net/af_xdp: document 32-bit OS kernel requirement

AF_XDP will not work on 32-bit kernels before version 5.4.
Document this restriction in the driver guide.

Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>

diff --git a/doc/guides/nics/af_xdp.rst b/doc/guides/nics/af_xdp.rst
index 052e59a..5ed2437 100644 (file)
--- a/doc/guides/nics/af_xdp.rst
+++ b/doc/guides/nics/af_xdp.rst
@@ -50,6 +50,7 @@ This is a Linux-specific PMD, thus the following prerequisites apply:
 *  For PMD zero copy, it requires kernel version later than v5.4-rc1;
 *  For shared_umem, it requires kernel version v5.10 or later and libbpf version
    v0.2.0 or later.
+*  For 32-bit OS, a kernel with version 5.4 or later is required.
 
 Set up an af_xdp interface
 -----------------------------