On Tue, Feb 25, 2020 at 10:55:10AM +0100, marcandre.lureau@xxxxxxxxxx wrote: > From: Marc-André Lureau <marcandre.lureau@xxxxxxxxxx> > > Signed-off-by: Marc-André Lureau <marcandre.lureau@xxxxxxxxxx> > --- > src/qemu/qemu_process.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c > index 8c1ed76677..3a6cb4b2b0 100644 > --- a/src/qemu/qemu_process.c > +++ b/src/qemu/qemu_process.c > @@ -58,6 +58,7 @@ > #include "qemu_extdevice.h" > #include "qemu_firmware.h" > #include "qemu_backup.h" > +#include "qemu_dbus.h" > > #include "cpu/cpu.h" > #include "cpu/cpu_x86.h" > @@ -6480,6 +6481,9 @@ qemuProcessPrepareHost(virQEMUDriverPtr driver, > qemuDomainObjPrivatePtr priv = vm->privateData; > g_autoptr(virQEMUDriverConfig) cfg = virQEMUDriverGetConfig(driver); > > + if (qemuDBusPrepareHost(driver) < 0) > + return -1; This launches dbus unconditionally for every VM regardless of whether its actually going to be used. There is certainly a nice conceptual simplicity in doing this, but I'm pretty concerned that there are going to be mgmt apps which do not like this extra overhead being added for every VM. I'm thinking KubeVirt and Kata containers in particular. This is also relevant for the libvirt embedded driver which is trying to eliminate all libvirt added overhead on managing QEMU, so that our fastest QEMU startup time can match that achieved by running QEMU directly. Unconditionally starting dbus will make that much more challenging. This is a long winded way of saying I think we need to do this only when it is actually required. This will certainly add complexity as we'll need to cope with dynamically launching DBus when we hotplug certain types of device which require it. I think we can ignore the hot-unplug case at least, as once you've taken the overhead for DBus for the VM, I don't think there's much to complain about, even if the device using it is unplugged. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
