Re: [Qemu-devel] [PATCH] target/aarch64: exit to main loop after handling MSR

[Paolo Bonzini]

On 14/06/2017 14:35, Alex Bennée wrote:
>> That would cause an unnecessary slowdown in code that runs with
>> interrupts disabled but does a lot of indirect jumps...  ppc's SLOF
>> firmware probably qualifies.
> 
> Really?

Yes. :)  SLOF basically runs a Forth interpreter.  If you run
"qemu-system-ppc64 -d in_asm", you'll see a lot of "bctr" and "bctrl"
instruction (respectively ARM's "br" and "blr" IIRC).

> I'd have to measure the change it makes. Is there a benchmark
> stanza for measuring the PPC slof firmware time?

Just booting.  PPC doesn't have tcg_gen_lookup_and_goto_ptr support yet,
so it would be a theoretical slowdown at this time.

Paolo

> I have 3 patches now which all fix the same thing so we can pick and
> choose which we should apply. Patches incoming...