[Qemu-devel] Re: [PATCH] kvm: Improve upgrade notes when facing unsupported kernels

[Avi Kivity]

Jan Kiszka wrote:
> Avi Kivity wrote:
>   
> > Jan Kiszka wrote:
> >     
> > > Users complained that it is not obvious what to do when kvm refuses to
> > > build or run due to an unsupported host kernel, so let's improve the
> > > hints.
> > >
> > > diff --git a/configure b/configure
> > > index 42d46f2..8ccb58c 100755
> > > --- a/configure
> > > +++ b/configure
> > > @@ -1158,7 +1158,9 @@ EOF
> > >      | grep "error: " \
> > >      | awk -F "error: " '{if (NR>1) printf(", "); printf("%s",$2);}'`
> > >        if test "$kvmerr" != "" ; then
> > > -        kvm="no - (${kvmerr})"
> > > +        kvm="no - (${kvmerr})\n\
> > > +    NOTE: To enable KVM support, update your kernel to 2.6.29+ or
> > > install \
> > > +recent kvm-kmod from http://sourceforge.net/projects/kvm.";
> > >        fi
> > >   
> > >       
> > Installing kvm-mod is insufficient, you need the headers from somewhere.
> >
> >     
>
> True. Hmm, wasn't there the plan to fix this by carrying them in-tree?
>   

Anthony even posted a patch but it was a bit excessive, carrying tons of 
kernel headers.  I think we'd be fine carrying just the kvm headers, 
same as qemu-kvm.  In which case the compile time test can go away.

Alternatively, I can make kvm-kmod install the necessary headers to 
/usr/local/include.  It's probably cleaner this way.

--
Do not meddle in the internals of kernels, for they are subtle and quick to 
panic.