>> Ok ... applied those two on top of my "UNTESTED" patch and injected an error >> to force a UCNA log. > > Ok, what error type is that in EINJ nomenclature? I had only > > /sys/kernel/debug/apei/einj/available_error_type:0x00000002 Processor > Uncorrectable non-fatal > /sys/kernel/debug/apei/einj/available_error_type:0x00000008 Memory > Correctable > /sys/kernel/debug/apei/einj/available_error_type:0x00000010 Memory > Uncorrectable non-fatal > > and I would've guessed it is the 0x10 type, i.e., the memory > uncorrectable which is non-fatal - assuming here - but that one got > promoted to a #MC on my box.
I juggled with the type of the injection and the instruction sequence to access the target location. I used 0x10 to inject an uncorrected memory error with "# echo 1 > notrigger" to make sure the EINJ driver skipped the trigger actions. Then I had a user mode test program write a byte to the cache line. That pulled the uncorrected data into the cache (which logged the UCNA error signaled with CMCI). But the processor didn't actually consume the poison (no registers had corrupted data), so there was no machine check. Sneaky, huh? -Tony
