Re: another xen-kernel UEFI story

From: Roger Pau Monné <royger_at_freebsd.org>
Date: Tue, 10 Aug 2021 07:38:58 UTC
On Mon, Aug 09, 2021 at 05:23:27PM +0200, lizbethmutterhunt@gmail.com wrote:
> could someone pleas check this link: 
> https://forums.freebsd.org/threads/xen-kernel-doesnt-start-at-all.81556/
> 
> does anyone has another idea then duplicating CURRENT and RELEASE via 
> Virtualbox or qemu?
> 
> XEN simply doesn't boot after setting xen_kernel on in /boot/loader.conf, we 
> tried different ways but none worked. It's loading [text], [data], [syms] and 
> the preconfig but afterwards there's just the reset-button option, because XEN 
> doesn't boot. 
> 
> any help appreciated!

Hello,

There are a couple of things to look at, first of all, do you have a
serial console attached to the box?

It seems like you do because you have the serial output options
enabled in loader.conf, in which case can you paste the output you get
from the serial when booting?

Also note that the line:

xen_cmdline="dom0_mem=4048M dom0_max_vcpus=4 dom0pvh=1 com1=115200,8n1 guest_loglvl=all loglvl=all"

Is wrong unless you are using Xen 4.7. The handbook [0] states
that for Xen 4.11 and greater dom0=pvh should be used instead of
dom0pvh=1.

Also note that the line:

hw.pci.mcfg=0

Is not needed unless you are using Xen 4.7.

If you don't have a serial console, and the above doesn't fix your
issue I would recommend that you switch to plain UEFI booting (ie: no
BIOS CSM), install FreeBSD 14 (current) and then try to boot Xen with
UEFI. FreeBSD 14 should have support for booting Xen from UEFI without
the need of the BIOS CSM mode.

Thanks, Roger.

[0] https://docs.freebsd.org/en/books/handbook/virtualization/#virtualization-host-xen