[PATCH 3/8] KVM: arm64: Drop useless PAN setting on host EL1 to EL2 transition

[Vladimir Murzin]

On 10/26/20 9:51 AM, Marc Zyngier wrote:
> Setting PSTATE.PAN when entering EL2 on nVHE doesn't make much
> sense as this bit only means something for translation regimes
> that include EL0. This obviously isn't the case in the nVHE case,
> so let's drop this setting.
> 
> Signed-off-by: Marc Zyngier <maz at kernel.org>
> ---
>  arch/arm64/kvm/hyp/nvhe/host.S | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/arch/arm64/kvm/hyp/nvhe/host.S b/arch/arm64/kvm/hyp/nvhe/host.S
> index ff9a0f547b9f..ed27f06a31ba 100644
> --- a/arch/arm64/kvm/hyp/nvhe/host.S
> +++ b/arch/arm64/kvm/hyp/nvhe/host.S
> @@ -17,8 +17,6 @@ SYM_FUNC_START(__host_exit)
>  
>  	get_host_ctxt	x0, x1
>  
> -	ALTERNATIVE(nop, SET_PSTATE_PAN(1), ARM64_HAS_PAN, CONFIG_ARM64_PAN)
> -
>  	/* Store the host regs x2 and x3 */
>  	stp	x2, x3,   [x0, #CPU_XREG_OFFSET(2)]
>  
> 

It was originally introduced in cb96408da4e1 (arm64: KVM: VHE: reset PSTATE.PAN on entry to EL2)
and indeed only applies to VHE (I even remember some attempts to put in under CONFIG_ARM64_VHE).

So, if it helps:
 
    Reviewed-by: Vladimir Murzin <vladimir.murzin at arm.com>

Cheers
Vladimir