Re: [Qemu-devel] irq latency and tcg

[Artyom Tarasenko]

2009/12/7 Paul Brook <address@hidden>:
> On Monday 07 December 2009, Artyom Tarasenko wrote:
>> Can it be that qemu (-system-sparc in my case, but I guess it's more
>> or less similar on all platforms) reacts to irqs slower than a real
>> hardware due to tcg optimizations?
>
> Interrupts generally only trigger at branch instructions, or similar.
>
> Using -icount should give you precise interrupt delivery.

That's what I thought, but as I reported a few days ago, I couldn't
find a good value for icount when using OBP.
I tried a few values but keep getting "qemu: fatal: Raised interrupt
while not in I/O function".
Also I got a report from other person where qemu crashed with another
message: "qemu: fatal: Trap 0x29 while interrupts disabled".

What could be a good value for -icount? Is it host-cpu specific? Isn't
it a bug that qemu crashes [at least] on some icount values?