Comment # 15 on bug 956526 from Jan Beulich

(In reply to boo35 boo35 from comment #14)
> (In reply to Jan Beulich from comment #10)
> > No, it's a firmware issue. The fact that Linux doesn't call certain runtime
> > services functions (because of there being so many bugs in the wild) doesn't
> > make it a Xen bug if the firmware writers don't produce usable code/data. As
> > you've seen we've added, over time, quite a number of workaround options.
> > Another one for you to try would btw be "efi=no-rs" (which goes on the
> > ordinary command line, and hence should avoid all the grub related issues).
> 
> Avoid, or simply mute?

Whatever term you prefer.

> I've found the commits for both the
> 
>   /mapbs
>   efi=no-rs
> 
> 'fix' options.  I'm not clear on what they do relative to one another.  Is
> one 'better' here than the other, or should both be in place?

Which one to use depends on the kind of brokenness of your firmware. I consider
/mapbs quite ugly, so would generally recommend to prefer efi=no-rs.

Now that you settled on which issue to deal with here, please note that there
was a complete log requested in #8 for that case.