Re: [PATCH v9 0/5] tpm: Command duration logging and chip-specific override

[Jason Gunthorpe]

On Wed, Jul 13, 2016 at 01:00:28PM -0700, Ed Swierk wrote:
> On Wed, Jul 13, 2016 at 10:36 AM, Jason Gunthorpe
> <jgunthorpe@xxxxxxxxxxxxxxxxxxxx> wrote:
> > I think your bios is broken?
> 
> The BIOS is broken in many ways. I already have to pass
> memmap=256M$0x80000000, otherwise PCIe extended config space
> (MMCONFIG) is inaccessible. Also I found memmap=0x7000$0x7a7d0000
> works around "APEI: Can not request [mem 0x7a7d0018-0x7a7d0067] for
> APEI ERST registers", as the BIOS seems to be mistakenly reserving
> 0x7b7d0000-7b7d7000 instead.

Is it is possible whatever causes the 'reserve RAM buffer' behavior in
the kernel is wonky with your BIOS? That seems to be a special Linux
action..

Could it be Xen related? The Xen hypervisor replaces the physical ram
map for the dom0 guest, which is why you get these sorts of prints:
 Xen: [mem 0x0000000000000000-0x000000000005ffff] usable
and not:
[    0.000000] BIOS-e820: [mem 0x0000000000000000-0x0000000000057fff] usable

Jason