[PATCH v2 05/13] KVM: arm64: Restore mdcr_el2 from vcpu

[Will Deacon]

On Tue, Jun 15, 2021 at 02:39:42PM +0100, Fuad Tabba wrote:
> On deactivating traps, restore the value of mdcr_el2 from the
> vcpu context, rather than directly reading the hardware register.
> Currently, the two values are the same, i.e., the hardware
> register and the vcpu one. A future patch will be changing the
> value of mdcr_el2 on activating traps, and this ensures that its
> value will be restored.
> 
> No functional change intended.
> 
> Signed-off-by: Fuad Tabba <tabba at google.com>
> ---
>  arch/arm64/kvm/hyp/nvhe/switch.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
> index f7af9688c1f7..430b5bae8761 100644
> --- a/arch/arm64/kvm/hyp/nvhe/switch.c
> +++ b/arch/arm64/kvm/hyp/nvhe/switch.c
> @@ -73,7 +73,7 @@ static void __deactivate_traps(struct kvm_vcpu *vcpu)
>  
>  	___deactivate_traps(vcpu);
>  
> -	mdcr_el2 = read_sysreg(mdcr_el2);
> +	mdcr_el2 = vcpu->arch.mdcr_el2;

Do you need to change the VHE code too?

Will