On Thu, 2025-05-22 at 12:21 +0300, Elena Reshetova wrote:
> --- a/tools/arch/x86/include/asm/cpufeatures.h
> +++ b/tools/arch/x86/include/asm/cpufeatures.h
> @@ -481,6 +481,7 @@
> #define X86_FEATURE_AMD_HTR_CORES (21*32+ 6) /* Heterogeneous Core
> Topology */
> #define X86_FEATURE_AMD_WORKLOAD_CLASS (21*32+ 7) /* Workload
> Classification */
> #define X86_FEATURE_PREFER_YMM (21*32+ 8) /* Avoid ZMM
> registers due to downclocking */
> +#define X86_FEATURE_SGX_EUPDATESVN (21*32+11) /* Support for
> ENCLS[EUPDATESVN] instruction */
[Sorry for not mentioning in the previous version.]
Nit:
I am not sure we need to change tool headers.
Per commit
f6d9883f8e68 ("tools/include: Sync x86 headers with the kernel sources")
.. and tools/include/uapi/README:
...
What we are doing now is a third option:
- A software-enforced copy-on-write mechanism of kernel headers to
tooling, driven by non-fatal warnings on the tooling side build when
kernel headers get modified:
Warning: Kernel ABI header differences:
diff -u tools/include/uapi/drm/i915_drm.h include/uapi/drm/i915_drm.h
diff -u tools/include/uapi/linux/fs.h include/uapi/linux/fs.h
diff -u tools/include/uapi/linux/kvm.h include/uapi/linux/kvm.h
...
The tooling policy is to always pick up the kernel side headers as-is,
and integate them into the tooling build. The warnings above serve as a
notification to tooling maintainers that there's changes on the kernel
side.
We've been using this for many years now, and it might seem hacky, but
works surprisingly well.
.. I interpret the updating to tools headers is not mandatory (unless building
tools fails w/o the new feature bit definition which I believe isn't the case of
SGX_UPDATESVN). The tools maintainers will eventually do the sync.
But on the other hand, modifying tools headers in this patch also reduces tools
maintainer's effort in the future.
That being said, I am unclear with the rule here. Perhaps Dave/Ingo can help to
clarify.
