Re: [PATCHv6 11/30] x86/tdx: Handle in-kernel MMIO

Thomas Gleixner
2022-03-17T11:48:27Z

On Wed, Mar 16 2022 at 14:53, Dave Hansen wrote:
> On 3/15/22 19:08, Kirill A. Shutemov wrote:
>> In other words, even if all of the work was done to paravirtualize all
>> x86 MMIO users and virtio, this approach would still be needed. There
>> is essentially no way to get rid of this code.
> ...
>> == Patching TDX drivers ==
> ...> This approach will be adopted in the future, removing the bulk of
>> MMIO #VEs. The #VE-based MMIO will remain serving non-virtio use cases.
>
> I still don't like this very much, but I can't argue with my own logic. :)
>
> BTW, TDX folks... I expect you to, today, start coming up with a
> comprehensive list of the MMIO-induced #VE's and the reasoning why they
> should or should not be paravirtualized. You're going to get grumpy
> maintainers if this is done haphazardly as one-offs when users hit
> performance issues.

Grumpy maintainers? That's a meme. I've never seen that happen. :)