linux-kernel - Re: [PATCH] x86/kvm/tdx: Save %rbp in TDX_MODULE

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <e2d844ad-182a-4fc0-a06a-d609c9cbef74@suse.com>
Date: Thu, 23 May 2024 07:56:39 +0200
From: Jürgen Groß <jgross@...e.com>
To: "Huang, Kai" <kai.huang@...el.com>,
 "kirill.shutemov@...ux.intel.com" <kirill.shutemov@...ux.intel.com>,
 "Hansen, Dave" <dave.hansen@...el.com>
Cc: "bp@...en8.de" <bp@...en8.de>,
 "dave.hansen@...ux.intel.com" <dave.hansen@...ux.intel.com>,
 "hpa@...or.com" <hpa@...or.com>, "mingo@...hat.com" <mingo@...hat.com>,
 "tglx@...utronix.de" <tglx@...utronix.de>, "x86@...nel.org"
 <x86@...nel.org>, "linux-kernel@...r.kernel.org"
 <linux-kernel@...r.kernel.org>,
 "linux-coco@...ts.linux.dev" <linux-coco@...ts.linux.dev>
Subject: Re: [PATCH] x86/kvm/tdx: Save %rbp in TDX_MODULE_CALL

On 20.05.24 13:54, Huang, Kai wrote:
> On Fri, 2024-05-17 at 09:48 -0700, Dave Hansen wrote:
>> On 5/17/24 08:58, Juergen Gross wrote:
>>> On 17.05.24 17:52, Dave Hansen wrote:
>> ..
>>>> Once we have the specific TDX module version, we can go ask the folks
>>>> who write it if there were any RBP clobbering bugs.
>>>
>>> Okay, how to get the TDX module version?
>>
>> You need something like this:
>>
>>> https://lore.kernel.org/all/20231012134136.1310650-1-yi.sun@intel.com/
> 
> This one prints TDX version info in the TDX guest, but not host.
> 
> The attached diff prints the TDX version (something like below) during
> module initialization, and should meet Juergen's needs for temporary use:
> 
> [  113.543538] virt/tdx: module verson: major 1, minor 5, internal 0
> 
>>
>> .. and yeah, this needs to be upstream.
>>
> 
>  From this thread I think it makes sense to add code to the TDX host code
> to print the TDX version during module initialization.  I'll start to work
> on this.
> 
> One thing is from the spec TDX has "4 versions": major, minor, update,
> internal.  They are all 16-bit, and the overall version can be written in:
> 
> 	<Major>.<Minor>.<Update>.<Internal>, e.g., 1.5.05.01
> 
> (see TDX module 1.5 API spec, section 3.3.2 "TDX Module Version".)
> 
> The attached diff only prints major, minor and internal, but leaves the
> update out because I believe it is for module runtime update (yet to
> confirm).
> 
> Given there are 4 versions, I think it makes sense to implement reading
> them based on this patchset ...
> 
> https://lore.kernel.org/kvm/6940c326-bfca-4c67-badf-ab5c086bf492@intel.com/T/
> 
> ... which extends the global metadata reading code to support any
> arbitrary struct and all element sizes (although all 4 versions are 16-
> bit)?

With that I got:

[   29.328484] virt/tdx: module verson: major 1, minor 5, internal 0


Juergen