[Qemu-devel] Re: link failure with s390

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

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.

> > 
> >> 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

???
-- 
MST