port-xen/44746: NetBSD 5.99.48 DomU crashes on using fdisk. (Xen 4, linux 2.6.32 Dom0 with pvops)

[bbartlomiej%gmail.com@localhost]

>Number:         44746
>Category:       port-xen
>Synopsis:       NetBSD 5.99.48 DomU crashes on using fdisk. (Xen 4, linux 
>2.6.32 Dom0 with pvops)
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    port-xen-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Mar 20 00:50:00 +0000 2011
>Originator:     Bartek Krawczyk
>Release:        5.99.48
>Organization:
>Environment:
NetBSD netbsd 5.99.48 NetBSD 5.99.48 (XEN3PAE_DOMU) #0: Thu Mar 17 18:03:10 UTC 
2011  
builds%b7.netbsd.org@localhost:/home/builds/ab/HEAD/i386/201103171400Z-obj/home/builds/ab/HEAD/src/sys/arch/i386/compile/XEN3PAE_DOMU
 i386

>Description:
I have just installed NetBSD 5.99.48 DomU (due to network copy mode on Xen 4 
Dom0) using loopback files. "/" is on /dev/xbd1a and I have added xbd0 to make 
swap partition on in. When I want to use fdisk on any of this disks i get this 
results:

netbsd# fdisk /dev/xbd0d
fdisk: primary partition table invalid, no magic in sector 0
fdisk: Cannot determine the number of heads
Disk: /dev/xbd0d
NetBSD disklabel disk geometry:
cylinders: 256, heads: 1, sectors/track: 2048 (2048 sectors/cylinder)
total sectors: 524288

BIOS disk geometry:
cylinders: 32, heads: 255, sectors/track: 63 (16065 sectors/cylinder)
total sectors: 524288

Partitions aligned to 16065 sector boundaries, offset 63

Partition table:
0: <UNUSED>
1: <UNUSED>
2: <UNUSED>
3: <UNUSED>
Bootselector disabled.
No active partition.
panic: kernel diagnostic assertion "rw_lock_held(&wl->wl_rwlock)" failed: file 
"/home/builds/ab/HEAD/src/sys/kern/vfs_wapbl.c", line 1628
cpu0: Begin traceback...
?(0,0,0,100400,1,4000,4000,8e08,0,cad20000) at 0xc0b89800
cpu0: End traceback...

dump to dev 142,9 not possible
rebooting...


On Dom0 xm dmesg shows:
(XEN) traps.c:2308:d9 Domain attempted WRMSR 00000277 from 00000501:00070406 to 
00070106:00070106.

NetBSD DomU dmesg shows during boot:
xbd0 at xenbus0 id 51713: Xen Virtual Block Device Interface
xbd0: using event channel 5
xbd0: 256 MB, 512 bytes/sect x 524288 sectors

Or should I maybe create a disklabel directly without a DOS partition table?

Regards,

>How-To-Repeat:

>Fix: