Re: fyi, Xen's EFI workarounds (/mapbs & efi=no-rs) on SuperMicro hardware; fixes solve 1/2 problems & SM responds that can't/won't fix their firmware

[PGNet Dev <pgnet.dev@gmail.com>]

On 12/07/2015 06:20 AM, Konrad Rzeszutek Wilk wrote:
> However I am wondering - why are you using '/mapbs' ? What did it
> help? (The combination of 'efi=no-rs' means you are in effect not
> using _any_ EFI operations - so doing /mapbs is not needed).

I used /mapbs because it was suggested in #irc by a dev (IIUC) @citrix 
to do exactly that in response to the crash.

What it helped is that it cured the crash.

I switched to using efi=no-rs _instead_ of /mapbs because it was 
recommended by a Xen dev that I do so, having called into question the 
robustness of /mapbs as a fix, calling it 'quite ugly'.

Using just efi=no-rs also cures the crash, with the additional removal 
of a non-fatal acpi error.

I'm now using more than just /mapbs -- specifically, adding efi=no-rs 
and reboot=acpi -- for, admittedly, no good reason other than you'd 
suggested I do so, above.

I'll see what I can manage with the patch you've provided.  First, tho, 
I need to reread all the various commentary, as I've completely lost 
track of what the functions and benefits of any one option, or combo 
thereof, are ...