[Qemu-devel] Re: link failure with s390

[Alexander Graf]

On 13.12.2009, at 23:13, Michael S. Tsirkin wrote:

> On Sun, Dec 13, 2009 at 10:44:04PM +0100, Alexander Graf wrote:
>> 
>> On 13.12.2009, at 21:19, Michael S. Tsirkin wrote:
>> 
>>> On Sun, Dec 13, 2009 at 09:15:30PM +0100, Alexander Graf wrote:
>>>> 
>>>> Am 13.12.2009 um 20:58 schrieb "Michael S. Tsirkin" <address@hidden>:
>>>> 
>>>>> On Sun, Dec 13, 2009 at 08:21:57PM +0100, Alexander Graf wrote:
>>>>>> 
>>>>>> On 13.12.2009, at 20:08, Michael S. Tsirkin wrote:
>>>>>> 
>>>>>>> On Sun, Dec 13, 2009 at 06:30:56PM +0100, Alexander Graf wrote:
>>>>>>>> 
>>>>>>>> On 13.12.2009, at 15:51, Michael S. Tsirkin wrote:
>>>>>>>> 
>>>>>>>>> s390-virtio-bus.o: In function `virtio_s390_notify':
>>>>>>>>> /scm/qemu/hw/s390-virtio-bus.c:310: undefined reference to
>>>>>>>>> `kvm_s390_virtio_irq'
>>>>>>>>> 
>>>>>>>> 
>>>>>>>> Are you sure you're building with --enable-kvm?
>>>>>>> 
>>>>>>> No, I did ./configure --taget-list=s390x-softmmu
>>>>>>> 
>>>>>>>> Currently there's no emulation target for S390.
>>>>>>> 
>>>>>>> So either configure should fail without --enable-kvm,
>>>>>>> or better enable kvm by default.
>>>>>> 
>>>>>> Well, that's why you have to explicitly do --target-list=s390- 
>>>>>> softmmu. I'd love to see S390 bumped to a normal qemu arch with both 
>>>>>> TCG and KVM backends. But for now we don't have that.
>>>>>> 
>>>>>> But yeah, we should probably add some sort of detection to  
>>>>>> configure, so it fails when you're building S390 on non-S390 and w/o 
>>>>>> KVM :-).
>>>>>> 
>>>>>> 
>>>>>> Alex
>>>>> 
>>>>> By the way, where do you get kernel headers for s390
>>>>> which are required to build with --enable-kvm?
>>>>> Which distro ships them?
>>>> 
>>>> Uh, that's just the normal kernel headers, right?
>>>> SLE11 definitely does ship them.
>>> 
>>> kvm has architecture specific defines, does it not?
>> 
>> In files called the same on x86, just with a different asm link.
> 
> Exactly.
> ls -l /usr/src/kernels/2.6.30.8-64.fc11.i586/include/asm lrwxrwxrwx 1 root 
> root 7 2009-10-04 17:53
> /usr/src/kernels/2.6.30.8-64.fc11.i586/include/asm -> asm-x86
> 
> so it won't find link for s390x.

Yes, because you can only build KVM for S390x on S390x :-).

> 
>>> 
>>>> Worst case you just install the kernel 
>>>> sources.
>>>> 
>>>> Alex
>>>>> 
>>> 
>>> kernel sources is the wrong things to use for qemu. qemu should use
>>> exported sanitized sources.
>> 
>> Same thing as on all other archs. What's your point here?
>> 
>> Alex
> 
> Hmm. I'm just trying to understand how does build find kvm headers for
> s390 since they are not linked to from asm. Possibly what happens is we just 
> pick
> a wrong arch and it kind of works most of the time?
> 
> anyway, with --enable-kvm I still get:
> 
> s390-virtio-bus.o: In function `virtio_s390_notify':
> /scm/qemu/hw/s390-virtio-bus.c:310: undefined reference to
> `kvm_s390_virtio_irq'
> collect2: ld returned 1 exit status

Are you sure you're building on s390x? What does uname -a say?

Alex