Re: [PATCH v6 11/14] reboot: Secure Launch SEXIT support on reboot paths

From: Matthew Garrett
Date: Fri May 12 2023 - 07:40:08 EST


On Thu, May 04, 2023 at 02:50:20PM +0000, Ross Philipson wrote:
> If the MLE kernel is being powered off, rebooted or halted,
> then SEXIT must be called. Note that the SEXIT GETSEC leaf
> can only be called after a machine_shutdown() has been done on
> these paths. The machine_shutdown() is not called on a few paths
> like when poweroff action does not have a poweroff callback (into
> ACPI code) or when an emergency reset is done. In these cases,
> just the TXT registers are finalized but SEXIT is skipped.

What are the consequences of SEXIT not being called, and why is it ok to
skip it in these circumstances?