Segher Boessenkool <seg...@kernel.crashing.org> writes: > Hi! > > On Fri, Nov 26, 2021 at 09:34:44AM +0100, Cédric Le Goater wrote: >> On 11/25/21 10:38, Segher Boessenkool wrote: >> >On Thu, Nov 25, 2021 at 01:45:00AM +0100, BALATON Zoltan wrote: >> >>As for guests, those running on the said PowerMac G4 should have support >> >>for these CPUs so maybe you can try some Mac OS X versions (or maybe >> > >> >OSX uses hardware pagetables. >> > >> >>MorphOS but that is not the best for debugging as there's no source >> >>available nor any help from its owners but just to see if it boots it may >> >>be sufficient, it should work on real PowerMac G4). >> > >> >I have no idea what MorphOS uses, but I bet HPT as well. That is >> >because HPT is fastest in general. Software TLB reloads are good in >> >special cases only; the most common is real-time OSes, which can use its >> >lower guaranteed latency for some special address spaces (and can have a >> >simpler address map in general). >> >> The support was added to QEMU knowing that Linux didn't handle soft TLBs. >> And the commit says that it was kept disabled initially. I guess that was >> broken these last years. > > Ah :-) So when was it enabled, do you know?
Hm.. That commit message does not match the code. They simply added the software TLB implementation to an already existing SOFT_74xx MMU model. I don't see anything that would keep it disabled at that time.