[Qemu-devel] Re: link failure with s390

["Michael S. Tsirkin" <mst@redhat.com>]

On Sun, Dec 13, 2009 at 11:19:40PM +0100, Alexander Graf wrote:
> 
> 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" <mst@redhat.com>:
> >>>> 
> >>>>> 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

No, I'm not.  Ah, I forgot, kvm needs to be built native.  My mistake,
sorry. And anyway, it won't be much help without kvm supporting
hardware.  Oh well, I will get by with compile test only without linking
it.

-- 
MST