@@ -405,6 +405,7 @@ EXESUF=""
DSOSUF=".so"
LDFLAGS_SHARED="-shared"
modules="no"
+module_upgrades="no"
prefix="/usr/local"
mandir="\${prefix}/share/man"
datadir="\${prefix}/share"
@@ -1032,6 +1033,10 @@ for opt do
--disable-modules)
modules="no"
;;
+ --disable-module-upgrades) module_upgrades="no"
+ ;;
+ --enable-module-upgrades) module_upgrades="yes"
+ ;;
--cpu=*)
;;
--target-list=*) target_list="$optarg"
@@ -1786,6 +1791,7 @@ disabled with --disable-FEATURE, default is enabled if available:
guest-agent-msi build guest agent Windows MSI installation package
pie Position Independent Executables
modules modules support (non-Windows)
+ module-upgrades try to load modules from alternate paths for upgrades
debug-tcg TCG debugging (default is disabled)
debug-info debugging information
sparse sparse checker
@@ -2049,6 +2055,11 @@ if test "$modules" = "yes" && test "$mingw32" = "yes" ; then
error_exit "Modules are not available for Windows"
fi
+# module_upgrades is only reasonable if modules are enabled
+if test "$modules" = "no" && test "$module_upgrades" = "yes" ; then
+ error_exit "Can't enable module-upgrades as Modules are not enabled"
+fi
+
# Static linking is not possible with modules or PIE
if test "$static" = "yes" ; then
if test "$modules" = "yes" ; then
@@ -6584,6 +6595,7 @@ if test "$slirp" != "no" ; then
echo "smbd $smbd"
fi
echo "module support $modules"
+echo "alt path mod load $module_upgrades"
echo "host CPU $cpu"
echo "host big endian $bigendian"
echo "target list $target_list"
@@ -6937,6 +6949,9 @@ if test "$modules" = "yes"; then
echo "CONFIG_STAMP=_$( (echo $qemu_version; echo $pkgversion; cat $0) | $shacmd - | cut -f1 -d\ )" >> $config_host_mak
echo "CONFIG_MODULES=y" >> $config_host_mak
fi
+if test "$module_upgrades" = "yes"; then
+ echo "CONFIG_MODULE_UPGRADES=y" >> $config_host_mak
+fi
if test "$have_x11" = "yes" && test "$need_x11" = "yes"; then
echo "CONFIG_X11=y" >> $config_host_mak
echo "X11_CFLAGS=$x11_cflags" >> $config_host_mak
@@ -19,6 +19,9 @@
#endif
#include "qemu/queue.h"
#include "qemu/module.h"
+#ifdef CONFIG_MODULE_UPGRADES
+#include "qemu-version.h"
+#endif
typedef struct ModuleEntry
{
@@ -170,6 +173,9 @@ bool module_load_one(const char *prefix, const char *lib_name)
#ifdef CONFIG_MODULES
char *fname = NULL;
char *exec_dir;
+#ifdef CONFIG_MODULE_UPGRADES
+ char *version_dir;
+#endif
const char *search_dir;
char *dirs[4];
char *module_name;
@@ -201,6 +207,14 @@ bool module_load_one(const char *prefix, const char *lib_name)
dirs[n_dirs++] = g_strdup_printf("%s", CONFIG_QEMU_MODDIR);
dirs[n_dirs++] = g_strdup_printf("%s/..", exec_dir ? : "");
dirs[n_dirs++] = g_strdup_printf("%s", exec_dir ? : "");
+
+#ifdef CONFIG_MODULE_UPGRADES
+ version_dir = g_strcanon(g_strdup(QEMU_PKGVERSION),
+ G_CSET_A_2_Z G_CSET_a_2_z G_CSET_DIGITS "+-.~",
+ '_');
+ dirs[n_dirs++] = g_strdup_printf("/var/run/qemu/%s", version_dir);
+#endif
+
assert(n_dirs <= ARRAY_SIZE(dirs));
g_free(exec_dir);
On upgrades the old .so files usually are replaced. But on the other hand since a qemu process represents a guest instance it is usually kept around. That makes late addition of dynamic features e.g. 'hot-attach of a ceph disk' fail by trying to load a new version of e.f. block-rbd.so into an old still running qemu binary. This adds a fallback to also load modules from a versioned directory in the temporary /var/run path. That way qemu is providing a way for packaging to store modules of an upgraded qemu package as needed until the next reboot. An example how that can then be used in packaging can be seen in: https://git.launchpad.net/~paelzer/ubuntu/+source/qemu/log/?h=bug-1847361-miss-old-so-on-upgrade-UBUNTU Fixes: https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/1847361 Signed-off-by: Christian Ehrhardt <christian.ehrhardt@canonical.com> --- configure | 15 +++++++++++++++ util/module.c | 14 ++++++++++++++ 2 files changed, 29 insertions(+)