@@ -321,6 +321,7 @@
#define X86_FEATURE_FRED (12*32+17) /* "fred" Flexible Return and Event Delivery */
#define X86_FEATURE_LKGS (12*32+18) /* Load "kernel" (userspace) GS */
#define X86_FEATURE_WRMSRNS (12*32+19) /* Non-serializing WRMSR */
+#define X86_FEATURE_NMI_SOURCE (12*32+20) /* NMI-Source reporting with FRED */
#define X86_FEATURE_AMX_FP16 (12*32+21) /* AMX fp16 Support */
#define X86_FEATURE_AVX_IFMA (12*32+23) /* Support for VPMADD52[H,L]UQ */
#define X86_FEATURE_LAM (12*32+26) /* "lam" Linear Address Masking */
@@ -88,6 +88,7 @@ static const struct cpuid_dep cpuid_deps[] = {
{ X86_FEATURE_AMX_INT8, X86_FEATURE_AMX_TILE },
{ X86_FEATURE_SHSTK, X86_FEATURE_XSAVES },
{ X86_FEATURE_FRED, X86_FEATURE_LKGS },
+ { X86_FEATURE_NMI_SOURCE, X86_FEATURE_FRED },
{ X86_FEATURE_SPEC_CTRL_SSBD, X86_FEATURE_SPEC_CTRL },
{}
};
NMI-source reporting is introduced to report the sources of NMIs with FRED event delivery based on vectors in NMI interrupt messages or the local APIC. This enables the kernel to avoid the latency incurred by going over the entire NMI handler list and reduces ambiguity about the source of an NMI. Enumerate NMI-source reporting in cpufeatures.h. Also, since NMI-source reporting uses the FRED event dispatch framework, make it dependent on FRED in the CPUID dependency table. This ensures that NMI-source reporting gets disabled when FRED is disabled. NMI-source reporting is intended as a kernel feature and does not need userspace enumeration or configuration. There is no need to expose it to userspace through /proc/cpuinfo. Originally-by: Jacob Pan <jacob.jun.pan@linux.intel.com> Signed-off-by: Sohil Mehta <sohil.mehta@intel.com> --- v7: No change. v6: No change. v5: Add NMI-source to the CPUID dependency table. Do not expose NMI-source feature through /proc/cpuinfo. --- arch/x86/include/asm/cpufeatures.h | 1 + arch/x86/kernel/cpu/cpuid-deps.c | 1 + 2 files changed, 2 insertions(+)