Add hard build dependency on glib

GLib is an extremely common library that has a portable thread implementation
along with tons of other goodies.

GLib and GObject have a fantastic amount of infrastructure we can leverage in
QEMU including an object oriented programming infrastructure.

Short term, it has a very nice thread pool implementation that we could leverage
in something like virtio-9p.  It also has a test harness implementation that
this series will use.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@gmail.com>
diff --git a/configure b/configure
index e57efb1..c0c8fdf 100755
--- a/configure
+++ b/configure
@@ -1803,6 +1803,18 @@
 fi
 
 ##########################################
+# glib support probe
+if $pkg_config --modversion gthread-2.0 gio-2.0 > /dev/null 2>&1 ; then
+    glib_cflags=`$pkg_config --cflags gthread-2.0 gio-2.0 2>/dev/null`
+    glib_libs=`$pkg_config --libs gthread-2.0 gio-2.0 2>/dev/null`
+    libs_softmmu="$glib_libs $libs_softmmu"
+    libs_tools="$glib_libs $libs_tools"
+else
+    echo "glib-2.0 required to compile QEMU"
+    exit 1
+fi
+
+##########################################
 # pthread probe
 PTHREADLIBS_LIST="-lpthread -lpthreadGC2"
 
@@ -2849,6 +2861,7 @@
   echo "CONFIG_BLUEZ=y" >> $config_host_mak
   echo "BLUEZ_CFLAGS=$bluez_cflags" >> $config_host_mak
 fi
+echo "GLIB_CFLAGS=$glib_cflags" >> $config_host_mak
 if test "$xen" = "yes" ; then
   echo "CONFIG_XEN_BACKEND=y" >> $config_host_mak
   echo "CONFIG_XEN_CTRL_INTERFACE_VERSION=$xen_ctrl_version" >> $config_host_mak