Re: [PATCH 09/17] KVM: TDX: Add helper to handle mapping leaf SPTE into S-EPT

Yan Zhao
2026-03-30T07:23:02Z

On Fri, Mar 27, 2026 at 01:14:13PM -0700, Rick Edgecombe wrote:
> From: Sean Christopherson <seanjc@google.com>
>
> Add a helper, tdx_sept_map_leaf_spte(), to wrap and isolate PAGE.ADD and
> PAGE.AUG operations, and thus complete tdx_sept_set_private_spte()'s
> transition into a "dispatch" routine for setting/writing S-EPT entries.
>
> No functional change intended.
>
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
> ---
> arch/x86/kvm/vmx/tdx.c | 21 +++++++++++++--------
> 1 file changed, 13 insertions(+), 8 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
> index 92a846b91bac..361a75b42ae7 100644
> --- a/arch/x86/kvm/vmx/tdx.c
> +++ b/arch/x86/kvm/vmx/tdx.c
> @@ -1689,18 +1689,12 @@ static int tdx_sept_link_private_spt(struct kvm *kvm, gfn_t gfn,
> return 0;
> }
>
> -static int tdx_sept_set_private_spte(struct kvm *kvm, gfn_t gfn,
> - enum pg_level level, u64 mirror_spte)
> +static int tdx_sept_map_leaf_spte(struct kvm *kvm, gfn_t gfn, enum pg_level level,
> + u64 mirror_spte)
> {
> struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
> kvm_pfn_t pfn = spte_to_pfn(mirror_spte);
>
> - if (KVM_BUG_ON(!is_shadow_present_pte(mirror_spte), kvm))
> - return -EIO;
> -
> - if (!is_last_spte(mirror_spte, level))
> - return tdx_sept_link_private_spt(kvm, gfn, level, mirror_spte);
> -
> /* TODO: handle large pages. */
> if (KVM_BUG_ON(level != PG_LEVEL_4K, kvm))
> return -EIO;
> @@ -1725,7 +1719,18 @@ static int tdx_sept_set_private_spte(struct kvm *kvm, gfn_t gfn,
> return tdx_mem_page_aug(kvm, gfn, level, pfn);
> }
>
> +static int tdx_sept_set_private_spte(struct kvm *kvm, gfn_t gfn,
> + enum pg_level level, u64 mirror_spte)
> +{
>
> + if (KVM_BUG_ON(!is_shadow_present_pte(mirror_spte), kvm))
> + return -EIO;
> +
> + if (!is_last_spte(mirror_spte, level))
> + return tdx_sept_link_private_spt(kvm, gfn, level, mirror_spte);
For symmetry, what about renaming tdx_sept_link_private_spt() to
tdx_sept_map_nonleaf_spte()?

> +
> + return tdx_sept_map_leaf_spte(kvm, gfn, level, mirror_spte);
> +}
>
> /*
> * Ensure shared and private EPTs to be flushed on all vCPUs.
> --
> 2.53.0
>