Re: [Qemu-devel] TSC in qem[-kvm] 1.1+ and in-kernel irqchip

[Jan Kiszka <jan.kiszka@siemens.com>]

On 2012-08-13 15:16, Michael Tokarev wrote:
> On 13.08.2012 17:07, Jan Kiszka wrote:
> []
>>> The bisecion leads to this commit:
>>>
>>> commit 17ee47418e65b1593defb30edbab33ccd47fc1f8
>>> Merge: 13b0496 5d17c0d
>>> Author: Jan Kiszka <jan.kiszka@siemens.com>
>>> Date:   Tue Apr 10 16:26:23 2012 +0200
>>>
>>>     Merge commit '5d17c0d2df4998598e6002b27b8e47e792899a0f' into queues/qemu-merge
> []
>>> Cc'ing Jan for help.  The short story: tsc timer calibration
>>> broke in 1.1+ with in-kernel irqchip (only) for several
>>> apps (seabios and grub are two examples), the time is ticking
>>> about 100 times faster.  In grub the timer is calibrated
>>> using pit.  The above commit is the result of bisection.
>>
>> Did the versions you tested include the commit 0cdd3d1444 (kvm: i8254:
>> Fix conversion of in-kernel to userspace state)?
> 
> While bisecting I didn't have this commit applied, since it were
> applied past (qemu)-1.1.  It is included into qemu-kvm 1.1.0
> (as 960d355dc60d9), and that version behaves _exactly_ the same -
> the time in grub is ticking 100 times faster.  I mentioned in this
> thread that the problem persists in current qemu (and qemu-kvm)
> git too.
> 
> I can repeat the bisection with this commit applied after the
> above "bad" commit.  Should I?

Don't think this will make a difference. There is some other issue. I
reproduced the bug, will see if I can analyze it.

Jan

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