Re: [PATCH] x86/tdx: Use pg_level in TDX APIs, not the TDX-Module's 0-based level
From: Edgecombe, Rick P
Date: Tue Jan 20 2026 - 17:38:17 EST
On Tue, 2026-01-20 at 12:39 -0800, Sean Christopherson wrote:
> > Rework the TDX APIs to take the kernel's 1-based pg_level enum, not the
> > TDX-Module's 0-based level. The APIs are _kernel_ APIs, not TDX-Module
> > APIs, and the kernel (and KVM) uses "enum pg_level" literally everywhere.
> >
> > Using "enum pg_level" eliminates ambiguity when looking at the APIs (it's
> > NOT clear that "int level" refers to the TDX-Module's level), and will
> > allow for using existing helpers like page_level_size() when support for
> > hugepages is added to the S-EPT APIs.
> >
> > No functional change intended.
Makes sense.
Reviewed-by: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx>
Tested-by: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx>
> >
> > Cc: Kai Huang <kai.huang@xxxxxxxxx>
> > Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
> > Cc: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx>
> > Cc: Yan Zhao <yan.y.zhao@xxxxxxxxx>
> > Cc: Vishal Annapurve <vannapurve@xxxxxxxxxx>
> > Cc: Ackerley Tng <ackerleytng@xxxxxxxxxx>
> > Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> > ---
> >
> > Compile-tested only. Came across this when looking at the S-EPT hugepage
> > series, specifically this code:
> >
> > unsigned long npages = 1 << (level * PTE_SHIFT);
> >
> > which I was _sure_ was broken, until I realized @level wasn't what I thought
> > it was.
> >
> > arch/x86/include/asm/tdx.h | 14 ++++----------
> > arch/x86/kvm/vmx/tdx.c | 11 ++++-------
> > arch/x86/virt/vmx/tdx/tdx.c | 26 ++++++++++++++++++--------
> > 3 files changed, 26 insertions(+), 25 deletions(-)
The line increase is just from wrapped lines, so it's kinda less code.
> >
> > diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h
> > index 6b338d7f01b7..bc0d03e70fd6 100644
> > --- a/arch/x86/include/asm/tdx.h
> > +++ b/arch/x86/include/asm/tdx.h
> > @@ -189,19 +189,13 @@ static inline u64 mk_keyed_paddr(u16 hkid, struct page *page)
> > return ret;
> > }
> >
> > -static inline int pg_level_to_tdx_sept_level(enum pg_level level)
> > -{
> > - WARN_ON_ONCE(level == PG_LEVEL_NONE);
> > - return level - 1;
> > -}
> > -
> > u64 tdh_vp_enter(struct tdx_vp *vp, struct tdx_module_args *args);
> > u64 tdh_mng_addcx(struct tdx_td *td, struct page *tdcs_page);
> > u64 tdh_mem_page_add(struct tdx_td *td, u64 gpa, struct page *page, struct page *source, u64 *ext_err1, u64 *ext_err2);
> > -u64 tdh_mem_sept_add(struct tdx_td *td, u64 gpa, int level, struct page *page, u64 *ext_err1, u64 *ext_err2);
> > +u64 tdh_mem_sept_add(struct tdx_td *td, u64 gpa, enum pg_level level, struct page *page, u64 *ext_err1, u64 *ext_err2);
> > u64 tdh_vp_addcx(struct tdx_vp *vp, struct page *tdcx_page);
> > -u64 tdh_mem_page_aug(struct tdx_td *td, u64 gpa, int level, struct page *page, u64 *ext_err1, u64 *ext_err2);
> > -u64 tdh_mem_range_block(struct tdx_td *td, u64 gpa, int level, u64 *ext_err1, u64 *ext_err2);
> > +u64 tdh_mem_page_aug(struct tdx_td *td, u64 gpa, enum pg_level level, struct page *page, u64 *ext_err1, u64 *ext_err2);
> > +u64 tdh_mem_range_block(struct tdx_td *td, u64 gpa, enum pg_level level, u64 *ext_err1, u64 *ext_err2);
> > u64 tdh_mng_key_config(struct tdx_td *td);
> > u64 tdh_mng_create(struct tdx_td *td, u16 hkid);
> > u64 tdh_vp_create(struct tdx_td *td, struct tdx_vp *vp);
> > @@ -217,7 +211,7 @@ u64 tdh_vp_rd(struct tdx_vp *vp, u64 field, u64 *data);
> > u64 tdh_vp_wr(struct tdx_vp *vp, u64 field, u64 data, u64 mask);
> > u64 tdh_phymem_page_reclaim(struct page *page, u64 *tdx_pt, u64 *tdx_owner, u64 *tdx_size);
> > u64 tdh_mem_track(struct tdx_td *tdr);
> > -u64 tdh_mem_page_remove(struct tdx_td *td, u64 gpa, u64 level, u64 *ext_err1, u64 *ext_err2);
^WTH, oops.
> > +u64 tdh_mem_page_remove(struct tdx_td *td, u64 gpa, enum pg_level level, u64 *ext_err1, u64 *ext_err2);
> > u64 tdh_phymem_cache_wb(bool resume);
> > u64 tdh_phymem_page_wbinvd_tdr(struct tdx_td *td);
> > u64 tdh_phymem_page_wbinvd_hkid(u64 hkid, struct page *page);