From 40b5ea86319f803cc4f5df6754b2cd1556f6bd94 Mon Sep 17 00:00:00 2001
From: Bhanuprakash Bodireddy <bhanuprakash.bodireddy@intel.com>
Date: Tue, 12 Apr 2016 11:44:15 +0100
Subject: [PATCH] acinclude: Autodetect DPDK location when configuring OVS

When using DPDK datapath, the OVS configure script requires the DPDK
build directory passed on --with-dpdk. This can be avoided if DPDK
library, headers are in standard compiler search paths.

This patch fixes the problem by searching for DPDK libraries in standard
locations and configure OVS sources for dpdk datapath.

If the install location is manually specified in "--with-dpdk"
autodiscovery shall be skipped.

Signed-off-by: Bhanuprakash Bodireddy <bhanuprakash.bodireddy@intel.com>
Signed-off-by: Daniele Di Proietto <diproiettod@vmware.com>
---
 AUTHORS      |  1 +
 acinclude.m4 | 76 +++++++++++++++++++++++++++++++++++++++++-------------------
 2 files changed, 53 insertions(+), 24 deletions(-)

diff --git a/acinclude.m4 b/acinclude.m4
index f345c31..acd7ce7 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -163,27 +163,50 @@ AC_DEFUN([OVS_CHECK_DPDK], [
               [AC_HELP_STRING([--with-dpdk=/path/to/dpdk],
                               [Specify the DPDK build directory])])
 
-  if test X"$with_dpdk" != X; then
-    RTE_SDK=$with_dpdk
+  AC_MSG_CHECKING([whether dpdk datapath is enabled])
+  if test -z "$with_dpdk" || test "$with_dpdk" = no; then
+    AC_MSG_RESULT([no])
+    DPDKLIB_FOUND=false
+  else
+    AC_MSG_RESULT([yes])
+    case "$with_dpdk" in
+      yes)
+        DPDK_AUTO_DISCOVER="true"
+        DPDK_INCLUDE="/usr/local/include/dpdk -I/usr/include/dpdk"
+        ;;
+      *)
+        DPDK_AUTO_DISCOVER="false"
+        DPDK_INCLUDE="$with_dpdk/include"
+        # If 'with_dpdk' is passed install directory, point to headers
+        # installed in $DESTDIR/$prefix/include/dpdk
+        AC_CHECK_FILE([$DPDK_INCLUDE/rte_config.h], [],
+                      [AC_CHECK_FILE([$DPDK_INCLUDE/dpdk/rte_config.h],
+                                     [DPDK_INCLUDE=$DPDK_INCLUDE/dpdk], [])])
+        DPDK_LIB_DIR="$with_dpdk/lib"
+        ;;
+    esac
 
-    DPDK_INCLUDE=$RTE_SDK/include
-    DPDK_LIB_DIR=$RTE_SDK/lib
     DPDK_LIB="-ldpdk"
     DPDK_EXTRA_LIB=""
-    RTE_SDK_FULL=`readlink -f $RTE_SDK`
-
-    AC_COMPILE_IFELSE(
-      [AC_LANG_PROGRAM([#include <$RTE_SDK_FULL/include/rte_config.h>
-#if !RTE_LIBRTE_VHOST_USER
-#error
-#endif], [])],
-                    [], [AC_DEFINE([VHOST_CUSE], [1], [DPDK vhost-cuse support enabled, vhost-user disabled.])
-                         DPDK_EXTRA_LIB="-lfuse"])
 
     ovs_save_CFLAGS="$CFLAGS"
     ovs_save_LDFLAGS="$LDFLAGS"
-    LDFLAGS="$LDFLAGS -L$DPDK_LIB_DIR"
     CFLAGS="$CFLAGS -I$DPDK_INCLUDE"
+    if test "$DPDK_AUTO_DISCOVER" = "false"; then
+      LDFLAGS="$LDFLAGS -L${DPDK_LIB_DIR}"
+    fi
+
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM(
+        [
+          #include <rte_config.h>
+#if !RTE_LIBRTE_VHOST_USER
+#error
+#endif
+        ], [])
+      ], [],
+      [AC_DEFINE([VHOST_CUSE], [1], [DPDK vhost-cuse support enabled, vhost-user disabled.])
+       DPDK_EXTRA_LIB="-lfuse"])
 
     # On some systems we have to add -ldl to link with dpdk
     #
@@ -192,7 +215,7 @@ AC_DEFUN([OVS_CHECK_DPDK], [
     # Before each attempt the search cache must be unset,
     # otherwise autoconf will stick with the old result
 
-    found=false
+    DPDKLIB_FOUND=false
     save_LIBS=$LIBS
     for extras in "" "-ldl"; do
         LIBS="$DPDK_LIB $extras $save_LIBS $DPDK_EXTRA_LIB"
@@ -201,17 +224,25 @@ AC_DEFUN([OVS_CHECK_DPDK], [
                              #include <rte_eal.h>],
                             [int rte_argc; char ** rte_argv;
                              rte_eal_init(rte_argc, rte_argv);])],
-           [found=true])
-        if $found; then
+           [DPDKLIB_FOUND=true])
+        if $DPDKLIB_FOUND; then
             break
         fi
     done
-    if $found; then :; else
-        AC_MSG_ERROR([cannot link with dpdk])
+
+    # If linking unsuccessful
+    if test "$DPDKLIB_FOUND" = "false" ; then
+      if $DPDK_AUTO_DISCOVER; then
+        AC_MSG_ERROR([Could not find DPDK library in default search path, Use --with-dpdk to specify the DPDK library installed in non-standard location])
+      else
+        AC_MSG_ERROR([Could not find DPDK libraries in $DPDK_LIB_DIR])
+      fi
     fi
     CFLAGS="$ovs_save_CFLAGS"
     LDFLAGS="$ovs_save_LDFLAGS"
-    OVS_LDFLAGS="$OVS_LDFLAGS -L$DPDK_LIB_DIR"
+    if test "$DPDK_AUTO_DISCOVER" = "false"; then
+      OVS_LDFLAGS="$OVS_LDFLAGS -L$DPDK_LIB_DIR"
+    fi
     OVS_CFLAGS="$OVS_CFLAGS -I$DPDK_INCLUDE"
     OVS_ENABLE_OPTION([-mssse3])
 
@@ -226,12 +257,9 @@ AC_DEFUN([OVS_CHECK_DPDK], [
     DPDK_vswitchd_LDFLAGS=-Wl,--whole-archive,$DPDK_LIB,--no-whole-archive
     AC_SUBST([DPDK_vswitchd_LDFLAGS])
     AC_DEFINE([DPDK_NETDEV], [1], [System uses the DPDK module.])
-
-  else
-    RTE_SDK=
   fi
 
-  AM_CONDITIONAL([DPDK_NETDEV], test -n "$RTE_SDK")
+  AM_CONDITIONAL([DPDK_NETDEV], test "$DPDKLIB_FOUND" = true)
 ])
 
 dnl OVS_GREP_IFELSE(FILE, REGEX, [IF-MATCH], [IF-NO-MATCH])
-- 
2.8.2