Re: [Qemu-devel] Problem with QEMU on KVM

[Gerhard Wiesinger]

On Sun, 11 Apr 2010, Mulyadi Santosa wrote:

> Hi...
>
> On Sun, Apr 11, 2010 at 03:09, Gerhard Wiesinger <address@hidden> wrote:
> > Hello,
> >
> > Booting DOS 6.22 with NT4 Bootloader works fine. With enabled KVM it boots,
> > but hangs at counting down the boot loader selection menu (30s, 29s, hang).
> > Booting Knoppix 6.2 from CD wwith KVM orks well.
> >
> > Versions (0.12.3):
> > x86_64-softmmu: OK
> > i386-softmmu: OK
> > x86_64-softmmu with -enable-kvm: Boot problem
> > i386-softmmu with -enable-kvm: Boot problem
> >
> > Host is: Fedora 11
> > 2.6.30.10-105.2.23.fc11.x86 on AMD Phenom II Quad Core
>
> IMHO, the problem is, we have to find out first, how the bootloader do
> the timing. Is it using tight loop? Counting from TSC? PIT? or else?
>
> I suggest to dump the executed TB in Qemu. Please read about -d option.
>
> NB: I am not an expert, just trying to help....

OK, uses the following ports:
Port 0x20: 8259 interrupt controller
Port 0x40: 8253 timer

Interrupt 0x1A:
ah=0x00: fetches system timer counters
ah=0x02: reads the clock
ah=0x04: fetches date

So there must be something wrong with KVM with the above functionality (I 
guess the timers).

Ciao,
Gerhard

--
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