`shutdown -p now` fails to power off with VirtualBox UEFI boot

[Yasuhiro KIMURA]

From: Yasuhiro KIMURA <yasu at utahime.org>
Subject: `shutdown -p now` fails to power off with VirtualBox UEFI boot
Date: Fri, 19 Jun 2020 05:23:48 +0900 (JST)

> I have VirtualBox VM running 13-CURRENT. In order to switch from
> legacy BIOS to UEFI I reinstalled OS by using
> FreeBSD-13.0-CURRENT-amd64-20200611-r362037-disc1.iso. After that
> `shutdow -p now` (or select 'ACPI shutdown' in VM menu) fails to power
> off. Shutdown itself completes successfully. But power off never
> happens and CPU usage keeps high until either closing or resetting VM.
> 
> I reinstalled OS by using
> FreeBSD-13.0-CURRENT-amd64-20200618-r362292-disc1.iso but the problem
> still happens. If I switch back to legacy BIOS then the problem
> disappears. And it doesn't happen with either 11.4-RELEASE and
> 12.1-RELEASE.

I tried bisect and found this problem happens with r342108 and
after. Commit message of r342108 says as following.

yasu at rolling-vm-freebsd5[1012]% LANG=C svn log -c 342108
------------------------------------------------------------------------
r342108 | cem | 2018-12-15 14:46:04 +0900 (Sat, 15 Dec 2018) | 7 lines

efirt: When present, attempt to use EFI runtime services to shutdown

PR:             maybe related to 233998 (inconclusive at this time)
Submitted by:   byuu <byuu AT tutanota.com> (previous version)
Reviewed by:    imp
Differential Revision:  https://reviews.freebsd.org/D18506

------------------------------------------------------------------------
yasu at rolling-vm-freebsd5[1013]% 

Judging from it, I think it's very likely that this commit caused the
problem.

Then is there anything I can do for further investigation?

---
Yasuhiro KIMURA