Re: [PATCH for-4.22] xen/arm: propagate secondary GIC initialization failures

[Oleksii Kurochko <oleksii.kurochko@gmail.com>]

On 7/10/26 12:20 PM, Mykola Kvach wrote:
> The GICv3 secondary_init() callback can fail while discovering or
> waking a Redistributor, enabling LPIs, or setting up an ITS collection.
> gic_init_secondary_cpu() currently discards that status. start_secondary()
> then marks the CPU online even though its per-CPU GIC interface may be
> unusable.
> 
> Return the callback status through the common GIC layer. Have
> start_secondary() report the failure and stop the affected CPU before it
> is added to cpu_online_map.
> 
> Fixes: bc183a0235e0 ("xen/arm: Add support for GIC v3")
> Signed-off-by: Mykola Kvach <mykola_kvach@epam.com>
> ---

This doesn't look release-critical. IIUC, the issue only occurs if 
`gic_hw_ops->secondary_init()` fails, which itself appears to require an 
abnormal condition (e.g. invalid DT data or a failure while initializing 
the GIC Redistributor/LPI/ITS state). On correctly configured systems, 
this path should never be taken. We've also been living with this 
behavior for a long time, so unless the maintainers feel strongly that 
it should go in now, I think we could postpone this patch until the 4.22 
release.

Thanks.

~ Oleksii