Re: [Qemu-devel] Does i386-linux-user build on an i686 host?

[Aleksandar Markovic]

On Fri, Aug 9, 2019 at 3:35 PM Daniel P. Berrangé <address@hidden>
wrote:

> On Fri, Aug 09, 2019 at 01:49:07PM +0100, Peter Maydell wrote:
> > On Fri, 9 Aug 2019 at 13:22, Peter Maydell <address@hidden>
> wrote:
> > >
> > > On Thu, 8 Aug 2019 at 16:37, Markus Armbruster <address@hidden>
> wrote:
> > > >
> > > > Fails for me, but perhaps I'm doing it wrong:
> > >
> > >
> > > > NOTE: cross-compilers enabled:  'cc'
> > > > $ make
> > > >   CC      i386-linux-user/linux-user/syscall.o
> > > > /home/armbru/qemu/linux-user/ioctls.h:306:9: error:
> ‘SNDCTL_DSP_MAPINBUF’ undeclared here (not in a function)
> > > >    IOCTL(SNDCTL_DSP_MAPINBUF, IOC_R,
> MK_PTR(MK_STRUCT(STRUCT_buffmem_desc)))
> > > >          ^
> > > > /home/armbru/qemu/linux-user/syscall.c:5023:23: note: in definition
> of macro ‘IOCTL’
> > > >      { TARGET_ ## cmd, cmd, #cmd, access, 0, {  __VA_ARGS__ } },
> > > >                        ^
> > > > /home/armbru/qemu/linux-user/ioctls.h:307:9: error:
> ‘SNDCTL_DSP_MAPOUTBUF’ undeclared here (not in a function)
> > > >    IOCTL(SNDCTL_DSP_MAPOUTBUF, IOC_R,
> MK_PTR(MK_STRUCT(STRUCT_buffmem_desc)))
> > > >          ^
> > > > /home/armbru/qemu/linux-user/syscall.c:5023:23: note: in definition
> of macro ‘IOCTL’
> > > >      { TARGET_ ## cmd, cmd, #cmd, access, 0, {  __VA_ARGS__ } },
> > > >                        ^
> > > > /home/armbru/qemu/linux-user/ioctls.h:362:9: error:
> ‘SOUND_MIXER_ACCESS’ undeclared here (not in a function)
> > > >    IOCTL(SOUND_MIXER_ACCESS, 0, TYPE_PTRVOID)
> > > >          ^
> > > > /home/armbru/qemu/linux-user/syscall.c:5023:23: note: in definition
> of macro ‘IOCTL’
> > > >      { TARGET_ ## cmd, cmd, #cmd, access, 0, {  __VA_ARGS__ } },
> > > >                        ^
> > >
> > > We expect these to be provided by the system's "linux/soundcard.h".
> > > For my Debian system that's provided by the linux-libc-dev package,
> > > but I imagine you have that installed or you wouldn't have got
> > > this far in the configure/compile process...
> >
> > Further investigation shows that this is because the system has
> > the 'oss4-dev' package installed, which diverts
> /usr/include/linux/soundcard.h
> > and installs its own version which doesn't provide all the symbols
> > that the kernel one does.
> >
> > Easy fix: uninstall oss4-dev.
>
> Perhaps also make 'configure' exit with an error if it detects the
> broken soundcard.h ?
>
>
Daniel, it looks to me that this is too drastic. Only applicable ioctl
support
could be removed for such case, QEMU is otherwise fine.

Yours,
Aleksandar



> > Better fix: patch QEMU to provide its own versions of these constants
> > if the system headers don't.
> >
> > Utopian fix: I've wondered occasionally whether for cases like this
> > where the constant is known to be the same for the host and the guest
> > we should have some sort of approach which lets us use the QEMU
> > copies of the linux kernel headers rather than having to rely on
> > the host system, which might have an older version that restricts
> > us unnecessarily on what we could support...
> >
> > Issue previously reported in 2016:
> > https://lists.gnu.org/archive/html/qemu-devel/2016-12/msg01421.html
> >
> > thanks
> > -- PMM
> >
>
> Regards,
> Daniel
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