mirror of https://github.com/torvalds/linux.git
b02dc185ee
Intel Advanced Performance Extensions (APX) introduce a new set of general-purpose registers, managed as an extended state component via the xstate management facility. Before enabling this new xstate, define a feature flag to clarify the dependency in xsave_cpuid_features[]. APX is enumerated under CPUID level 7 with EDX=1. Since this CPUID leaf is not yet allocated, place the flag in a scattered feature word. While this feature is intended only for userspace, exposing it via /proc/cpuinfo is unnecessary. Instead, the existing arch_prctl(2) mechanism with the ARCH_GET_XCOMP_SUPP option can be used to query the feature availability. Finally, clarify that APX depends on XSAVE. Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Sohil Mehta <sohil.mehta@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Link: https://lore.kernel.org/r/20250416021720.12305-2-chang.seok.bae@intel.com |
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| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
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README
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.