xen/arm: Introduce enable callback to enable a capabilities on each online CPU
Once Xen knows what features/workarounds present on the platform, it
might be necessary to configure each online CPU.
Introduce a new callback "enable" that will be called on each online CPU to
configure the "capability".
The code is based on Linux v4.14 (where cpufeature.c comes from), the
explanation of why using stop_machine_run is kept as we have similar
problem in the future.
Lastly introduce enable_errata_workaround that will be called once CPUs
have booted and before the hardware domain is created.
This is part of XSA-254.
Signed-of-by: Julien Grall <julien.grall@linaro.org>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
projects / xen.git / commit