bhyve regression (head): windows VMs failing with error 0xc000021a

Hi,

I've recently updated my current machines to git commit 
525a177c165740fc697df3de5b92e58b3b41477c (Sun Oct 20 22:43:41 2024 
-0800) and just have Windows 10 VMs fail to start in bhyve with the 
error in the subject.

I've been unable to recover them with usual tricks (automatic recovery, 
chkdsk, and other tools provided by the OS). Looks like the machine 
fails to read C: after boot.

These machines were working fine before the update, so my suspect is 
that some recent change in bhyve is causing the issue and the VMs would 
be otherwise fine.

The VMs have their filesystems in compressed zvols.

Anyone has an idea or can point to some change I can test reverting?

I an also try bisecting, I'd guess the issue is quite recent.

Thanks in advance for any advice.

Obviously if any further info is needed just ask.

-- 
Guido Falsi <mad@madpilot.net>