Re: [PATCH v1 37/40] x86/cacheinfo: Extract out cache self-snoop checks

From: Ahmed S. Darwish
Date: Wed Mar 05 2025 - 14:00:30 EST


On Wed, 05 Mar 2025, Andrew Cooper wrote:
...
> It turns out not to be safe in cases where the underlying physical
> memory changes from cacheable to unchangeable.  By skipping the WBINVD
> as part of changing the memory type, you end up with spurious writebacks
> at a later point when the memory is expected to be UC.  Apparently this
> is a problem for CLX devices, hence the change in the SDM.
...
>
> CLX (Cascade Lake) != CXL (Compute eXpress Link).
>
> CXL is the new PCIe.  (So say the CXL consortium at least.)
>

Oh, sorry, you wrote "CLX devices" above, not CXL... Only thing my poor
brain could come up with was CASCADELAKE_X :)