Re: [Qemu-devel] [PATCH] kvm: workaround build break on gcc-7.1.1 / fedora26

[Greg Kurz]

On Thu, 3 Aug 2017 10:46:47 -0300
Philippe Mathieu-Daudé <address@hidden> wrote:

> Hi Greg,
> 
> On 08/02/2017 11:47 AM, Greg Kurz wrote:
> > Building QEMU on fedora26 with the latest gcc package fails:
> > 
> >    CC      ppc64-softmmu/target/ppc/kvm.o
> > In file included from include/sysemu/hw_accel.h:16:0,
> >                   from target/ppc/kvm.c:31:
> > target/ppc/kvm.c: In function ‘kvmppc_booke_watchdog_enable’:
> > include/sysemu/kvm.h:449:35: error: ‘args_tmp[i]’ may be used uninitialized
> >   in this function [-Werror=maybe-uninitialized]
> >               cap.args[i] = args_tmp[i];                               \
> >                                     ^
> > target/ppc/kvm.c: In function ‘kvmppc_set_papr’:
> > include/sysemu/kvm.h:449:35: error: ‘args_tmp[i]’ may be used uninitialized
> >   in this function [-Werror=maybe-uninitialized]
> > cc1: all warnings being treated as errors  
> 
> I'm trying to reproduce this in our docker images (all x86_64 based) but 
> can't reproduce.
> 
> ./configure shows:
> 
> KVM support       yes
> 
> but in "sysemu/kvm.h" CONFIG_KVM_IS_POSSIBLE is not defined
> 
> I can see CONFIG_KVM defined, but no NEED_CPU_H.
> 
>  >
>  > $ rpm -q gcc
>  > gcc-7.1.1-3.fc26.ppc64le  
> 
> I don't have native ppc64le to build, do you know if it is possible to 
> cross-compile enabling kvm? It seems I have the correct Linux headers, I 
> wonder if this isn't a ./configure test which disable the kvm cross-build.
> 

I don't cross-compile personally but I see no reasons why it wouldn't be
possible. I'd say the biggest churn is to setup the cross-compile environment :)

> Regards,
> 
> Phil.

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