Re: [PATCH v3 5/5] intel_iommu: Optimize out some unnecessary UNMAP calls

[Peter Xu]

On Fri, Jun 09, 2023 at 05:49:06AM +0000, Duan, Zhenzhong wrote:
> Seems vtd_page_walk_one() already works in above way, checking mapping
> changes and calling kernel for changed entries?

Agreed in most cases, but the path this patch modified is not?  E.g. it
happens in rare cases where we simply want to unmap everything (e.g. on a
system reset, or invalid context entry)?

That's also why I'm curious whether perf of this path matters at all (and
assuming now we all agree that's the only goal now..), because afaiu it
didn't really trigger in common paths.

-- 
Peter Xu