Re: [PATCH v9 13/13] cxl: Disable HPA/SPA translation handlers for Normalized Addressing

[Jonathan Cameron <jonathan.cameron@huawei.com>]

On Sat, 10 Jan 2026 12:46:58 +0100
Robert Richter <rrichter@amd.com> wrote:

> The root decoder provides the callbacks hpa_to_spa and spa_to_hpa to
> perform Host Physical Address (HPA) and System Physical Address
> translations, respectively. The callbacks are required to convert
> addresses when HPA != SPA. XOR interleaving depends on this mechanism,
> and the necessary handlers are implemented.
> 
> The translation handlers are used for poison injection
> (trace_cxl_poison, cxl_poison_inject_fops) and error handling
> (cxl_event_trace_record).
> 
> In AMD Zen5 systems with Normalized Addressing, endpoint addresses are
> not SPAs, and translation handlers are required for these features to
> function correctly.
> 
> Now, as ACPI PRM translation could be expensive in tracing or error
> handling code paths, do not yet enable translations to avoid its
> intensive use. Instead, disable those features which are used only for
> debugging and enhanced logging.
> 
> Introduce the flag CXL_REGION_F_NORM_ADDR that indicates Normalized
> Addressing for a region and use it to disable poison injection and DPA
> to HPA conversion.
> 
> Note: Dropped unused CXL_DECODER_F_MASK macro.

Meh, ideally that would be a precusor patch that Dave could pick up immediately.

Hopefully the whole thing merges though and so we don't have to care
about that.

Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>