From: Mike Larkin <mlarkin@nested.page>
Subject: Re: [0/5] vmd: generate and expose ACPI tables to the guest via fw_cfg
To: Miguel Landaeta <miguel@miguel.cc>
Cc: tech@openbsd.org
Date: Mon, 15 Jun 2026 16:42:28 -0700

On Mon, Jun 15, 2026 at 10:20:11AM +0000, Miguel Landaeta wrote:
> On Fri, Jun 12, 2026 at 01:56:40AM +0000, Mike Larkin wrote:
> >
> > yes this is where we are headed.
> >
> > your full diff available somewhere?
>
> This is my diff so far:
>
> https://github.com/openbsd/src/compare/master...nomadium:src:vmd-multi-vcpu.patch
>
> It boots a multi-VCPU guest to single-user via vmctl start -b /bsd.
> I've tested with 1, 2, 3, and 4 VCPUs (8 also works but is noticeably slower).
>
> Known limitations:
>
> - Firmware (SeaBIOS) boot is broken. Not yet investigated.
>
> - LAPIC timer is not implemented. APs execute work dispatched to them,
>   but the guest scheduler cannot do preemptive time-slicing on them
>   without timer interrupts.
>
> - Tested on Intel (i5-8350U / Kaby Lake-R, Thinkpad T480) only. AMD not tested.
>
> A few diagnostic log_warnx commits are still in the branch, happy to
> strip them if you'd prefer a cleaner diff.

how do you deliver IPIs without a lapic?