On Mon, Aug 05, 2013 at 11:16:17AM +0300, Gleb Natapov wrote: > On Mon, Aug 05, 2013 at 11:10:55AM +0300, Michael S. Tsirkin wrote: > > On Mon, Aug 05, 2013 at 03:47:23PM +0800, Hu Tao wrote: > > > pvpanic device is an internal default device in qemu. It may cause > > > problem when upgrading qemu from a version without pvpanic. > > > > > > 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. On a cluster with hundreds of such VMs, If that cluster has > > > a health monitoring service it may show all the VMs in a "not healthy" > > > state. > > > > > > This patch is a workaround to not show pvpanic in UI to avoid the > > > problem in Windows. > > > > > > Cc: Marcel Apfelbaum <marce...@redhat.com> > > > Cc: "Michael S. Tsirkin" <m...@redhat.com> > > > Cc: Paolo Bonzini <pbonz...@redhat.com> > > > Cc: Gerd Hoffmann <kra...@redhat.com> > > > Cc: Eric Blake <ebl...@redhat.com> > > > Cc: "Daniel P. Berrange" <berra...@redhat.com> > > > Cc: Andreas Färber <afaer...@suse.de> > > > Signed-off-by: Hu Tao <hu...@cn.fujitsu.com> > > > > Quoting from this discussion: > > >That may "fix" the issue of a windows guest showing the yellow ! mark, > > >but what if, down the road, someone writes an actual windows driver > > that > > >is aware of that port and how to make a windows BSOD write a panic > > >notification to the port? How does a user go about installing such a > > >driver if the device is not exposed in the user interface list of > > >devices? > > > > I think the correct way to address this is: > > - don't create the device by default, only when -device pvpanic is > > present > > - teach management to supply said -device pvpanic for guests which > > support the pvpanic device > > > That's just pushing the problem elsewhere. How management suppose to know if > guest support pvpanic device?
Same as any PV device really. It's exactly the same problem as with virtio: user configures the XML properly. > What if initially guest did not have a > driver, but the it was installed? You can reconfigure XML and reboot. > If device appears for old machine > models this is bug, otherwise I fail to see any problem. Care answering the question that Eric Blake posed (above)? > -- > Gleb. _______________________________________________ SeaBIOS mailing list SeaBIOS@seabios.org http://www.seabios.org/mailman/listinfo/seabios
