[libvirt] [PATCH] qemu: fix improper initialization of cgroupControllers bitmap
virQEMUDriverConfigNew() always initializes the bitmap in its
cgroupControllers member to -1 (i.e. all 1's).
Prior to commit a9331394, if qemu.conf had a line with
"cgroup_controllers", cgroupControllers would get reset to 0 before
going through a loop setting a bit for each named cgroup
controller. commit a9331394 left out the "reset to 0" part, so
cgroupControllers would always be -1; if you didn't want a controller
included, there was no longer a way to make that happen.
This was discovered by users who were using qemu commandline
passthrough to use the "input-linux" method of directing
keyboard/mouse input to a virtual machine:
https://www.redhat.com/archives/vfio-users/2016-April/msg00105.html
Here's the first report I found of the problem encountered after
upgrading libvirt beyond v2.0.0:
https://www.redhat.com/archives/vfio-users/2016-August/msg00053.html
Thanks to sL1pKn07 SpinFlo <sl1pkn07(a)gmail.com> for bringing the
problem up in IRC, and then taking the time to do a git bisect and
find the patch that started the problem.
---
src/qemu/qemu_conf.c | 19 +++++++++++--------
1 file changed, 11 insertions(+), 8 deletions(-)
diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c
index e7b2d8d..dad8334 100644
--- a/src/qemu/qemu_conf.c
+++ b/src/qemu/qemu_conf.c
@@ -613,15 +613,18 @@ int virQEMUDriverConfigLoadFile(virQEMUDriverConfigPtr cfg,
&controllers) < 0)
goto cleanup;
- for (i = 0; controllers != NULL && controllers[i] != NULL; i++) {
- int ctl;
- if ((ctl = virCgroupControllerTypeFromString(controllers[i])) < 0) {
- virReportError(VIR_ERR_CONF_SYNTAX,
- _("Unknown cgroup controller '%s'"),
- controllers[i]);
- goto cleanup;
+ if (controllers) {
+ cfg-> cgroupControllers = 0;
+ for (i = 0; controllers[i] != NULL; i++) {
+ int ctl;
+ if ((ctl = virCgroupControllerTypeFromString(controllers[i])) < 0) {
+ virReportError(VIR_ERR_CONF_SYNTAX,
+ _("Unknown cgroup controller '%s'"),
+ controllers[i]);
+ goto cleanup;
+ }
+ cfg->cgroupControllers |= (1 << ctl);
}
- cfg->cgroupControllers |= (1 << ctl);
}
if (virConfGetValueStringList(conf, "cgroup_device_acl", false,
--
2.7.4