Re: [Qemu-ppc] system-ppcemb -M bamboo, troubles with RTC

[Alexander Graf]

Hi Nello,

On 01.07.2013, at 03:29, nello martuscielli wrote:

> On Sun, Jun 30, 2013 at 2:26 PM, Alexander Graf <address@hidden> wrote:
>> 
>> Hi Nello,
>> 
>> On 30.06.2013, at 12:01, nello martuscielli wrote:
>> 
>> hi, i'm giving a try to have a working qemu-system-ppcemb -M bamboo but i've 
>> some troubles how to set RTC . I'm using qemu-1.5.1 on a real PowerPC 32bit 
>> machine (iBook G4).
>> 
>> 
>> Phew. That must be terribly slow. I'd certainly recommend a recent x86 
>> machine as the host if you want to actually work with your guest. Running on 
>> a PPC host in TCG mode (emulation) doesn't really buy you anything.
>> 
> 
> hallo Alexander,
> 
> indeed it's quite slow. I hoped to use TCG and/or KVM but if i try to
> build qemu-1.5.1 with --enable-tcg-interpreter i get:

The TCG interpreter is an even slower variant of TCG :). You really don't want 
that on a G4.

> 
> [...]
> CC    hw/virtio/dataplane/vring.o
>  GEN   ppc-softmmu/hmp-commands.h
>  GEN   ppc-softmmu/qmp-commands-old.h
>  GEN   ppc-softmmu/config-target.h
>  CC    ppc-softmmu/exec.o
>  CC    ppc-softmmu/translate-all.o
>  CC    ppc-softmmu/cpu-exec.o
>  CC    ppc-softmmu/tcg/tcg.o
> In file included from 
> /home/ports/Qemu/qemu/work/src/qemu-1.5.1/tcg/tcg.h:49:0,
>                 from 
> /home/ports/Qemu/qemu/work/src/qemu-1.5.1/tcg/tcg-op.h:24,
>                 from /home/ports/Qemu/qemu/work/src/qemu-1.5.1/tcg/tcg.c:50:
> /home/ports/Qemu/qemu/work/src/qemu-1.5.1/tcg/tci/tcg-target.h:174:20:
> error: redefinition of 'flush_icache_range'
> /home/ports/Qemu/qemu/work/src/qemu-1.5.1/include/qemu/cache-utils.h:18:20:
> note: previous definition of 'flush_icache_range' was here
> make[1]: *** [tcg/tcg.o] Error 1
> make: *** [subdir-ppc-softmmu] Error 2

However, it should compile. CC'ing Stefan.

> 
> and when i try to use -enable-kvm running qemu-system-ppc i get:
> 
> [...]
> KVM: invalid SPR write: 1013
> mtspr: unknown spr 3f5
> Couldn't emulate instruction 0x7c75fba6 (op 31 xop 467)
> kvmppc_handle_exit: emulation at 700 failed (7c75fba6)
> 
> in my host dmesg and a kernel panic booting my guest.

Yes, that is also expected. KVM is only able to do very limited 
cross-virtualization. You can run a G3/G4/Gekko guest on a G5/P7. But that's 
about as far as it goes. 440 is a completely different specification, rendering 
it vastly incompatible with your G4. They are only mostly compatible from a 
user space perspective.

So if you want to use KVM on your G4, I'd be more than happy to see you doing 
so, but please use -M g3beige or -M mac99 with -cpu G3 or G4 :).


Alex