On 02/16/2017 12:13 PM, Borislav Petkov wrote: > On Thu, Feb 16, 2017 at 09:42:36AM -0600, Tom Lendacky wrote: >> Update the CPU features to include identifying and reporting on the >> Secure Memory Encryption (SME) feature. SME is identified by CPUID >> 0x8000001f, but requires BIOS support to enable it (set bit 23 of >> SYS_CFG MSR). Only show the SME feature as available if reported by >> CPUID and enabled by BIOS. >> >> Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx> >> --- >> arch/x86/include/asm/cpufeature.h | 7 +++++-- >> arch/x86/include/asm/cpufeatures.h | 5 ++++- >> arch/x86/include/asm/disabled-features.h | 3 ++- >> arch/x86/include/asm/msr-index.h | 2 ++ >> arch/x86/include/asm/required-features.h | 3 ++- >> arch/x86/kernel/cpu/common.c | 19 +++++++++++++++++++ >> 6 files changed, 34 insertions(+), 5 deletions(-) > > What happened here? > > You had it already: > > https://lkml.kernel.org/r/20161110003459.3280.25796.stgit@xxxxxxxxxxxxxxxxxxxxxxxxx > > The bit in get_cpu_cap() with checking the MSR you can add at the end of > init_amd() for example. I realize it's a bit more code and expands the changes but I thought it would be a bit clearer as to what was going on this way. And then the follow on patch for the physical address reduction goes in nicely, too. If you prefer I stay with the scattered feature approach and then clear the bit based on the MSR at the end of init_amd() I can do that. I'm not attached to either method. Thanks, Tom >
