On 6/12/2025 2:48 PM, Sohil Mehta wrote:

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[off-list ref]
Signed-off-by: Sohil Mehta<redacted>

Reviewed-by: Xin Li (Intel) <xin@zytor.com>