As mentioned in LP:1179104 ( https://bugs.launchpad.net/qemu/+bug/1179104 ), there's a segfault bug in qemu process once guest tries to use some TRIM command against an IDE device on PPC. This makes qemu-system-ppc basically unusable with any modern distribution, since mke2fs now issues TRIM commands during install by default. I think it is critical enough bug to warrant some last-minute hunting/fixing, and it'd be a shame to make a release of qemu with this bug.
That's more or less a JFYI for now, but I don't really know what other info is needed, -- I already provided some structures content from a gdb session. Thanks, /mjt