On 8/29/2025 8:06 AM, Sean Christopherson wrote:
> Fold tdx_sept_drop_private_spte() into tdx_sept_remove_private_spte() to
> avoid having to differnatiate between "zap", "drop", and "remove", and to
> eliminate dead code due to redundant checks, e.g. on an HKID being
> assigned.
>
> No functional change intended.
>
> Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
> ---
> arch/x86/kvm/vmx/tdx.c | 90 +++++++++++++++++++-----------------------
> 1 file changed, 40 insertions(+), 50 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
> index 50a9d81dad53..8cb6a2627eb2 100644
> --- a/arch/x86/kvm/vmx/tdx.c
> +++ b/arch/x86/kvm/vmx/tdx.c
> @@ -1651,55 +1651,6 @@ static int tdx_sept_set_private_spte(struct kvm *kvm, gfn_t gfn,
> return tdx_mem_page_record_premap_cnt(kvm, gfn, level, pfn);
> }
>
> -static int tdx_sept_drop_private_spte(struct kvm *kvm, gfn_t gfn,
> - enum pg_level level, struct page *page)
> -{
> - int tdx_level = pg_level_to_tdx_sept_level(level);
> - struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
> - gpa_t gpa = gfn_to_gpa(gfn);
> - u64 err, entry, level_state;
> -
> - /* TODO: handle large pages. */
> - if (KVM_BUG_ON(level != PG_LEVEL_4K, kvm))
> - return -EIO;
> -
> - if (KVM_BUG_ON(!is_hkid_assigned(kvm_tdx), kvm))
> - return -EIO;
> -
> - /*
> - * When zapping private page, write lock is held. So no race condition
> - * with other vcpu sept operation.
> - * Race with TDH.VP.ENTER due to (0-step mitigation) and Guest TDCALLs.
> - */
> - err = tdh_mem_page_remove(&kvm_tdx->td, gpa, tdx_level, &entry,
> - &level_state);
> -
> - if (unlikely(tdx_operand_busy(err))) {
> - /*
> - * The second retry is expected to succeed after kicking off all
> - * other vCPUs and prevent them from invoking TDH.VP.ENTER.
> - */
> - tdx_no_vcpus_enter_start(kvm);
> - err = tdh_mem_page_remove(&kvm_tdx->td, gpa, tdx_level, &entry,
> - &level_state);
> - tdx_no_vcpus_enter_stop(kvm);
> - }
> -
> - if (KVM_BUG_ON(err, kvm)) {
> - pr_tdx_error_2(TDH_MEM_PAGE_REMOVE, err, entry, level_state);
> - return -EIO;
> - }
> -
> - err = tdh_phymem_page_wbinvd_hkid((u16)kvm_tdx->hkid, page);
> -
> - if (KVM_BUG_ON(err, kvm)) {
> - pr_tdx_error(TDH_PHYMEM_PAGE_WBINVD, err);
> - return -EIO;
> - }
> - tdx_clear_page(page);
> - return 0;
> -}
> -
> static int tdx_sept_link_private_spt(struct kvm *kvm, gfn_t gfn,
> enum pg_level level, void *private_spt)
> {
> @@ -1861,7 +1812,11 @@ static int tdx_sept_free_private_spt(struct kvm *kvm, gfn_t gfn,
> static int tdx_sept_remove_private_spte(struct kvm *kvm, gfn_t gfn,
> enum pg_level level, kvm_pfn_t pfn)
> {
> + int tdx_level = pg_level_to_tdx_sept_level(level);
> + struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
> struct page *page = pfn_to_page(pfn);
> + gpa_t gpa = gfn_to_gpa(gfn);
> + u64 err, entry, level_state;
> int ret;
>
> /*
> @@ -1872,6 +1827,10 @@ static int tdx_sept_remove_private_spte(struct kvm *kvm, gfn_t gfn,
> if (KVM_BUG_ON(!is_hkid_assigned(to_kvm_tdx(kvm)), kvm))
> return -EIO;
>
> + /* TODO: handle large pages. */
> + if (KVM_BUG_ON(level != PG_LEVEL_4K, kvm))
> + return -EIO;
> +
> ret = tdx_sept_zap_private_spte(kvm, gfn, level, page);
> if (ret <= 0)
> return ret;
> @@ -1882,7 +1841,38 @@ static int tdx_sept_remove_private_spte(struct kvm *kvm, gfn_t gfn,
> */
> tdx_track(kvm);
>
> - return tdx_sept_drop_private_spte(kvm, gfn, level, page);
> + /*
> + * When zapping private page, write lock is held. So no race condition
> + * with other vcpu sept operation.
> + * Race with TDH.VP.ENTER due to (0-step mitigation) and Guest TDCALLs.
> + */
> + err = tdh_mem_page_remove(&kvm_tdx->td, gpa, tdx_level, &entry,
> + &level_state);
> +
> + if (unlikely(tdx_operand_busy(err))) {
> + /*
> + * The second retry is expected to succeed after kicking off all
> + * other vCPUs and prevent them from invoking TDH.VP.ENTER.
> + */
> + tdx_no_vcpus_enter_start(kvm);
> + err = tdh_mem_page_remove(&kvm_tdx->td, gpa, tdx_level, &entry,
> + &level_state);
> + tdx_no_vcpus_enter_stop(kvm);
> + }
> +
> + if (KVM_BUG_ON(err, kvm)) {
> + pr_tdx_error_2(TDH_MEM_PAGE_REMOVE, err, entry, level_state);
> + return -EIO;
> + }
> +
> + err = tdh_phymem_page_wbinvd_hkid((u16)kvm_tdx->hkid, page);
> + if (KVM_BUG_ON(err, kvm)) {
> + pr_tdx_error(TDH_PHYMEM_PAGE_WBINVD, err);
> + return -EIO;
> + }
> +
> + tdx_clear_page(page);
> + return 0;
> }
>
> void tdx_deliver_interrupt(struct kvm_lapic *apic, int delivery_mode,