Create Ubuntu hvm machine with file disk

[Roger Pau Monné <roger.pau%entel.upc.edu@localhost>]

Hello,

I'm trying to create a Ubuntu HVM under Xen 4.1 using a file as the
disk. I've tried creating the disk with dd and with qemu-img-xen, in
raw and qcow2 formats, but the disk is never recognized by the
installation. Here is my config file:

kernel = '/usr/pkg/lib/xen/boot/hvmloader'
builder = 'hvm'
memory = '1024'
device_model='/usr/pkg/libexec/qemu-dm'

disk = [ 'file:/home/xen/ubuntu.img,ioemu:hda,w',
          'file:/home/xen/ubuntu.iso,ioemu:hdb:cdrom,r', ]

# Hostname
name = "ubuntu11"

vif = [ 'type=ioemu, bridge=bridge1' ]

boot= 'dc'
vnc = 1
vnclisten="0.0.0.0"
vncpasswd='xxxxxx'
usbdevice = 'tablet' # Helps with mouse pointer positioning

The qemu log shows some errors related to gnttab:

domid: 9
-videoram option does not work with cirrus vga device model. Videoram set to 4M.
Strip off blktap sub-type prefix to /home/xen/ubuntu.img (drv 'aio')
Using file /home/xen/ubuntu.img in read-write mode
Strip off blktap sub-type prefix to /home/xen/ubuntu.iso (drv 'aio')
Using file /home/xen/ubuntu.iso in read-only mode
Watching /local/domain/0/device-model/9/logdirty/cmd
Watching /local/domain/0/device-model/9/command
Watching /local/domain/9/cpu
qemu_map_cache_init nr_buckets = 10000 size 4194304
shared page at pfn feffd
buffered io page at pfn feffb
Guest uuid = d0f3f187-f395-e011-81cc-1803730a9a51
xen be core: xen be core: can't open gnttab device
can't open gnttab device
xen be core: xen be core: can't open gnttab device
can't open gnttab device
xen be core: xen be core: can't open gnttab device
can't open gnttab device
populating video RAM at ff000000
mapping video RAM from ff000000
Register xen platform.
Done register platform.
platform_fixed_ioport: changed ro/rw state of ROM memory area. now is rw state.
medium change watch on `hdb' (index: 1): aio:/home/xen/ubuntu.iso
I/O request not ready: 0, ptr: 0, port: 0, data: 0, count: 0, size: 0
Log-dirty: no command yet.
vcpu-set: watch node error.
xs_read(/local/domain/9/log-throttling): read error
qemu: ignoring not-understood drive `/local/domain/9/log-throttling'
medium change watch on `/local/domain/9/log-throttling' - unknown
device, ignored
cirrus vga map change while on lfb mode
mapping vram to f0000000 - f0400000
platform_fixed_ioport: changed ro/rw state of ROM memory area. now is rw state.
platform_fixed_ioport: changed ro/rw state of ROM memory area. now is ro state.
Unknown PV product 3 loaded in guest
PV driver build 1
region type 1 at [c100,c200).
region type 0 at [f3001000,f3001100).
squash iomem [f3001000, f3001100).

I'm running NetBSD-current and Xen4.1, using the XEN3_DOM0, does
someone know how to solve this problem?

Thanks, Roger.