From cf2a78cbbb463d5716da9805c8fc5758937924d8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alex=20Benn=C3=A9e?= <alex.bennee@linaro.org>
Date: Mon, 16 Sep 2024 09:53:43 +0100
Subject: deprecation: don't enable TCG plugins by default on 32 bit hosts
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The existing plugins already liberally use host pointer stuffing for
passing user data which will fail when doing 64 bit guests on 32 bit
hosts. We should discourage this by officially deprecating support and
adding another nail to the 32 bit host coffin.

Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240916085400.1046925-2-alex.bennee@linaro.org>
---
 configure | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

(limited to 'configure')

diff --git a/configure b/configure
index f3e7572afb..cc8e1ed5b8 100755
--- a/configure
+++ b/configure
@@ -516,6 +516,25 @@ case "$cpu" in
     ;;
 esac
 
+# Now we have our CPU_CFLAGS we can check if we are targeting a 32 or
+# 64 bit host.
+
+check_64bit_host() {
+cat > $TMPC <<EOF
+#if __SIZEOF_POINTER__ != 8
+#error not 64 bit system
+#endif
+int main(void) { return 0; }
+EOF
+  compile_object "$1"
+}
+
+if check_64bit_host "$CPU_CFLAGS"; then
+    host_bits=64
+else
+    host_bits=32
+fi
+
 if test -n "$host_arch" && {
     ! test -d "$source_path/linux-user/include/host/$host_arch" ||
     ! test -d "$source_path/common-user/host/$host_arch"; }; then
@@ -1028,7 +1047,7 @@ if test "$static" = "yes" ; then
   fi
   plugins="no"
 fi
-if test "$plugins" != "no"; then
+if test "$plugins" != "no" && test $host_bits -eq 64; then
   plugins=yes
   subdirs="$subdirs contrib/plugins"
 fi
-- 
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