Re: [PATCH 2/4] swiotlb: Add a new cc-swiotlb implementation for Confidential VMs

Andi Kleen
2023-01-31T17:18:12Z

>No, this cannot guarantee we always have sufficient TLB caches, so we
can also have a "No memory for cc-swiotlb buffer" warning.

It's not just a warning, it will be IO errors, right?

>
> But I want to emphasize that in this case, the current implementation
> is no worse than the legacy implementation. Moreover, dynamic TLB
> allocation is more suitable for situations where more disks/network
> devices will be hotplugged, in which case you cannot pre-set a
> reasonable value.

That's a reasonable stand point, but have to emphasize that is
"probabilistic" in all the descriptions and comments.

I assume you did some stress testing (E.g. all cores submitting at full
bandwidth) to validate that it works for you?

-Andi