From nobody Sun Feb 8 20:33:14 2026 Received: from mail-pl1-f201.google.com (mail-pl1-f201.google.com [209.85.214.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1B4603314C5 for ; Thu, 29 Jan 2026 01:16:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769649396; cv=none; b=N5+ijKjRf9XQB5VeSSxh7YNAZzXaOtBShf1/O4O7yRESLJy6WAoZVKtnsCiOY6CobhL+FFZS9/Zo9LtZXSqWZ6TM1RQ1sWVQ5N3IgQrkkvBc0AJQtl985uUxCCrlfAtkjp/PjzPOhY+vauZWxV9bYZAWp5fO/jHKhatwsCCs1UM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769649396; c=relaxed/simple; bh=kJQ9hFNF5ygDouQFKIpQgR+27T82l54AJAavRy375H8=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=geOQMpulhIpBXVGDGKCJn1R0Fp6FXDPfhKCjVVX+LfBuQ8DaWgHzk2XRaBscTTx6AxcMnOGJz3D1SwgzHiCsiPiQlLBwiyB4LLYL/UvfF10h7XWN4r/Q6MNrl/WM/PD9BNDMU1BvZxQ9bK4TidXcNfsp4i/+S9F00gRfAsapcOs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=4pjbbzou; arc=none smtp.client-ip=209.85.214.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="4pjbbzou" Received: by mail-pl1-f201.google.com with SMTP id d9443c01a7336-2a7701b6353so3720175ad.3 for ; Wed, 28 Jan 2026 17:16:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1769649394; x=1770254194; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=hk2OrgovQOMb8nY4yl86VZzMpQRRHhLb7boChViJO8g=; b=4pjbbzouSAHOfeCMbJTJQjatZ6ebS4fVvg3et4OTAM6aOvrTt+ZH/yy9ulQrRRyCBQ ot7I4xF2zR72+Hahb/2TMcjfvulGbfAWlDmvfZwoE+OYAaVQ39yRunyzd4SbNDPHos24 Vhca8yDkjahNkN39jhk40Fz53W3XGS0qKYQs2Jcz7ujyzC4KZZA0eeKT2ZbvNMSTvKDT i3SHsKQOt+4MlLY6do7IjNJzOZ4Jxl6tZz65v/BY9OTpyDAcIT6MWmri24MccQvvPDKS eCrpcmToZr799m0bAmva+rt0OSFspkk7tyIYInxgxNjyxTZCHjUxnA+sICfr4kf5GdOy D2iQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1769649394; x=1770254194; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=hk2OrgovQOMb8nY4yl86VZzMpQRRHhLb7boChViJO8g=; b=qaRTvSXQsaeHKUKks8SRfc/iUjPJcKOskIa9TjnkLwxyuKCg8VkameJlWJVGjOOdyo Aw/UynyuqgR9NOJiMsAcKrXU8kER0XhYhLu0tPOvDnwE0rF39OyMw9HK0nFKDG+v+FT1 PZVyAoA01rYZ7HjGaXtSFfHsuIcZvK3MnWTD+pCM3g91EAPjmUVxcWZrKcyVublOHtlM 1wVUKv3L9Cgrel17xXvML7CFnT3kQea4/4vk983PwR3lxCyF+RSi0mTKsJnroRzQIa+P 12pP/UJyqhtQ2SLi+/3du6GLmGgQo9+8dT/IFTBC67Kzw26Fu2qdJK5NNVHH4bpnbXuf PMUA== X-Gm-Message-State: AOJu0YzdH561olbcnuy0oRq9z0QqCq31/kH+OeGgDB+iyfTitLeIe6hV 3nzYMevOkXUNzecygzsaAWQx92HCD07M9HbbN2pXABZPj9jnSxOOlmJ9dRWbMIcKb8dsWxAtMWX 5fmah+w== X-Received: from plqu6.prod.google.com ([2002:a17:902:a606:b0:2a7:cf29:aee1]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:903:8cd:b0:2a7:a653:5203 with SMTP id d9443c01a7336-2a870de43ccmr68752745ad.27.1769649394405; Wed, 28 Jan 2026 17:16:34 -0800 (PST) Reply-To: Sean Christopherson Date: Wed, 28 Jan 2026 17:15:07 -0800 In-Reply-To: <20260129011517.3545883-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260129011517.3545883-1-seanjc@google.com> X-Mailer: git-send-email 2.53.0.rc1.217.geba53bf80e-goog Message-ID: <20260129011517.3545883-36-seanjc@google.com> Subject: [RFC PATCH v5 35/45] KVM: TDX: Add helper to handle mapping leaf SPTE into S-EPT From: Sean Christopherson To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, Kiryl Shutsemau , Sean Christopherson , Paolo Bonzini Cc: linux-kernel@vger.kernel.org, linux-coco@lists.linux.dev, kvm@vger.kernel.org, Kai Huang , Rick Edgecombe , Yan Zhao , Vishal Annapurve , Ackerley Tng , Sagi Shahar , Binbin Wu , Xiaoyao Li , Isaku Yamahata Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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. Opportunistically tweak the prototypes for tdx_sept_remove_private_spte() and tdx_sept_link_private_spt() to align with tdx_sept_set_private_spte() and tdx_sept_map_leaf_spte(). No functional change intended. Signed-off-by: Sean Christopherson --- arch/x86/kvm/vmx/tdx.c | 97 ++++++++++++++++++++++-------------------- 1 file changed, 51 insertions(+), 46 deletions(-) diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c index 9f7789c5f0a7..e6ac4aca8114 100644 --- a/arch/x86/kvm/vmx/tdx.c +++ b/arch/x86/kvm/vmx/tdx.c @@ -1670,6 +1670,50 @@ static int tdx_mem_page_aug(struct kvm *kvm, gfn_t g= fn, return 0; } =20 +static int tdx_sept_map_leaf_spte(struct kvm *kvm, gfn_t gfn, u64 new_spte, + enum pg_level level) +{ + struct kvm_vcpu *vcpu =3D kvm_get_running_vcpu(); + struct kvm_tdx *kvm_tdx =3D to_kvm_tdx(kvm); + kvm_pfn_t pfn =3D spte_to_pfn(new_spte); + int ret; + + /* TODO: handle large pages. */ + if (KVM_BUG_ON(level !=3D PG_LEVEL_4K, kvm)) + return -EIO; + + if (KVM_BUG_ON(!vcpu, kvm)) + return -EINVAL; + + WARN_ON_ONCE((new_spte & VMX_EPT_RWX_MASK) !=3D VMX_EPT_RWX_MASK); + + ret =3D tdx_pamt_get(pfn, level, &to_tdx(vcpu)->pamt_cache); + if (ret) + return ret; + + /* + * Ensure pre_fault_allowed is read by kvm_arch_vcpu_pre_fault_memory() + * before kvm_tdx->state. Userspace must not be allowed to pre-fault + * arbitrary memory until the initial memory image is finalized. Pairs + * with the smp_wmb() in tdx_td_finalize(). + */ + smp_rmb(); + + /* + * If the TD isn't finalized/runnable, then userspace is initializing + * the VM image via KVM_TDX_INIT_MEM_REGION; ADD the page to the TD. + */ + if (likely(kvm_tdx->state =3D=3D TD_STATE_RUNNABLE)) + ret =3D tdx_mem_page_aug(kvm, gfn, level, pfn); + else + ret =3D tdx_mem_page_add(kvm, gfn, level, pfn); + + if (ret) + tdx_pamt_put(pfn, level); + + return ret; +} + /* * Ensure shared and private EPTs to be flushed on all vCPUs. * tdh_mem_track() is the only caller that increases TD epoch. An increase= in @@ -1729,14 +1773,14 @@ static struct page *tdx_spte_to_external_spt(struct= kvm *kvm, gfn_t gfn, return virt_to_page(sp->external_spt); } =20 -static int tdx_sept_link_private_spt(struct kvm *kvm, gfn_t gfn, - enum pg_level level, u64 mirror_spte) +static int tdx_sept_link_private_spt(struct kvm *kvm, gfn_t gfn, u64 new_s= pte, + enum pg_level level) { gpa_t gpa =3D gfn_to_gpa(gfn); u64 err, entry, level_state; struct page *external_spt; =20 - external_spt =3D tdx_spte_to_external_spt(kvm, gfn, mirror_spte, level); + external_spt =3D tdx_spte_to_external_spt(kvm, gfn, new_spte, level); if (!external_spt) return -EIO; =20 @@ -1752,7 +1796,7 @@ static int tdx_sept_link_private_spt(struct kvm *kvm,= gfn_t gfn, } =20 static int tdx_sept_remove_private_spte(struct kvm *kvm, gfn_t gfn, - enum pg_level level, u64 old_spte) + u64 old_spte, enum pg_level level) { struct kvm_tdx *kvm_tdx =3D to_kvm_tdx(kvm); kvm_pfn_t pfn =3D spte_to_pfn(old_spte); @@ -1806,55 +1850,16 @@ static int tdx_sept_remove_private_spte(struct kvm = *kvm, gfn_t gfn, static int tdx_sept_set_private_spte(struct kvm *kvm, gfn_t gfn, u64 old_s= pte, u64 new_spte, enum pg_level level) { - struct kvm_vcpu *vcpu =3D kvm_get_running_vcpu(); - struct kvm_tdx *kvm_tdx =3D to_kvm_tdx(kvm); - kvm_pfn_t pfn =3D spte_to_pfn(new_spte); - struct vcpu_tdx *tdx =3D to_tdx(vcpu); - int ret; - if (is_shadow_present_pte(old_spte)) - return tdx_sept_remove_private_spte(kvm, gfn, level, old_spte); - - if (KVM_BUG_ON(!vcpu, kvm)) - return -EINVAL; + return tdx_sept_remove_private_spte(kvm, gfn, old_spte, level); =20 if (KVM_BUG_ON(!is_shadow_present_pte(new_spte), kvm)) return -EIO; =20 if (!is_last_spte(new_spte, level)) - return tdx_sept_link_private_spt(kvm, gfn, level, new_spte); + return tdx_sept_link_private_spt(kvm, gfn, new_spte, level); =20 - /* TODO: handle large pages. */ - if (KVM_BUG_ON(level !=3D PG_LEVEL_4K, kvm)) - return -EIO; - - WARN_ON_ONCE((new_spte & VMX_EPT_RWX_MASK) !=3D VMX_EPT_RWX_MASK); - - ret =3D tdx_pamt_get(pfn, level, &tdx->pamt_cache); - if (ret) - return ret; - - /* - * Ensure pre_fault_allowed is read by kvm_arch_vcpu_pre_fault_memory() - * before kvm_tdx->state. Userspace must not be allowed to pre-fault - * arbitrary memory until the initial memory image is finalized. Pairs - * with the smp_wmb() in tdx_td_finalize(). - */ - smp_rmb(); - - /* - * If the TD isn't finalized/runnable, then userspace is initializing - * the VM image via KVM_TDX_INIT_MEM_REGION; ADD the page to the TD. - */ - if (likely(kvm_tdx->state =3D=3D TD_STATE_RUNNABLE)) - ret =3D tdx_mem_page_aug(kvm, gfn, level, pfn); - else - ret =3D tdx_mem_page_add(kvm, gfn, level, pfn); - - if (ret) - tdx_pamt_put(pfn, level); - - return ret; + return tdx_sept_map_leaf_spte(kvm, gfn, new_spte, level); } =20 static void tdx_sept_reclaim_private_sp(struct kvm *kvm, gfn_t gfn, --=20 2.53.0.rc1.217.geba53bf80e-goog