[PATCH] eal: increase max file descriptor for secondary process device

[Stephen Hemminger <stephen@networkplumber.org>]

The TAP and XDP driver both are limited to only 8 queues when
because of the small limit imposed by EAL. Increase the limit
now since this release allows changing ABI.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
 doc/guides/rel_notes/release_24_11.rst | 5 +++++
 lib/eal/include/rte_eal.h              | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/doc/guides/rel_notes/release_24_11.rst b/doc/guides/rel_notes/release_24_11.rst
index 0ff70d9057..5af70e04c5 100644
--- a/doc/guides/rel_notes/release_24_11.rst
+++ b/doc/guides/rel_notes/release_24_11.rst
@@ -100,6 +100,11 @@ ABI Changes
    Also, make sure to start the actual text at the margin.
    =======================================================
 
+* The maximum number of file descriptors that can be passed to a secondary process
+  has been increased from 8 to 253 (which is the maximum possible with Unix domain
+  socket). This allows for more queues when using software devices such as TAP
+  and XDP.
+
 
 Known Issues
 ------------
diff --git a/lib/eal/include/rte_eal.h b/lib/eal/include/rte_eal.h
index c2256f832e..c826e143f1 100644
--- a/lib/eal/include/rte_eal.h
+++ b/lib/eal/include/rte_eal.h
@@ -155,7 +155,7 @@ int rte_eal_primary_proc_alive(const char *config_file_path);
  */
 bool rte_mp_disable(void);
 
-#define RTE_MP_MAX_FD_NUM	8    /* The max amount of fds */
+#define RTE_MP_MAX_FD_NUM	253  /* The max amount of fds (see SCM_MAX_FD) */
 #define RTE_MP_MAX_NAME_LEN	64   /* The max length of action name */
 #define RTE_MP_MAX_PARAM_LEN	256  /* The max length of param */
 struct rte_mp_msg {
-- 
2.45.2