Re: [Qemu-devel] QEMU with KVM does not start Win8 on kernel 3.4.67 and core2duo

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

On 2014-09-12 19:15, Jan Kiszka wrote:
> On 2014-09-12 14:29, Erik Rull wrote:
>>> On September 11, 2014 at 3:32 PM Jan Kiszka <jan.kiszka@siemens.com> wrote:
>>>
>>>
>>> On 2014-09-11 15:25, Erik Rull wrote:
>>>>> On August 6, 2014 at 1:19 PM Erik Rull <erik.rull@rdsoftware.de> wrote:
>>>>>
>>>>>
>>>>> Hi all,
>>>>>
>>>>> I did already several tests and I'm not completely sure what's going wrong,
>>>>> but
>>>>> here my scenario:
>>>>>
>>>>> When I start up QEMU w/ KVM 1.7.0 on a Core2Duo machine running a vanilla
>>>>> kernel
>>>>> 3.4.67 to run a Windows 8.0 guest, the guest freezes at boot without any
>>>>> error.
>>>>> When I dump the CPU registers via "info registers", nothing changes, that
>>>>> means
>>>>> the system really stalled. Same happens with QEMU 2.0.0.
>>>>>
>>>>> But - when I run the very same guest using Kernel 2.6.32.12 and QEMU 1.7.0
>>>>> on
>>>>> the host side it works on the Core2Duo. Also the system above but just with
>>>>> an
>>>>> i3 or i5 CPU it works, too.
>>>>>
>>>>> I already disabled networking and USB for the guest and changed the
>>>>> graphics
>>>>> card - no effect. I assume that some mean bits and bytes have to be set up
>>>>> properly to get the thing running.
>>>>>
>>>>> Any hint what to change / test would be really appreciated.
>>>>>
>>>>> Thanks in advance,
>>>>>
>>>>> Best regards,
>>>>>
>>>>> Erik
>>>>>
>>>>
>>>> Hi all,
>>>>
>>>> I opened a qemu bug report on that and Jan helped me creating a kvm trace. I
>>>> attached it to the bug report.
>>>> https://bugs.launchpad.net/qemu/+bug/1366836
>>>>
>>>> If you have further questions, please let me know.
>>>
>>> "File possibly truncated. Need at least 346583040, but file size is
>>> 133414912."
>>>
>>> Does "trace-cmd report" work for you? Is your file larger?
>>>
>>> Again, please also validate the behavior on latest next branch from kvm.git.
>>>
>>> Jan
>>>
>>
>> Hi all,
>>
>> confirmed. The issue is still existing in the kvm.git Version of the kernel.
>> The trace.tgz was uploaded to the bugtracker.
> 
> Thanks. Could you provide a good-case of your setup as well, i.e. with
> that older kernel version? At least I'm not yet seeing something
> obviously wrong.

Well, except that we have continuously EXTERNAL_INTERRUPTs, vector 0xf6,
throughout most of the trace. Maybe a self-IPI (this is single-core),
maybe something external that is stuck. You could do a full trace (-e
all) and check for what happens after things like

kvm_exit: reason EXTERNAL_INTERRUPT rip 0x8168ed83 info 0 800000ef

Jan

-- 
Siemens AG, Corporate Technology, CT RTC ITP SES-DE
Corporate Competence Center Embedded Linux