Red Hat Bugzilla – Bug 506348
i386 pv guests are uninstallable on x86_64 dom0 amd quad-core opteron 8356 processors
Last modified: 2013-11-03 20:42:45 EST
Description of problem:
Trying to install an i386 paravirt guests on a machine with amd quad-core opteron processor causes kernel crash with:
Unable to handle kernel paging request------------[ cut here ]------------
kernel BUG at include/asm/mach-xen/asm/maddr.h:34!
invalid operand: 0000 [#1]
Modules linked in:
EIP: 0061:[<c0113fbf>] Not tainted VLI
EFLAGS: 00010006 (2.6.9-89.ELxenU)
EIP is at do_page_fault+0x7ab/0x867
Version-Release number of selected component (if applicable):
# rpm -qa | grep xen
Very. This is with less than 64 GB of ram.
Steps to Reproduce:
1. The particular machine I used was hp-dl785g5-01.rhts.bos.redhat.com .
Hm, logging onto hp-dl785g5-01.rhts.bos.redhat.com, I see that it actually has 128GB of memory (look at the output from xm info). We automatically limit the *dom0* memory to 32GB, though. In any case, on a machine with > 64GB, i386 RHEL-4 Xen is known broken, so I'm going to close this as a dup of 504988.
*** This bug has been marked as a duplicate of bug 504988 ***
I don't believe this is still fixed. Since 5u2, dom0's with greater than 64GB of ram cannot install i386 guest vms. Solution has always been to use less ram than 64GB. This is still reproducible in 5u4 x86_64 dom0 with 5u2 i386 vms (as well as 5u3 vms; 5u4 guests however, do work).
This isn't a solution though and its still a problem after 3 updates!
(In reply to comment #2)
> I don't believe this is still fixed. Since 5u2, dom0's with greater than 64GB
> of ram cannot install i386 guest vms. Solution has always been to use less ram
> than 64GB. This is still reproducible in 5u4 x86_64 dom0 with 5u2 i386 vms (as
> well as 5u3 vms; 5u4 guests however, do work).
> This isn't a solution though and its still a problem after 3 updates!
Well, that is actually a different bug. There was a bug in the *guest* kernel on hosts with > 64GB of RAM; that bug was fixed in 5.4, so you'll need to update your guest kernel to at least 5.4 to run i386 guests on x86_64 dom0's with > 64GB of RAM.