Comment # 7 on bug 956526 from boo35 boo35

Note that there are other EFI flags that are available/useful.

E.g., in the Xen thread alone are mentioned

  /basevideo, /mapbs, noexitboot & /query

I'd guess a longer list can be extracted from the tiaonocore sources.  I'm not
sure which vendors are using the tiaonocore UEFI vs. 'other'.

Although auto-detection may be possible, for which failure?  Only one? More?

Trying to identify all cases of failure, and all possible flag-combo solutions
isn't a tenable solution.

The flexibility to have the enduser diagnose (nrokennesss, performances issue,
etc), and add flags to config -- as is currently often done for both Kernel &
Xen 
is imo preferable.  The "SUSE_EFI_XEN_LOADER_CMDLINE" string seems a simple
enough approach.

If/when grub@suse and grub@upstream coordinate, pushing that cmdline upstream
makes sense.

Of course, getting EFI fixed is the best solution; I've already contacted the
H/W vendor, and they're working on this issue.