JBeulich at suse
May 7, 2012, 1:31 AM
Post #2 of 2
>>> On 06.05.12 at 17:11, Yaqub Alwan <sillyyax [at] gmail> wrote:
Re: "UEFI firmware, Xen not detecting e820 map"
[In reply to]
> I was in the ##xen freenode channel seeking help for an issue with memory
> being unrecognised above 512mb, and iommu not being detected using xen
> 4.1.2. The guys there determined that xen was not recognising my system
> e820 map and using only the e801 map, and recommended I emailed the details
> to this list. I appreciate that this list is not for technical queries, so
> I do not expect any help, but write this to enable xen developers to
> troubleshoot the issue for future patches.
> My system is a Supermicro X9SCV-Q with 16GB of installed memory and a
> 2720QM CPU. The motherboard, as far as I am aware, only supports EFI
> booting (I have a query with the manufacturer to find out if it supports
> legacy boot).
> Xen hypervisor only detects 511MB memory, but If I boot the regular linux
> kernel, I get the full 16GB.
> Please find the output from xm dmesg here: http://pastebin.com/a1LC2csr
> Please find the output from normal linux boot dmesg here:
> You can see that native Linux kernel is finding the e820 memory map, but
> xen only sees e801 map.
The Linux boot you looked at is an EFI one, so in order to do a proper
comparison you should look at Xen booting from EFI too, without any
intermediate boot loader involved (which requires that you use -unstable
or a 4.1.x code base that backports the native EFI boot support, e.g.
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