Re: [ndctl PATCH 0/6] Add error injection support

[Ben Cheatham <benjamin.cheatham@amd.com>]

On 4/28/25 9:35 PM, Alison Schofield wrote:
> On Thu, Apr 24, 2025 at 04:23:55PM -0500, Ben Cheatham wrote:
>> This series adds support for injecting CXL protocol (CXL.cache/mem)
>> errors[1] into CXL RCH Downstream ports and VH root ports[2] and
>> poison into CXL memory devices through the CXL debugfs. Errors are
>> injected using a new 'inject-error' command, while errors are reported
>> using a new cxl-list "-N"/"--injectable-errors" option.
>>
>> The 'inject-error' command and "-N" option of cxl-list both require
>> access to the CXL driver's debugfs. Because the debugfs doesn't have a
>> required mount point, a "--debugfs" option is added to both cxl-list and
>> cxl-inject-error to specify the path to the debugfs if it isn't mounted
>> to the usual place (/sys/kernel/debug).
>>
>> The documentation for the new cxl-inject-error command shows both usage
>> and the possible device/error types, as well as how to retrieve them
>> using cxl-list. The documentation for cxl-list has also been updated to
>> show the usage of the new injectable errors and debugfs options.
>>
>> [1]: ACPI v6.5 spec, section 18.6.4
>> [2]: ACPI v6.5 spec, table 18.31
> 
> Hi Ben,
> 
> Junkyeok Im posted a set for inject & clear poison back in 2023.[1] It
> went through one round of review but was a bit ahead of it's time as we
> were still working out the presentation of media-errors in the trigger
> poison patch set. I'll 'cc them here in case they have interest and can
> help review thi set.

Thanks for pointing this out. I forgot to look for an existing set before
implementing it myself, sorry about that :/.

I'd be willing to drop the poison support from this set and use Junhyeok's
instead, integrate it into this one, or leave it as-is.

> 
> How come you're not interested in implementing clear-poison?

It is implemented, it's a flag ("--clear") for the inject-error command. I forgot
to mention it in the cover letter, I can add it in v2.

Thanks,
Ben