On Sat, Jul 24, 2010 at 09:35:44AM +0900, Jun Koi wrote: > On Sat, Jul 24, 2010 at 2:53 AM, Aurelien Jarno <aurel...@aurel32.net> wrote: > > On Fri, Jul 23, 2010 at 08:59:54PM +0900, Jun Koi wrote: > >> Hi, > >> > >> I am looking at the save_globals() of TCG code, and it seems this > >> function saves regular registers like EAX, ..., EDI back to CPU state. > >> > >> But I am not sure if it also saves value of other registers, like > >> EFlags, Segments, CR*, DR*, ... (?) > >> From what I saw, it doesnt seem to do so. Is it correct? > >> > > > > save_globals() is run before calling a function that can trigger a CPU > > exception, to make sure that in that case all TCG variables are synced > > with the CPU state. > > Is it correct? I always assume that save_globals() is also called at > end of each block.
Correct also here. > > > > Given the CPU state only uses "normal" registers, there is no need to > > save the other registers. > > Why do you say that CPU state includes only normal registers, given > that, like on x86, CPUState has also segs[], cr[] and dr[]? > > > > Another question: if save_globals() only saves regular registers, > where Qemu saves other registers like segs[], cr[]? Or do they always > sync, all the time? It's actually the same question. You are mixing host and target registers. save_globals() only saves "normal" host registers. Host registers can then contain whatever registers from the target, and more precisely the one declared as globals. > Finally, how about Eflags? I remember that Eflags is "lazy sync", but > does it sync at end of each block? > It's the same. Eflags are actually stored in a lazy way in cc_* globals. They are therefore synced with save_globals(). -- Aurelien Jarno GPG: 1024D/F1BCDB73 aurel...@aurel32.net http://www.aurel32.net
