port-xen/39452: "Internal error" with Xen 3.1.4 and HVM

[thomas%feddersen-engineering.de@localhost]

>Number:         39452
>Category:       port-xen
>Synopsis:       "Internal error" with Xen 3.1.4 and HVM
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    port-xen-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Sep 02 13:50:00 +0000 2008
>Originator:     Thomas Feddersen
>Release:        NetBSD 4.0
>Organization:
Dipl.-Ing. Thomas Feddersen, Beratender Ingenieur
>Environment:
NetBSD bremen.feddersen.xx 4.0 NetBSD 4.0 (XEN3_DOM0) #0: Sun Dec 16 01:20:31 
PST 2007  
builds@wb34:/home/builds/ab/netbsd-4-0-RELEASE/i386/200712160005Z-obj/home/builds/ab/netbsd-4-0-RELEASE/src/sys/arch/i386/compile/XEN3_DOM0
 i386
>Description:
XEN3_DOM0 i386 and XEN3_DOMU i386 run fine, attempting to start WinXP as a 
HVM-DomU results in an errormessage:

# xm create winxp
Using config file "/usr/pkg/etc/xen/winxp".
Error: (1, 'Internal error', 'Could not deallocate guard page for HVM guest.\n 
(25 = Inappropriate ioctl for device)')

Before output of errormessage the debugger (green letters) echoes to console:
sys_ioctl: _IOWR('P', 0, 24) returned -1: pid=489 comm=python2.4

# ps -p 489
PID TTY STAT    TIME COMMAND
489 ?   Ia   0:01.64 /usr/pkg/bin/python2.4 /usr/pkg/sbin/xend start
>How-To-Repeat:
Install NetBSD 4.0 and make from Pkgsrc:
grub-0.97nb8
xentools3-3.1.4
xentools3-hvm-3.1.4
xenkernel3-3.1.4

and configure according http://www.netbsd.org/ports/xen/howto.html

# cat /usr/pkg/etc/xen/winxp
kernel = "/usr/pkg/lib/xen/boot/hvmloader"
builder='hvm'
memory = 512
name = "winxp"
vif = [ 'mac=00:16:3e:00:01:13, bridge=bridge0, type=ioemu' ]
device_model = '/usr/pkg/libexec/qemu-dm'
disk = [ 'file:/home/domains/winxp,ioemu:hda,w' ]
boot='c'
usb=1
usbdevice='tablet'
>Fix:
the HVM-DomU previously worked fine using 
- NetBSD 4.0_BETA2 
- Xen 3.0.3

(current NetBSD 4.0 is a fresh install, not an update)