On 27/01/2017 09:52, Paolo Bonzini wrote: > >> This is a port to ppc of the i386 commit: >> 00f4d64 kvmclock: clock should count only if vm is running >> >> We remove timebase_/pre_save/post_load/ functions, >> and use the VM state change handler to save and restore >> the guest_timebase (on stop and continue). >> >> Time base offset has originally been introduced by commit >> 98a8b52 spapr: Add support for time base offset migration >> >> So while VM is paused, the time is stopped. This allows to have >> the same result with date (based on Time Base Register) and >> hwclock (based on "get-time-of-day" RTAS call). >> >> Moreover in TCG mode, the Time Base is always paused, so this >> patch also adjust the behavior between TCG and KVM. >> >> VM state field "time_of_the_day_ns" is now useless but we keep >> it to be able to migrate to older version of the machine. >> >> As vmstate_ppc_timebase structure (with timebase_pre_save() and >> timebase_post_load() functions) was only used by vmstate_spapr, >> we register the VM state change handler only in ppc_spapr_init(). >> >> Signed-off-by: Laurent Vivier <[email protected]> > > I think you should keep the pre_save handler, otherwise after > migration the timebase register will be off by as long as the > time needed to do the final RAM transfer. See commit 6053a86 > ("kvmclock: reduce kvmclock difference on migration", 2016-12-22).
I will. Thank you, Laurent
