Am 13.08.2013 16:54, schrieb Paolo Bonzini: > Il 13/08/2013 16:11, Anthony Liguori ha scritto: >>>> Fix this up, clean up a trivial code duplication >>>> and add a comment explaining why we special-case 1.5 >>>> with respect to pvpanic. >>>> >>>> Reported-by: Markus Armbruster <arm...@redhat.com> >>>> Signed-off-by: Michael S. Tsirkin <m...@redhat.com> >> Thanks for catching this. I'm a little disturbed by this. I use git-am >> --3way specifically to avoid problems from fuzzing but I guess merge >> artifacts are possible. >> > > I wonder if we shouldn't disable pvpanic in 1.5 too, one-off behavior is > ugly and likely no one will notice.
I had rejected the previous attempt to completely disable pvpanic device because it looked to me as if this compatibility aspect had been forgotten. I didn't imagine the resulting code to look as ugly though, with us "skipping" _1_5 to not have 1.5 overwrite has_pvpanic for 1.6+. mst suggested to patch stable-1.5 to disable it there, too. I am not against but have doubts as to how well that works with migration, since 1.5.3 is still a bit off and I would expect 1.5.2 -> 1.6.0 migration to work without guest-visible changes... We could argue that having to use -M pc-i440fx-1.5 we can also expect users to add -device pvpanic; question would be how to convey that knowledge of if-you-use-pc-x.y-then-you-also-need-to-do-Z to users, which compat_props usually handle under the hood. We could misuse pvpanic.ioport=0 for that purpose until we have a better solution. Regards, Andreas -- SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg
