Re: [PATCH v2 01/11] KVM: arm64: initialize HCRX_EL2

Marc Zyngier
2023-06-03T08:39:21Z

On Tue, 09 May 2023 15:22:25 +0100,
Kristina Martsenko <kristina.martsenko@arm.com> wrote:
>
> ARMv8.7/9.2 adds a new hypervisor configuration register HCRX_EL2.
> Initialize the register to a safe value (all fields 0), to be robust
> against firmware that has not initialized it. This is also needed to
> ensure that the register is reinitialized after a kexec by a future
> kernel.
>
> In addition, move SMPME setup over to the new flags, as it would
> otherwise get overridden. It is safe to set the bit even if SME is not
> (uniformly) supported, as it will write to a RES0 bit (having no
> effect), and SME will be disabled by the cpufeature framework.
> (Similar to how e.g. the API bit is handled in HCR_HOST_NVHE_FLAGS.)
>
> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>

Acked-by: Marc Zyngier <maz@kernel.org>

M.

--
Without deviation from the norm, progress is not possible.