Re: [PATCH 00/15] kasan: x86: arm64: risc-v: KASAN tag-based mode for x86

[Dave Hansen]

On 2/4/25 10:58, Christoph Lameter (Ampere) wrote:
> ARM64 supports MTE which is hardware support for tagging 16 byte granules
> and verification of tags in pointers all in hardware and on some platforms
> with *no* performance penalty since the tag is stored in the ECC areas of
> DRAM and verified at the same time as the ECC.
> 
> Could we get support for that? This would allow us to enable tag checking
> in production systems without performance penalty and no memory overhead.

At least on the Intel side, there's no trajectory for doing something
like the MTE architecture for memory tagging. The DRAM "ECC" area is in
very high demand and if anything things are moving away from using ECC
"bits" for anything other than actual ECC. Even the MKTME+integrity
(used for TDX) metadata is probably going to find a new home at some point.

This shouldn't be a surprise to anyone on cc here. If it is, you should
probably be reaching out to Intel over your normal channels.