Re: [PATCH v4 03/16] x86emul: support AVX10.1

[Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>]

On 4/9/26 5:03 PM, Jan Beulich wrote:
> This requires relaxing various pre-existing AVX512* checks, as AVX10.1
> covers all AVX512* except PF, ER, 4FMAPS, 4VNNIW (support for all of
> which was removed meanwhile anyway), and VP2INTERSECT. At the same time
> all vector widths are always supported.
>
> Note that visa_check(), replacing host_and_vcpu_must_have() uses, checks
> only the guest capability: We wouldn't expose AVX512* (nor AVX10)
> without the hardware supporting it. Similarly in avx512_vlen_check() the
> original host_and_vcpu_must_have() is reduced just vcpu_must_have().
> This also simplifies (resulting) code in the test and fuzzing harnesses,
> as there the XCR0 checks that are part of cpu_has_avx512* are only
> needed in local code, not in the emulator itself (where respective
> checking occurs elsewhere anyway, utilizing emul_test_read_xcr()).
>
> While in most cases the changes to x86_emulate() are entirely
> mechanical, for opmask insns earlier unconditional AVX512F checks are
> converted into "else" clauses to existing if/else-if ones.
>
> To be certain that no uses remain, also drop respective cpu_has_avx512*
> (except in the test harness) and vcpu_has_avx512*().
>
> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
> ---
> Probably avx512_vlen_check() should have the avx512_ prefix dropped, now
> that it also covers AVX10. But if so that wants to be either a prereq or
> a follow-on patch.
>
> visa_check() won't cover AVX10.2 and higher, but probably we will want
> independent checking logic for that anyway.
>
> Spec version 2 still leaves unclear what the xstate components are which
> would need enabling for AVX10/256. x86emul_get_fpu() is therefore
> untouched for now.
>
> Since it'll be reducing code size, we may want to further convert
> host_and_vcpu_must_have() to just vcpu_must_have() where appropriate
> (should be [almost?] everywhere).
> ---
> v4: Switch to using fallthrough pseudo-keyword. Drop new _vlen_check()
>      helper again. Re-base.
> v3: Add ChangeLog entry.
> v2: Drop use of vsz128 field. Re-base, in particular over dropping of
>      Xeon Phi support.
>
> --- a/CHANGELOG.md
> +++ b/CHANGELOG.md
> @@ -16,6 +16,7 @@ The format is based on [Keep a Changelog
>        mitigate (by rate-limiting) the system wide impact of an HVM guest
>        misusing atomic instructions.
>      - Support for CPIO microcode in discrete multiboot modules.
> +   - Support for AVX10.1. (Experimental)
Acked-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>.

What should be done else to have not experimental support of AVX10.1?

Thanks.

~ Oleksii