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    Subject[PATCH v8 3/8] x86/cpu, kvm: Add the NO_NESTED_DATA_BP feature
    Date
    The "Processor ignores nested data breakpoints" feature was being
    open-coded for KVM. Add the feature to its newly introduced
    CPUID leaf 0x80000021 EAX proper.

    Signed-off-by: Kim Phillips <kim.phillips@amd.com>
    ---
    arch/x86/include/asm/cpufeatures.h | 3 +++
    arch/x86/kvm/cpuid.c | 2 +-
    2 files changed, 4 insertions(+), 1 deletion(-)

    diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
    index a84536876794..7f0fb894e432 100644
    --- a/arch/x86/include/asm/cpufeatures.h
    +++ b/arch/x86/include/asm/cpufeatures.h
    @@ -428,6 +428,9 @@
    #define X86_FEATURE_V_TSC_AUX (19*32+ 9) /* "" Virtual TSC_AUX */
    #define X86_FEATURE_SME_COHERENT (19*32+10) /* "" AMD hardware-enforced cache coherency */

    +/* AMD-defined Extended Feature 2 EAX, CPUID level 0x80000021 (EAX), word 20 */
    +#define X86_FEATURE_NO_NESTED_DATA_BP (20*32+ 0) /* "" No Nested Data Breakpoints */
    +
    /*
    * BUG word(s)
    */
    diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
    index 3930452bf06e..13bd2769fa5a 100644
    --- a/arch/x86/kvm/cpuid.c
    +++ b/arch/x86/kvm/cpuid.c
    @@ -742,7 +742,7 @@ void kvm_set_cpu_caps(void)
    F(SME_COHERENT));

    kvm_cpu_cap_mask(CPUID_8000_0021_EAX,
    - BIT(0) /* NO_NESTED_DATA_BP */ | 0 /* SmmPgCfgLock */ |
    + F(NO_NESTED_DATA_BP) | 0 /* SmmPgCfgLock */ |
    BIT(6) /* NULL_SEL_CLR_BASE */ | 0 /* PrefetchCtlMsr */
    );
    if (cpu_feature_enabled(X86_FEATURE_LFENCE_RDTSC))
    --
    2.34.1
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