x86/cpufeatures: Add the CPU feature bit for FRED
authorH. Peter Anvin (Intel) <hpa@zytor.com>
Tue, 5 Dec 2023 10:49:55 +0000 (02:49 -0800)
committerThomas Gleixner <tglx@linutronix.de>
Thu, 25 Jan 2024 18:10:30 +0000 (19:10 +0100)
commit51c158f7aaccc6f6423a61a1df4a0d4c0d9d22a9
treec7fd3310169d737a4686f7abd564841ee5b4a126
parent2cce95918d635126098d784c040b59333c464b20
x86/cpufeatures: Add the CPU feature bit for FRED

Any FRED enabled CPU will always have the following features as its
baseline:

  1) LKGS, load attributes of the GS segment but the base address into
     the IA32_KERNEL_GS_BASE MSR instead of the GS segment’s descriptor
     cache.

  2) WRMSRNS, non-serializing WRMSR for faster MSR writes.

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Shan Kang <shan.kang@intel.com>
Link: https://lore.kernel.org/r/20231205105030.8698-7-xin3.li@intel.com
arch/x86/include/asm/cpufeatures.h
arch/x86/kernel/cpu/cpuid-deps.c
tools/arch/x86/include/asm/cpufeatures.h