Subject: [RFC] ARM VM System Sepcification

From: [email-masked] (Paolo Bonzini)
Date: Sat, 22 Mar 2014 09:08:37 +0100

Il 22/03/2014 03:29, Christoffer Dall ha scritto:
> 1. Simply mandate that VM implementations support persistent variables
>    for their UEFI implementation - with whatever constraints that may
>    put on higher level tools.
>
> 2. Require that OSes shipped as part of compliant VM images make no
>    assumption that changes to the UEFI environment will be stored.
>
> I feel that option number two will break in all sorts of cases, just
> like Grant stated above, and it is fundamentally not practical; if a
> distribution ships Linux with a UEFI stub that expects to be able to do
> something, distributions must modify Linux to conform to this spec.  I
> think imagining that this spec controls how UEFI support in Linux/Grub
> is done in general would be overreaching.  Additionally, Michael brought
> up the fact that it would be non-UEFI compliant.

OSes are already able to cope with loss of changes to UEFI environment 
are stored, because losing persistent variables is what happens if you 
copy an image to a new hard disk.

Asking implementations for support of persistent variables is a good 
idea; however, independent of what is in the spec, OSes should not 
expect that users will enable that support---most of them won't.

Paolo