This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


Re: [Xen-users] Problems with >4GB memory with 64-bit Xen kernel

On May 27, 2008, at 1:46 PM, Ross S. W. Walker wrote:

Matthew Ragan wrote:

I've been running the 64-bit version of the Xen 3.1.4 hypervisor with
a NetBSD (recent -current) dom0 for a number of weeks now, and haven't
had any real problems with it.  Previously, the system that I am
running this on (Dell Dimension E510, Pentium D 940) has been running
fine with 1GB of memory in the system.  Because I want to use this
system to house a number of database VMs that may chew memory, I put
8GB in the system today, and now the system refuses to boot unless I
specify 'mem=4G', which somewhat defeats the purpose of having 8GB in
the box.

I know other people have more than 4GB in their running systems, and
NetBSD boots fine and finds all 8G when I boot it without using Xen,
so I'm not sure what the issue is.  I've tried this with a number of
different 3.1.0 and 3.2.x kernels, and all have similar problems.
Setting 'mem=' to other values above 4GB results in the same errors,
except for the ending value in the last (usable) line.

Boot shows:

(XEN) Command line: (hd0,3,a)/xen.gz dom0_mem=256m
(XEN)  0000000000000000 - 0000000000000000 (usable)
(XEN)  00000000000f0000 - 0000000000100000 (reserved)
(XEN)  0000000000010000 - 00000000dfe88000 (usable)
(XEN)  00000000dfe88c00 - 00000000dfe8ac00 (ACPI NVS)
(XEN)  00000000dfe8ac00 - 00000000dfe8cc00 (ACPI data)
(XEN)  00000000dfe8cc00 - 00000000e0000000 (reserved)
(XEN)  00000000f0000000 - 00000000f4000000 (reserved)
(XEN)  00000000fec00000 - 00000000fed00400 (reserved)
(XEN)  00000000fed20000 - 00000000feda0000 (reserved)
(XEN)  00000000fee00000 - 00000000fef00000 (reserved)
(XEN)  00000000ffb00000 - 0000000100000000 (reserved)
(XEN)  0000000100000000 - 0000000200000000 (usable)
(XEN) System RAM: 7678MB (7862432kB)
(XEN) Xen heap: 13MB (14032kB)
(XEN) Domain heap initialised: DMA width 32 bits
(XEN) ****************************************
(XEN) Panic on CPU 0:
(XEN) Early fatal page fault at e008:ffff8300001129d4
(cr2=ffffffffffffffff, ec=0002)
(XEN) ****************************************
(XEN) Reboot in five seconds...
(XEN) Unknown interrupt

You need to make sure the dom0 kernel is compiled PAE.


The dom0 kernel is 64-bit, and the Xen kernel doesn't even get to the point of starting the dom0.

 -- Matt

Xen-users mailing list

<Prev in Thread] Current Thread [Next in Thread>