[PATCH v3 13/25] KVM: TDX: Fold tdx_mem_page_record_premap_cnt() into its sole caller

[Binbin Wu]

On 10/17/2025 8:32 AM, Sean Christopherson wrote:
> Fold tdx_mem_page_record_premap_cnt() into tdx_sept_set_private_spte() as
> providing a one-off helper for effectively three lines of code is at best a
> wash, and splitting the code makes the comment for smp_rmb()  _extremely_
> confusing as the comment talks about reading kvm->arch.pre_fault_allowed
> before kvm_tdx->state, but the immediately visible code does the exact
> opposite.
>
> Opportunistically rewrite the comments to more explicitly explain who is
> checking what, as well as _why_ the ordering matters.
>
> No functional change intended.
>
> Reviewed-by: Rick Edgecombe <rick.p.edgecombe at intel.com>
> Signed-off-by: Sean Christopherson <seanjc at google.com>

Reviewed-by: Binbin Wu <binbin.wu at linux.intel.com>

One nit below.

[...]
> +	/*
> +	 * If the TD isn't finalized/runnable, then userspace is initializing
> +	 * the VM image via KVM_TDX_INIT_MEM_REGION.  Increment the number of
> +	 * pages that need to be mapped and initialized via TDH.MEM.PAGE.ADD.
> +	 * KVM_TDX_FINALIZE_VM checks the counter to ensure all mapped pages
                                                                    ^
                                                 Nit: Is pre-mapped better?
> +	 * have been added to the image, to prevent running the TD with a
> +	 * valid mapping in the mirror EPT, but not in the S-EPT.
> +	 */
> +	if (unlikely(kvm_tdx->state != TD_STATE_RUNNABLE)) {
> +		if (KVM_BUG_ON(kvm->arch.pre_fault_allowed, kvm))
> +			return -EIO;
> +
> +		atomic64_inc(&kvm_tdx->nr_premapped);
> +		return 0;
> +	}
> +
> +	return tdx_mem_page_aug(kvm, gfn, level, pfn);
>   }
>   
>   static int tdx_sept_link_private_spt(struct kvm *kvm, gfn_t gfn,