Re: [virtio-dev] Re: [PATCH 0/5] virtio: introduce SUSPEND bit and vq state

Zhu, Lingshan
2023-09-21T09:55:18Z

On 9/21/2023 5:26 PM, Parav Pandit wrote:
>
>> From: Zhu, Lingshan <lingshan.zhu@intel.com>
>> Sent: Thursday, September 21, 2023 2:49 PM
>> TDISP devices can not be migrated for now, and the TDISP spec make clear
>> examples of attacking models, your admin vq LM on the PF exactly match the
>> model.
> I gave hint yesterday to you to consult Ravi at Intel who showed TDISP migration using a dedicated TVM using similar mechanism as admin command.
> But you sadly ignored...
>
> So let me make another attempt to explain,
>
> When in future TDISP device migration to be supported, the admin command will be done through a dedicated PF or a VF that resides in another trust domain, for example another TVM.
> Such admin virtio device will not be located in the hypervisor.
> Thereby, it will be secure.
> The admin commands pave the road to make this happen. Only thing changes is delegation of admin commands to another admin device instead of a PF.
if you plan to do it in future, then lets discuss in the future.

And TDISP can be migrated in future does not mean admin vq LM is secure,
I have repeated for so many times of the attacking model. and I will not
repeat again.
>
> There are other solutions too that will arise.
> I have seen another one too, may be DPU.
>
> In all the 2 approaches, TDISP is migratable and spec will evolve as multiple vendors including Intel, AMD and others showed the path towards it without mediation.
> Virtio will be able to leverage that as well using admin commands.
>
> I want to emphasize again, do not keep repeating AQ in your comments.
> It is admin commands in proposal [1].
we are discussing LM, right? Can TDISP help you here? TDISP spec gives
examples of attacking models, and your admin vq matches it, I gave you
quote of the spec yesterday.

This thread is about live migration anyway, not TDISP.
>
> As Michael also requested, I kindly request to co-operate on doing join technical work, shared ideas, knowledge and improve the spec.
>
> [1] https://lore.kernel.org/virtio-comment/20230909142911.524407-7-parav@nvidia.com/T/#mf15b68617f772770c6bf79f70e8ddc6fea834cfa
see other threads, I propose to reuse the basic facilities of live
migration in admin vq.