Re: Regression since Linux Kernel 3.12 due to 64bit pvguest NMIs

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Tue, May 13, 2014 at 10:18:53AM +0200, Sebastian Faerber wrote:
> >
> > Could you patch your kernel with this patch to double check that it is OK?
> >
> > Is it OK for me to put 'Reported-and-Tested-by: Sebastian Faerber <email>'
> > on it?
> 
> Your patch works, thanks for taking care of the issue, much appreciated!
> Sure, you can include me in your commit.

Excellent.
> Could you also CC this patch to the stable kernel people? Would be
> great if i could
> run unmodified kernels once the commit gets picked up.
>

Sure.
 
> >
> > diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
> > index 201d09a..c19ae00 100644
> > --- a/arch/x86/xen/enlighten.c
> > +++ b/arch/x86/xen/enlighten.c
> > @@ -746,11 +746,14 @@ static int cvt_gate_to_trap(int vector, const gate_desc *val,
> >                  */
> >                 ;
> >  #endif
> > -       } else if (addr == (unsigned long)nmi)
> > +       } else if (addr == (unsigned long)nmi) {
> >                 /*
> > -                * Use the native version as well.
> > +                * Use the native version as well, but for RHEL5
> > +                * hypervisors it is not implemented.
> >                  */
> > -               ;
> > +               if (!xen_running_on_version_or_later(4,0))
> > +                       return 0;
> > +       }
> >         else {
> >                 /* Some other trap using IST? */
> >                 if (WARN_ON(val->ist != 0))
> > diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
> > index 0982233..aa3fd34 100644
> > --- a/arch/x86/xen/setup.c
> > +++ b/arch/x86/xen/setup.c
> > @@ -576,6 +576,8 @@ void xen_enable_syscall(void)
> >  }
> >  void xen_enable_nmi(void)
> >  {
> > +       if (!xen_running_on_version_or_later(4,0))
> > +               return;
> >  #ifdef CONFIG_X86_64
> >         if (register_callback(CALLBACKTYPE_nmi, (char *)nmi))
> >                 BUG();
> >
> >