Re: NetBSD 10.0 RC1 PVH and XenServer/XCP

[Stephen Borrill <netbsd%precedence.co.uk@localhost>]

On Mon, 13 Nov 2023, Brian Buhrow wrote:
> 	hello.  If you place an uncompressed copy of netbsd-INSTALL.gz from the kernels directory of a
> release build as /netbsd on the iso image that you boot from, do you then find you can boot
> and, then, format and populate the xbd disk that shows up?  I've done this to build NetBSD
> systems under hosted VM offerings, specifically Linode's offerings.

I expect this would get the installer going, but without the cd being 
accessible, I would have to resort to trying to fetch the sets over the 
network. Lack of access to the ISO library may cause problems later too.

In PVH mode, the cdrom device is present in the xenstore at all times, but 
its status does not change when an ISO image is inserted:

# xenstore-read domid
11
# xenstore-ls /local/domain/20/device/vbd
[snip]
5696 = ""
 backend = "/local/domain/0/backend/vbd3/20/5696"
 backend-id = "0"
 device-type = "cdrom"
 state = "1"
 virtual-device = "5696"

Compare this to PV mode. The vbd only appears when the ISO image is 
inserted, but looks like this:

# xenstore-read domid
11
# xenstore-ls /local/domain/11/device/vbd
[snip]
51760 = ""
 backend = "/local/domain/0/backend/vbd3/11/51760"
 backend-id = "0"
 device-type = "cdrom"
 event-channel = "19"
 protocol = "x86_64-abi"
 ring-ref = "494"
 state = "4"
 virtual-device = "51760"

From this it is clear the PVH device is not properly initialised and a 
clue to this is found in dmesg:
xenbus0: ignoring device/vbd/5696 type cdrom


> On Nov 13,  4:25pm, Stephen Borrill wrote:
> } Subject: NetBSD 10.0 RC1 PVH and XenServer/XCP
> } It is also not possible to boot an alternative kernel (such as
> } netbsd-INSTALL.gz) as the boot loader appears unable to read anything
> } except for files in the root of the ISO:
> }