[PATCH v2 19/26] KVM: arm64: nv: Add trap forwarding for HFGxTR_EL2

[Oliver Upton]

Hey Marc,

On Fri, Jul 28, 2023 at 09:29:45AM +0100, Marc Zyngier wrote:

[...]

> @@ -943,6 +1025,27 @@ void __init populate_nv_trap_config(void)
>  	kvm_info("nv: %ld coarse grained trap handlers\n",
>  		 ARRAY_SIZE(encoding_to_cgt));

It might make sense to skip insertion of the FGT trap controls if the
system doesn't have FGT in the first place.

> +	for (int i = 0; i < ARRAY_SIZE(encoding_to_fgt); i++) {
> +		const struct encoding_to_trap_config *fgt = &encoding_to_fgt[i];
> +		union trap_config tc;
> +
> +		tc = get_trap_config(fgt->encoding);
> +
> +		WARN(tc.fgt,
> +		     "Duplicate FGT for sys_reg(%d, %d, %d, %d, %d)\n",
> +		     sys_reg_Op0(fgt->encoding),
> +		     sys_reg_Op1(fgt->encoding),
> +		     sys_reg_CRn(fgt->encoding),
> +		     sys_reg_CRm(fgt->encoding),
> +		     sys_reg_Op2(fgt->encoding));

Same comment here, we should just bail.

> +		tc.val |= fgt->tc.val;
> +		xa_store(&sr_forward_xa, fgt->encoding,
> +			 xa_mk_value(tc.val), GFP_KERNEL);
> +	}
> +
> +	kvm_info("nv: %ld fine grained trap handlers\n",
> +		 ARRAY_SIZE(encoding_to_fgt));
>  }

-- 
Thanks,
Oliver