Re: [PATCH for-4.21??? 0/3] x86/vLAPIC: CMCI LVT handling

[Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>]

On 10/8/25 2:07 PM, Jan Beulich wrote:

> 1: add indirection to LVT handling
> 2: drop VLAPIC_VERSION
> 3: properly support the CMCI LVT
>
> Now having this coded up, I realize it may be too intrusive at this point of
> the release cycle. Still I wanted to propose it ...
>     
IIUC (not being an x86 expert, please take that into account),
Xen advertises CMCI support but doesn’t emulate it properly, which means
the guest stops noticing corrected errors. This could result in lost error
reports or potential guest kernel warnings, right?
Would that lead to inconsistencies in the MCE subsystem?
I’m not entirely sure this issue is critical, as the related Linux
configurations can be disabled, or MCE can be turned off using mce=off.
At the very least, CMCI can be disabled with mce=no_cmci. So, unless there are
other objections, I think this can be deferred until 4.22.

Thanks.

~ Oleksii