Re: [Qemu-ppc] KVM on PPC host

[Mark Cave-Ayland]

On 16/01/18 12:06, Jd Lyons wrote:

> First, it seems someone changed something in the master in the last few days 
> that broke linking when building on linux PPC.
>
> I pulled the master a few days ago, and it still builds and links fine, but 
> something has broken it now, please fix.
>
>    LINK    ppc-softmmu/qemu-system-ppc
> ../migration/postcopy-ram.o: In function `mark_postcopy_blocktime_end':
> /home/jam/qemu2/qemu-master/migration/postcopy-ram.c:717: undefined reference 
> to `__atomic_fetch_add_8'
> /home/jam/qemu2/qemu-master/migration/postcopy-ram.c:738: undefined reference 
> to `__atomic_fetch_add_8'
> ../migration/postcopy-ram.o: In function `mark_postcopy_blocktime_begin':
> /home/jam/qemu2/qemu-master/migration/postcopy-ram.c:651: undefined reference 
> to `__atomic_exchange_8'
> /home/jam/qemu2/qemu-master/migration/postcopy-ram.c:652: undefined reference 
> to `__atomic_exchange_8'
> /home/jam/qemu2/qemu-master/migration/postcopy-ram.c:661: undefined reference 
> to `__atomic_exchange_8'
> collect2: error: ld returned 1 exit status
> Makefile:193: recipe for target 'qemu-system-ppc' failed
> make[1]: *** [qemu-system-ppc] Error 1
> Makefile:387: recipe for target 'subdir-ppc-softmmu' failed
> make: *** [subdir-ppc-softmmu] Error 2

Unless someone else is aware, you might need to bisect this. Perhaps 
post the above output along with compiler and version to qemu-devel as 
it could easily have been introduced via a non-PPC patch?

> Also, it seems with KVM I can't use -cpu host with qemu-system-ppc or 
> qemu-system-ppc64, I've read a few people on the web where able to use this, 
> but it doesn't work for me on a Powerbook G4 with Debian 8.10 host, with kernel 
> 4.14.13.
>
> qemu-system-ppc64: unable to find CPU model 'host'
> qemu-system-ppc: unable to find CPU model 'host'
>
> Not sure if something changed from older verssions, or I need to add something 
> to ./configure to get -cpu host to work?

Perhaps one of the PPC guys can confirm how/why this has changed?

> Also, using -cpu G4 or -cpu 7410, -cpu G3, -cpu 604, with --enable-kvm results 
> in this when booting the Mac OS 9.2.2 Retail CD:
>
> KVM: unknown exit, hardware reason 80021070
> NIP 0000000000000700   LR 00000000fbf15928 CTR 0000000000000000 XER 
> 0000000020000100 CPU#0
> MSR 0000000000000000 HID0 0000000000000000  HF 0000000000000000 iidx 3 didx 3
> TB 00000000 00000000 DECR 00000000
> GPR00 0000000000000000 000000000fbfe000 0000000000000000 0000000068fff000
> GPR04 0000000068080000 000000000fee5000 0000000000000000 0000000000000000
> GPR08 0000000000000000 0000000000000000 000000006806e908 000000000002d032
> GPR12 000000006806e8b8 0000000000000000 0000000000000000 0000000000004010
> GPR16 0000000000a80000 0000000049610008 0000000068ffffac 0000000068ffffb0
> GPR20 0000000000000000 0000000000000000 0000000000f15eb4 00000000fbf15928
> GPR24 000000000fbfe360 0000000000f1595c 0000000000000057 0000000068ffffac
> GPR28 0000000000f15eb4 000000000fbfe000 00000000b0000023 000000000fbff112
> CR 24202857  [ E  G  E  -  E  L  GO GO ]             RES ffffffffffffffff
> FPR00 0000000000000000 0000000000000000 0000000000000000 0000000000000000
> FPR04 0000000000000000 0000000000000000 0000000000000000 0000000000000000
> FPR08 0000000000000000 0000000000000000 0000000000000000 0000000000000000
> FPR12 0000000000000000 0000000000000000 0000000000000000 0000000000000000
> FPR16 0000000000000000 0000000000000000 0000000000000000 0000000000000000
> FPR20 0000000000000000 0000000000000000 0000000000000000 0000000000000000
> FPR24 0000000000000000 0000000000000000 0000000000000000 0000000000000000
> FPR28 0000000000000000 0000000000000000 0000000000000000 0000000000000000
> FPSCR fff8000000000000
>   SRR0 0000000000f13558  SRR1 0000000000000000    PVR 0000000000080301 VRSAVE 
> 0000000000000000
> SPRG0 000000000fbfe000 SPRG1 000000000fbfe000  SPRG2 0000000000f15eb4  SPRG3 
> 000000000fbfe4e0
> SPRG4 0000000000000000 SPRG5 0000000000000000  SPRG6 0000000000000000  SPRG7 
> 0000000000000000
>   SDR1 000000000fc0001f   DAR 0000000068ffffac  DSISR 0000000042000000
>   
> With --enable-kvm qemu-system-ppc can boot Mac OS X Panther v10.3.0 CD, but installing fails. With Mac OS X Triger 10.4.x it boots and installs, but the install seems to get corrupted. Seems an issue with disk corruption with kvm enabled?
>
> Even when I just use emulation of the G4, without kvm, system won't boot to the 
> 10.3 installer.

Is this under qemu-system-ppc or qemu-system-ppc64? I'm presuming the 
former. Regarding the G4 CPU I'm not sure whether that's a compatible 
setup for the given MacOS version and ROM, but someone else would need 
to confirm...

> Seems there is some bad reversion going on in the latest builds from the master 
> as far as Linux PPC 32bit hosts.

I remember when Alex did the initial MacOS X work back around 2015 he 
seemed confident that things were working well then, so it might be that 
you need to go back a few years to see where things started to go amiss.

Regarding OS 9 IIRC the issue there was related to KVM not supporting 
the correct MMU modes (which is likely given that the new MMU index code 
tended to break OS 9 as it was being developed) so that might require 
some kernel work.

Given that very few people have access to your hardware there's a fair 
chance that you'll need to do quite a bit of the investigation work 
yourself, but there are people around who can point you in the right 
direction.


ATB,

Mark.