Re: [PATCH 00/21] x86: Trenchboot Secure Launch DRTM (Xen)

[Nicola Vetrini <nicola.vetrini@bugseng.com>]

On 2025-04-22 19:14, Andrew Cooper wrote:
> On 22/04/2025 4:06 pm, Sergii Dmytruk wrote:
>> The aim of the [TrenchBoot] project is to provide an implementation of
>> DRTM that is generic enough to cover various use cases:
>>  - Intel TXT and AMD SKINIT on x86 CPUs
>>  - legacy and UEFI boot
>>  - TPM1.2 and TPM2.0
>>  - (in the future) DRTM on Arm CPUs
>> 
>> DRTM is a version of a measured launch that starts on request rather
>> than at the start of a boot cycle.  One of its advantages is in not
>> including the firmware in the chain of trust.
>> 
>> Xen already supports DRTM via [tboot] which targets Intel TXT only.
>> tboot employs encapsulates some of the DRTM details within itself 
>> while
>> with TrenchBoot Xen (or Linux) is meant to be a self-contained payload
>> for a TrenchBoot-enabled bootloader (think GRUB).  The one exception 
>> is
>> that UEFI case requires calling back into bootloader to initiate DRTM,
>> which is necessary to give Xen a chance of querying all the 
>> information
>> it needs from the firmware before performing DRTM start.
>> 
>> From reading the above tboot might seem like a more abstracted, but 
>> the
>> reality is that the payload needs to have DRTM-specific knowledge 
>> either
>> way.  TrenchBoot in principle allows coming up with independent
>> implementations of bootloaders and payloads that are compatible with
>> each other.
>> 
>> The "x86/boot: choose AP stack based on APIC ID" patch is shared with
>> [Parallelize AP bring-up] series which is required here because Intel
>> TXT always releases all APs simultaneously.  The rest of the patches 
>> are
>> unique.
> 
> I've stripped out the sha2 patch and fixed up to use the existing sha2,
> then kicked off some CI testing:
> 
> https://gitlab.com/xen-project/hardware/xen-staging/-/pipelines/1780285393
> https://cirrus-ci.com/build/5452335868018688
> 
> When the dust has settled, I'll talk you through the failures.
> 

Accidental use of C18 here

https://saas.eclairit.com:3787/fs/var/local/eclair/xen-project.ecdf/xen-project/hardware/xen-staging/ECLAIR_normal/andrew/tb-v1.1/X86_64/9791028023/PROJECT.ecd;/by_service/MC3A2.D1.1.html

> ~Andrew

-- 
Nicola Vetrini, B.Sc.
Software Engineer
BUGSENG (https://bugseng.com)
LinkedIn: https://www.linkedin.com/in/nicola-vetrini-a42471253