Re: [PATCH] x86/hpet: Read HPET directly if panic in progress

From: Tony W Wang-oc
Date: Thu Jun 06 2024 - 04:45:18 EST




On 2024/6/5 23:51, Luck, Tony wrote:


[这封邮件来自外部发件人 谨防风险]

Which types exactly do you mean when you're looking at the severities[]
array in severity.c?

And what scenario are you talking about?

To get an #MC exception and detect only UCNA/SRAO errors? Can that even
happen on any hardware?


Yes, I mean an #MC exception happened and detect only like SRAO errors
like below:

MCESEV(
AO, "Action optional: memory scrubbing error",
SER, MASK(MCI_UC_AR|MCACOD_SCRUBMSK,
MCI_STATUS_UC|MCACOD_SCRUB)
),
MCESEV(
AO, "Action optional: last level cache writeback error",
SER, MASK(MCI_UC_AR|MCACOD, MCI_STATUS_UC|MCACOD_L3WB)
),

I think these errors are actually encountered on some platforms that
support these type of errors report to the #MC.

Intel servers from Nehalem through Cascade Lake reported memory controller
patrol scrub uncorrected error with #MC and SRAO signature.

Icelake and newer use CMCI with a UCNA signature.


I have a question, does Intel use #MC to report UCNA errors?

Sincerely
TonyWWang-oc