abd16d68d6
After changing the argument of __raw_xsave_addr() from a mask to number Dave suggested to check if it makes sense to do the same for get_xsave_addr(). As it turns out it does. Only get_xsave_addr() needs the mask to check if the requested feature is part of what is supported/saved and then uses the number again. The shift operation is cheaper compared to fls64() (find last bit set). Also, the feature number uses less opcode space compared to the mask. :) Make the get_xsave_addr() argument a xfeature number instead of a mask and fix up its callers. Furthermore, use xfeature_nr and xfeature_mask consistently. This results in the following changes to the kvm code: feature -> xfeature_mask index -> xfeature_nr Suggested-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: kvm ML <kvm@vger.kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Rik van Riel <riel@surriel.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Siarhei Liakh <Siarhei.Liakh@concurrent-rt.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190403164156.19645-12-bigeasy@linutronix.de
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 Restructured Text 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.