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From:   isaku.yamahata@intel.com
To:     kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     isaku.yamahata@intel.com, isaku.yamahata@gmail.com,
        Paolo Bonzini <pbonzini@redhat.com>, erdemaktas@google.com,
        Sean Christopherson <seanjc@google.com>,
        Sagi Shahar <sagis@google.com>
Subject: [RFC PATCH v6 047/104] KVM: x86/tdp_mmu: Support TDX private mapping for TDP MMU
Date:   Thu,  5 May 2022 11:14:41 -0700
Message-Id: <653230043fdb2d20e871e79e73f757134ca92eeb.1651774250.git.isaku.yamahata@intel.com>
In-Reply-To: <cover.1651774250.git.isaku.yamahata@intel.com>
References: <cover.1651774250.git.isaku.yamahata@intel.com>
MIME-Version: 1.0
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Precedence: bulk

From: Isaku Yamahata <isaku.yamahata@intel.com>

Allocate mirrored private page table for private page table, and add hooks
to operate on mirrored private page table.  This patch adds only hooks. As
kvm_gfn_shared_mask() returns false always, those hooks aren't called yet.

Because private guest page is protected, page copy with mmu_notifier to
migrate page doesn't work.  Callback from backing store is needed.
Instead, pin the page for now.  Page migration is future task.

When the faulting GPA is private, the KVM fault is also called private.
When resolving private KVM, allocate mirrored private page table and call
hooks to operate on mirrored private page table. On the change of the
private PTE entry, invoke kvm_x86_ops hook in __handle_changed_spte() to
propagate the change to mirrored private page table. The following depicts
the relationship.

  private KVM page fault   |
      |                    |
      V                    |
 private GPA               |
      |                    |
      V                    |
 KVM private PT root       |  CPU private PT root
      |                    |           |
      V                    |           V
   private PT ---hook to mirror--->mirrored private PT
      |                    |           |
      \--------------------+------\    |
                           |      |    |
                           |      V    V
                           |    private guest page
                           |
                           |
     non-encrypted memory  |    encrypted memory
                           |
PT: page table

The existing KVM TDP MMU code uses atomic update of SPTE.  On populating
the EPT entry, atomically set the entry.  However, it requires TLB
shootdown to zap SPTE.  To address it, the entry is frozen with the special
SPTE value that clears the present bit. After the TLB shootdown, the entry
is set to the eventual value (unfreeze).

For mirrored private page table, hooks are called to update mirrored
private page table in addition to direct access to the private SPTE. For
the zapping case, it works to freeze the SPTE. It can call hooks in
addition to TLB shootdown.  For populating the private SPTE entry, there
can be a race condition without further protection

  vcpu 1: populating 2M private SPTE
  vcpu 2: populating 4K private SPTE
  vcpu 2: TDX SEAMCALL to update 4K mirrored private SPTE => error
  vcpu 1: TDX SEAMCALL to update 2M mirrored private SPTE

To avoid the race, the frozen SPTE is utilized.  Instead of atomic update
of the private entry, freeze the entry, call the hook that update mirrored
private SPTE, set the entry to the final value.

Support 4K page only at this stage.  2M page support can be done in future
patches.

Add is_private member to kvm_page_fault to indicate the fault is private.
Also is_private member to struct tdp_inter to propagate it.

Co-developed-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
 arch/x86/include/asm/kvm-x86-ops.h |   2 +
 arch/x86/include/asm/kvm_host.h    |  20 +++
 arch/x86/kvm/mmu.h                 |   4 +
 arch/x86/kvm/mmu/mmu.c             |  91 ++++++++++-
 arch/x86/kvm/mmu/mmu_internal.h    |  35 +++++
 arch/x86/kvm/mmu/paging_tmpl.h     |   2 +-
 arch/x86/kvm/mmu/tdp_iter.c        |   1 +
 arch/x86/kvm/mmu/tdp_iter.h        |   5 +-
 arch/x86/kvm/mmu/tdp_mmu.c         | 240 +++++++++++++++++++++++------
 arch/x86/kvm/mmu/tdp_mmu.h         |   7 +-
 virt/kvm/kvm_main.c                |   1 +
 11 files changed, 349 insertions(+), 59 deletions(-)

diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
index 32a6df784ea6..6982d57e4518 100644
--- a/arch/x86/include/asm/kvm-x86-ops.h
+++ b/arch/x86/include/asm/kvm-x86-ops.h
@@ -93,6 +93,8 @@ KVM_X86_OP_OPTIONAL_RET0(set_tss_addr)
 KVM_X86_OP_OPTIONAL_RET0(set_identity_map_addr)
 KVM_X86_OP(get_mt_mask)
 KVM_X86_OP(load_mmu_pgd)
+KVM_X86_OP_OPTIONAL(free_private_sp)
+KVM_X86_OP_OPTIONAL(handle_changed_private_spte)
 KVM_X86_OP(has_wbinvd_exit)
 KVM_X86_OP(get_l2_tsc_offset)
 KVM_X86_OP(get_l2_tsc_multiplier)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 8ef83bcefa57..88c3e9c78797 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -437,6 +437,7 @@ struct kvm_mmu {
 			 struct kvm_mmu_page *sp);
 	void (*invlpg)(struct kvm_vcpu *vcpu, gva_t gva, hpa_t root_hpa);
 	struct kvm_mmu_root_info root;
+	hpa_t private_root_hpa;
 	union kvm_cpu_role cpu_role;
 	union kvm_mmu_page_role root_role;
 
@@ -1339,6 +1340,20 @@ static inline u16 kvm_lapic_irq_dest_mode(bool dest_mode_logical)
 	return dest_mode_logical ? APIC_DEST_LOGICAL : APIC_DEST_PHYSICAL;
 }
 
+struct kvm_spte {
+	kvm_pfn_t pfn;
+	bool is_present;
+	bool is_leaf;
+};
+
+struct kvm_spte_change {
+	gfn_t gfn;
+	enum pg_level level;
+	struct kvm_spte old;
+	struct kvm_spte new;
+	void *sept_page;
+};
+
 struct kvm_x86_ops {
 	const char *name;
 
@@ -1451,6 +1466,11 @@ struct kvm_x86_ops {
 	void (*load_mmu_pgd)(struct kvm_vcpu *vcpu, hpa_t root_hpa,
 			     int root_level);
 
+	int (*free_private_sp)(struct kvm *kvm, gfn_t gfn, enum pg_level level,
+			       void *private_sp);
+	void (*handle_changed_private_spte)(
+		struct kvm *kvm, const struct kvm_spte_change *change);
+
 	bool (*has_wbinvd_exit)(void);
 
 	u64 (*get_l2_tsc_offset)(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index a37b2efec4a8..d02c0274777a 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -179,6 +179,7 @@ struct kvm_page_fault {
 	/* Derived from mmu and global state.  */
 	const bool is_tdp;
 	const bool nx_huge_page_workaround_enabled;
+	const bool is_private;
 
 	/*
 	 * Whether a >4KB mapping can be created or is forbidden due to NX
@@ -224,6 +225,8 @@ static inline bool is_nx_huge_page_enabled(void)
 	return READ_ONCE(nx_huge_pages);
 }
 
+static inline bool kvm_is_private_gpa(const struct kvm *kvm, gpa_t gpa);
+
 static inline int kvm_mmu_do_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
 					u32 err, bool prefetch)
 {
@@ -238,6 +241,7 @@ static inline int kvm_mmu_do_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
 		.prefetch = prefetch,
 		.is_tdp = likely(vcpu->arch.mmu->page_fault == kvm_tdp_page_fault),
 		.nx_huge_page_workaround_enabled = is_nx_huge_page_enabled(),
+		.is_private = kvm_is_private_gpa(vcpu->kvm, cr2_or_gpa),
 
 		.max_level = vcpu->kvm->arch.tdp_max_page_level,
 		.req_level = PG_LEVEL_4K,
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 7e4c96605261..f4284e9cf9ec 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -1600,7 +1600,11 @@ bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range)
 		flush = kvm_handle_gfn_range(kvm, range, kvm_unmap_rmapp);
 
 	if (is_tdp_mmu_enabled(kvm))
-		flush = kvm_tdp_mmu_unmap_gfn_range(kvm, range, flush);
+		/*
+		 * private page needs to be kept and handle page migration
+		 * on next EPT violation.
+		 */
+		flush = kvm_tdp_mmu_unmap_gfn_range(kvm, range, flush, false);
 
 	return flush;
 }
@@ -3107,7 +3111,8 @@ static bool handle_abnormal_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fa
 		 * SPTE value without #VE suppress bit cleared
 		 * (kvm->arch.shadow_mmio_value = 0).
 		 */
-		if (unlikely(!vcpu->kvm->arch.enable_mmio_caching) ||
+		if (unlikely(!vcpu->kvm->arch.enable_mmio_caching &&
+			     !kvm_gfn_shared_mask(vcpu->kvm)) ||
 		    unlikely(fault->gfn > kvm_mmu_max_gfn())) {
 			*ret_val = RET_PF_EMULATE;
 			return true;
@@ -3461,7 +3466,12 @@ static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu)
 		goto out_unlock;
 
 	if (is_tdp_mmu_enabled(vcpu->kvm)) {
-		root = kvm_tdp_mmu_get_vcpu_root_hpa(vcpu);
+		if (kvm_gfn_shared_mask(vcpu->kvm) &&
+		    !VALID_PAGE(mmu->private_root_hpa)) {
+			root = kvm_tdp_mmu_get_vcpu_root_hpa(vcpu, true);
+			mmu->private_root_hpa = root;
+		}
+		root = kvm_tdp_mmu_get_vcpu_root_hpa(vcpu, false);
 		mmu->root.hpa = root;
 	} else if (shadow_root_level >= PT64_ROOT_4LEVEL) {
 		root = mmu_alloc_root(vcpu, 0, 0, shadow_root_level, true);
@@ -4014,6 +4024,38 @@ static bool kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
 				  kvm_vcpu_gfn_to_hva(vcpu, gfn), &arch);
 }
 
+/*
+ * Private page can't be release on mmu_notifier without losing page contents.
+ * The help, callback, from backing store is needed to allow page migration.
+ * For now, pin the page.
+ */
+static bool kvm_faultin_pfn_private(struct kvm_vcpu *vcpu,
+				    struct kvm_page_fault *fault, int *r)
+{
+	hva_t hva = gfn_to_hva_memslot(fault->slot, fault->gfn);
+	struct page *page[1];
+	unsigned int flags;
+	int npages;
+
+	fault->map_writable = false;
+	fault->pfn = KVM_PFN_ERR_FAULT;
+	*r = -1;
+	if (hva == KVM_HVA_ERR_RO_BAD || hva == KVM_HVA_ERR_BAD)
+		return true;
+
+	/* TDX allows only RWX.  Read-only isn't supported. */
+	WARN_ON_ONCE(!fault->write);
+	flags = FOLL_WRITE | FOLL_LONGTERM;
+
+	npages = pin_user_pages_fast(hva, 1, flags, page);
+	if (npages != 1)
+		return true;
+
+	fault->map_writable = true;
+	fault->pfn = page_to_pfn(page[0]);
+	return false;
+}
+
 static bool kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, int *r)
 {
 	struct kvm_memory_slot *slot = fault->slot;
@@ -4048,6 +4090,9 @@ static bool kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault,
 		}
 	}
 
+	if (fault->is_private)
+		return kvm_faultin_pfn_private(vcpu, fault, r);
+
 	async = false;
 	fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, &async,
 					  fault->write, &fault->map_writable,
@@ -4103,6 +4148,18 @@ static bool is_page_fault_stale(struct kvm_vcpu *vcpu,
 	       mmu_notifier_retry_hva(vcpu->kvm, mmu_seq, fault->hva);
 }
 
+void kvm_mmu_release_fault(struct kvm *kvm, struct kvm_page_fault *fault, int r)
+{
+	if (is_error_noslot_pfn(fault->pfn) || kvm_is_reserved_pfn(fault->pfn))
+		return;
+
+	if (fault->is_private) {
+		if (r != RET_PF_FIXED)
+			unpin_user_page(pfn_to_page(fault->pfn));
+	} else
+		kvm_release_pfn_clean(fault->pfn);
+}
+
 static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
 {
 	bool is_tdp_mmu_fault = is_tdp_mmu(vcpu->arch.mmu);
@@ -4157,7 +4214,7 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
 		read_unlock(&vcpu->kvm->mmu_lock);
 	else
 		write_unlock(&vcpu->kvm->mmu_lock);
-	kvm_release_pfn_clean(fault->pfn);
+	kvm_mmu_release_fault(vcpu->kvm, fault, r);
 	return r;
 }
 
@@ -5654,6 +5711,7 @@ static int __kvm_mmu_create(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu)
 
 	mmu->root.hpa = INVALID_PAGE;
 	mmu->root.pgd = 0;
+	mmu->private_root_hpa = INVALID_PAGE;
 	for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++)
 		mmu->prev_roots[i] = KVM_MMU_ROOT_INFO_INVALID;
 
@@ -5842,6 +5900,10 @@ static void kvm_mmu_zap_all_fast(struct kvm *kvm)
 	 * lead to use-after-free.
 	 */
 	if (is_tdp_mmu_enabled(kvm))
+		/*
+		 * For now private root is never invalidate during VM is running,
+		 * so this can only happen for shared roots.
+		 */
 		kvm_tdp_mmu_zap_invalidated_roots(kvm);
 }
 
@@ -5869,7 +5931,8 @@ static void kvm_mmu_zap_memslot(struct kvm *kvm, struct kvm_memory_slot *slot)
 		      .may_block = false,
 		};
 
-		flush = kvm_tdp_mmu_unmap_gfn_range(kvm, &range, flush);
+		/* All private page should be zapped on memslot deletion. */
+		flush = kvm_tdp_mmu_unmap_gfn_range(kvm, &range, flush, true);
 	} else {
 		flush = slot_handle_level(kvm, slot, kvm_zap_rmapp, PG_LEVEL_4K,
 					  KVM_MAX_HUGEPAGE_LEVEL, true);
@@ -5977,7 +6040,7 @@ void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end)
 	if (is_tdp_mmu_enabled(kvm)) {
 		for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++)
 			flush = kvm_tdp_mmu_zap_leafs(kvm, i, gfn_start,
-						      gfn_end, true, flush);
+						      gfn_end, true, flush, false);
 	}
 
 	if (flush)
@@ -6010,6 +6073,11 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm,
 		write_unlock(&kvm->mmu_lock);
 	}
 
+	/*
+	 * For now this can only happen for non-TD VM, because TD private
+	 * mapping doesn't support write protection.  kvm_tdp_mmu_wrprot_slot()
+	 * will give a WARN() if it hits for TD.
+	 */
 	if (is_tdp_mmu_enabled(kvm)) {
 		read_lock(&kvm->mmu_lock);
 		flush |= kvm_tdp_mmu_wrprot_slot(kvm, memslot, start_level);
@@ -6098,6 +6166,9 @@ static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm,
 		sp = sptep_to_sp(sptep);
 		pfn = spte_to_pfn(*sptep);
 
+		/* Private page dirty logging is not supported. */
+		KVM_BUG_ON(is_private_sptep(sptep), kvm);
+
 		/*
 		 * We cannot do huge page mapping for indirect shadow pages,
 		 * which are found on the last rmap (level = 1) when not using
@@ -6138,6 +6209,11 @@ void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm,
 		write_unlock(&kvm->mmu_lock);
 	}
 
+	/*
+	 * This should only be reachable in case of log-dirty, wihch TD private
+	 * mapping doesn't support so far.  kvm_tdp_mmu_zap_collapsible_sptes()
+	 * internally gives a WARN() when it hits.
+	 */
 	if (is_tdp_mmu_enabled(kvm)) {
 		read_lock(&kvm->mmu_lock);
 		kvm_tdp_mmu_zap_collapsible_sptes(kvm, slot);
@@ -6424,6 +6500,9 @@ int kvm_mmu_vendor_module_init(void)
 void kvm_mmu_destroy(struct kvm_vcpu *vcpu)
 {
 	kvm_mmu_unload(vcpu);
+	if (is_tdp_mmu_enabled(vcpu->kvm))
+		mmu_free_root_page(vcpu->kvm, &vcpu->arch.mmu->private_root_hpa,
+				NULL);
 	free_mmu_pages(&vcpu->arch.root_mmu);
 	free_mmu_pages(&vcpu->arch.guest_mmu);
 	mmu_free_memory_caches(vcpu);
diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h
index 123736d651e3..affbfe895dab 100644
--- a/arch/x86/kvm/mmu/mmu_internal.h
+++ b/arch/x86/kvm/mmu/mmu_internal.h
@@ -6,6 +6,8 @@
 #include <linux/kvm_host.h>
 #include <asm/kvm_host.h>
 
+#include "mmu.h"
+
 #undef MMU_DEBUG
 
 #ifdef MMU_DEBUG
@@ -164,11 +166,30 @@ static inline void kvm_mmu_alloc_private_sp(
 	WARN_ON_ONCE(!sp->private_sp);
 }
 
+static inline int kvm_alloc_private_sp_for_split(
+	struct kvm_mmu_page *sp, gfp_t gfp)
+{
+	gfp &= ~__GFP_ZERO;
+	sp->private_sp = (void*)__get_free_page(gfp);
+	if (!sp->private_sp)
+		return -ENOMEM;
+	return 0;
+}
+
 static inline void kvm_mmu_free_private_sp(struct kvm_mmu_page *sp)
 {
 	if (sp->private_sp != KVM_MMU_PRIVATE_SP_ROOT)
 		free_page((unsigned long)sp->private_sp);
 }
+
+static inline gfn_t kvm_gfn_for_root(struct kvm *kvm, struct kvm_mmu_page *root,
+				     gfn_t gfn)
+{
+	if (is_private_sp(root))
+		return kvm_gfn_private(kvm, gfn);
+	else
+		return kvm_gfn_shared(kvm, gfn);
+}
 #else
 static inline bool is_private_sp(struct kvm_mmu_page *sp)
 {
@@ -194,11 +215,25 @@ static inline void kvm_mmu_alloc_private_sp(
 {
 }
 
+static inline int kvm_alloc_private_sp_for_split(
+	struct kvm_mmu_page *sp, gfp_t gfp)
+{
+	return -ENOMEM;
+}
+
 static inline void kvm_mmu_free_private_sp(struct kvm_mmu_page *sp)
 {
 }
+
+static inline gfn_t kvm_gfn_for_root(struct kvm *kvm, struct kvm_mmu_page *root,
+				     gfn_t gfn)
+{
+	return gfn;
+}
 #endif
 
+void kvm_mmu_release_fault(struct kvm *kvm, struct kvm_page_fault *fault, int r);
+
 static inline bool kvm_mmu_page_ad_need_write_protect(struct kvm_mmu_page *sp)
 {
 	/*
diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
index 1850689fa76c..7adf70c9a672 100644
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -876,7 +876,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
 
 out_unlock:
 	write_unlock(&vcpu->kvm->mmu_lock);
-	kvm_release_pfn_clean(fault->pfn);
+	kvm_mmu_release_fault(vcpu->kvm, fault, r);
 	return r;
 }
 
diff --git a/arch/x86/kvm/mmu/tdp_iter.c b/arch/x86/kvm/mmu/tdp_iter.c
index 6d3b3e5a5533..fc427425e0b4 100644
--- a/arch/x86/kvm/mmu/tdp_iter.c
+++ b/arch/x86/kvm/mmu/tdp_iter.c
@@ -53,6 +53,7 @@ void tdp_iter_start(struct tdp_iter *iter, struct kvm_mmu_page *root,
 	iter->min_level = min_level;
 	iter->pt_path[iter->root_level - 1] = (tdp_ptep_t)root->spt;
 	iter->as_id = kvm_mmu_page_as_id(root);
+	iter->is_private = is_private_sp(root);
 
 	tdp_iter_restart(iter);
 }
diff --git a/arch/x86/kvm/mmu/tdp_iter.h b/arch/x86/kvm/mmu/tdp_iter.h
index b1eaf6ec0e0b..882fe7ba4ddb 100644
--- a/arch/x86/kvm/mmu/tdp_iter.h
+++ b/arch/x86/kvm/mmu/tdp_iter.h
@@ -41,7 +41,7 @@ struct tdp_iter {
 	tdp_ptep_t pt_path[PT64_ROOT_MAX_LEVEL];
 	/* A pointer to the current SPTE */
 	tdp_ptep_t sptep;
-	/* The lowest GFN mapped by the current SPTE */
+	/* The lowest GFN (shared bits included) mapped by the current SPTE */
 	gfn_t gfn;
 	/* The level of the root page given to the iterator */
 	int root_level;
@@ -64,6 +64,9 @@ struct tdp_iter {
 	 * level instead of advancing to the next entry.
 	 */
 	bool yielded;
+
+	/* True if this iter is handling private KVM page fault. */
+	bool is_private;
 };
 
 /*
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index 9e015b3e0578..ae2ee7cc948a 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -278,18 +278,24 @@ static struct kvm_mmu_page *tdp_mmu_next_root(struct kvm *kvm,
 		    kvm_mmu_page_as_id(_root) != _as_id) {		\
 		} else
 
-static struct kvm_mmu_page *tdp_mmu_alloc_sp(struct kvm_vcpu *vcpu)
+static struct kvm_mmu_page *tdp_mmu_alloc_sp(
+	struct kvm_vcpu *vcpu, bool private, bool is_root)
 {
 	struct kvm_mmu_page *sp;
 
 	sp = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache);
 	sp->spt = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_shadow_page_cache);
 
+	if (private)
+		kvm_mmu_alloc_private_sp(vcpu, sp, is_root);
+	else
+		kvm_mmu_init_private_sp(sp);
+
 	return sp;
 }
 
-static void tdp_mmu_init_sp(struct kvm_mmu_page *sp, tdp_ptep_t sptep,
-			    gfn_t gfn, union kvm_mmu_page_role role)
+static void tdp_mmu_init_sp(struct kvm_mmu_page *sp, tdp_ptep_t sptep, gfn_t gfn,
+			    union kvm_mmu_page_role role)
 {
 	set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
 
@@ -297,7 +303,6 @@ static void tdp_mmu_init_sp(struct kvm_mmu_page *sp, tdp_ptep_t sptep,
 	sp->gfn = gfn;
 	sp->ptep = sptep;
 	sp->tdp_mmu_page = true;
-	kvm_mmu_init_private_sp(sp);
 
 	trace_kvm_mmu_get_page(sp, true);
 }
@@ -316,7 +321,8 @@ static void tdp_mmu_init_child_sp(struct kvm_mmu_page *child_sp,
 	tdp_mmu_init_sp(child_sp, iter->sptep, iter->gfn, role);
 }
 
-hpa_t kvm_tdp_mmu_get_vcpu_root_hpa(struct kvm_vcpu *vcpu)
+static struct kvm_mmu_page *kvm_tdp_mmu_get_vcpu_root(struct kvm_vcpu *vcpu,
+						      bool private)
 {
 	union kvm_mmu_page_role role = vcpu->arch.mmu->root_role;
 	struct kvm *kvm = vcpu->kvm;
@@ -330,11 +336,12 @@ hpa_t kvm_tdp_mmu_get_vcpu_root_hpa(struct kvm_vcpu *vcpu)
 	 */
 	for_each_tdp_mmu_root(kvm, root, kvm_mmu_role_as_id(role)) {
 		if (root->role.word == role.word &&
+		    is_private_sp(root) == private &&
 		    kvm_tdp_mmu_get_root(root))
 			goto out;
 	}
 
-	root = tdp_mmu_alloc_sp(vcpu);
+	root = tdp_mmu_alloc_sp(vcpu, private, true);
 	tdp_mmu_init_sp(root, NULL, 0, role);
 
 	refcount_set(&root->tdp_mmu_root_count, 1);
@@ -344,12 +351,17 @@ hpa_t kvm_tdp_mmu_get_vcpu_root_hpa(struct kvm_vcpu *vcpu)
 	spin_unlock(&kvm->arch.tdp_mmu_pages_lock);
 
 out:
-	return __pa(root->spt);
+	return root;
+}
+
+hpa_t kvm_tdp_mmu_get_vcpu_root_hpa(struct kvm_vcpu *vcpu, bool private)
+{
+	return __pa(kvm_tdp_mmu_get_vcpu_root(vcpu, private)->spt);
 }
 
 static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
-				u64 old_spte, u64 new_spte, int level,
-				bool shared);
+				bool private_spte, u64 old_spte,
+				u64 new_spte, int level, bool shared);
 
 static void handle_changed_spte_acc_track(u64 old_spte, u64 new_spte, int level)
 {
@@ -422,7 +434,8 @@ static void tdp_mmu_unlink_sp(struct kvm *kvm, struct kvm_mmu_page *sp,
  * this thread will be responsible for ensuring the page is freed. Hence the
  * early rcu_dereferences in the function.
  */
-static void handle_removed_pt(struct kvm *kvm, tdp_ptep_t pt, bool shared)
+static void handle_removed_pt(struct kvm *kvm, tdp_ptep_t pt, bool is_private,
+			      bool shared)
 {
 	struct kvm_mmu_page *sp = sptep_to_sp(rcu_dereference(pt));
 	int level = sp->role.level;
@@ -477,11 +490,22 @@ static void handle_removed_pt(struct kvm *kvm, tdp_ptep_t pt, bool shared)
 			 */
 			WRITE_ONCE(*sptep, REMOVED_SPTE);
 		}
-		handle_changed_spte(kvm, kvm_mmu_page_as_id(sp), gfn,
+		handle_changed_spte(kvm, kvm_mmu_page_as_id(sp), gfn, is_private,
 				    old_child_spte, REMOVED_SPTE, level,
 				    shared);
 	}
 
+	if (is_private && WARN_ON(static_call(kvm_x86_free_private_sp)(
+					  kvm, sp->gfn, sp->role.level,
+					  kvm_mmu_private_sp(sp)))) {
+		/*
+		 * Failed to unlink Secure EPT page and there is nothing to do
+		 * further.  Intentionally leak the page to prevent the kernel
+		 * from accessing the encrypted page.
+		 */
+		kvm_mmu_init_private_sp(sp);
+	}
+
 	call_rcu(&sp->rcu_head, tdp_mmu_free_sp_rcu_callback);
 }
 
@@ -490,6 +514,7 @@ static void handle_removed_pt(struct kvm *kvm, tdp_ptep_t pt, bool shared)
  * @kvm: kvm instance
  * @as_id: the address space of the paging structure the SPTE was a part of
  * @gfn: the base GFN that was mapped by the SPTE
+ * @private_spte: the SPTE is private or not
  * @old_spte: The value of the SPTE before the change
  * @new_spte: The value of the SPTE after the change
  * @level: the level of the PT the SPTE is part of in the paging structure
@@ -501,14 +526,30 @@ static void handle_removed_pt(struct kvm *kvm, tdp_ptep_t pt, bool shared)
  * This function must be called for all TDP SPTE modifications.
  */
 static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
-				  u64 old_spte, u64 new_spte, int level,
-				  bool shared)
+				  bool private_spte, u64 old_spte,
+				  u64 new_spte, int level, bool shared)
 {
 	bool was_present = is_shadow_present_pte(old_spte);
 	bool is_present = is_shadow_present_pte(new_spte);
 	bool was_leaf = was_present && is_last_spte(old_spte, level);
 	bool is_leaf = is_present && is_last_spte(new_spte, level);
-	bool pfn_changed = spte_to_pfn(old_spte) != spte_to_pfn(new_spte);
+	kvm_pfn_t old_pfn = spte_to_pfn(old_spte);
+	kvm_pfn_t new_pfn = spte_to_pfn(new_spte);
+	bool pfn_changed = old_pfn != new_pfn;
+	struct kvm_spte_change change = {
+		.gfn = gfn,
+		.level = level,
+		.old = {
+			.pfn = old_pfn,
+			.is_present = was_present,
+			.is_leaf = was_leaf,
+		},
+		.new = {
+			.pfn = new_pfn,
+			.is_present = is_present,
+			.is_leaf = is_leaf,
+		},
+	};
 
 	WARN_ON(level > PT64_ROOT_MAX_LEVEL);
 	WARN_ON(level < PG_LEVEL_4K);
@@ -575,7 +616,7 @@ static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
 
 	if (was_leaf && is_dirty_spte(old_spte) &&
 	    (!is_present || !is_dirty_spte(new_spte) || pfn_changed))
-		kvm_set_pfn_dirty(spte_to_pfn(old_spte));
+		kvm_set_pfn_dirty(old_pfn);
 
 	/*
 	 * Recursively handle child PTs if the change removed a subtree from
@@ -584,16 +625,47 @@ static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
 	 * pages are kernel allocations and should never be migrated.
 	 */
 	if (was_present && !was_leaf &&
-	    (is_leaf || !is_present || WARN_ON_ONCE(pfn_changed)))
-		handle_removed_pt(kvm, spte_to_child_pt(old_spte, level), shared);
+	    (is_leaf || !is_present || WARN_ON_ONCE(pfn_changed))) {
+		WARN_ON(private_spte !=
+			is_private_sptep(spte_to_child_pt(old_spte, level)));
+		handle_removed_pt(kvm, spte_to_child_pt(old_spte, level),
+				  private_spte, shared);
+	}
+
+	/*
+	 * Special handling for the private mapping.  We are either
+	 * setting up new mapping at middle level page table, or leaf,
+	 * or tearing down existing mapping.
+	 *
+	 * This is after handling lower page table by above
+	 * handle_remove_tdp_mmu_page().  S-EPT requires to remove S-EPT tables
+	 * after removing childrens.
+	 */
+	if (private_spte &&
+	    /* Ignore change of software only bits. e.g. host_writable */
+	    (was_leaf != is_leaf || was_present != is_present || pfn_changed)) {
+		void *sept_page = NULL;
+
+		if (is_present && !is_leaf) {
+			struct kvm_mmu_page *sp = to_shadow_page(pfn_to_hpa(new_pfn));
+
+			sept_page = kvm_mmu_private_sp(sp);
+			WARN_ON(!sept_page);
+			WARN_ON(sp->role.level + 1 != level);
+			WARN_ON(sp->gfn != gfn);
+		}
+		change.sept_page = sept_page;
+
+		static_call(kvm_x86_handle_changed_private_spte)(kvm, &change);
+	}
 }
 
 static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
-				u64 old_spte, u64 new_spte, int level,
-				bool shared)
+				bool private_spte, u64 old_spte, u64 new_spte,
+				int level, bool shared)
 {
-	__handle_changed_spte(kvm, as_id, gfn, old_spte, new_spte, level,
-			      shared);
+	__handle_changed_spte(kvm, as_id, gfn, private_spte,
+			old_spte, new_spte, level, shared);
 	handle_changed_spte_acc_track(old_spte, new_spte, level);
 	handle_changed_spte_dirty_log(kvm, as_id, gfn, old_spte,
 				      new_spte, level);
@@ -620,6 +692,8 @@ static inline int tdp_mmu_set_spte_atomic(struct kvm *kvm,
 					  struct tdp_iter *iter,
 					  u64 new_spte)
 {
+	bool freeze_spte = iter->is_private && !is_removed_spte(new_spte);
+	u64 tmp_spte = freeze_spte ? REMOVED_SPTE : new_spte;
 	u64 *sptep = rcu_dereference(iter->sptep);
 	u64 old_spte;
 
@@ -637,7 +711,7 @@ static inline int tdp_mmu_set_spte_atomic(struct kvm *kvm,
 	 * Note, fast_pf_fix_direct_spte() can also modify TDP MMU SPTEs and
 	 * does not hold the mmu_lock.
 	 */
-	old_spte = cmpxchg64(sptep, iter->old_spte, new_spte);
+	old_spte = cmpxchg64(sptep, iter->old_spte, tmp_spte);
 	if (old_spte != iter->old_spte) {
 		/*
 		 * The page table entry was modified by a different logical
@@ -649,10 +723,14 @@ static inline int tdp_mmu_set_spte_atomic(struct kvm *kvm,
 		return -EBUSY;
 	}
 
-	__handle_changed_spte(kvm, iter->as_id, iter->gfn, iter->old_spte,
-			      new_spte, iter->level, true);
+	__handle_changed_spte(
+		kvm, iter->as_id, iter->gfn, iter->is_private,
+		iter->old_spte, new_spte, iter->level, true);
 	handle_changed_spte_acc_track(iter->old_spte, new_spte, iter->level);
 
+	if (freeze_spte)
+		kvm_tdp_mmu_write_spte(sptep, new_spte);
+
 	return 0;
 }
 
@@ -715,10 +793,12 @@ static inline int tdp_mmu_zap_spte_atomic(struct kvm *kvm,
  *		      unless performing certain dirty logging operations.
  *		      Leaving record_dirty_log unset in that case prevents page
  *		      writes from being double counted.
+ * @is_private:       The fault is private.
  */
 static void __tdp_mmu_set_spte(struct kvm *kvm, int as_id, tdp_ptep_t sptep,
 			       u64 old_spte, u64 new_spte, gfn_t gfn, int level,
-			       bool record_acc_track, bool record_dirty_log)
+			       bool record_acc_track, bool record_dirty_log,
+			       bool is_private)
 {
 	lockdep_assert_held_write(&kvm->mmu_lock);
 
@@ -733,7 +813,8 @@ static void __tdp_mmu_set_spte(struct kvm *kvm, int as_id, tdp_ptep_t sptep,
 
 	kvm_tdp_mmu_write_spte(sptep, new_spte);
 
-	__handle_changed_spte(kvm, as_id, gfn, old_spte, new_spte, level, false);
+	__handle_changed_spte(kvm, as_id, gfn, is_private,
+			      old_spte, new_spte, level, false);
 
 	if (record_acc_track)
 		handle_changed_spte_acc_track(old_spte, new_spte, level);
@@ -750,7 +831,7 @@ static inline void _tdp_mmu_set_spte(struct kvm *kvm, struct tdp_iter *iter,
 
 	__tdp_mmu_set_spte(kvm, iter->as_id, iter->sptep, iter->old_spte,
 			   new_spte, iter->gfn, iter->level,
-			   record_acc_track, record_dirty_log);
+			   record_acc_track, record_dirty_log, iter->is_private);
 }
 
 static inline void tdp_mmu_set_spte(struct kvm *kvm, struct tdp_iter *iter,
@@ -783,8 +864,11 @@ static inline void tdp_mmu_set_spte_no_dirty_log(struct kvm *kvm,
 			continue;					\
 		else
 
-#define tdp_mmu_for_each_pte(_iter, _mmu, _start, _end)		\
-	for_each_tdp_pte(_iter, to_shadow_page(_mmu->root.hpa), _start, _end)
+#define tdp_mmu_for_each_pte(_iter, _mmu, _private, _start, _end)	\
+	for_each_tdp_pte(_iter,						\
+		 to_shadow_page((_private) ? _mmu->private_root_hpa :	\
+				_mmu->root.hpa),			\
+		_start, _end)
 
 /*
  * Yield if the MMU lock is contended or this thread needs to return control
@@ -921,7 +1005,7 @@ bool kvm_tdp_mmu_zap_sp(struct kvm *kvm, struct kvm_mmu_page *sp)
 
 	__tdp_mmu_set_spte(kvm, kvm_mmu_page_as_id(sp), sp->ptep, old_spte,
 			   SHADOW_NONPRESENT_VALUE, sp->gfn, sp->role.level + 1,
-			   true, true);
+			   true, true, is_private_sp(sp));
 
 	return true;
 }
@@ -937,13 +1021,21 @@ bool kvm_tdp_mmu_zap_sp(struct kvm *kvm, struct kvm_mmu_page *sp)
  * operation can cause a soft lockup.
  */
 static bool tdp_mmu_zap_leafs(struct kvm *kvm, struct kvm_mmu_page *root,
-			      gfn_t start, gfn_t end, bool can_yield, bool flush)
+			      gfn_t start, gfn_t end, bool can_yield, bool flush,
+			      bool drop_private)
 {
 	struct tdp_iter iter;
 
 	end = min(end, tdp_mmu_max_gfn_exclusive());
 
 	lockdep_assert_held_write(&kvm->mmu_lock);
+	/*
+	 * Extend [start, end) to include GFN shared bit when TDX is enabled,
+	 * and for shared mapping range.
+	 */
+	WARN_ON_ONCE(!is_private_sp(root) && drop_private);
+	start = kvm_gfn_for_root(kvm, root, start);
+	end = kvm_gfn_for_root(kvm, root, end);
 
 	rcu_read_lock();
 
@@ -978,12 +1070,13 @@ static bool tdp_mmu_zap_leafs(struct kvm *kvm, struct kvm_mmu_page *root,
  * MMU lock.
  */
 bool kvm_tdp_mmu_zap_leafs(struct kvm *kvm, int as_id, gfn_t start, gfn_t end,
-			   bool can_yield, bool flush)
+			   bool can_yield, bool flush, bool drop_private)
 {
 	struct kvm_mmu_page *root;
 
 	for_each_tdp_mmu_root_yield_safe(kvm, root, as_id)
-		flush = tdp_mmu_zap_leafs(kvm, root, start, end, can_yield, flush);
+		flush = tdp_mmu_zap_leafs(kvm, root, start, end, can_yield, flush,
+					  drop_private && is_private_sp(root));
 
 	return flush;
 }
@@ -1043,6 +1136,12 @@ void kvm_tdp_mmu_invalidate_all_roots(struct kvm *kvm)
 
 	lockdep_assert_held_write(&kvm->mmu_lock);
 	list_for_each_entry(root, &kvm->arch.tdp_mmu_roots, link) {
+		/*
+		 * Skip private root since private page table
+		 * is only torn down when VM is destroyed.
+		 */
+		if (is_private_sp(root))
+			continue;
 		if (!root->role.invalid &&
 		    !WARN_ON_ONCE(!kvm_tdp_mmu_get_root(root))) {
 			root->role.invalid = true;
@@ -1063,14 +1162,22 @@ static int tdp_mmu_map_handle_target_level(struct kvm_vcpu *vcpu,
 	u64 new_spte;
 	int ret = RET_PF_FIXED;
 	bool wrprot = false;
+	unsigned long pte_access = ACC_ALL;
+	gfn_t gfn_unalias = iter->gfn & ~kvm_gfn_shared_mask(vcpu->kvm);
 
 	WARN_ON(sp->role.level != fault->goal_level);
+
+	/* TDX shared GPAs are no executable, enforce this for the SDV. */
+	if (kvm_gfn_shared_mask(vcpu->kvm) && !fault->is_private)
+		pte_access &= ~ACC_EXEC_MASK;
+
 	if (unlikely(!fault->slot))
-		new_spte = make_mmio_spte(vcpu, iter->gfn, ACC_ALL);
+		new_spte = make_mmio_spte(vcpu, gfn_unalias, pte_access);
 	else
-		wrprot = make_spte(vcpu, sp, fault->slot, ACC_ALL, iter->gfn,
-					 fault->pfn, iter->old_spte, fault->prefetch, true,
-					 fault->map_writable, &new_spte);
+		wrprot = make_spte(vcpu, sp, fault->slot, pte_access,
+				   gfn_unalias, fault->pfn, iter->old_spte,
+				   fault->prefetch, true, fault->map_writable,
+				   &new_spte);
 
 	if (new_spte == iter->old_spte)
 		ret = RET_PF_SPURIOUS;
@@ -1149,8 +1256,7 @@ static int tdp_mmu_link_sp(struct kvm *kvm, struct tdp_iter *iter,
 	return 0;
 }
 
-static int tdp_mmu_populate_nonleaf(
-	struct kvm_vcpu *vcpu, struct tdp_iter *iter, bool account_nx)
+static int tdp_mmu_populate_nonleaf(struct kvm_vcpu *vcpu, struct tdp_iter *iter, bool account_nx)
 {
 	struct kvm_mmu_page *sp;
 	int ret;
@@ -1158,7 +1264,7 @@ static int tdp_mmu_populate_nonleaf(
 	WARN_ON(is_shadow_present_pte(iter->old_spte));
 	WARN_ON(is_removed_spte(iter->old_spte));
 
-	sp = tdp_mmu_alloc_sp(vcpu);
+	sp = tdp_mmu_alloc_sp(vcpu, iter->is_private, false);
 	tdp_mmu_init_child_sp(sp, iter);
 
 	ret = tdp_mmu_link_sp(vcpu->kvm, iter, sp, account_nx, true);
@@ -1175,6 +1281,8 @@ int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
 {
 	struct kvm_mmu *mmu = vcpu->arch.mmu;
 	struct tdp_iter iter;
+	gfn_t raw_gfn;
+	bool is_private = fault->is_private;
 	int ret;
 
 	kvm_mmu_hugepage_adjust(vcpu, fault);
@@ -1183,7 +1291,16 @@ int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
 
 	rcu_read_lock();
 
-	tdp_mmu_for_each_pte(iter, mmu, fault->gfn, fault->gfn + 1) {
+	raw_gfn = gpa_to_gfn(fault->addr);
+
+	if (is_error_noslot_pfn(fault->pfn) || kvm_is_reserved_pfn(fault->pfn)) {
+		if (is_private) {
+			rcu_read_unlock();
+			return -EFAULT;
+		}
+	}
+
+	tdp_mmu_for_each_pte(iter, mmu, is_private, raw_gfn, raw_gfn + 1) {
 		if (fault->nx_huge_page_workaround_enabled)
 			disallowed_hugepage_adjust(fault, iter.old_spte, iter.level);
 
@@ -1199,6 +1316,12 @@ int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
 		    is_large_pte(iter.old_spte)) {
 			if (tdp_mmu_zap_spte_atomic(vcpu->kvm, &iter))
 				break;
+			/*
+			 * TODO: large page support.
+			 * Doesn't support large page for TDX now
+			 */
+			WARN_ON(is_private_sptep(iter.sptep));
+
 
 			/*
 			 * The iter must explicitly re-read the spte here
@@ -1240,11 +1363,13 @@ int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
 	return ret;
 }
 
+/* Used by mmu notifier via kvm_unmap_gfn_range() */
 bool kvm_tdp_mmu_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range,
-				 bool flush)
+				 bool flush, bool drop_private)
 {
 	return kvm_tdp_mmu_zap_leafs(kvm, range->slot->as_id, range->start,
-				     range->end, range->may_block, flush);
+				     range->end, range->may_block, flush,
+				     drop_private);
 }
 
 typedef bool (*tdp_handler_t)(struct kvm *kvm, struct tdp_iter *iter,
@@ -1427,7 +1552,8 @@ bool kvm_tdp_mmu_wrprot_slot(struct kvm *kvm,
 	return spte_set;
 }
 
-static struct kvm_mmu_page *__tdp_mmu_alloc_sp_for_split(gfp_t gfp)
+static struct kvm_mmu_page *__tdp_mmu_alloc_sp_for_split(
+	gfp_t gfp, bool is_private)
 {
 	struct kvm_mmu_page *sp;
 
@@ -1438,6 +1564,12 @@ static struct kvm_mmu_page *__tdp_mmu_alloc_sp_for_split(gfp_t gfp)
 		return NULL;
 
 	sp->spt = (void *)__get_free_page(gfp);
+	if (is_private) {
+		if (kvm_alloc_private_sp_for_split(sp, gfp)) {
+			free_page((unsigned long)sp->spt);
+			sp->spt = NULL;
+		}
+	}
 	if (!sp->spt) {
 		kmem_cache_free(mmu_page_header_cache, sp);
 		return NULL;
@@ -1451,6 +1583,11 @@ static struct kvm_mmu_page *tdp_mmu_alloc_sp_for_split(struct kvm *kvm,
 						       bool shared)
 {
 	struct kvm_mmu_page *sp;
+	bool is_private = iter->is_private;
+
+	/* TODO: For now large page isn't supported for private SPTE. */
+	WARN_ON(is_private);
+	WARN_ON(iter->is_private != is_private_sptep(iter->sptep));
 
 	/*
 	 * Since we are allocating while under the MMU lock we have to be
@@ -1461,7 +1598,7 @@ static struct kvm_mmu_page *tdp_mmu_alloc_sp_for_split(struct kvm *kvm,
 	 * If this allocation fails we drop the lock and retry with reclaim
 	 * allowed.
 	 */
-	sp = __tdp_mmu_alloc_sp_for_split(GFP_NOWAIT | __GFP_ACCOUNT);
+	sp = __tdp_mmu_alloc_sp_for_split(GFP_NOWAIT | __GFP_ACCOUNT, is_private);
 	if (sp)
 		return sp;
 
@@ -1473,7 +1610,7 @@ static struct kvm_mmu_page *tdp_mmu_alloc_sp_for_split(struct kvm *kvm,
 		write_unlock(&kvm->mmu_lock);
 
 	iter->yielded = true;
-	sp = __tdp_mmu_alloc_sp_for_split(GFP_KERNEL_ACCOUNT);
+	sp = __tdp_mmu_alloc_sp_for_split(GFP_KERNEL_ACCOUNT, is_private);
 
 	if (shared)
 		read_lock(&kvm->mmu_lock);
@@ -1863,10 +2000,14 @@ int kvm_tdp_mmu_get_walk(struct kvm_vcpu *vcpu, u64 addr, u64 *sptes,
 	struct kvm_mmu *mmu = vcpu->arch.mmu;
 	gfn_t gfn = addr >> PAGE_SHIFT;
 	int leaf = -1;
+	bool is_private = kvm_is_private_gpa(vcpu->kvm, addr);
 
 	*root_level = vcpu->arch.mmu->root_role.level;
 
-	tdp_mmu_for_each_pte(iter, mmu, gfn, gfn + 1) {
+	if (WARN_ON(is_private))
+		return leaf;
+
+	tdp_mmu_for_each_pte(iter, mmu, false, gfn, gfn + 1) {
 		leaf = iter.level;
 		sptes[leaf] = iter.old_spte;
 	}
@@ -1893,7 +2034,10 @@ u64 *kvm_tdp_mmu_fast_pf_get_last_sptep(struct kvm_vcpu *vcpu, u64 addr,
 	gfn_t gfn = addr >> PAGE_SHIFT;
 	tdp_ptep_t sptep = NULL;
 
-	tdp_mmu_for_each_pte(iter, mmu, gfn, gfn + 1) {
+	/* fast page fault for private GPA isn't supported. */
+	WARN_ON_ONCE(kvm_is_private_gpa(vcpu->kvm, addr));
+
+	tdp_mmu_for_each_pte(iter, mmu, false, gfn, gfn + 1) {
 		*spte = iter.old_spte;
 		sptep = iter.sptep;
 	}
diff --git a/arch/x86/kvm/mmu/tdp_mmu.h b/arch/x86/kvm/mmu/tdp_mmu.h
index c163f7cc23ca..d1655571eb2f 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.h
+++ b/arch/x86/kvm/mmu/tdp_mmu.h
@@ -5,7 +5,7 @@
 
 #include <linux/kvm_host.h>
 
-hpa_t kvm_tdp_mmu_get_vcpu_root_hpa(struct kvm_vcpu *vcpu);
+hpa_t kvm_tdp_mmu_get_vcpu_root_hpa(struct kvm_vcpu *vcpu, bool private);
 
 __must_check static inline bool kvm_tdp_mmu_get_root(struct kvm_mmu_page *root)
 {
@@ -16,7 +16,8 @@ void kvm_tdp_mmu_put_root(struct kvm *kvm, struct kvm_mmu_page *root,
 			  bool shared);
 
 bool kvm_tdp_mmu_zap_leafs(struct kvm *kvm, int as_id, gfn_t start,
-				 gfn_t end, bool can_yield, bool flush);
+				gfn_t end, bool can_yield, bool flush,
+				bool drop_private);
 bool kvm_tdp_mmu_zap_sp(struct kvm *kvm, struct kvm_mmu_page *sp);
 void kvm_tdp_mmu_zap_all(struct kvm *kvm);
 void kvm_tdp_mmu_invalidate_all_roots(struct kvm *kvm);
@@ -25,7 +26,7 @@ void kvm_tdp_mmu_zap_invalidated_roots(struct kvm *kvm);
 int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault);
 
 bool kvm_tdp_mmu_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range,
-				 bool flush);
+				 bool flush, bool drop_private);
 bool kvm_tdp_mmu_age_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range);
 bool kvm_tdp_mmu_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range);
 bool kvm_tdp_mmu_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 6edce5de54ff..0ed431a1e35f 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -196,6 +196,7 @@ bool kvm_is_reserved_pfn(kvm_pfn_t pfn)
 
 	return true;
 }
+EXPORT_SYMBOL_GPL(kvm_is_reserved_pfn);
 
 /*
  * Switches to specified vcpu, until a matching vcpu_put()
-- 
2.25.1