Re: [PATCH] arch/cacheflush: Introduce flush_all_caches()

[Peter Zijlstra]

On Tue, Aug 16, 2022 at 10:42:03AM -0700, Dan Williams wrote:

> I also think this cache_flush_region() API wants a prominent comment
> clarifying the limited applicability of this API. I.e. that it is not
> for general purpose usage, not for VMs, and only for select bare metal
> scenarios that instantaneously invalidate wide swaths of memory.
> Otherwise, I can now see how this looks like a potentially scary
> expansion of the usage of wbinvd.

This; because adding a generic API like this makes it ripe for usage.
And this is absolutely the very last thing we want used.