On Thu, 2013-08-01 at 19:31 +0300, Michael S. Tsirkin wrote: > On Thu, Aug 01, 2013 at 10:26:53AM -0600, Eric Blake wrote: > > On 08/01/2013 08:18 AM, Gerd Hoffmann wrote: > > > On 08/01/13 15:08, Marcel Apfelbaum wrote: > > >> Hi, > > >> > > >> The problem with pvpanic being an internal device is that VMs running > > >> operating systems without a driver for this device will have problems > > >> when qemu will be upgraded (from qemu without this pvpanic). > > >> > > >> The outcome may be, for example: in Windows(let's say XP) the Device manager > > >> will open a "new device" wizard and the device will appear as an unrecognized device. > > > > > > Only happens when also changing the machine type on upgrade as it is > > > turned off on old machine types. > > > > > > But, yes, pvpanic will show up as "Unknown device" without driver and > > > with the funky yellow exclamation mark in device manager in windows > > > guests. Newer windows versions don't kick the "new device" wizard. But > > > still I have my doubts that it is a good idea to add it unconditionally ... > > > > Automatic devices with no command line argument have proven to be a > > nightmare for libvirt as well. Although the just-released libvirt 1.1.1 > > now supports the <on_crash> element for controlling the command line > > parameters of qemu related to how qemu will behave when the pvpanic > > device is triggered, I would also welcome having the ability to control > > whether the guest even has a pvpanic device exposed, just as we can > > control whether a guest has a memballoon device exposed. > > > A natural way to do this would be with -device pvpanic. > I'm not sure why it wasn't done like this from the beginning, > but it shouldn't be hard to redo, hopefully we can fix this > bug in time for 1.6. > I'll come up with something, hopefully in time. Marcel -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list