Re: [ANNOUNCEMENT] COCONUT Secure VM Service Module for SEV-SNP

From: James Bottomley <jejb@linux.ibm.com>
To: "Tom Lendacky" <thomas.lendacky@amd.com>,
	"Jörg Rödel" <jroedel@suse.de>,
	amd-sev-snp@lists.suse.com, linux-coco@lists.linux.dev,
	kvm@vger.kernel.org
Subject: Re: [ANNOUNCEMENT] COCONUT Secure VM Service Module for SEV-SNP
Date: Thu, 13 Apr 2023 12:57:38 -0400	[thread overview]
Message-ID: <5ab2bca5dab750cce82df5e28db5ebb8f657e3ed.camel@linux.ibm.com> (raw)
In-Reply-To: <bf7f82ab-3cd3-a5f6-74ec-270d3ca6c766@amd.com>

On Tue, 2023-04-11 at 14:57 -0500, Tom Lendacky wrote:
> On 3/21/23 04:29, Jörg Rödel wrote:
> > Hi,
> > 
> > We are happy to announce that last week our secure VM service
> > module (SVSM) went public on GitHub for everyone to try it out and
> > participate in its further development. It is dual-licensed under
> > the MIT and APACHE-2.0 licenses.
> > 
> > The project is written in Rust and can be cloned from:
> > 
> >         https://github.com/coconut-svsm/svsm
> > 
> > There are also repositories in the github project with the Linux
> > host and guest, EDK2 and QEMU changes needed to run the SVSM and
> > boot up a full Linux guest.
> > 
> > The SVSM repository contains an installation guide in the
> > INSTALL.md file and contributor hints in CONTRIBUTING.md.
> > 
> > A blog entry with more details is here:
> > 
> >         https://www.suse.com/c/suse-open-sources-secure-vm-service-
> > module-for-confidential-computing/
> > 
> > We also thank AMD for implementing and providing the necessary
> > changes to Linux and EDK2 to make an SVSM possible.
> 
> Just wanted to let everyone know that I'm looking into what we can do
> to  move towards a single SVSM project so that resources aren't split
> between  the two.
> 
> I was hoping to have a comparison, questions and observations between
> the two available by now, however, I'm behind on that... but, I am
> working on it.

We (IBM) did look at what it might take to add a vTPM to Coconut, but
we ran into the problem that if we do it at CPL3 (which looks
desirable), then we have to wait until pretty much every one of the
twelve(!) tasks in this list is complete:

https://github.com/coconut-svsm/svsm/issues/16

At a conservative estimate, it looks like completion of all twelve
would take a team of people over a year to achieve.  Some of these
tasks, like task switching and a syscall interface, really don't look
like they belong in a simple service module, like we were imagining an
SVSM would operate, is there some rationale behind this (or ideally
some architecture document that gives the justifications)?  I think
what I'm really asking is can we get to CPL3 separation way sooner than
completion of all these tasks?

Regards,

James