Re: [Xen-devel] Can't see more than 3.5GB of RAM / UEFI / no e820 memory map detected

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 23.08.12 at 10:07, Jonathan Tripathy <jonnyt@xxxxxxxxxxx> wrote:

> On 23.08.2012 08:39, Jan Beulich wrote:
>>>>> Jonathan Tripathy <jonnyt@xxxxxxxxxxx> 08/23/12 9:29 AM >>>
>>>I'm guessing xen.efi (from 4.2) just replaces grub??
>>
>> "Replaces" is the wrong term. It simply makes the use of grub.efi (or 
>> however
>> it's named) unnecessary.
>>
>>>Also, if I were to apply that patch from superuser
>>>(http://serverfault.com/questions/342109/xen-only-sees-512mb-of-system-ram-sh
>>> 
> ould-be-8gb-uefi-boot),
>>>would have have any bad consequences? I'm very security conscience as
>>>the DomUs are untrusted...
>>
>> If you wanted to do that, I'd strongly recommend only removing the 
>> E801 code
>> (obviously, from your log, you don't get E820 entries reported
>> anyway, so this
>> would be to not harm using hypervisors built from the same source on 
>> other
>> systems) or simply swapping the E801 and multiboot handling order 
>> (which may
>> actually be something to consider even upstream, so you'd be welcome 
>> to post
>> such a patch).
>>
>> But in the end, in order to indeed use UEFI as intended, you'll need
>> to switch to
>> using xen.efi and an EFI-enabled Dom0 kernel (which upstream pv-ops 
>> for now
>> isn't).
> 
> I'll submit a patch with the map entries in the if block swapped. I'll 
> make the patch, then test it for you guys, then post it. Do I just send 
> it to this list (for the benefit of others and for upstream 
> consideration)?

Yes.

> When you say "use UEFI as intended", is there something wrong with just 
> flipping the if block on its head?

That flipping has nothing to do with UEFI, just with the way grub.efi
works.

Proper UEFI support implies use of EFI's boot and run time services,
which only xen.efi currently does (and which, for those run time
services that get made available for use by Dom0, also requires an
enabled Dom0 kernel).

Jan


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel