Re: Problems booting NetBSD/Xen on Intel NUC 12 Extreme w/ i9-12900

[Johan Stenstam <johani%johani.org@localhost>]

Hi Brad and Brian,

From Brad:

> While using Linux on a NetBSD DOMU should be fine for PVH guests, you
> might have a problem with PV guests.  In the MESSAGE file for pkgsrc Xen
> kernel there is this:
> 
> -----
> Note that unlike upstream Xen, pv-linear-pt defaults to true.
> You can disable it using pv-linear-pt=false on the Xen command line,
> but then you can't boot NetBSD in PV mode.
> 
> Unlike upstream Xen, 32bits PV guests support is enabled by default, but
> this is not security-supported anymore, and will be disabled in the next
> pkgsrc release. Switch to pvshim (for netbsd-9 or older) or pvh (for
> netbsd-current).

Aha! 

From Brian:

> there was a problem under early versions of NetBSD-9 and earlier where xen domu kernels would
> perform MSR instructions which wer disallowed for security reasons sometime around xen-4.15 or
> so.  If you add the line:
> msr_relaxed = 1
> to your domu config on the broken installations, do you get any different results?

Aha! You found the smoking gun!

So, yes, I’m using pure PV 64-bit DOMUs, with 9.2 on both DOMUs and DOM0s w/xen4.11 on my working systems. This system it is 10_BETA + xen 4.15.

So the suggestion to add the one-liner “msr_relaxed=1” to my old 9.2 config… WORKS!

The suggestion to switch to PVH-mode (with a GENERIC current- or at least 10_BETA kernel in the DOMU) … ALSO WORKS!

For kicks I also tried HVM-mode (with a 9.2 GENERIC kernel). That one does not work, but it fails on the old confusion around the device name for the disk. Suddenly that became a show stopper:

bash-5.2# xl create -c master-hvm.conf 
Parsing config from master-hvm.conf
libxl: warning: libxl_dm.c:1877:libxl__build_device_model_args_new: Domain 7:unable to determine disk number for 0x0
libxl: error: libxl_dm.c:3148:device_model_spawn_outcome: Domain 7:domain 7 device model: spawn failed (rc=-3)
libxl: error: libxl_dm.c:3368:device_model_postconfig_done: Domain 7:Post DM startup configs failed, rc=-3
libxl: error: libxl_create.c:1837:domcreate_devmodel_started: Domain 7:device model did not start: -3
libxl: error: libxl_aoutils.c:646:libxl__kill_xs_path: Device Model already exited
libxl: error: libxl_domain.c:1182:libxl__destroy_domid: Domain 7:Non-existant domain
libxl: error: libxl_domain.c:1136:domain_destroy_callback: Domain 7:Unable to destroy guest
libxl: error: libxl_domain.c:1063:domain_destroy_cb: Domain 7:Destruction of domain failed

I have no idea why, but it doesn’t really matter to me at the moment. Of course I’m aware that there are still real problems with the Xen console handover to the 10_BETA DOM0 but I will not worry about that today as I’m delighted to *finally* have DOMUs up and running on this new box.

Many, many thanks to all involved. I am truly grateful for all your help!

Regards,
Johan