DomU Windows Server Essentials crashes with xen 4.16 but works with xen 4.14

[Steffen Einsle <einsle@xxxxxxxxxx>]

Hello Everyone,

I have some xen servers I recently tried to update from xen 4.14 to xen 4.16

Everything worked without problem, except for the Windows Server 
Essentials DomUs.
With xen 4.16 those domains crashed (reproducable) during boot - 
KMODE_EXCEPTION_NOT_HANDLED.
I tried to install a new DomU Windows Server 2019 Essentials - this VM 
crashed at the first reboot
(still in the installation routine) with the same error. No PV-drivers 
installed yet.
I switched back to xen 4.14 and all VMs booted ok without problem.

All other VMs (Linux-PV, Windows-HVM (2008r2, 2012r2, 2016, 2019, 2022)  
show no problems, only
the Windows Server Essentials crashes with xen 4.16.

The system is a gentoo kernel 5.17.3, qemu-6.2.0-r4, xen-4.16.0-r5, 
xen-tools-4.16.0-r1
My working configuration is gentoo kernel 5.17.3, qemu-5.2.0-r2, 
xen-4.14.3-r2, xen-tools-4.14.3
My DomU config file looks like this

name = 'DC-Server'
type = 'hvm'
memory = '8192'
vcpus = '6'
vif = [ 'mac=00:16:3E:ab:cd:50,bridge=br0' ]
disk = [ '/dev/vg1/ServerSys,raw,hda,rw',
              '/dev/vg1/ServerData,raw,hdb,rw' ]
viridian = 'all'
localtime = '1'
vnc = '1'
keymap = 'de'
vnclisten = '0.0.0.0:10,websocket'
usb = '1'
usbdevice = 'tablet'
on_crash  = 'restart'
boot = 'c'
xen_platform_pci = '1'
max_grant_frames = 128

I tried disabling viridian but this made no change.

Is this a known problem?


--

Steffen