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    SubjectRe: [PATCH v6 0/5] x86: Enable LKGS instruction

    * Xin Li <xin3.li@intel.com> wrote:

    > LKGS instruction is introduced with Intel FRED (flexible return and event
    > delivery) specification. As LKGS is independent of FRED, we enable it as
    > a standalone CPU feature.
    >
    > LKGS behaves like the MOV to GS instruction except that it loads the base
    > address into the IA32_KERNEL_GS_BASE MSR instead of the GS segment’s
    > descriptor cache, which is exactly what Linux kernel does to load user
    > level GS base. Thus, with LKGS, there is no need to SWAPGS away from the
    > kernel GS base.

    Ok, this looks good to me.

    I've applied the first 4 patches to tip:x86/cpu, as the instruction exists
    in a public document and these patches are fine stand-alone as well, such
    as the factoring out of load_gs_index() methods from a high-use low level
    header into a new header file.

    Planning to apply the final, LKGS enabler patch as well, unless there's any
    objections from others?

    Thanks,

    Ingo

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