Should arm64 have a custom crash shutdown handler?

[Guilherme G. Piccoli]

On 05/05/2022 10:52, Vitaly Kuznetsov wrote:
> [...]
> For Hyper-V, the situation is similar: hv_crash_handler() intitiates
> VMbus unload on the crashing CPU only, there's no mechanism to do
> 'global' unload so other CPUs will likely not be able to connect Vmbus
> devices in kdump kernel but this should not be necessary.
> 
> There's a crash_kexec_post_notifiers mechanism which can be used instead
> but it's disabled by default so using machine_ops.crash_shutdown is
> better.
> 

Thanks a bunch Vitaly, for the clarification!

Just as a heads-up: there's been a panic notifiers refactor proposed [0]
in which some notifiers will run before kdump by default, not requiring
"crash_kexec_post_notifiers" (which BTW is *unfortunately* hardcoded as
'Y' for hyper-v, since a11589563e96).

Cheers,


Guilherme


[0]
https://lore.kernel.org/lkml/20220427224924.592546-1-gpiccoli@igalia.com/