib64/libbpf.so.0 (0x00007f2ceb86f000)
         ....

Again, 'LD_LIBRARY_PATH' works:
$ LD_LIBRARY_PATH=/usr/local/lib64/ ldd build/drivers/librte_net_af_xdp.so
         libxdp.so.1 => /usr/local/lib64/libxdp.so.1 (0x00007fefa792e000)
         libbpf.so.0 => /usr/local/lib64/libbpf.so.0 (0x00007fefa78dc000)


But same question, why 'LD_LIBRARY_PATH' is not required for libbpf, but
required for libxdp, any idea?



[1]
./build/app/dpdk-testpmd: error while loading shared libraries: libxdp.so.1: cannot open shared object file: No such file or directory

Re: [PATCH v3] net/af_xdp: use libxdp if available

[Bruce Richardson]

On Mon, Jan 31, 2022 at 05:59:53PM +0000, Ferruh Yigit wrote:
> On 1/28/2022 9:50 AM, Ciara Loftus wrote:
> > AF_XDP support is deprecated in libbpf since v0.7.0 [1]. The libxdp
> > library now provides the functionality which once was in libbpf and
> > which the AF_XDP PMD relies on. This commit updates the AF_XDP meson
> > build to use the libxdp library if a version >= v1.2.2 is available. If
> > it is not available, only versions of libbpf prior to v0.7.0 are
> > allowed, as they still contain the required AF_XDP functionality.
> > 
> > libbpf still remains a dependency even if libxdp is present, as we use
> > libbpf APIs for program loading.
> > 
> > The minimum required kernel version for libxdp for use with AF_XDP is
> > v5.3.  For the library to be fully-featured, a kernel v5.10 or newer is
> > recommended. The full compatibility information can be found in the
> > libxdp README.
> > 
> > v1.2.2 of libxdp includes an important fix required for linking with
> > DPDK which is why this version or greater is required. Meson uses
> > pkg-config to verify the version of libxdp on the system, so it is
> > necessary that the library is discoverable using pkg-config in order
> > for the PMD to use it. To verify this, you can run: pkg-config
> > --modversion libxdp
> > 
> > [1] https://github.com/libbpf/libbpf/commit/277846bc6c15
> > 
> > Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
> 
> Tested build with combination of following, build looks good libxdp
> 1.2.0, libxdp 1.2.2 libbpf 0.7.0, libbpf 0.4.0
> 
> 
> But while running testpmd can't find the libxdp.so by default [1],
> although setting 'LD_LIBRARY_PATH' works
> (LD_LIBRARY_PATH=/usr/local/lib64/ for my case), this wasn't required for
> libbpf, just checking if this is expected?
> 
> Similarly for 'build/drivers/librte_net_af_xdp.so', ldd can find 'libbpf'
> but not libxdp.so (although they are in same folder): $ ldd
> build/drivers/librte_net_af_xdp.so libxdp.so.1 => not found libbpf.so.0
> => /usr/local/lib64/libbpf.so.0 (0x00007f2ceb86f000) ....
> 
> Again, 'LD_LIBRARY_PATH' works: $ LD_LIBRARY_PATH=/usr/local/lib64/ ldd
> build/drivers/librte_net_af_xdp.so libxdp.so.1 =>
> /usr/local/lib64/libxdp.so.1 (0x00007fefa792e000) libbpf.so.0 =>
> /usr/local/lib64/libbpf.so.0 (0x00007fefa78dc000)
> 
> 
> But same question, why 'LD_LIBRARY_PATH' is not required for libbpf, but
> required for libxdp, any idea?
> 
Did you rerun "ldconfig" to refresh the ldd cache after installing the
new library?

Re: [PATCH v3] net/af_xdp: use libxdp if available

[Ferruh Yigit]

On 1/31/2022 6:05 PM, Bruce Richardson wrote:
> On Mon, Jan 31, 2022 at 05:59:53PM +0000, Ferruh Yigit wrote:
>> On 1/28/2022 9:50 AM, Ciara Loftus wrote:
>>> AF_XDP support is deprecated in libbpf since v0.7.0 [1]. The libxdp
>>> library now provides the functionality which once was in libbpf and
>>> which the AF_XDP PMD relies on. This commit updates the AF_XDP meson
>>> build to use the libxdp library if a version >= v1.2.2 is available. If
>>> it is not available, only versions of libbpf prior to v0.7.0 are
>>> allowed, as they still contain the required AF_XDP functionality.
>>>
>>> libbpf still remains a dependency even if libxdp is present, as we use
>>> libbpf APIs for program loading.
>>>
>>> The minimum required kernel version for libxdp for use with AF_XDP is
>>> v5.3.  For the library to be fully-featured, a kernel v5.10 or newer is
>>> recommended. The full compatibility information can be found in the
>>> libxdp README.
>>>
>>> v1.2.2 of libxdp includes an important fix required for linking with
>>> DPDK which is why this version or greater is required. Meson uses
>>> pkg-config to verify the version of libxdp on the system, so it is
>>> necessary that the library is discoverable using pkg-config in order
>>> for the PMD to use it. To verify this, you can run: pkg-config
>>> --modversion libxdp
>>>
>>> [1] https://github.com/libbpf/libbpf/commit/277846bc6c15
>>>
>>> Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
>>
>> Tested build with combination of following, build looks good libxdp
>> 1.2.0, libxdp 1.2.2 libbpf 0.7.0, libbpf 0.4.0
>>
>>
>> But while running testpmd can't find the libxdp.so by default [1],
>> although setting 'LD_LIBRARY_PATH' works
>> (LD_LIBRARY_PATH=/usr/local/lib64/ for my case), this wasn't required for
>> libbpf, just checking if this is expected?
>>
>> Similarly for 'build/drivers/librte_net_af_xdp.so', ldd can find 'libbpf'
>> but not libxdp.so (although they are in same folder): $ ldd
>> build/drivers/librte_net_af_xdp.so libxdp.so.1 => not found libbpf.so.0
>> => /usr/local/lib64/libbpf.so.0 (0x00007f2ceb86f000) ....
>>
>> Again, 'LD_LIBRARY_PATH' works: $ LD_LIBRARY_PATH=/usr/local/lib64/ ldd
>> build/drivers/librte_net_af_xdp.so libxdp.so.1 =>
>> /usr/local/lib64/libxdp.so.1 (0x00007fefa792e000) libbpf.so.0 =>
>> /usr/local/lib64/libbpf.so.0 (0x00007fefa78dc000)
>>
>>
>> But same question, why 'LD_LIBRARY_PATH' is not required for libbpf, but
>> required for libxdp, any idea?
>>
> Did you rerun "ldconfig" to refresh the ldd cache after installing the
> new library?

No I didn't.
But it works as expected next day without me doing anything, if the issue
was ldconfig there can be regular periodic runs for it (I expect installing
a new library automatically trigger the ldconfig).

Anyway, I am proceeding with patch as it is working now as expected.

Re: [PATCH v3] net/af_xdp: use libxdp if available

[Ferruh Yigit]

On 1/28/2022 9:50 AM, Ciara Loftus wrote:
> AF_XDP support is deprecated in libbpf since v0.7.0 [1]. The libxdp library
> now provides the functionality which once was in libbpf and which the
> AF_XDP PMD relies on. This commit updates the AF_XDP meson build to use the
> libxdp library if a version >= v1.2.2 is available. If it is not available,
> only versions of libbpf prior to v0.7.0 are allowed, as they still contain
> the required AF_XDP functionality.
> 
> libbpf still remains a dependency even if libxdp is present, as we use
> libbpf APIs for program loading.
> 
> The minimum required kernel version for libxdp for use with AF_XDP is v5.3.
> For the library to be fully-featured, a kernel v5.10 or newer is
> recommended. The full compatibility information can be found in the libxdp
> README.
> 
> v1.2.2 of libxdp includes an important fix required for linking with DPDK
> which is why this version or greater is required. Meson uses pkg-config to
> verify the version of libxdp on the system, so it is necessary that the
> library is discoverable using pkg-config in order for the PMD to use it. To
> verify this, you can run: pkg-config --modversion libxdp
> 
> [1]https://github.com/libbpf/libbpf/commit/277846bc6c15
> 
> Signed-off-by: Ciara Loftus<ciara.loftus@intel.com>


Applied to dpdk-next-net/main, thanks.