On Thu, Nov 03, 2022 at 11:23:04AM +0800, silviazhao-oc wrote:
Nano processor may not fully support rdpmc instruction,
What does that even mean? Not fully support?
it works well for reading general pmc counter, but will lead
GP(general protection) when accessing fixed pmc counter.
RDPMC will #GP when the perf counter specified cannot be read.
AFAICT, that is RCX: 0000000040000001 which looks like perf counter index 1 with INTEL_PMC_FIXED_RDPMC_BASE ORed in.
Furthermore, family/mode information is same between Nano processor
and ZX-C processor, it leads to zhaoxin pmu driver is wrongly loaded
for Nano processor, which resulting boot kernal fail.
So *that* is the real problem - it tries to access perf counters thinking it is running on architectural perf counters implementation but nano doesn't have that.
To solve this problem, stepping information will be checked to
distinguish between Nano processor and ZX-C processor.
Why doesn't that ZXC thing doesn't have a CPUID flag to check instead of looking at models and steppings and thus confusing it with a nano CPU?
[https://bugzilla.kernel.org/show_bug.cgi?id=212389]
Reported-by: Arjan <8vvbbqzo567a@xxxxxxxxxxxxxxxxx>
Does Arjan have a last name?
Signed-off-by: silviazhao-oc <silviazhao-oc@xxxxxxxxxxx>
I'm assuming your name is properly spelled "Silvia Zhao" and not in a single word with a "-oc" string appended at the end, yes?
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette