diff --git a/.gitignore b/.gitignore
index 3a7e01dc6a..b5e115d96b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -113,6 +113,7 @@
 /docs/version.texi
 *.tps
 .stgit-*
+.git-submodule-status
 cscope.*
 tags
 TAGS
diff --git a/MAINTAINERS b/MAINTAINERS
index 772ac209e1..bb585bbd8f 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1949,3 +1949,9 @@ M: Daniel P. Berrange <berrange@redhat.com>
 S: Odd Fixes
 F: docs/devel/build-system.txt
 
+Build System
+------------
+GIT submodules
+M: Daniel P. Berrange <berrange@redhat.com>
+S: Odd Fixes
+F: scripts/git-submodule.sh
diff --git a/Makefile b/Makefile
index 97b4508d7d..9866909e08 100644
--- a/Makefile
+++ b/Makefile
@@ -14,6 +14,27 @@ ifneq ($(wildcard config-host.mak),)
 all:
 include config-host.mak
 
+git-submodule-update:
+
+.PHONY: git-submodule-update
+
+ifeq (0,$(MAKELEVEL))
+  git_module_status := $(shell \
+    cd '$(SRC_PATH)' && \
+    ./scripts/git-submodule.sh status $(GIT_SUBMODULES); \
+    echo $$?; \
+  )
+
+ifeq (1,$(git_module_status))
+git-submodule-update:
+	$(call quiet-command, \
+          (cd $(SRC_PATH) && ./scripts/git-submodule.sh update $(GIT_SUBMODULES)), \
+          "GIT","$(GIT_SUBMODULES)")
+endif
+endif
+
+.git-submodule-status: git-submodule-update
+
 # Check that we're not trying to do an out-of-tree build from
 # a tree that's been used for an in-tree build.
 ifneq ($(realpath $(SRC_PATH)),$(realpath .))
@@ -84,6 +105,7 @@ endif
 GENERATED_FILES += $(TRACE_HEADERS)
 GENERATED_FILES += $(TRACE_SOURCES)
 GENERATED_FILES += $(BUILD_DIR)/trace-events-all
+GENERATED_FILES += .git-submodule-status
 
 trace-group-name = $(shell dirname $1 | sed -e 's/[^a-zA-Z0-9]/_/g')
 
@@ -330,7 +352,7 @@ DTC_MAKE_ARGS=-I$(SRC_PATH)/dtc VPATH=$(SRC_PATH)/dtc -C dtc V="$(V)" LIBFDT_src
 DTC_CFLAGS=$(CFLAGS) $(QEMU_CFLAGS)
 DTC_CPPFLAGS=-I$(BUILD_DIR)/dtc -I$(SRC_PATH)/dtc -I$(SRC_PATH)/dtc/libfdt
 
-subdir-dtc:dtc/libfdt dtc/tests
+subdir-dtc: .git-submodule-status dtc/libfdt dtc/tests
 	$(call quiet-command,$(MAKE) $(DTC_MAKE_ARGS) CPPFLAGS="$(DTC_CPPFLAGS)" CFLAGS="$(DTC_CFLAGS)" LDFLAGS="$(LDFLAGS)" ARFLAGS="$(ARFLAGS)" CC="$(CC)" AR="$(AR)" LD="$(LD)" $(SUBDIR_MAKEFLAGS) libfdt/libfdt.a,)
 
 dtc/%:
diff --git a/configure b/configure
index 6587e8014b..38f1710c80 100755
--- a/configure
+++ b/configure
@@ -264,6 +264,7 @@ cc_i386=i386-pc-linux-gnu-gcc
 libs_qga=""
 debug_info="yes"
 stack_protector=""
+git_submodules=""
 
 # Don't accept a target_list environment variable.
 unset target_list
@@ -3584,27 +3585,30 @@ EOF
   if compile_prog "" "$fdt_libs" ; then
     # system DTC is good - use it
     fdt=yes
-  elif test -d ${source_path}/dtc/libfdt ; then
-    # have submodule DTC - use it
-    fdt=yes
-    dtc_internal="yes"
-    mkdir -p dtc
-    if [ "$pwd_is_source_path" != "y" ] ; then
-       symlink "$source_path/dtc/Makefile" "dtc/Makefile"
-       symlink "$source_path/dtc/scripts" "dtc/scripts"
-    fi
-    fdt_cflags="-I\$(SRC_PATH)/dtc/libfdt"
-    fdt_libs="-L\$(BUILD_DIR)/dtc/libfdt $fdt_libs"
-  elif test "$fdt" = "yes" ; then
-    # have neither and want - prompt for system/submodule install
-    error_exit "DTC (libfdt) version >= 1.4.2 not present. Your options:" \
-        "  (1) Preferred: Install the DTC (libfdt) devel package" \
-        "  (2) Fetch the DTC submodule, using:" \
-        "      git submodule update --init dtc"
   else
-    # don't have and don't want
-    fdt_libs=
-    fdt=no
+      # have GIT checkout, so activate dtc submodule
+      if test -e "${source_path}/.git" ; then
+          git_submodules="${git_submodules} dtc"
+      fi
+      if test -d "${source_path}/dtc/libfdt" || test -e "${source_path}/.git" ; then
+          fdt=yes
+          dtc_internal="yes"
+          mkdir -p dtc
+          if [ "$pwd_is_source_path" != "y" ] ; then
+              symlink "$source_path/dtc/Makefile" "dtc/Makefile"
+              symlink "$source_path/dtc/scripts" "dtc/scripts"
+          fi
+          fdt_cflags="-I\$(SRC_PATH)/dtc/libfdt"
+          fdt_libs="-L\$(BUILD_DIR)/dtc/libfdt $fdt_libs"
+      elif test "$fdt" = "yes" ; then
+          # Not a git build & no libfdt found, prompt for system install
+          error_exit "DTC (libfdt) version >= 1.4.2 not present." \
+                     "Please install the DTC (libfdt) devel package"
+      else
+          # don't have and don't want
+          fdt_libs=
+          fdt=no
+      fi
   fi
 fi
 
@@ -5295,6 +5299,7 @@ echo "local state directory   queried at runtime"
 echo "Windows SDK       $win_sdk"
 fi
 echo "Source path       $source_path"
+echo "GIT submodules    $git_submodules"
 echo "C compiler        $cc"
 echo "Host C compiler   $host_cc"
 echo "C++ compiler      $cxx"
@@ -5483,6 +5488,7 @@ echo "extra_cxxflags=$EXTRA_CXXFLAGS" >> $config_host_mak
 echo "extra_ldflags=$EXTRA_LDFLAGS" >> $config_host_mak
 echo "qemu_localedir=$qemu_localedir" >> $config_host_mak
 echo "libs_softmmu=$libs_softmmu" >> $config_host_mak
+echo "GIT_SUBMODULES=$git_submodules" >> $config_host_mak
 
 echo "ARCH=$ARCH" >> $config_host_mak
 
diff --git a/scripts/git-submodule.sh b/scripts/git-submodule.sh
new file mode 100755
index 0000000000..d8fbc7e47e
--- /dev/null
+++ b/scripts/git-submodule.sh
@@ -0,0 +1,38 @@
+#!/bin/sh
+#
+# This code is licensed under the GPL version 2 or later.  See
+# the COPYING file in the top-level directory.
+
+set -e
+
+substat=".git-submodule-status"
+
+command=$1
+shift
+modules="$@"
+
+if test -z "$modules"
+then
+    test -e $substat || touch $substat
+    exit 0
+fi
+
+if ! test -e ".git"
+then
+    echo "$0: unexpectedly called with submodules but no git checkout exists"
+    exit 1
+fi
+
+case "$command" in
+status)
+    test -f "$substat" || exit 1
+    trap "rm -f ${substat}.tmp" EXIT
+    git submodule status $modules > "${substat}.tmp"
+    diff "${substat}" "${substat}.tmp" >/dev/null
+    exit $?
+    ;;
+update)
+    git submodule update --init $modules 1>/dev/null 2>&1
+    git submodule status $modules > "${substat}"
+    ;;
+esac