Re: [PATCH 3/4] Add lockdown mode

[Kevin Lampis <kevin.lampis@xxxxxxxxx>]

On Tue, May 6, 2025 at 5:49 PM Teddy Astie <teddy.astie@xxxxxxxxxx> wrote:
> (I can't find the PATCH 4/4)

I apologize. The missing patch will be posted as soon as we can.

> I am not convinced of the efficiency of being able to toggle lockdown
> (including disabling it) mode from command-line.

As you say a malicious userland could hijack the xen command-line arguments.
Patch 4 is about ignoring potentially dangerous command line arguments
when lockdown mode is enabled.
It is not about disabling lockdown mode itself. Sorry if the
description was confusing.

>Do we consider Dom0 kernel-space as well (thus Dom0 as a whole)

Dom0 kernel is part of the trusted computing base for Secure Boot so
we don't need to worry about that.

>what about privcmd device (which can issue hypercalls) ?

We do have a solution for securing hypercalls but I believe it will be
part of another patch series.