Re: [PATCH 18/22] KVM: arm64: nv: Set access flag on table descriptors at stage-2

[Leonardo Bras <leo.bras@arm.com>]

On Tue, Jun 23, 2026 at 11:41:57AM -0700, Oliver Upton wrote:
> Implement access flag updates on table descriptors as required by
> FEAT_HAFT.
> 
> Signed-off-by: Oliver Upton <oupton@kernel.org>
> ---
>  arch/arm64/kvm/nested.c | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c
> index 2408d604a1e1..6f540d3481d5 100644
> --- a/arch/arm64/kvm/nested.c
> +++ b/arch/arm64/kvm/nested.c
> @@ -133,6 +133,7 @@ struct s2_walk_info {
>  	bool		be;
>  	bool		ha;
>  	bool		hd;
> +	bool		haft;
>  };
>  
>  struct s2_walk_step {
> @@ -234,12 +235,15 @@ static bool should_set_access_flag(struct s2_walk_info *wi, struct s2_walk_step
>  	if (access->type == WALK_ACCESS_NONARCH)
>  		return false;
>  
> -	return wi->ha;
> +	return kvm_pte_table(ws->desc, ws->level) ? wi->haft : wi->ha;
>  }
>  
>  static bool should_set_dirty_state(struct s2_walk_info *wi, struct s2_walk_step *ws,
>  				   struct kvm_s2_trans *out, struct kvm_walk_access *access)
>  {
> +	if (kvm_pte_table(ws->desc, ws->level))
> +		return false;
> +
>  	switch (access->type) {
>  	/* R_RKMHW */
>  	case WALK_ACCESS_CMO:
> @@ -424,6 +428,10 @@ static int walk_nested_s2_pgd(struct kvm_vcpu *vcpu, struct kvm_walk_access *acc
>  			return 1;
>  		}
>  
> +		ret = handle_desc_update(vcpu, wi, &ws, out, access);
> +		if (ret)
> +			return ret;
> +
>  		base_addr = ws.desc & GENMASK_ULL(47, wi->pgshift);
>  
>  		ws.level += 1;
> @@ -562,6 +570,7 @@ static void setup_s2_walk(struct kvm_vcpu *vcpu, struct s2_walk_info *wi)
>  	wi->ha = vtcr & VTCR_EL2_HA;
>  	wi->be = vcpu_read_sys_reg(vcpu, SCTLR_EL2) & SCTLR_ELx_EE;
>  	wi->hd = wi->ha && (vtcr & VTCR_EL2_HD);
> +	wi->haft = wi->ha && (vtcr & VTCR_EL2_HAFT);
>  }
>  
>  int kvm_walk_nested_s2(struct kvm_vcpu *vcpu, struct kvm_walk_access *access,
> -- 
> 2.47.3
> 


To me it looks the same as the previous one but for S2, and seems correct.

FWIW:
Reviewed-by: Leonardo Bras <leo.bras@arm.com>

Thanks!
Leo