HVM boot fail, BETA-1 and current

[Alexander Motin]

Hi.

Sean Bruno wrote:
> Tried to boot up an BETA-1 XENHVM kernel today, apparently CAMATA
> doesn't work in this environment. Let me know if you want access to this
> VM as its in the cluster and I can trivially get you on the machine.

Disks in XENHVM are usually not related to CAM. Once hypervisor detects
use of PV drivers, it blocks disks detection via ATA emulation and
exposes them as PV block devices.

> xbd0: 607MB <Virtual Block Device> at device/vbd/5632 on xenbusb_front0
> xbd0: attaching as ad2
> xbd1: 10240MB <Virtual Block Device> at device/vbd/768 on xenbusb_front0
> xbd1: attaching as ad0
...
> GEOM: new disk ad2
> GEOM: new disk ad0
...
> Trying to mount root from ufs:/dev/ada0p2 [rw]...
> mountroot: waiting for device /dev/ada0p2 ...
> Mounting from ufs:/dev/ada0p2 failed with error 19.

The only problem here is that xbd driver still tries to mimic old ATA
device naming. Probably it should be fixed, but I don't see how to do it
correctly. Its behavior with old ATA was closer, but IMHO was also not
exactly correct. It could cause unit numbers collision if somebody
decided to pass some PCI ATA controller inside the virtual machine.

-- 
Alexander Motin