Re: [Qemu-devel] [qemu-s390x] [PULL 2/2] iotests: simple mirror test with kvm on 1G image

[Christian Borntraeger]

On 05.12.2018 13:00, Vladimir Sementsov-Ogievskiy wrote:
> 05.12.2018 12:01, Christian Borntraeger wrote:
>>
>>
>> On 05.12.2018 09:46, Kevin Wolf wrote:
>>> Am 05.12.2018 um 09:23 hat Christian Borntraeger geschrieben:
>>>>>>> +# prepare source image
>>>>>>> +qemu_img_create('-f', iotests.imgfmt, '-o', 'preallocation=metadata', 
>>>>>>> disk,
>>>>>>> +                str(size))
>>>>>>> +
>>>>>>> +vm = QEMUMachine(iotests.qemu_prog)
>>>>>>> +vm.add_args('-machine', 'pc,accel=kvm')
>>>>
>>>> This (pc) clearly does not work on other architectures.
>>>> In addition to that, I also need to add -no-shutdown on s390 (see 068 for 
>>>> a similar case)
>>>
>>> Leaving out pc definitely makes sense, and the bug still reproduces for
>>> me without it.
>>>
>>> I don't understand the -no-shutdown, though. Already for 068, neither
>>> the code nor the commit message when it was added explain why this is
>>> needed.
>>>
>>> Can you turn this into a proper patch and add a comment why -no-shutdown
>>> is needed?
>>
>> I already sent this patch. The reason is that there is no BIOS in a 
>> classical sense
>> on s390x. If no bootable image (external kernel or from disk) is found, the 
>> small boot
>> bios loads a disabled wait PSW. The default action for that is then shutdown.
>>
> 
> Is it an option for you just drop the whole line "vm.add_args('-machine', 
> 'pc,accel=kvm')"?
> The problem without it for me was that gdb failed to produce full and nice 
> backtrace, but
> test worked anyway

In the commid message Vladimir said that kvm is necessary to trigger the 
problem.