Merge branch kvm-arm64/pkvm-np-guest into kvmarm-master/next

* kvm-arm64/pkvm-np-guest:
: .
: pKVM support for non-protected guests using the standard MM
: infrastructure, courtesy of Quentin Perret. From the cover letter:
:
: "This series moves the stage-2 page-table management of non-protected
: guests to EL2 when pKVM is enabled. This is only intended as an
: incremental step towards a 'feature-complete' pKVM, there is however a
: lot more that needs to come on top.
:
: With that series applied, pKVM provides near-parity with standard KVM
: from a functional perspective all while Linux no longer touches the
: stage-2 page-tables itself at EL1. The majority of mm-related KVM
: features work out of the box, including MMU notifiers, dirty logging,
: RO memslots and things of that nature. There are however two gotchas:
:
: - We don't support mapping devices into guests: this requires
: additional hypervisor support for tracking the 'state' of devices,
: which will come in a later series. No device assignment until then.
:
: - Stage-2 mappings are forced to page-granularity even when backed by a
: huge page for the sake of simplicity of this series. I'm only aiming
: at functional parity-ish (from userspace's PoV) for now, support for
: HP can be added on top later as a perf improvement."
: .
KVM: arm64: Plumb the pKVM MMU in KVM
KVM: arm64: Introduce the EL1 pKVM MMU
KVM: arm64: Introduce __pkvm_tlb_flush_vmid()
KVM: arm64: Introduce __pkvm_host_mkyoung_guest()
KVM: arm64: Introduce __pkvm_host_test_clear_young_guest()
KVM: arm64: Introduce __pkvm_host_wrprotect_guest()
KVM: arm64: Introduce __pkvm_host_relax_guest_perms()
KVM: arm64: Introduce __pkvm_host_unshare_guest()
KVM: arm64: Introduce __pkvm_host_share_guest()
KVM: arm64: Introduce __pkvm_vcpu_{load,put}()
KVM: arm64: Add {get,put}_pkvm_hyp_vm() helpers
KVM: arm64: Make kvm_pgtable_stage2_init() a static inline function
KVM: arm64: Pass walk flags to kvm_pgtable_stage2_relax_perms
KVM: arm64: Pass walk flags to kvm_pgtable_stage2_mkyoung
KVM: arm64: Move host page ownership tracking to the hyp vmemmap
KVM: arm64: Make hyp_page::order a u8
KVM: arm64: Move enum pkvm_page_state to memory.h
KVM: arm64: Change the layout of enum pkvm_page_state

Signed-off-by: Marc Zyngier <[e-mail]>

# Conflicts:
# arch/arm64/kvm/arm.c

arch/arm64/include/asm/kvm_asm.h

···
 	/* Hypercalls available after pKVM finalisation */
 	__KVM_HOST_SMCCC_FUNC___pkvm_host_share_hyp,
 	__KVM_HOST_SMCCC_FUNC___pkvm_host_unshare_hyp,
+	__KVM_HOST_SMCCC_FUNC___pkvm_host_share_guest,
+	__KVM_HOST_SMCCC_FUNC___pkvm_host_unshare_guest,
+	__KVM_HOST_SMCCC_FUNC___pkvm_host_relax_perms_guest,
+	__KVM_HOST_SMCCC_FUNC___pkvm_host_wrprotect_guest,
+	__KVM_HOST_SMCCC_FUNC___pkvm_host_test_clear_young_guest,
+	__KVM_HOST_SMCCC_FUNC___pkvm_host_mkyoung_guest,
 	__KVM_HOST_SMCCC_FUNC___kvm_adjust_pc,
 	__KVM_HOST_SMCCC_FUNC___kvm_vcpu_run,
 	__KVM_HOST_SMCCC_FUNC___kvm_flush_vm_context,
···
 	__KVM_HOST_SMCCC_FUNC___pkvm_init_vm,
 	__KVM_HOST_SMCCC_FUNC___pkvm_init_vcpu,
 	__KVM_HOST_SMCCC_FUNC___pkvm_teardown_vm,
+	__KVM_HOST_SMCCC_FUNC___pkvm_vcpu_load,
+	__KVM_HOST_SMCCC_FUNC___pkvm_vcpu_put,
+	__KVM_HOST_SMCCC_FUNC___pkvm_tlb_flush_vmid,
 };
 
 #define DECLARE_KVM_VHE_SYM(sym)	extern char sym[]

arch/arm64/include/asm/kvm_host.h

···
 struct kvm_hyp_memcache {
 	phys_addr_t head;
 	unsigned long nr_pages;
+	struct pkvm_mapping *mapping; /* only used from EL1 */
 };
 
 static inline void push_hyp_memcache(struct kvm_hyp_memcache *mc,
···
 
 	/* Cache some mmu pages needed inside spinlock regions */
 	struct kvm_mmu_memory_cache mmu_page_cache;
+
+	/* Pages to top-up the pKVM/EL2 guest pool */
+	struct kvm_hyp_memcache pkvm_memcache;
 
 	/* Virtual SError ESR to restore when HCR_EL2.VSE is set */
 	u64 vsesr_el2;

arch/arm64/include/asm/kvm_mmu.h

···
 	return &kvm->arch.mmu != mmu;
 }
 
+static inline void kvm_fault_lock(struct kvm *kvm)
+{
+	if (is_protected_kvm_enabled())
+		write_lock(&kvm->mmu_lock);
+	else
+		read_lock(&kvm->mmu_lock);
+}
+
+static inline void kvm_fault_unlock(struct kvm *kvm)
+{
+	if (is_protected_kvm_enabled())
+		write_unlock(&kvm->mmu_lock);
+	else
+		read_unlock(&kvm->mmu_lock);
+}
+
 #ifdef CONFIG_PTDUMP_STAGE2_DEBUGFS
 void kvm_s2_ptdump_create_debugfs(struct kvm *kvm);
 #else

arch/arm64/include/asm/kvm_pgtable.h

···
  *			be used instead of block mappings.
  */
 struct kvm_pgtable {
-	u32					ia_bits;
-	s8					start_level;
-	kvm_pteref_t				pgd;
-	struct kvm_pgtable_mm_ops		*mm_ops;
+	union {
+		struct rb_root					pkvm_mappings;
+		struct {
+			u32					ia_bits;
+			s8					start_level;
+			kvm_pteref_t				pgd;
+			struct kvm_pgtable_mm_ops		*mm_ops;
 
-	/* Stage-2 only */
-	struct kvm_s2_mmu			*mmu;
-	enum kvm_pgtable_stage2_flags		flags;
-	kvm_pgtable_force_pte_cb_t		force_pte_cb;
+			/* Stage-2 only */
+			enum kvm_pgtable_stage2_flags		flags;
+			kvm_pgtable_force_pte_cb_t		force_pte_cb;
+		};
+	};
+	struct kvm_s2_mmu					*mmu;
 };
 
 /**
···
 			      enum kvm_pgtable_stage2_flags flags,
 			      kvm_pgtable_force_pte_cb_t force_pte_cb);
 
-#define kvm_pgtable_stage2_init(pgt, mmu, mm_ops) \
-	__kvm_pgtable_stage2_init(pgt, mmu, mm_ops, 0, NULL)
+static inline int kvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm_s2_mmu *mmu,
+					  struct kvm_pgtable_mm_ops *mm_ops)
+{
+	return __kvm_pgtable_stage2_init(pgt, mmu, mm_ops, 0, NULL);
+}
 
 /**
  * kvm_pgtable_stage2_destroy() - Destroy an unused guest stage-2 page-table.
···
  * kvm_pgtable_stage2_mkyoung() - Set the access flag in a page-table entry.
  * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init*().
  * @addr:	Intermediate physical address to identify the page-table entry.
+ * @flags:	Flags to control the page-table walk (ex. a shared walk)
  *
  * The offset of @addr within a page is ignored.
  *
  * If there is a valid, leaf page-table entry used to translate @addr, then
  * set the access flag in that entry.
  */
-void kvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr);
+void kvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr,
+				enum kvm_pgtable_walk_flags flags);
 
 /**
  * kvm_pgtable_stage2_test_clear_young() - Test and optionally clear the access
···
  * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init*().
  * @addr:	Intermediate physical address to identify the page-table entry.
  * @prot:	Additional permissions to grant for the mapping.
+ * @flags:	Flags to control the page-table walk (ex. a shared walk)
  *
  * The offset of @addr within a page is ignored.
  *
···
  * Return: 0 on success, negative error code on failure.
  */
 int kvm_pgtable_stage2_relax_perms(struct kvm_pgtable *pgt, u64 addr,
-				   enum kvm_pgtable_prot prot);
+				   enum kvm_pgtable_prot prot,
+				   enum kvm_pgtable_walk_flags flags);
 
 /**
  * kvm_pgtable_stage2_flush_range() - Clean and invalidate data cache to Point

arch/arm64/include/asm/kvm_pkvm.h

···
 			SVE_SIG_REGS_SIZE(sve_vq_from_vl(kvm_host_sve_max_vl)));
 }
 
+struct pkvm_mapping {
+	struct rb_node node;
+	u64 gfn;
+	u64 pfn;
+};
+
+int pkvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm_s2_mmu *mmu,
+			     struct kvm_pgtable_mm_ops *mm_ops);
+void pkvm_pgtable_stage2_destroy(struct kvm_pgtable *pgt);
+int pkvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size, u64 phys,
+			    enum kvm_pgtable_prot prot, void *mc,
+			    enum kvm_pgtable_walk_flags flags);
+int pkvm_pgtable_stage2_unmap(struct kvm_pgtable *pgt, u64 addr, u64 size);
+int pkvm_pgtable_stage2_wrprotect(struct kvm_pgtable *pgt, u64 addr, u64 size);
+int pkvm_pgtable_stage2_flush(struct kvm_pgtable *pgt, u64 addr, u64 size);
+bool pkvm_pgtable_stage2_test_clear_young(struct kvm_pgtable *pgt, u64 addr, u64 size, bool mkold);
+int pkvm_pgtable_stage2_relax_perms(struct kvm_pgtable *pgt, u64 addr, enum kvm_pgtable_prot prot,
+				    enum kvm_pgtable_walk_flags flags);
+void pkvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr,
+				 enum kvm_pgtable_walk_flags flags);
+int pkvm_pgtable_stage2_split(struct kvm_pgtable *pgt, u64 addr, u64 size,
+			      struct kvm_mmu_memory_cache *mc);
+void pkvm_pgtable_stage2_free_unlinked(struct kvm_pgtable_mm_ops *mm_ops, void *pgtable, s8 level);
+kvm_pte_t *pkvm_pgtable_stage2_create_unlinked(struct kvm_pgtable *pgt, u64 phys, s8 level,
+					       enum kvm_pgtable_prot prot, void *mc,
+					       bool force_pte);
 #endif	/* __ARM64_KVM_PKVM_H__ */

arch/arm64/kvm/arm.c

···
 
 void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
 {
-	kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_cache);
+	if (!is_protected_kvm_enabled())
+		kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_cache);
+	else
+		free_hyp_memcache(&vcpu->arch.pkvm_memcache);
 	kvm_timer_vcpu_terminate(vcpu);
 	kvm_pmu_vcpu_destroy(vcpu);
 	kvm_vgic_vcpu_destroy(vcpu);
···
 	struct kvm_s2_mmu *mmu;
 	int *last_ran;
 
+	if (is_protected_kvm_enabled())
+		goto nommu;
+
 	if (vcpu_has_nv(vcpu))
 		kvm_vcpu_load_hw_mmu(vcpu);
 
···
 		*last_ran = vcpu->vcpu_idx;
 	}
 
+nommu:
 	vcpu->cpu = cpu;
 
 	kvm_vgic_load(vcpu);
···
 
 	vcpu_set_pauth_traps(vcpu);
 
+	if (is_protected_kvm_enabled()) {
+		kvm_call_hyp_nvhe(__pkvm_vcpu_load,
+				  vcpu->kvm->arch.pkvm.handle,
+				  vcpu->vcpu_idx, vcpu->arch.hcr_el2);
+		kvm_call_hyp(__vgic_v3_restore_vmcr_aprs,
+			     &vcpu->arch.vgic_cpu.vgic_v3);
+	}
+
 	if (!cpumask_test_cpu(cpu, vcpu->kvm->arch.supported_cpus))
 		vcpu_set_on_unsupported_cpu(vcpu);
 }
 
 void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
 {
+	if (is_protected_kvm_enabled()) {
+		kvm_call_hyp(__vgic_v3_save_vmcr_aprs,
+			     &vcpu->arch.vgic_cpu.vgic_v3);
+		kvm_call_hyp_nvhe(__pkvm_vcpu_put);
+	}
+
 	kvm_vcpu_put_debug(vcpu);
 	kvm_arch_vcpu_put_fp(vcpu);
 	if (has_vhe())

arch/arm64/kvm/hyp/include/nvhe/gfp.h

···
 #include <nvhe/memory.h>
 #include <nvhe/spinlock.h>
 
-#define HYP_NO_ORDER	USHRT_MAX
+#define HYP_NO_ORDER	((u8)(~0))
 
 struct hyp_pool {
 	/*
···
 	struct list_head free_area[NR_PAGE_ORDERS];
 	phys_addr_t range_start;
 	phys_addr_t range_end;
-	unsigned short max_order;
+	u8 max_order;
 };
 
 /* Allocation */
-void *hyp_alloc_pages(struct hyp_pool *pool, unsigned short order);
+void *hyp_alloc_pages(struct hyp_pool *pool, u8 order);
 void hyp_split_page(struct hyp_page *page);
 void hyp_get_page(struct hyp_pool *pool, void *addr);
 void hyp_put_page(struct hyp_pool *pool, void *addr);

arch/arm64/kvm/hyp/include/nvhe/mem_protect.h

···
 #include <asm/kvm_mmu.h>
 #include <asm/kvm_pgtable.h>
 #include <asm/virt.h>
+#include <nvhe/memory.h>
 #include <nvhe/pkvm.h>
 #include <nvhe/spinlock.h>
-
-/*
- * SW bits 0-1 are reserved to track the memory ownership state of each page:
- *   00: The page is owned exclusively by the page-table owner.
- *   01: The page is owned by the page-table owner, but is shared
- *       with another entity.
- *   10: The page is shared with, but not owned by the page-table owner.
- *   11: Reserved for future use (lending).
- */
-enum pkvm_page_state {
-	PKVM_PAGE_OWNED			= 0ULL,
-	PKVM_PAGE_SHARED_OWNED		= KVM_PGTABLE_PROT_SW0,
-	PKVM_PAGE_SHARED_BORROWED	= KVM_PGTABLE_PROT_SW1,
-	__PKVM_PAGE_RESERVED		= KVM_PGTABLE_PROT_SW0 |
-					  KVM_PGTABLE_PROT_SW1,
-
-	/* Meta-states which aren't encoded directly in the PTE's SW bits */
-	PKVM_NOPAGE,
-};
-
-#define PKVM_PAGE_STATE_PROT_MASK	(KVM_PGTABLE_PROT_SW0 | KVM_PGTABLE_PROT_SW1)
-static inline enum kvm_pgtable_prot pkvm_mkstate(enum kvm_pgtable_prot prot,
-						 enum pkvm_page_state state)
-{
-	return (prot & ~PKVM_PAGE_STATE_PROT_MASK) | state;
-}
-
-static inline enum pkvm_page_state pkvm_getstate(enum kvm_pgtable_prot prot)
-{
-	return prot & PKVM_PAGE_STATE_PROT_MASK;
-}
 
 struct host_mmu {
 	struct kvm_arch arch;
···
 int __pkvm_hyp_donate_host(u64 pfn, u64 nr_pages);
 int __pkvm_host_share_ffa(u64 pfn, u64 nr_pages);
 int __pkvm_host_unshare_ffa(u64 pfn, u64 nr_pages);
+int __pkvm_host_share_guest(u64 pfn, u64 gfn, struct pkvm_hyp_vcpu *vcpu,
+			    enum kvm_pgtable_prot prot);
+int __pkvm_host_unshare_guest(u64 gfn, struct pkvm_hyp_vm *hyp_vm);
+int __pkvm_host_relax_perms_guest(u64 gfn, struct pkvm_hyp_vcpu *vcpu, enum kvm_pgtable_prot prot);
+int __pkvm_host_wrprotect_guest(u64 gfn, struct pkvm_hyp_vm *hyp_vm);
+int __pkvm_host_test_clear_young_guest(u64 gfn, bool mkold, struct pkvm_hyp_vm *vm);
+int __pkvm_host_mkyoung_guest(u64 gfn, struct pkvm_hyp_vcpu *vcpu);
 
 bool addr_is_memory(phys_addr_t phys);
 int host_stage2_idmap_locked(phys_addr_t addr, u64 size, enum kvm_pgtable_prot prot);

arch/arm64/kvm/hyp/include/nvhe/memory.h

···
 
 #include <linux/types.h>
 
+/*
+ * Bits 0-1 are reserved to track the memory ownership state of each page:
+ *   00: The page is owned exclusively by the page-table owner.
+ *   01: The page is owned by the page-table owner, but is shared
+ *       with another entity.
+ *   10: The page is shared with, but not owned by the page-table owner.
+ *   11: Reserved for future use (lending).
+ */
+enum pkvm_page_state {
+	PKVM_PAGE_OWNED			= 0ULL,
+	PKVM_PAGE_SHARED_OWNED		= BIT(0),
+	PKVM_PAGE_SHARED_BORROWED	= BIT(1),
+	__PKVM_PAGE_RESERVED		= BIT(0) | BIT(1),
+
+	/* Meta-states which aren't encoded directly in the PTE's SW bits */
+	PKVM_NOPAGE			= BIT(2),
+};
+#define PKVM_PAGE_META_STATES_MASK	(~__PKVM_PAGE_RESERVED)
+
+#define PKVM_PAGE_STATE_PROT_MASK	(KVM_PGTABLE_PROT_SW0 | KVM_PGTABLE_PROT_SW1)
+static inline enum kvm_pgtable_prot pkvm_mkstate(enum kvm_pgtable_prot prot,
+						 enum pkvm_page_state state)
+{
+	prot &= ~PKVM_PAGE_STATE_PROT_MASK;
+	prot |= FIELD_PREP(PKVM_PAGE_STATE_PROT_MASK, state);
+	return prot;
+}
+
+static inline enum pkvm_page_state pkvm_getstate(enum kvm_pgtable_prot prot)
+{
+	return FIELD_GET(PKVM_PAGE_STATE_PROT_MASK, prot);
+}
+
 struct hyp_page {
-	unsigned short refcount;
-	unsigned short order;
+	u16 refcount;
+	u8 order;
+
+	/* Host (non-meta) state. Guarded by the host stage-2 lock. */
+	enum pkvm_page_state host_state : 8;
+
+	u32 host_share_guest_count;
 };
 
 extern u64 __hyp_vmemmap;
···
 
 #define hyp_phys_to_pfn(phys)	((phys) >> PAGE_SHIFT)
 #define hyp_pfn_to_phys(pfn)	((phys_addr_t)((pfn) << PAGE_SHIFT))
-#define hyp_phys_to_page(phys)	(&hyp_vmemmap[hyp_phys_to_pfn(phys)])
+
+static inline struct hyp_page *hyp_phys_to_page(phys_addr_t phys)
+{
+	BUILD_BUG_ON(sizeof(struct hyp_page) != sizeof(u64));
+	return &hyp_vmemmap[hyp_phys_to_pfn(phys)];
+}
+
 #define hyp_virt_to_page(virt)	hyp_phys_to_page(__hyp_pa(virt))
 #define hyp_virt_to_pfn(virt)	hyp_phys_to_pfn(__hyp_pa(virt))
 

arch/arm64/kvm/hyp/include/nvhe/pkvm.h

···
 
 	/* Backpointer to the host's (untrusted) vCPU instance. */
 	struct kvm_vcpu *host_vcpu;
+
+	/*
+	 * If this hyp vCPU is loaded, then this is a backpointer to the
+	 * per-cpu pointer tracking us. Otherwise, NULL if not loaded.
+	 */
+	struct pkvm_hyp_vcpu **loaded_hyp_vcpu;
 };
 
 /*
···
 	return vcpu_is_protected(&hyp_vcpu->vcpu);
 }
 
+static inline bool pkvm_hyp_vm_is_protected(struct pkvm_hyp_vm *hyp_vm)
+{
+	return kvm_vm_is_protected(&hyp_vm->kvm);
+}
+
 void pkvm_hyp_vm_table_init(void *tbl);
 
 int __pkvm_init_vm(struct kvm *host_kvm, unsigned long vm_hva,
···
 struct pkvm_hyp_vcpu *pkvm_load_hyp_vcpu(pkvm_handle_t handle,
 					 unsigned int vcpu_idx);
 void pkvm_put_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu);
+struct pkvm_hyp_vcpu *pkvm_get_loaded_hyp_vcpu(void);
+
+struct pkvm_hyp_vm *get_pkvm_hyp_vm(pkvm_handle_t handle);
+struct pkvm_hyp_vm *get_np_pkvm_hyp_vm(pkvm_handle_t handle);
+void put_pkvm_hyp_vm(struct pkvm_hyp_vm *hyp_vm);
 
 #endif /* __ARM64_KVM_NVHE_PKVM_H__ */

arch/arm64/kvm/hyp/nvhe/hyp-main.c

···
 	/* Limit guest vector length to the maximum supported by the host.  */
 	hyp_vcpu->vcpu.arch.sve_max_vl	= min(host_vcpu->arch.sve_max_vl, kvm_host_sve_max_vl);
 
-	hyp_vcpu->vcpu.arch.hw_mmu	= host_vcpu->arch.hw_mmu;
-
 	hyp_vcpu->vcpu.arch.mdcr_el2	= host_vcpu->arch.mdcr_el2;
 	hyp_vcpu->vcpu.arch.hcr_el2 &= ~(HCR_TWI | HCR_TWE);
 	hyp_vcpu->vcpu.arch.hcr_el2 |= READ_ONCE(host_vcpu->arch.hcr_el2) &
···
 		host_cpu_if->vgic_lr[i] = hyp_cpu_if->vgic_lr[i];
 }
 
+static void handle___pkvm_vcpu_load(struct kvm_cpu_context *host_ctxt)
+{
+	DECLARE_REG(pkvm_handle_t, handle, host_ctxt, 1);
+	DECLARE_REG(unsigned int, vcpu_idx, host_ctxt, 2);
+	DECLARE_REG(u64, hcr_el2, host_ctxt, 3);
+	struct pkvm_hyp_vcpu *hyp_vcpu;
+
+	if (!is_protected_kvm_enabled())
+		return;
+
+	hyp_vcpu = pkvm_load_hyp_vcpu(handle, vcpu_idx);
+	if (!hyp_vcpu)
+		return;
+
+	if (pkvm_hyp_vcpu_is_protected(hyp_vcpu)) {
+		/* Propagate WFx trapping flags */
+		hyp_vcpu->vcpu.arch.hcr_el2 &= ~(HCR_TWE | HCR_TWI);
+		hyp_vcpu->vcpu.arch.hcr_el2 |= hcr_el2 & (HCR_TWE | HCR_TWI);
+	}
+}
+
+static void handle___pkvm_vcpu_put(struct kvm_cpu_context *host_ctxt)
+{
+	struct pkvm_hyp_vcpu *hyp_vcpu;
+
+	if (!is_protected_kvm_enabled())
+		return;
+
+	hyp_vcpu = pkvm_get_loaded_hyp_vcpu();
+	if (hyp_vcpu)
+		pkvm_put_hyp_vcpu(hyp_vcpu);
+}
+
 static void handle___kvm_vcpu_run(struct kvm_cpu_context *host_ctxt)
 {
 	DECLARE_REG(struct kvm_vcpu *, host_vcpu, host_ctxt, 1);
 	int ret;
 
-	host_vcpu = kern_hyp_va(host_vcpu);
-
 	if (unlikely(is_protected_kvm_enabled())) {
-		struct pkvm_hyp_vcpu *hyp_vcpu;
-		struct kvm *host_kvm;
+		struct pkvm_hyp_vcpu *hyp_vcpu = pkvm_get_loaded_hyp_vcpu();
 
 		/*
 		 * KVM (and pKVM) doesn't support SME guests for now, and
···
 			goto out;
 		}
 
-		host_kvm = kern_hyp_va(host_vcpu->kvm);
-		hyp_vcpu = pkvm_load_hyp_vcpu(host_kvm->arch.pkvm.handle,
-					      host_vcpu->vcpu_idx);
 		if (!hyp_vcpu) {
 			ret = -EINVAL;
 			goto out;
···
 		ret = __kvm_vcpu_run(&hyp_vcpu->vcpu);
 
 		sync_hyp_vcpu(hyp_vcpu);
-		pkvm_put_hyp_vcpu(hyp_vcpu);
 	} else {
 		/* The host is fully trusted, run its vCPU directly. */
-		ret = __kvm_vcpu_run(host_vcpu);
+		ret = __kvm_vcpu_run(kern_hyp_va(host_vcpu));
 	}
+out:
+	cpu_reg(host_ctxt, 1) =  ret;
+}
 
+static int pkvm_refill_memcache(struct pkvm_hyp_vcpu *hyp_vcpu)
+{
+	struct kvm_vcpu *host_vcpu = hyp_vcpu->host_vcpu;
+
+	return refill_memcache(&hyp_vcpu->vcpu.arch.pkvm_memcache,
+			       host_vcpu->arch.pkvm_memcache.nr_pages,
+			       &host_vcpu->arch.pkvm_memcache);
+}
+
+static void handle___pkvm_host_share_guest(struct kvm_cpu_context *host_ctxt)
+{
+	DECLARE_REG(u64, pfn, host_ctxt, 1);
+	DECLARE_REG(u64, gfn, host_ctxt, 2);
+	DECLARE_REG(enum kvm_pgtable_prot, prot, host_ctxt, 3);
+	struct pkvm_hyp_vcpu *hyp_vcpu;
+	int ret = -EINVAL;
+
+	if (!is_protected_kvm_enabled())
+		goto out;
+
+	hyp_vcpu = pkvm_get_loaded_hyp_vcpu();
+	if (!hyp_vcpu || pkvm_hyp_vcpu_is_protected(hyp_vcpu))
+		goto out;
+
+	ret = pkvm_refill_memcache(hyp_vcpu);
+	if (ret)
+		goto out;
+
+	ret = __pkvm_host_share_guest(pfn, gfn, hyp_vcpu, prot);
+out:
+	cpu_reg(host_ctxt, 1) =  ret;
+}
+
+static void handle___pkvm_host_unshare_guest(struct kvm_cpu_context *host_ctxt)
+{
+	DECLARE_REG(pkvm_handle_t, handle, host_ctxt, 1);
+	DECLARE_REG(u64, gfn, host_ctxt, 2);
+	struct pkvm_hyp_vm *hyp_vm;
+	int ret = -EINVAL;
+
+	if (!is_protected_kvm_enabled())
+		goto out;
+
+	hyp_vm = get_np_pkvm_hyp_vm(handle);
+	if (!hyp_vm)
+		goto out;
+
+	ret = __pkvm_host_unshare_guest(gfn, hyp_vm);
+	put_pkvm_hyp_vm(hyp_vm);
+out:
+	cpu_reg(host_ctxt, 1) =  ret;
+}
+
+static void handle___pkvm_host_relax_perms_guest(struct kvm_cpu_context *host_ctxt)
+{
+	DECLARE_REG(u64, gfn, host_ctxt, 1);
+	DECLARE_REG(enum kvm_pgtable_prot, prot, host_ctxt, 2);
+	struct pkvm_hyp_vcpu *hyp_vcpu;
+	int ret = -EINVAL;
+
+	if (!is_protected_kvm_enabled())
+		goto out;
+
+	hyp_vcpu = pkvm_get_loaded_hyp_vcpu();
+	if (!hyp_vcpu || pkvm_hyp_vcpu_is_protected(hyp_vcpu))
+		goto out;
+
+	ret = __pkvm_host_relax_perms_guest(gfn, hyp_vcpu, prot);
+out:
+	cpu_reg(host_ctxt, 1) = ret;
+}
+
+static void handle___pkvm_host_wrprotect_guest(struct kvm_cpu_context *host_ctxt)
+{
+	DECLARE_REG(pkvm_handle_t, handle, host_ctxt, 1);
+	DECLARE_REG(u64, gfn, host_ctxt, 2);
+	struct pkvm_hyp_vm *hyp_vm;
+	int ret = -EINVAL;
+
+	if (!is_protected_kvm_enabled())
+		goto out;
+
+	hyp_vm = get_np_pkvm_hyp_vm(handle);
+	if (!hyp_vm)
+		goto out;
+
+	ret = __pkvm_host_wrprotect_guest(gfn, hyp_vm);
+	put_pkvm_hyp_vm(hyp_vm);
+out:
+	cpu_reg(host_ctxt, 1) = ret;
+}
+
+static void handle___pkvm_host_test_clear_young_guest(struct kvm_cpu_context *host_ctxt)
+{
+	DECLARE_REG(pkvm_handle_t, handle, host_ctxt, 1);
+	DECLARE_REG(u64, gfn, host_ctxt, 2);
+	DECLARE_REG(bool, mkold, host_ctxt, 3);
+	struct pkvm_hyp_vm *hyp_vm;
+	int ret = -EINVAL;
+
+	if (!is_protected_kvm_enabled())
+		goto out;
+
+	hyp_vm = get_np_pkvm_hyp_vm(handle);
+	if (!hyp_vm)
+		goto out;
+
+	ret = __pkvm_host_test_clear_young_guest(gfn, mkold, hyp_vm);
+	put_pkvm_hyp_vm(hyp_vm);
+out:
+	cpu_reg(host_ctxt, 1) = ret;
+}
+
+static void handle___pkvm_host_mkyoung_guest(struct kvm_cpu_context *host_ctxt)
+{
+	DECLARE_REG(u64, gfn, host_ctxt, 1);
+	struct pkvm_hyp_vcpu *hyp_vcpu;
+	int ret = -EINVAL;
+
+	if (!is_protected_kvm_enabled())
+		goto out;
+
+	hyp_vcpu = pkvm_get_loaded_hyp_vcpu();
+	if (!hyp_vcpu || pkvm_hyp_vcpu_is_protected(hyp_vcpu))
+		goto out;
+
+	ret = __pkvm_host_mkyoung_guest(gfn, hyp_vcpu);
 out:
 	cpu_reg(host_ctxt, 1) =  ret;
 }
···
 	DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1);
 
 	__kvm_tlb_flush_vmid(kern_hyp_va(mmu));
+}
+
+static void handle___pkvm_tlb_flush_vmid(struct kvm_cpu_context *host_ctxt)
+{
+	DECLARE_REG(pkvm_handle_t, handle, host_ctxt, 1);
+	struct pkvm_hyp_vm *hyp_vm;
+
+	if (!is_protected_kvm_enabled())
+		return;
+
+	hyp_vm = get_np_pkvm_hyp_vm(handle);
+	if (!hyp_vm)
+		return;
+
+	__kvm_tlb_flush_vmid(&hyp_vm->kvm.arch.mmu);
+	put_pkvm_hyp_vm(hyp_vm);
 }
 
 static void handle___kvm_flush_cpu_context(struct kvm_cpu_context *host_ctxt)
···
 
 	HANDLE_FUNC(__pkvm_host_share_hyp),
 	HANDLE_FUNC(__pkvm_host_unshare_hyp),
+	HANDLE_FUNC(__pkvm_host_share_guest),
+	HANDLE_FUNC(__pkvm_host_unshare_guest),
+	HANDLE_FUNC(__pkvm_host_relax_perms_guest),
+	HANDLE_FUNC(__pkvm_host_wrprotect_guest),
+	HANDLE_FUNC(__pkvm_host_test_clear_young_guest),
+	HANDLE_FUNC(__pkvm_host_mkyoung_guest),
 	HANDLE_FUNC(__kvm_adjust_pc),
 	HANDLE_FUNC(__kvm_vcpu_run),
 	HANDLE_FUNC(__kvm_flush_vm_context),
···
 	HANDLE_FUNC(__pkvm_init_vm),
 	HANDLE_FUNC(__pkvm_init_vcpu),
 	HANDLE_FUNC(__pkvm_teardown_vm),
+	HANDLE_FUNC(__pkvm_vcpu_load),
+	HANDLE_FUNC(__pkvm_vcpu_put),
+	HANDLE_FUNC(__pkvm_tlb_flush_vmid),
 };
 
 static void handle_host_hcall(struct kvm_cpu_context *host_ctxt)

arch/arm64/kvm/hyp/nvhe/mem_protect.c

···
 
 	memset(addr, 0, PAGE_SIZE);
 	p = hyp_virt_to_page(addr);
-	memset(p, 0, sizeof(*p));
 	p->refcount = 1;
+	p->order = 0;
 
 	return addr;
 }
···
 
 void reclaim_guest_pages(struct pkvm_hyp_vm *vm, struct kvm_hyp_memcache *mc)
 {
+	struct hyp_page *page;
 	void *addr;
 
 	/* Dump all pgtable pages in the hyp_pool */
···
 	/* Drain the hyp_pool into the memcache */
 	addr = hyp_alloc_pages(&vm->pool, 0);
 	while (addr) {
-		memset(hyp_virt_to_page(addr), 0, sizeof(struct hyp_page));
+		page = hyp_virt_to_page(addr);
+		page->refcount = 0;
+		page->order = 0;
 		push_hyp_memcache(mc, addr, hyp_virt_to_phys);
 		WARN_ON(__pkvm_hyp_donate_host(hyp_virt_to_pfn(addr), 1));
 		addr = hyp_alloc_pages(&vm->pool, 0);
···
 	return !!find_mem_range(phys, &range);
 }
 
-static bool addr_is_allowed_memory(phys_addr_t phys)
+static bool is_in_mem_range(u64 addr, struct kvm_mem_range *range)
+{
+	return range->start <= addr && addr < range->end;
+}
+
+static int check_range_allowed_memory(u64 start, u64 end)
 {
 	struct memblock_region *reg;
 	struct kvm_mem_range range;
 
-	reg = find_mem_range(phys, &range);
+	/*
+	 * Callers can't check the state of a range that overlaps memory and
+	 * MMIO regions, so ensure [start, end[ is in the same kvm_mem_range.
+	 */
+	reg = find_mem_range(start, &range);
+	if (!is_in_mem_range(end - 1, &range))
+		return -EINVAL;
 
-	return reg && !(reg->flags & MEMBLOCK_NOMAP);
-}
+	if (!reg || reg->flags & MEMBLOCK_NOMAP)
+		return -EPERM;
 
-static bool is_in_mem_range(u64 addr, struct kvm_mem_range *range)
-{
-	return range->start <= addr && addr < range->end;
+	return 0;
 }
 
 static bool range_is_memory(u64 start, u64 end)
···
 	if (kvm_pte_valid(pte))
 		return -EAGAIN;
 
-	if (pte)
+	if (pte) {
+		WARN_ON(addr_is_memory(addr) && hyp_phys_to_page(addr)->host_state != PKVM_NOPAGE);
 		return -EPERM;
+	}
 
 	do {
 		u64 granule = kvm_granule_size(level);
···
 	return host_stage2_try(__host_stage2_idmap, addr, addr + size, prot);
 }
 
+static void __host_update_page_state(phys_addr_t addr, u64 size, enum pkvm_page_state state)
+{
+	phys_addr_t end = addr + size;
+
+	for (; addr < end; addr += PAGE_SIZE)
+		hyp_phys_to_page(addr)->host_state = state;
+}
+
 int host_stage2_set_owner_locked(phys_addr_t addr, u64 size, u8 owner_id)
 {
-	return host_stage2_try(kvm_pgtable_stage2_set_owner, &host_mmu.pgt,
-			       addr, size, &host_s2_pool, owner_id);
+	int ret;
+
+	if (!addr_is_memory(addr))
+		return -EPERM;
+
+	ret = host_stage2_try(kvm_pgtable_stage2_set_owner, &host_mmu.pgt,
+			      addr, size, &host_s2_pool, owner_id);
+	if (ret)
+		return ret;
+
+	/* Don't forget to update the vmemmap tracking for the host */
+	if (owner_id == PKVM_ID_HOST)
+		__host_update_page_state(addr, size, PKVM_PAGE_OWNED);
+	else
+		__host_update_page_state(addr, size, PKVM_NOPAGE);
+
+	return 0;
 }
 
 static bool host_stage2_force_pte_cb(u64 addr, u64 end, enum kvm_pgtable_prot prot)
···
 	return kvm_pgtable_walk(pgt, addr, size, &walker);
 }
 
-static enum pkvm_page_state host_get_page_state(kvm_pte_t pte, u64 addr)
-{
-	if (!addr_is_allowed_memory(addr))
-		return PKVM_NOPAGE;
-
-	if (!kvm_pte_valid(pte) && pte)
-		return PKVM_NOPAGE;
-
-	return pkvm_getstate(kvm_pgtable_stage2_pte_prot(pte));
-}
-
 static int __host_check_page_state_range(u64 addr, u64 size,
 					 enum pkvm_page_state state)
 {
-	struct check_walk_data d = {
-		.desired	= state,
-		.get_page_state	= host_get_page_state,
-	};
+	u64 end = addr + size;
+	int ret;
+
+	ret = check_range_allowed_memory(addr, end);
+	if (ret)
+		return ret;
 
 	hyp_assert_lock_held(&host_mmu.lock);
-	return check_page_state_range(&host_mmu.pgt, addr, size, &d);
+	for (; addr < end; addr += PAGE_SIZE) {
+		if (hyp_phys_to_page(addr)->host_state != state)
+			return -EPERM;
+	}
+
+	return 0;
 }
 
 static int __host_set_page_state_range(u64 addr, u64 size,
 				       enum pkvm_page_state state)
 {
-	enum kvm_pgtable_prot prot = pkvm_mkstate(PKVM_HOST_MEM_PROT, state);
+	if (hyp_phys_to_page(addr)->host_state == PKVM_NOPAGE) {
+		int ret = host_stage2_idmap_locked(addr, size, PKVM_HOST_MEM_PROT);
 
-	return host_stage2_idmap_locked(addr, size, prot);
+		if (ret)
+			return ret;
+	}
+
+	__host_update_page_state(addr, size, state);
+
+	return 0;
 }
 
 static int host_request_owned_transition(u64 *completer_addr,
···
 	enum kvm_pgtable_prot prot = pkvm_mkstate(PAGE_HYP, PKVM_PAGE_OWNED);
 
 	return pkvm_create_mappings_locked(start, end, prot);
+}
+
+static enum pkvm_page_state guest_get_page_state(kvm_pte_t pte, u64 addr)
+{
+	if (!kvm_pte_valid(pte))
+		return PKVM_NOPAGE;
+
+	return pkvm_getstate(kvm_pgtable_stage2_pte_prot(pte));
+}
+
+static int __guest_check_page_state_range(struct pkvm_hyp_vcpu *vcpu, u64 addr,
+					  u64 size, enum pkvm_page_state state)
+{
+	struct pkvm_hyp_vm *vm = pkvm_hyp_vcpu_to_hyp_vm(vcpu);
+	struct check_walk_data d = {
+		.desired	= state,
+		.get_page_state	= guest_get_page_state,
+	};
+
+	hyp_assert_lock_held(&vm->lock);
+	return check_page_state_range(&vm->pgt, addr, size, &d);
 }
 
 static int check_share(struct pkvm_mem_share *share)
···
 
 	host_lock_component();
 	ret = do_unshare(&share);
+	host_unlock_component();
+
+	return ret;
+}
+
+int __pkvm_host_share_guest(u64 pfn, u64 gfn, struct pkvm_hyp_vcpu *vcpu,
+			    enum kvm_pgtable_prot prot)
+{
+	struct pkvm_hyp_vm *vm = pkvm_hyp_vcpu_to_hyp_vm(vcpu);
+	u64 phys = hyp_pfn_to_phys(pfn);
+	u64 ipa = hyp_pfn_to_phys(gfn);
+	struct hyp_page *page;
+	int ret;
+
+	if (prot & ~KVM_PGTABLE_PROT_RWX)
+		return -EINVAL;
+
+	ret = check_range_allowed_memory(phys, phys + PAGE_SIZE);
+	if (ret)
+		return ret;
+
+	host_lock_component();
+	guest_lock_component(vm);
+
+	ret = __guest_check_page_state_range(vcpu, ipa, PAGE_SIZE, PKVM_NOPAGE);
+	if (ret)
+		goto unlock;
+
+	page = hyp_phys_to_page(phys);
+	switch (page->host_state) {
+	case PKVM_PAGE_OWNED:
+		WARN_ON(__host_set_page_state_range(phys, PAGE_SIZE, PKVM_PAGE_SHARED_OWNED));
+		break;
+	case PKVM_PAGE_SHARED_OWNED:
+		if (page->host_share_guest_count)
+			break;
+		/* Only host to np-guest multi-sharing is tolerated */
+		WARN_ON(1);
+		fallthrough;
+	default:
+		ret = -EPERM;
+		goto unlock;
+	}
+
+	WARN_ON(kvm_pgtable_stage2_map(&vm->pgt, ipa, PAGE_SIZE, phys,
+				       pkvm_mkstate(prot, PKVM_PAGE_SHARED_BORROWED),
+				       &vcpu->vcpu.arch.pkvm_memcache, 0));
+	page->host_share_guest_count++;
+
+unlock:
+	guest_unlock_component(vm);
+	host_unlock_component();
+
+	return ret;
+}
+
+static int __check_host_shared_guest(struct pkvm_hyp_vm *vm, u64 *__phys, u64 ipa)
+{
+	enum pkvm_page_state state;
+	struct hyp_page *page;
+	kvm_pte_t pte;
+	u64 phys;
+	s8 level;
+	int ret;
+
+	ret = kvm_pgtable_get_leaf(&vm->pgt, ipa, &pte, &level);
+	if (ret)
+		return ret;
+	if (level != KVM_PGTABLE_LAST_LEVEL)
+		return -E2BIG;
+	if (!kvm_pte_valid(pte))
+		return -ENOENT;
+
+	state = guest_get_page_state(pte, ipa);
+	if (state != PKVM_PAGE_SHARED_BORROWED)
+		return -EPERM;
+
+	phys = kvm_pte_to_phys(pte);
+	ret = check_range_allowed_memory(phys, phys + PAGE_SIZE);
+	if (WARN_ON(ret))
+		return ret;
+
+	page = hyp_phys_to_page(phys);
+	if (page->host_state != PKVM_PAGE_SHARED_OWNED)
+		return -EPERM;
+	if (WARN_ON(!page->host_share_guest_count))
+		return -EINVAL;
+
+	*__phys = phys;
+
+	return 0;
+}
+
+int __pkvm_host_unshare_guest(u64 gfn, struct pkvm_hyp_vm *vm)
+{
+	u64 ipa = hyp_pfn_to_phys(gfn);
+	struct hyp_page *page;
+	u64 phys;
+	int ret;
+
+	host_lock_component();
+	guest_lock_component(vm);
+
+	ret = __check_host_shared_guest(vm, &phys, ipa);
+	if (ret)
+		goto unlock;
+
+	ret = kvm_pgtable_stage2_unmap(&vm->pgt, ipa, PAGE_SIZE);
+	if (ret)
+		goto unlock;
+
+	page = hyp_phys_to_page(phys);
+	page->host_share_guest_count--;
+	if (!page->host_share_guest_count)
+		WARN_ON(__host_set_page_state_range(phys, PAGE_SIZE, PKVM_PAGE_OWNED));
+
+unlock:
+	guest_unlock_component(vm);
+	host_unlock_component();
+
+	return ret;
+}
+
+int __pkvm_host_relax_perms_guest(u64 gfn, struct pkvm_hyp_vcpu *vcpu, enum kvm_pgtable_prot prot)
+{
+	struct pkvm_hyp_vm *vm = pkvm_hyp_vcpu_to_hyp_vm(vcpu);
+	u64 ipa = hyp_pfn_to_phys(gfn);
+	u64 phys;
+	int ret;
+
+	if (prot & ~KVM_PGTABLE_PROT_RWX)
+		return -EINVAL;
+
+	host_lock_component();
+	guest_lock_component(vm);
+
+	ret = __check_host_shared_guest(vm, &phys, ipa);
+	if (!ret)
+		ret = kvm_pgtable_stage2_relax_perms(&vm->pgt, ipa, prot, 0);
+
+	guest_unlock_component(vm);
+	host_unlock_component();
+
+	return ret;
+}
+
+int __pkvm_host_wrprotect_guest(u64 gfn, struct pkvm_hyp_vm *vm)
+{
+	u64 ipa = hyp_pfn_to_phys(gfn);
+	u64 phys;
+	int ret;
+
+	host_lock_component();
+	guest_lock_component(vm);
+
+	ret = __check_host_shared_guest(vm, &phys, ipa);
+	if (!ret)
+		ret = kvm_pgtable_stage2_wrprotect(&vm->pgt, ipa, PAGE_SIZE);
+
+	guest_unlock_component(vm);
+	host_unlock_component();
+
+	return ret;
+}
+
+int __pkvm_host_test_clear_young_guest(u64 gfn, bool mkold, struct pkvm_hyp_vm *vm)
+{
+	u64 ipa = hyp_pfn_to_phys(gfn);
+	u64 phys;
+	int ret;
+
+	host_lock_component();
+	guest_lock_component(vm);
+
+	ret = __check_host_shared_guest(vm, &phys, ipa);
+	if (!ret)
+		ret = kvm_pgtable_stage2_test_clear_young(&vm->pgt, ipa, PAGE_SIZE, mkold);
+
+	guest_unlock_component(vm);
+	host_unlock_component();
+
+	return ret;
+}
+
+int __pkvm_host_mkyoung_guest(u64 gfn, struct pkvm_hyp_vcpu *vcpu)
+{
+	struct pkvm_hyp_vm *vm = pkvm_hyp_vcpu_to_hyp_vm(vcpu);
+	u64 ipa = hyp_pfn_to_phys(gfn);
+	u64 phys;
+	int ret;
+
+	host_lock_component();
+	guest_lock_component(vm);
+
+	ret = __check_host_shared_guest(vm, &phys, ipa);
+	if (!ret)
+		kvm_pgtable_stage2_mkyoung(&vm->pgt, ipa, 0);
+
+	guest_unlock_component(vm);
 	host_unlock_component();
 
 	return ret;

arch/arm64/kvm/hyp/nvhe/page_alloc.c

···
  */
 static struct hyp_page *__find_buddy_nocheck(struct hyp_pool *pool,
 					     struct hyp_page *p,
-					     unsigned short order)
+					     u8 order)
 {
 	phys_addr_t addr = hyp_page_to_phys(p);
 
···
 /* Find a buddy page currently available for allocation */
 static struct hyp_page *__find_buddy_avail(struct hyp_pool *pool,
 					   struct hyp_page *p,
-					   unsigned short order)
+					   u8 order)
 {
 	struct hyp_page *buddy = __find_buddy_nocheck(pool, p, order);
 
···
 			      struct hyp_page *p)
 {
 	phys_addr_t phys = hyp_page_to_phys(p);
-	unsigned short order = p->order;
+	u8 order = p->order;
 	struct hyp_page *buddy;
 
 	memset(hyp_page_to_virt(p), 0, PAGE_SIZE << p->order);
···
 
 static struct hyp_page *__hyp_extract_page(struct hyp_pool *pool,
 					   struct hyp_page *p,
-					   unsigned short order)
+					   u8 order)
 {
 	struct hyp_page *buddy;
 
···
 
 void hyp_split_page(struct hyp_page *p)
 {
-	unsigned short order = p->order;
+	u8 order = p->order;
 	unsigned int i;
 
 	p->order = 0;
···
 	}
 }
 
-void *hyp_alloc_pages(struct hyp_pool *pool, unsigned short order)
+void *hyp_alloc_pages(struct hyp_pool *pool, u8 order)
 {
-	unsigned short i = order;
 	struct hyp_page *p;
+	u8 i = order;
 
 	hyp_spin_lock(&pool->lock);
 

arch/arm64/kvm/hyp/nvhe/pkvm.c

···
 unsigned int kvm_host_sve_max_vl;
 
 /*
+ * The currently loaded hyp vCPU for each physical CPU. Used only when
+ * protected KVM is enabled, but for both protected and non-protected VMs.
+ */
+static DEFINE_PER_CPU(struct pkvm_hyp_vcpu *, loaded_hyp_vcpu);
+
+/*
  * Set trap register values based on features in ID_AA64PFR0.
  */
 static void pvm_init_traps_aa64pfr0(struct kvm_vcpu *vcpu)
···
 	struct pkvm_hyp_vcpu *hyp_vcpu = NULL;
 	struct pkvm_hyp_vm *hyp_vm;
 
+	/* Cannot load a new vcpu without putting the old one first. */
+	if (__this_cpu_read(loaded_hyp_vcpu))
+		return NULL;
+
 	hyp_spin_lock(&vm_table_lock);
 	hyp_vm = get_vm_by_handle(handle);
 	if (!hyp_vm || hyp_vm->nr_vcpus <= vcpu_idx)
 		goto unlock;
 
 	hyp_vcpu = hyp_vm->vcpus[vcpu_idx];
+
+	/* Ensure vcpu isn't loaded on more than one cpu simultaneously. */
+	if (unlikely(hyp_vcpu->loaded_hyp_vcpu)) {
+		hyp_vcpu = NULL;
+		goto unlock;
+	}
+
+	hyp_vcpu->loaded_hyp_vcpu = this_cpu_ptr(&loaded_hyp_vcpu);
 	hyp_page_ref_inc(hyp_virt_to_page(hyp_vm));
 unlock:
 	hyp_spin_unlock(&vm_table_lock);
+
+	if (hyp_vcpu)
+		__this_cpu_write(loaded_hyp_vcpu, hyp_vcpu);
 	return hyp_vcpu;
 }
 
···
 	struct pkvm_hyp_vm *hyp_vm = pkvm_hyp_vcpu_to_hyp_vm(hyp_vcpu);
 
 	hyp_spin_lock(&vm_table_lock);
+	hyp_vcpu->loaded_hyp_vcpu = NULL;
+	__this_cpu_write(loaded_hyp_vcpu, NULL);
 	hyp_page_ref_dec(hyp_virt_to_page(hyp_vm));
 	hyp_spin_unlock(&vm_table_lock);
+}
+
+struct pkvm_hyp_vcpu *pkvm_get_loaded_hyp_vcpu(void)
+{
+	return __this_cpu_read(loaded_hyp_vcpu);
+
+}
+
+struct pkvm_hyp_vm *get_pkvm_hyp_vm(pkvm_handle_t handle)
+{
+	struct pkvm_hyp_vm *hyp_vm;
+
+	hyp_spin_lock(&vm_table_lock);
+	hyp_vm = get_vm_by_handle(handle);
+	if (hyp_vm)
+		hyp_page_ref_inc(hyp_virt_to_page(hyp_vm));
+	hyp_spin_unlock(&vm_table_lock);
+
+	return hyp_vm;
+}
+
+void put_pkvm_hyp_vm(struct pkvm_hyp_vm *hyp_vm)
+{
+	hyp_spin_lock(&vm_table_lock);
+	hyp_page_ref_dec(hyp_virt_to_page(hyp_vm));
+	hyp_spin_unlock(&vm_table_lock);
+}
+
+struct pkvm_hyp_vm *get_np_pkvm_hyp_vm(pkvm_handle_t handle)
+{
+	struct pkvm_hyp_vm *hyp_vm = get_pkvm_hyp_vm(handle);
+
+	if (hyp_vm && pkvm_hyp_vm_is_protected(hyp_vm)) {
+		put_pkvm_hyp_vm(hyp_vm);
+		hyp_vm = NULL;
+	}
+
+	return hyp_vm;
 }
 
 static void pkvm_init_features_from_host(struct pkvm_hyp_vm *hyp_vm, const struct kvm *host_kvm)
···
 	/* Push the metadata pages to the teardown memcache */
 	for (idx = 0; idx < hyp_vm->nr_vcpus; ++idx) {
 		struct pkvm_hyp_vcpu *hyp_vcpu = hyp_vm->vcpus[idx];
+		struct kvm_hyp_memcache *vcpu_mc = &hyp_vcpu->vcpu.arch.pkvm_memcache;
+
+		while (vcpu_mc->nr_pages) {
+			void *addr = pop_hyp_memcache(vcpu_mc, hyp_phys_to_virt);
+
+			push_hyp_memcache(mc, addr, hyp_virt_to_phys);
+			unmap_donated_memory_noclear(addr, PAGE_SIZE);
+		}
 
 		teardown_donated_memory(mc, hyp_vcpu, sizeof(*hyp_vcpu));
 	}

arch/arm64/kvm/hyp/nvhe/setup.c

···
 static int fix_host_ownership_walker(const struct kvm_pgtable_visit_ctx *ctx,
 				     enum kvm_pgtable_walk_flags visit)
 {
-	enum kvm_pgtable_prot prot;
 	enum pkvm_page_state state;
 	phys_addr_t phys;
 
···
 	case PKVM_PAGE_OWNED:
 		return host_stage2_set_owner_locked(phys, PAGE_SIZE, PKVM_ID_HYP);
 	case PKVM_PAGE_SHARED_OWNED:
-		prot = pkvm_mkstate(PKVM_HOST_MEM_PROT, PKVM_PAGE_SHARED_BORROWED);
+		hyp_phys_to_page(phys)->host_state = PKVM_PAGE_SHARED_BORROWED;
 		break;
 	case PKVM_PAGE_SHARED_BORROWED:
-		prot = pkvm_mkstate(PKVM_HOST_MEM_PROT, PKVM_PAGE_SHARED_OWNED);
+		hyp_phys_to_page(phys)->host_state = PKVM_PAGE_SHARED_OWNED;
 		break;
 	default:
 		return -EINVAL;
 	}
 
-	return host_stage2_idmap_locked(phys, PAGE_SIZE, prot);
+	return 0;
 }
 
 static int fix_hyp_pgtable_refcnt_walker(const struct kvm_pgtable_visit_ctx *ctx,

arch/arm64/kvm/hyp/pgtable.c

···
 					NULL, NULL, 0);
 }
 
-void kvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr)
+void kvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr,
+				enum kvm_pgtable_walk_flags flags)
 {
 	int ret;
 
 	ret = stage2_update_leaf_attrs(pgt, addr, 1, KVM_PTE_LEAF_ATTR_LO_S2_AF, 0,
-				       NULL, NULL,
-				       KVM_PGTABLE_WALK_HANDLE_FAULT |
-				       KVM_PGTABLE_WALK_SHARED);
+				       NULL, NULL, flags);
 	if (!ret)
 		dsb(ishst);
 }
···
 }
 
 int kvm_pgtable_stage2_relax_perms(struct kvm_pgtable *pgt, u64 addr,
-				   enum kvm_pgtable_prot prot)
+				   enum kvm_pgtable_prot prot, enum kvm_pgtable_walk_flags flags)
 {
 	int ret;
 	s8 level;
···
 	if (prot & KVM_PGTABLE_PROT_X)
 		clr |= KVM_PTE_LEAF_ATTR_HI_S2_XN;
 
-	ret = stage2_update_leaf_attrs(pgt, addr, 1, set, clr, NULL, &level,
-				       KVM_PGTABLE_WALK_HANDLE_FAULT |
-				       KVM_PGTABLE_WALK_SHARED);
+	ret = stage2_update_leaf_attrs(pgt, addr, 1, set, clr, NULL, &level, flags);
 	if (!ret || ret == -EAGAIN)
 		kvm_call_hyp(__kvm_tlb_flush_vmid_ipa_nsh, pgt->mmu, addr, level);
 	return ret;

arch/arm64/kvm/mmu.c

···
 #include <asm/kvm_arm.h>
 #include <asm/kvm_mmu.h>
 #include <asm/kvm_pgtable.h>
+#include <asm/kvm_pkvm.h>
 #include <asm/kvm_ras.h>
 #include <asm/kvm_asm.h>
 #include <asm/kvm_emulate.h>
···
 static phys_addr_t __ro_after_init hyp_idmap_vector;
 
 static unsigned long __ro_after_init io_map_base;
+
+#define KVM_PGT_FN(fn)		(!is_protected_kvm_enabled() ? fn : p ## fn)
 
 static phys_addr_t __stage2_range_addr_end(phys_addr_t addr, phys_addr_t end,
 					   phys_addr_t size)
···
 			return -EINVAL;
 
 		next = __stage2_range_addr_end(addr, end, chunk_size);
-		ret = kvm_pgtable_stage2_split(pgt, addr, next - addr, cache);
+		ret = KVM_PGT_FN(kvm_pgtable_stage2_split)(pgt, addr, next - addr, cache);
 		if (ret)
 			break;
 	} while (addr = next, addr != end);
···
  */
 int kvm_arch_flush_remote_tlbs(struct kvm *kvm)
 {
-	kvm_call_hyp(__kvm_tlb_flush_vmid, &kvm->arch.mmu);
+	if (is_protected_kvm_enabled())
+		kvm_call_hyp_nvhe(__pkvm_tlb_flush_vmid, kvm->arch.pkvm.handle);
+	else
+		kvm_call_hyp(__kvm_tlb_flush_vmid, &kvm->arch.mmu);
 	return 0;
 }
 
 int kvm_arch_flush_remote_tlbs_range(struct kvm *kvm,
 				      gfn_t gfn, u64 nr_pages)
 {
-	kvm_tlb_flush_vmid_range(&kvm->arch.mmu,
-				gfn << PAGE_SHIFT, nr_pages << PAGE_SHIFT);
+	u64 size = nr_pages << PAGE_SHIFT;
+	u64 addr = gfn << PAGE_SHIFT;
+
+	if (is_protected_kvm_enabled())
+		kvm_call_hyp_nvhe(__pkvm_tlb_flush_vmid, kvm->arch.pkvm.handle);
+	else
+		kvm_tlb_flush_vmid_range(&kvm->arch.mmu, addr, size);
 	return 0;
 }
 
···
 	void *pgtable = page_to_virt(page);
 	s8 level = page_private(page);
 
-	kvm_pgtable_stage2_free_unlinked(&kvm_s2_mm_ops, pgtable, level);
+	KVM_PGT_FN(kvm_pgtable_stage2_free_unlinked)(&kvm_s2_mm_ops, pgtable, level);
 }
 
 static void stage2_free_unlinked_table(void *addr, s8 level)
···
 
 	lockdep_assert_held_write(&kvm->mmu_lock);
 	WARN_ON(size & ~PAGE_MASK);
-	WARN_ON(stage2_apply_range(mmu, start, end, kvm_pgtable_stage2_unmap,
+	WARN_ON(stage2_apply_range(mmu, start, end, KVM_PGT_FN(kvm_pgtable_stage2_unmap),
 				   may_block));
 }
 
···
 
 void kvm_stage2_flush_range(struct kvm_s2_mmu *mmu, phys_addr_t addr, phys_addr_t end)
 {
-	stage2_apply_range_resched(mmu, addr, end, kvm_pgtable_stage2_flush);
+	stage2_apply_range_resched(mmu, addr, end, KVM_PGT_FN(kvm_pgtable_stage2_flush));
 }
 
 static void stage2_flush_memslot(struct kvm *kvm,
···
 		return -ENOMEM;
 
 	mmu->arch = &kvm->arch;
-	err = kvm_pgtable_stage2_init(pgt, mmu, &kvm_s2_mm_ops);
+	err = KVM_PGT_FN(kvm_pgtable_stage2_init)(pgt, mmu, &kvm_s2_mm_ops);
 	if (err)
 		goto out_free_pgtable;
+
+	mmu->pgt = pgt;
+	if (is_protected_kvm_enabled())
+		return 0;
 
 	mmu->last_vcpu_ran = alloc_percpu(typeof(*mmu->last_vcpu_ran));
 	if (!mmu->last_vcpu_ran) {
···
 	mmu->split_page_chunk_size = KVM_ARM_EAGER_SPLIT_CHUNK_SIZE_DEFAULT;
 	mmu->split_page_cache.gfp_zero = __GFP_ZERO;
 
-	mmu->pgt = pgt;
 	mmu->pgd_phys = __pa(pgt->pgd);
 
 	if (kvm_is_nested_s2_mmu(kvm, mmu))
···
 	return 0;
 
 out_destroy_pgtable:
-	kvm_pgtable_stage2_destroy(pgt);
+	KVM_PGT_FN(kvm_pgtable_stage2_destroy)(pgt);
 out_free_pgtable:
 	kfree(pgt);
 	return err;
···
 	write_unlock(&kvm->mmu_lock);
 
 	if (pgt) {
-		kvm_pgtable_stage2_destroy(pgt);
+		KVM_PGT_FN(kvm_pgtable_stage2_destroy)(pgt);
 		kfree(pgt);
 	}
 }
···
 
 void free_hyp_memcache(struct kvm_hyp_memcache *mc)
 {
-	if (is_protected_kvm_enabled())
-		__free_hyp_memcache(mc, hyp_mc_free_fn,
-				    kvm_host_va, NULL);
+	if (!is_protected_kvm_enabled())
+		return;
+
+	kfree(mc->mapping);
+	__free_hyp_memcache(mc, hyp_mc_free_fn, kvm_host_va, NULL);
 }
 
 int topup_hyp_memcache(struct kvm_hyp_memcache *mc, unsigned long min_pages)
 {
 	if (!is_protected_kvm_enabled())
 		return 0;
+
+	if (!mc->mapping) {
+		mc->mapping = kzalloc(sizeof(struct pkvm_mapping), GFP_KERNEL_ACCOUNT);
+		if (!mc->mapping)
+			return -ENOMEM;
+	}
 
 	return __topup_hyp_memcache(mc, min_pages, hyp_mc_alloc_fn,
 				    kvm_host_pa, NULL);
···
 			break;
 
 		write_lock(&kvm->mmu_lock);
-		ret = kvm_pgtable_stage2_map(pgt, addr, PAGE_SIZE, pa, prot,
-					     &cache, 0);
+		ret = KVM_PGT_FN(kvm_pgtable_stage2_map)(pgt, addr, PAGE_SIZE,
+				 pa, prot, &cache, 0);
 		write_unlock(&kvm->mmu_lock);
 		if (ret)
 			break;
···
  */
 void kvm_stage2_wp_range(struct kvm_s2_mmu *mmu, phys_addr_t addr, phys_addr_t end)
 {
-	stage2_apply_range_resched(mmu, addr, end, kvm_pgtable_stage2_wrprotect);
+	stage2_apply_range_resched(mmu, addr, end, KVM_PGT_FN(kvm_pgtable_stage2_wrprotect));
 }
 
 /**
···
 	unsigned long mmu_seq;
 	phys_addr_t ipa = fault_ipa;
 	struct kvm *kvm = vcpu->kvm;
-	struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache;
 	struct vm_area_struct *vma;
 	short vma_shift;
+	void *memcache;
 	gfn_t gfn;
 	kvm_pfn_t pfn;
 	bool logging_active = memslot_is_logging(memslot);
···
 	enum kvm_pgtable_prot prot = KVM_PGTABLE_PROT_R;
 	struct kvm_pgtable *pgt;
 	struct page *page;
+	enum kvm_pgtable_walk_flags flags = KVM_PGTABLE_WALK_HANDLE_FAULT | KVM_PGTABLE_WALK_SHARED;
 
 	if (fault_is_perm)
 		fault_granule = kvm_vcpu_trap_get_perm_fault_granule(vcpu);
···
 	 * and a write fault needs to collapse a block entry into a table.
 	 */
 	if (!fault_is_perm || (logging_active && write_fault)) {
-		ret = kvm_mmu_topup_memory_cache(memcache,
-						 kvm_mmu_cache_min_pages(vcpu->arch.hw_mmu));
+		int min_pages = kvm_mmu_cache_min_pages(vcpu->arch.hw_mmu);
+
+		if (!is_protected_kvm_enabled()) {
+			memcache = &vcpu->arch.mmu_page_cache;
+			ret = kvm_mmu_topup_memory_cache(memcache, min_pages);
+		} else {
+			memcache = &vcpu->arch.pkvm_memcache;
+			ret = topup_hyp_memcache(memcache, min_pages);
+		}
 		if (ret)
 			return ret;
 	}
···
 	 * logging_active is guaranteed to never be true for VM_PFNMAP
 	 * memslots.
 	 */
-	if (logging_active) {
+	if (logging_active || is_protected_kvm_enabled()) {
 		force_pte = true;
 		vma_shift = PAGE_SHIFT;
 	} else {
···
 		prot |= kvm_encode_nested_level(nested);
 	}
 
-	read_lock(&kvm->mmu_lock);
+	kvm_fault_lock(kvm);
 	pgt = vcpu->arch.hw_mmu->pgt;
 	if (mmu_invalidate_retry(kvm, mmu_seq)) {
 		ret = -EAGAIN;
···
 		 * PTE, which will be preserved.
 		 */
 		prot &= ~KVM_NV_GUEST_MAP_SZ;
-		ret = kvm_pgtable_stage2_relax_perms(pgt, fault_ipa, prot);
+		ret = KVM_PGT_FN(kvm_pgtable_stage2_relax_perms)(pgt, fault_ipa, prot, flags);
 	} else {
-		ret = kvm_pgtable_stage2_map(pgt, fault_ipa, vma_pagesize,
+		ret = KVM_PGT_FN(kvm_pgtable_stage2_map)(pgt, fault_ipa, vma_pagesize,
 					     __pfn_to_phys(pfn), prot,
-					     memcache,
-					     KVM_PGTABLE_WALK_HANDLE_FAULT |
-					     KVM_PGTABLE_WALK_SHARED);
+					     memcache, flags);
 	}
 
 out_unlock:
 	kvm_release_faultin_page(kvm, page, !!ret, writable);
-	read_unlock(&kvm->mmu_lock);
+	kvm_fault_unlock(kvm);
 
 	/* Mark the page dirty only if the fault is handled successfully */
 	if (writable && !ret)
···
 /* Resolve the access fault by making the page young again. */
 static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
 {
+	enum kvm_pgtable_walk_flags flags = KVM_PGTABLE_WALK_HANDLE_FAULT | KVM_PGTABLE_WALK_SHARED;
 	struct kvm_s2_mmu *mmu;
 
 	trace_kvm_access_fault(fault_ipa);
 
 	read_lock(&vcpu->kvm->mmu_lock);
 	mmu = vcpu->arch.hw_mmu;
-	kvm_pgtable_stage2_mkyoung(mmu->pgt, fault_ipa);
+	KVM_PGT_FN(kvm_pgtable_stage2_mkyoung)(mmu->pgt, fault_ipa, flags);
 	read_unlock(&vcpu->kvm->mmu_lock);
 }
 
···
 		}
 
 		/* Falls between the IPA range and the PARange? */
-		if (fault_ipa >= BIT_ULL(vcpu->arch.hw_mmu->pgt->ia_bits)) {
+		if (fault_ipa >= BIT_ULL(VTCR_EL2_IPA(vcpu->arch.hw_mmu->vtcr))) {
 			fault_ipa |= kvm_vcpu_get_hfar(vcpu) & GENMASK(11, 0);
 
 			if (is_iabt)
···
 	if (!kvm->arch.mmu.pgt)
 		return false;
 
-	return kvm_pgtable_stage2_test_clear_young(kvm->arch.mmu.pgt,
+	return KVM_PGT_FN(kvm_pgtable_stage2_test_clear_young)(kvm->arch.mmu.pgt,
 						   range->start << PAGE_SHIFT,
 						   size, true);
 	/*
···
 	if (!kvm->arch.mmu.pgt)
 		return false;
 
-	return kvm_pgtable_stage2_test_clear_young(kvm->arch.mmu.pgt,
+	return KVM_PGT_FN(kvm_pgtable_stage2_test_clear_young)(kvm->arch.mmu.pgt,
 						   range->start << PAGE_SHIFT,
 						   size, false);
 }

arch/arm64/kvm/pkvm.c

···
 #include <linux/init.h>
 #include <linux/kmemleak.h>
 #include <linux/kvm_host.h>
+#include <asm/kvm_mmu.h>
 #include <linux/memblock.h>
 #include <linux/mutex.h>
 #include <linux/sort.h>
···
 	return ret;
 }
 device_initcall_sync(finalize_pkvm);
+
+static int cmp_mappings(struct rb_node *node, const struct rb_node *parent)
+{
+	struct pkvm_mapping *a = rb_entry(node, struct pkvm_mapping, node);
+	struct pkvm_mapping *b = rb_entry(parent, struct pkvm_mapping, node);
+
+	if (a->gfn < b->gfn)
+		return -1;
+	if (a->gfn > b->gfn)
+		return 1;
+	return 0;
+}
+
+static struct rb_node *find_first_mapping_node(struct rb_root *root, u64 gfn)
+{
+	struct rb_node *node = root->rb_node, *prev = NULL;
+	struct pkvm_mapping *mapping;
+
+	while (node) {
+		mapping = rb_entry(node, struct pkvm_mapping, node);
+		if (mapping->gfn == gfn)
+			return node;
+		prev = node;
+		node = (gfn < mapping->gfn) ? node->rb_left : node->rb_right;
+	}
+
+	return prev;
+}
+
+/*
+ * __tmp is updated to rb_next(__tmp) *before* entering the body of the loop to allow freeing
+ * of __map inline.
+ */
+#define for_each_mapping_in_range_safe(__pgt, __start, __end, __map)				\
+	for (struct rb_node *__tmp = find_first_mapping_node(&(__pgt)->pkvm_mappings,		\
+							     ((__start) >> PAGE_SHIFT));	\
+	     __tmp && ({									\
+				__map = rb_entry(__tmp, struct pkvm_mapping, node);		\
+				__tmp = rb_next(__tmp);						\
+				true;								\
+		       });									\
+	    )											\
+		if (__map->gfn < ((__start) >> PAGE_SHIFT))					\
+			continue;								\
+		else if (__map->gfn >= ((__end) >> PAGE_SHIFT))					\
+			break;									\
+		else
+
+int pkvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm_s2_mmu *mmu,
+			     struct kvm_pgtable_mm_ops *mm_ops)
+{
+	pgt->pkvm_mappings	= RB_ROOT;
+	pgt->mmu		= mmu;
+
+	return 0;
+}
+
+void pkvm_pgtable_stage2_destroy(struct kvm_pgtable *pgt)
+{
+	struct kvm *kvm = kvm_s2_mmu_to_kvm(pgt->mmu);
+	pkvm_handle_t handle = kvm->arch.pkvm.handle;
+	struct pkvm_mapping *mapping;
+	struct rb_node *node;
+
+	if (!handle)
+		return;
+
+	node = rb_first(&pgt->pkvm_mappings);
+	while (node) {
+		mapping = rb_entry(node, struct pkvm_mapping, node);
+		kvm_call_hyp_nvhe(__pkvm_host_unshare_guest, handle, mapping->gfn);
+		node = rb_next(node);
+		rb_erase(&mapping->node, &pgt->pkvm_mappings);
+		kfree(mapping);
+	}
+}
+
+int pkvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size,
+			   u64 phys, enum kvm_pgtable_prot prot,
+			   void *mc, enum kvm_pgtable_walk_flags flags)
+{
+	struct kvm *kvm = kvm_s2_mmu_to_kvm(pgt->mmu);
+	struct pkvm_mapping *mapping = NULL;
+	struct kvm_hyp_memcache *cache = mc;
+	u64 gfn = addr >> PAGE_SHIFT;
+	u64 pfn = phys >> PAGE_SHIFT;
+	int ret;
+
+	if (size != PAGE_SIZE)
+		return -EINVAL;
+
+	lockdep_assert_held_write(&kvm->mmu_lock);
+	ret = kvm_call_hyp_nvhe(__pkvm_host_share_guest, pfn, gfn, prot);
+	if (ret) {
+		/* Is the gfn already mapped due to a racing vCPU? */
+		if (ret == -EPERM)
+			return -EAGAIN;
+	}
+
+	swap(mapping, cache->mapping);
+	mapping->gfn = gfn;
+	mapping->pfn = pfn;
+	WARN_ON(rb_find_add(&mapping->node, &pgt->pkvm_mappings, cmp_mappings));
+
+	return ret;
+}
+
+int pkvm_pgtable_stage2_unmap(struct kvm_pgtable *pgt, u64 addr, u64 size)
+{
+	struct kvm *kvm = kvm_s2_mmu_to_kvm(pgt->mmu);
+	pkvm_handle_t handle = kvm->arch.pkvm.handle;
+	struct pkvm_mapping *mapping;
+	int ret = 0;
+
+	lockdep_assert_held_write(&kvm->mmu_lock);
+	for_each_mapping_in_range_safe(pgt, addr, addr + size, mapping) {
+		ret = kvm_call_hyp_nvhe(__pkvm_host_unshare_guest, handle, mapping->gfn);
+		if (WARN_ON(ret))
+			break;
+		rb_erase(&mapping->node, &pgt->pkvm_mappings);
+		kfree(mapping);
+	}
+
+	return ret;
+}
+
+int pkvm_pgtable_stage2_wrprotect(struct kvm_pgtable *pgt, u64 addr, u64 size)
+{
+	struct kvm *kvm = kvm_s2_mmu_to_kvm(pgt->mmu);
+	pkvm_handle_t handle = kvm->arch.pkvm.handle;
+	struct pkvm_mapping *mapping;
+	int ret = 0;
+
+	lockdep_assert_held(&kvm->mmu_lock);
+	for_each_mapping_in_range_safe(pgt, addr, addr + size, mapping) {
+		ret = kvm_call_hyp_nvhe(__pkvm_host_wrprotect_guest, handle, mapping->gfn);
+		if (WARN_ON(ret))
+			break;
+	}
+
+	return ret;
+}
+
+int pkvm_pgtable_stage2_flush(struct kvm_pgtable *pgt, u64 addr, u64 size)
+{
+	struct kvm *kvm = kvm_s2_mmu_to_kvm(pgt->mmu);
+	struct pkvm_mapping *mapping;
+
+	lockdep_assert_held(&kvm->mmu_lock);
+	for_each_mapping_in_range_safe(pgt, addr, addr + size, mapping)
+		__clean_dcache_guest_page(pfn_to_kaddr(mapping->pfn), PAGE_SIZE);
+
+	return 0;
+}
+
+bool pkvm_pgtable_stage2_test_clear_young(struct kvm_pgtable *pgt, u64 addr, u64 size, bool mkold)
+{
+	struct kvm *kvm = kvm_s2_mmu_to_kvm(pgt->mmu);
+	pkvm_handle_t handle = kvm->arch.pkvm.handle;
+	struct pkvm_mapping *mapping;
+	bool young = false;
+
+	lockdep_assert_held(&kvm->mmu_lock);
+	for_each_mapping_in_range_safe(pgt, addr, addr + size, mapping)
+		young |= kvm_call_hyp_nvhe(__pkvm_host_test_clear_young_guest, handle, mapping->gfn,
+					   mkold);
+
+	return young;
+}
+
+int pkvm_pgtable_stage2_relax_perms(struct kvm_pgtable *pgt, u64 addr, enum kvm_pgtable_prot prot,
+				    enum kvm_pgtable_walk_flags flags)
+{
+	return kvm_call_hyp_nvhe(__pkvm_host_relax_perms_guest, addr >> PAGE_SHIFT, prot);
+}
+
+void pkvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr,
+				 enum kvm_pgtable_walk_flags flags)
+{
+	WARN_ON(kvm_call_hyp_nvhe(__pkvm_host_mkyoung_guest, addr >> PAGE_SHIFT));
+}
+
+void pkvm_pgtable_stage2_free_unlinked(struct kvm_pgtable_mm_ops *mm_ops, void *pgtable, s8 level)
+{
+	WARN_ON_ONCE(1);
+}
+
+kvm_pte_t *pkvm_pgtable_stage2_create_unlinked(struct kvm_pgtable *pgt, u64 phys, s8 level,
+					enum kvm_pgtable_prot prot, void *mc, bool force_pte)
+{
+	WARN_ON_ONCE(1);
+	return NULL;
+}
+
+int pkvm_pgtable_stage2_split(struct kvm_pgtable *pgt, u64 addr, u64 size,
+			      struct kvm_mmu_memory_cache *mc)
+{
+	WARN_ON_ONCE(1);
+	return -EINVAL;
+}

arch/arm64/kvm/vgic/vgic-v3.c

···
 {
 	struct vgic_v3_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v3;
 
-	kvm_call_hyp(__vgic_v3_restore_vmcr_aprs, cpu_if);
+	if (likely(!is_protected_kvm_enabled()))
+		kvm_call_hyp(__vgic_v3_restore_vmcr_aprs, cpu_if);
 
 	if (has_vhe())
 		__vgic_v3_activate_traps(cpu_if);
···
 {
 	struct vgic_v3_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v3;
 
-	kvm_call_hyp(__vgic_v3_save_vmcr_aprs, cpu_if);
+	if (likely(!is_protected_kvm_enabled()))
+		kvm_call_hyp(__vgic_v3_save_vmcr_aprs, cpu_if);
 	WARN_ON(vgic_v4_put(vcpu));
 
 	if (has_vhe())