On Tue, Aug 06, 2013 at 11:56:11AM +0200, Markus Armbruster wrote: > Andreas Färber <afaer...@suse.de> writes: > > > Am 06.08.2013 10:36, schrieb Gleb Natapov: > >> On Tue, Aug 06, 2013 at 11:33:10AM +0300, Michael S. Tsirkin wrote: > >>> On Tue, Aug 06, 2013 at 10:21:52AM +0300, Gleb Natapov wrote: > >>>>> If you see a mouse in a room, how likely is it that there's > >>>>> a single mouse there? > >>>>> > >>>>> This is a PV technology which to me looks like it was > >>>>> rushed through and not only set on by default, but > >>>>> without a way to disable it - apparently on the assumption > >>>>> there's 0 chance it can cause any damage. Now that > >>>>> we do know the chance it's not there, why not go back > >>>>> to the standard interface, and why not give > >>>>> users a chance to enable/disable it? > >>>> You should be able to disable it with: -device pvpanic,ioport=0 > >>> > >>> Doesn't work for me. > >> Bug that should be fixed. With this command line _STA should return > >> zero. > >> > >>> Besides, both -device pvpanic and use of ioport=0 to disable it > >>> are completely undocumented. > >>> > >> Not the only undocumented thing in QEMU command line :) > > [snip] > > > > I disagree: -device adds a device, not removes one. It will still be > > present. > > > > I am neutral as to whether qemu-system-x86_64 should have it enabled by > > default or not. > > Me too.
In general, me neither. But we have -device to add a device, it's nicely self-documenting, We don't have -nodevice to remove a device except the big -nodefaults, and -nodefaults is not self-documenting, and it's not clear how it can be made self-documenting.
