From: Crystal Kolipe <kolipe.c@exoticsilicon.com>
Subject: Re: vmd(8): Use 32-bit direct kernel launch for both amd64 and i386
To: tech@openbsd.org, hshoexer@yerbouti.franken.de
Date: Wed, 19 Nov 2025 14:12:06 +0000

On Wed, Nov 19, 2025 at 12:48:59PM +0100, Hans-Jrg Hxer wrote:
> Hi,
> 
> I'd like to revisit this diff.  Here' the context from before the last
> release:
> 
>  o I want to use 32-bit (legacy) mode for direct kernel launch for both
>    amd64 and i386; this will simplify the SEV-ES related code dealing
>    with #VC traps during locore0
> 
>  o right now we actually use compatibility mode; this implies that
>    exceptions will be raised by 64 bit rules, etc.
> 
>  o the problem with my initial diff was, that it broke VMX/EPT support
>    in vmm(4) by tricking vmm(4) into assuming "restricted" guest mode;
>    even when the CPU actually supports unrestricted guests
> 
>  o mlarkin removed the support for restricted guests [1]; with this my
>    diff works now on both VMX/EPT and SVM/RVI
> 
> Tests are welcome :-)

I've just tested this version of the diff on one of the systems that the
previous version broke, and it seems to be working just fine.

Context: I previously backported the change to 7.7-release (*) because at the
time the systems that I wanted to test were not running -current.  One of
those systems is still running 7.7-release so I had the opportunity to test
this version of your patch on the same setup.  No problems observed so far.

(*) actually 7.7-release plus a ton of local patches, but mostly unrelated.