On 10/08/15 13:34, Peter Maydell wrote: > This patchset updates target-sparc to use VMStateDescription > rather than hand-written save/load functions. (This and CRIS > are the last two targets still using the old approach.) > > It's based on some patches from back in 2012 by Juan which > I've updated, rebased and made some tweaks to. > > This is a migration compatibility break; we don't care about > cross-version migration on SPARC guests, and not having to > maintain the old wire format allows a cleaner vmstate > description in several ways. > > NB that the 'split cpu_put_psr' patch seems to me to be a > bugfix in and of itself, since currently we might try to > call cpu_check_irqs() and deliver interrupts while we're > halfway through updating a PSR value... > > Juan Quintela (2): > vmstate: introduce CPU_DoubleU arrays > target-sparc: Convert to VMStateDescription > > Peter Maydell (2): > target-sparc: Split cpu_put_psr into side-effect and no-side-effect > parts > target-sparc: Don't flush TLB in cpu_load function > > hw/sparc64/sun4u.c | 20 --- > include/migration/vmstate.h | 7 + > migration/vmstate.c | 23 +++ > target-sparc/cpu-qom.h | 4 + > target-sparc/cpu.c | 1 + > target-sparc/cpu.h | 7 +- > target-sparc/machine.c | 360 > ++++++++++++++++++++------------------------ > target-sparc/win_helper.c | 19 ++- > 8 files changed, 210 insertions(+), 231 deletions(-)
Hi Peter, Thanks for looking into this! In general the patches look very reasonable (although I will need to give them a more thorough testing when I get a chance) - my only concern is the break in migration compatibility. Am I right in thinking that with this patch applied a loadvm cannot restore a savevm from an earlier version? Not so much for qemu-system-sparc64 which is still somewhat experimental, however qemu-system-sparc has become very usable since 2012 with the advent of the cg3 and OpenBIOS changes that can now run Solaris/SunOS and I do have a slight concern that people could lose their qcow2 snapshots. Then again if we document this loudly in the release notes then I guess it is possible to convert a snapshot back to a raw, boot that and then savevm it back to the newer qcow2 again... ATB, Mark.
