Re: [PATCH v11 1/3] ACPI: APEI: send SIGBUS to current task if synchronous memory error not recovered

Dan Williams
2024-02-24T19:42:51Z

Jonathan Cameron wrote:
[..]
> > > None of the CXL component errors should be handled as synchronous
> > > events. They are either asynchronous protocol errors, or effectively
> > > equivalent to CPER_SEC_PLATFORM_MEM notifications.
> >
> > Not a good example, CPER_SEC_PLATFORM_MEM is sometimes signaled via SEA.
> >
>
> Premature send.:(
>
> One example I can point at is how we do signaling of memory
> errors detected by the host into a VM on arm64.
> https://elixir.bootlin.com/qemu/latest/source/hw/acpi/ghes.c#L391
> CPER_SEC_PLATFORM_MEM via ARM Synchronous External Abort (SEA).
>
> Right now we've only used async in QEMU for proposed CXL error
> CPER records signalling but your reference to them being similar
> to CPER_SEC_PLATFORM_MEM is valid so 'maybe' they will be
> synchronous in some physical systems as it's one viable way to
> provide rich information for synchronous reception of poison.
> For the VM case my assumption today is we don't care about providing the
> VM with rich data, so CPER_SEC_PLATFORM_MEM is fine as a path for
> errors whether from CXL CPER records or not.

Makes sense... and I was not precise when I mentioned the equivalency, I
was only considering x86.