Merge branch kvm-arm64/pkvm-hyp-sharing into kvmarm-master/next

* kvm-arm64/pkvm-hyp-sharing:
  : .
  : Series from Quentin Perret, implementing HYP page share/unshare:
  :
  : This series implements an unshare hypercall at EL2 in nVHE
  : protected mode, and makes use of it to unmmap guest-specific
  : data-structures from EL2 stage-1 during guest tear-down.
  : Crucially, the implementation of the share and unshare
  : routines use page refcounts in the host kernel to avoid
  : accidentally unmapping data-structures that overlap a common
  : page.
  : [...]
  : .
  KVM: arm64: pkvm: Unshare guest structs during teardown
  KVM: arm64: Expose unshare hypercall to the host
  KVM: arm64: Implement do_unshare() helper for unsharing memory
  KVM: arm64: Implement __pkvm_host_share_hyp() using do_share()
  KVM: arm64: Implement do_share() helper for sharing memory
  KVM: arm64: Introduce wrappers for host and hyp spin lock accessors
  KVM: arm64: Extend pkvm_page_state enumeration to handle absent pages
  KVM: arm64: pkvm: Refcount the pages shared with EL2
  KVM: arm64: Introduce kvm_share_hyp()
  KVM: arm64: Implement kvm_pgtable_hyp_unmap() at EL2
  KVM: arm64: Hook up ->page_count() for hypervisor stage-1 page-table
  KVM: arm64: Fixup hyp stage-1 refcount
  KVM: arm64: Refcount hyp stage-1 pgtable pages
  KVM: arm64: Provide {get,put}_page() stubs for early hyp allocator
Signed-off-by: Marc Zyngier <maz@kernel.org>

arch/arm64/include/asm/kvm_asm.h

@@ -63,6 +63,7 @@ enum __kvm_host_smccc_func {
 
 	/* 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___kvm_adjust_pc,
 	__KVM_HOST_SMCCC_FUNC___kvm_vcpu_run,
 	__KVM_HOST_SMCCC_FUNC___kvm_flush_vm_context,

arch/arm64/include/asm/kvm_host.h

@@ -321,6 +321,7 @@ struct kvm_vcpu_arch {
 	struct kvm_guest_debug_arch external_debug_state;
 
 	struct user_fpsimd_state *host_fpsimd_state;	/* hyp VA */
+	struct task_struct *parent_task;
 
 	struct {
 		/* {Break,watch}point registers */
@@ -737,6 +738,7 @@ void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu);
 void kvm_arch_vcpu_ctxflush_fp(struct kvm_vcpu *vcpu);
 void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu);
 void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu);
+void kvm_vcpu_unshare_task_fp(struct kvm_vcpu *vcpu);
 
 static inline bool kvm_pmu_counter_deferred(struct perf_event_attr *attr)
 {

arch/arm64/include/asm/kvm_mmu.h

@@ -150,6 +150,8 @@ static __always_inline unsigned long __kern_hyp_va(unsigned long v)
 #include <asm/kvm_pgtable.h>
 #include <asm/stage2_pgtable.h>
 
+int kvm_share_hyp(void *from, void *to);
+void kvm_unshare_hyp(void *from, void *to);
 int create_hyp_mappings(void *from, void *to, enum kvm_pgtable_prot prot);
 int create_hyp_io_mappings(phys_addr_t phys_addr, size_t size,
 			   void __iomem **kaddr,

arch/arm64/include/asm/kvm_pgtable.h

@@ -251,6 +251,27 @@ void kvm_pgtable_hyp_destroy(struct kvm_pgtable *pgt);
 int kvm_pgtable_hyp_map(struct kvm_pgtable *pgt, u64 addr, u64 size, u64 phys,
 			enum kvm_pgtable_prot prot);
 
+/**
+ * kvm_pgtable_hyp_unmap() - Remove a mapping from a hypervisor stage-1 page-table.
+ * @pgt:	Page-table structure initialised by kvm_pgtable_hyp_init().
+ * @addr:	Virtual address from which to remove the mapping.
+ * @size:	Size of the mapping.
+ *
+ * The offset of @addr within a page is ignored, @size is rounded-up to
+ * the next page boundary and @phys is rounded-down to the previous page
+ * boundary.
+ *
+ * TLB invalidation is performed for each page-table entry cleared during the
+ * unmapping operation and the reference count for the page-table page
+ * containing the cleared entry is decremented, with unreferenced pages being
+ * freed. The unmapping operation will stop early if it encounters either an
+ * invalid page-table entry or a valid block mapping which maps beyond the range
+ * being unmapped.
+ *
+ * Return: Number of bytes unmapped, which may be 0.
+ */
+u64 kvm_pgtable_hyp_unmap(struct kvm_pgtable *pgt, u64 addr, u64 size);
+
 /**
  * kvm_get_vtcr() - Helper to construct VTCR_EL2
  * @mmfr0:	Sanitized value of SYS_ID_AA64MMFR0_EL1 register.

arch/arm64/kvm/arm.c

@@ -146,7 +146,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 	if (ret)
 		return ret;
 
-	ret = create_hyp_mappings(kvm, kvm + 1, PAGE_HYP);
+	ret = kvm_share_hyp(kvm, kvm + 1);
 	if (ret)
 		goto out_free_stage2_pgd;
 
@@ -188,6 +188,8 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
 		}
 	}
 	atomic_set(&kvm->online_vcpus, 0);
+
+	kvm_unshare_hyp(kvm, kvm + 1);
 }
 
 int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
@@ -342,7 +344,7 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
 	if (err)
 		return err;
 
-	return create_hyp_mappings(vcpu, vcpu + 1, PAGE_HYP);
+	return kvm_share_hyp(vcpu, vcpu + 1);
 }
 
 void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)

arch/arm64/kvm/fpsimd.c

@@ -14,6 +14,19 @@
 #include <asm/kvm_mmu.h>
 #include <asm/sysreg.h>
 
+void kvm_vcpu_unshare_task_fp(struct kvm_vcpu *vcpu)
+{
+	struct task_struct *p = vcpu->arch.parent_task;
+	struct user_fpsimd_state *fpsimd;
+
+	if (!is_protected_kvm_enabled() || !p)
+		return;
+
+	fpsimd = &p->thread.uw.fpsimd_state;
+	kvm_unshare_hyp(fpsimd, fpsimd + 1);
+	put_task_struct(p);
+}
+
 /*
  * Called on entry to KVM_RUN unless this vcpu previously ran at least
  * once and the most recent prior KVM_RUN for this vcpu was called from
@@ -29,12 +42,27 @@ int kvm_arch_vcpu_run_map_fp(struct kvm_vcpu *vcpu)
 
 	struct user_fpsimd_state *fpsimd = &current->thread.uw.fpsimd_state;
 
+	kvm_vcpu_unshare_task_fp(vcpu);
+
 	/* Make sure the host task fpsimd state is visible to hyp: */
-	ret = create_hyp_mappings(fpsimd, fpsimd + 1, PAGE_HYP);
-	if (!ret)
+	ret = kvm_share_hyp(fpsimd, fpsimd + 1);
+	if (ret)
+		return ret;
+
 	vcpu->arch.host_fpsimd_state = kern_hyp_va(fpsimd);
 
-	return ret;
+	/*
+	 * We need to keep current's task_struct pinned until its data has been
+	 * unshared with the hypervisor to make sure it is not re-used by the
+	 * kernel and donated to someone else while already shared -- see
+	 * kvm_vcpu_unshare_task_fp() for the matching put_task_struct().
+	 */
+	if (is_protected_kvm_enabled()) {
+		get_task_struct(current);
+		vcpu->arch.parent_task = current;
+	}
+
+	return 0;
 }
 
 /*

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

@@ -24,6 +24,11 @@ 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)
@@ -50,6 +55,7 @@ extern const u8 pkvm_hyp_id;
 
 int __pkvm_prot_finalize(void);
 int __pkvm_host_share_hyp(u64 pfn);
+int __pkvm_host_unshare_hyp(u64 pfn);
 
 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/nvhe/early_alloc.c

@@ -43,6 +43,9 @@ void *hyp_early_alloc_page(void *arg)
 	return hyp_early_alloc_contig(1);
 }
 
+static void hyp_early_alloc_get_page(void *addr) { }
+static void hyp_early_alloc_put_page(void *addr) { }
+
 void hyp_early_alloc_init(void *virt, unsigned long size)
 {
 	base = cur = (unsigned long)virt;
@@ -51,4 +54,6 @@ void hyp_early_alloc_init(void *virt, unsigned long size)
 	hyp_early_alloc_mm_ops.zalloc_page = hyp_early_alloc_page;
 	hyp_early_alloc_mm_ops.phys_to_virt = hyp_phys_to_virt;
 	hyp_early_alloc_mm_ops.virt_to_phys = hyp_virt_to_phys;
+	hyp_early_alloc_mm_ops.get_page = hyp_early_alloc_get_page;
+	hyp_early_alloc_mm_ops.put_page = hyp_early_alloc_put_page;
 }

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

@@ -147,6 +147,13 @@ static void handle___pkvm_host_share_hyp(struct kvm_cpu_context *host_ctxt)
 	cpu_reg(host_ctxt, 1) = __pkvm_host_share_hyp(pfn);
 }
 
+static void handle___pkvm_host_unshare_hyp(struct kvm_cpu_context *host_ctxt)
+{
+	DECLARE_REG(u64, pfn, host_ctxt, 1);
+
+	cpu_reg(host_ctxt, 1) = __pkvm_host_unshare_hyp(pfn);
+}
+
 static void handle___pkvm_create_private_mapping(struct kvm_cpu_context *host_ctxt)
 {
 	DECLARE_REG(phys_addr_t, phys, host_ctxt, 1);
@@ -184,6 +191,7 @@ static const hcall_t host_hcall[] = {
 	HANDLE_FUNC(__pkvm_prot_finalize),
 
 	HANDLE_FUNC(__pkvm_host_share_hyp),
+	HANDLE_FUNC(__pkvm_host_unshare_hyp),
 	HANDLE_FUNC(__kvm_adjust_pc),
 	HANDLE_FUNC(__kvm_vcpu_run),
 	HANDLE_FUNC(__kvm_flush_vm_context),

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

@@ -166,6 +166,7 @@ static int finalize_host_mappings_walker(u64 addr, u64 end, u32 level,
 					 enum kvm_pgtable_walk_flags flag,
 					 void * const arg)
 {
+	struct kvm_pgtable_mm_ops *mm_ops = arg;
 	enum kvm_pgtable_prot prot;
 	enum pkvm_page_state state;
 	kvm_pte_t pte = *ptep;
@@ -174,6 +175,15 @@ static int finalize_host_mappings_walker(u64 addr, u64 end, u32 level,
 	if (!kvm_pte_valid(pte))
 		return 0;
 
+	/*
+	 * Fix-up the refcount for the page-table pages as the early allocator
+	 * was unable to access the hyp_vmemmap and so the buddy allocator has
+	 * initialised the refcount to '1'.
+	 */
+	mm_ops->get_page(ptep);
+	if (flag != KVM_PGTABLE_WALK_LEAF)
+		return 0;
+
 	if (level != (KVM_PGTABLE_MAX_LEVELS - 1))
 		return -EINVAL;
 
@@ -206,7 +216,8 @@ static int finalize_host_mappings(void)
 {
 	struct kvm_pgtable_walker walker = {
 		.cb	= finalize_host_mappings_walker,
-		.flags	= KVM_PGTABLE_WALK_LEAF,
+		.flags	= KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST,
+		.arg	= pkvm_pgtable.mm_ops,
 	};
 	int i, ret;
 
@@ -241,19 +252,20 @@ void __noreturn __pkvm_init_finalise(void)
 	if (ret)
 		goto out;
 
-	ret = finalize_host_mappings();
-	if (ret)
-		goto out;
-
 	pkvm_pgtable_mm_ops = (struct kvm_pgtable_mm_ops) {
 		.zalloc_page = hyp_zalloc_hyp_page,
 		.phys_to_virt = hyp_phys_to_virt,
 		.virt_to_phys = hyp_virt_to_phys,
 		.get_page = hpool_get_page,
 		.put_page = hpool_put_page,
+		.page_count = hyp_page_count,
 	};
 	pkvm_pgtable.mm_ops = &pkvm_pgtable_mm_ops;
 
+	ret = finalize_host_mappings();
+	if (ret)
+		goto out;
+
 out:
 	/*
 	 * We tail-called to here from handle___pkvm_init() and will not return,

arch/arm64/kvm/hyp/pgtable.c

@@ -383,21 +383,6 @@ enum kvm_pgtable_prot kvm_pgtable_hyp_pte_prot(kvm_pte_t pte)
 	return prot;
 }
 
-static bool hyp_pte_needs_update(kvm_pte_t old, kvm_pte_t new)
-{
-	/*
-	 * Tolerate KVM recreating the exact same mapping, or changing software
-	 * bits if the existing mapping was valid.
-	 */
-	if (old == new)
-		return false;
-
-	if (!kvm_pte_valid(old))
-		return true;
-
-	return !WARN_ON((old ^ new) & ~KVM_PTE_LEAF_ATTR_HI_SW);
-}
-
 static bool hyp_map_walker_try_leaf(u64 addr, u64 end, u32 level,
 				    kvm_pte_t *ptep, struct hyp_map_data *data)
 {
@@ -407,11 +392,16 @@ static bool hyp_map_walker_try_leaf(u64 addr, u64 end, u32 level,
 	if (!kvm_block_mapping_supported(addr, end, phys, level))
 		return false;
 
+	data->phys += granule;
 	new = kvm_init_valid_leaf_pte(phys, data->attr, level);
-	if (hyp_pte_needs_update(old, new))
-		smp_store_release(ptep, new);
+	if (old == new)
+		return true;
+	if (!kvm_pte_valid(old))
+		data->mm_ops->get_page(ptep);
+	else if (WARN_ON((old ^ new) & ~KVM_PTE_LEAF_ATTR_HI_SW))
+		return false;
 
-	data->phys += granule;
+	smp_store_release(ptep, new);
 	return true;
 }
 
@@ -433,6 +423,7 @@ static int hyp_map_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep,
 		return -ENOMEM;
 
 	kvm_set_table_pte(ptep, childp, mm_ops);
+	mm_ops->get_page(ptep);
 	return 0;
 }
 
@@ -460,6 +451,69 @@ int kvm_pgtable_hyp_map(struct kvm_pgtable *pgt, u64 addr, u64 size, u64 phys,
 	return ret;
 }
 
+struct hyp_unmap_data {
+	u64				unmapped;
+	struct kvm_pgtable_mm_ops	*mm_ops;
+};
+
+static int hyp_unmap_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep,
+			    enum kvm_pgtable_walk_flags flag, void * const arg)
+{
+	kvm_pte_t pte = *ptep, *childp = NULL;
+	u64 granule = kvm_granule_size(level);
+	struct hyp_unmap_data *data = arg;
+	struct kvm_pgtable_mm_ops *mm_ops = data->mm_ops;
+
+	if (!kvm_pte_valid(pte))
+		return -EINVAL;
+
+	if (kvm_pte_table(pte, level)) {
+		childp = kvm_pte_follow(pte, mm_ops);
+
+		if (mm_ops->page_count(childp) != 1)
+			return 0;
+
+		kvm_clear_pte(ptep);
+		dsb(ishst);
+		__tlbi_level(vae2is, __TLBI_VADDR(addr, 0), level);
+	} else {
+		if (end - addr < granule)
+			return -EINVAL;
+
+		kvm_clear_pte(ptep);
+		dsb(ishst);
+		__tlbi_level(vale2is, __TLBI_VADDR(addr, 0), level);
+		data->unmapped += granule;
+	}
+
+	dsb(ish);
+	isb();
+	mm_ops->put_page(ptep);
+
+	if (childp)
+		mm_ops->put_page(childp);
+
+	return 0;
+}
+
+u64 kvm_pgtable_hyp_unmap(struct kvm_pgtable *pgt, u64 addr, u64 size)
+{
+	struct hyp_unmap_data unmap_data = {
+		.mm_ops	= pgt->mm_ops,
+	};
+	struct kvm_pgtable_walker walker = {
+		.cb	= hyp_unmap_walker,
+		.arg	= &unmap_data,
+		.flags	= KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST,
+	};
+
+	if (!pgt->mm_ops->page_count)
+		return 0;
+
+	kvm_pgtable_walk(pgt, addr, size, &walker);
+	return unmap_data.unmapped;
+}
+
 int kvm_pgtable_hyp_init(struct kvm_pgtable *pgt, u32 va_bits,
 			 struct kvm_pgtable_mm_ops *mm_ops)
 {
@@ -482,8 +536,16 @@ static int hyp_free_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep,
 			   enum kvm_pgtable_walk_flags flag, void * const arg)
 {
 	struct kvm_pgtable_mm_ops *mm_ops = arg;
+	kvm_pte_t pte = *ptep;
+
+	if (!kvm_pte_valid(pte))
+		return 0;
+
+	mm_ops->put_page(ptep);
+
+	if (kvm_pte_table(pte, level))
+		mm_ops->put_page(kvm_pte_follow(pte, mm_ops));
 
-	mm_ops->put_page((void *)kvm_pte_follow(*ptep, mm_ops));
 	return 0;
 }
 
@@ -491,7 +553,7 @@ void kvm_pgtable_hyp_destroy(struct kvm_pgtable *pgt)
 {
 	struct kvm_pgtable_walker walker = {
 		.cb	= hyp_free_walker,
-		.flags	= KVM_PGTABLE_WALK_TABLE_POST,
+		.flags	= KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST,
 		.arg	= pgt->mm_ops,
 	};
 

arch/arm64/kvm/mmu.c

@@ -284,14 +284,117 @@ static phys_addr_t kvm_kaddr_to_phys(void *kaddr)
 	}
 }
 
-static int pkvm_share_hyp(phys_addr_t start, phys_addr_t end)
+struct hyp_shared_pfn {
+	u64 pfn;
+	int count;
+	struct rb_node node;
+};
+
+static DEFINE_MUTEX(hyp_shared_pfns_lock);
+static struct rb_root hyp_shared_pfns = RB_ROOT;
+
+static struct hyp_shared_pfn *find_shared_pfn(u64 pfn, struct rb_node ***node,
+					      struct rb_node **parent)
 {
-	phys_addr_t addr;
+	struct hyp_shared_pfn *this;
+
+	*node = &hyp_shared_pfns.rb_node;
+	*parent = NULL;
+	while (**node) {
+		this = container_of(**node, struct hyp_shared_pfn, node);
+		*parent = **node;
+		if (this->pfn < pfn)
+			*node = &((**node)->rb_left);
+		else if (this->pfn > pfn)
+			*node = &((**node)->rb_right);
+		else
+			return this;
+	}
+
+	return NULL;
+}
+
+static int share_pfn_hyp(u64 pfn)
+{
+	struct rb_node **node, *parent;
+	struct hyp_shared_pfn *this;
+	int ret = 0;
+
+	mutex_lock(&hyp_shared_pfns_lock);
+	this = find_shared_pfn(pfn, &node, &parent);
+	if (this) {
+		this->count++;
+		goto unlock;
+	}
+
+	this = kzalloc(sizeof(*this), GFP_KERNEL);
+	if (!this) {
+		ret = -ENOMEM;
+		goto unlock;
+	}
+
+	this->pfn = pfn;
+	this->count = 1;
+	rb_link_node(&this->node, parent, node);
+	rb_insert_color(&this->node, &hyp_shared_pfns);
+	ret = kvm_call_hyp_nvhe(__pkvm_host_share_hyp, pfn, 1);
+unlock:
+	mutex_unlock(&hyp_shared_pfns_lock);
+
+	return ret;
+}
+
+static int unshare_pfn_hyp(u64 pfn)
+{
+	struct rb_node **node, *parent;
+	struct hyp_shared_pfn *this;
+	int ret = 0;
+
+	mutex_lock(&hyp_shared_pfns_lock);
+	this = find_shared_pfn(pfn, &node, &parent);
+	if (WARN_ON(!this)) {
+		ret = -ENOENT;
+		goto unlock;
+	}
+
+	this->count--;
+	if (this->count)
+		goto unlock;
+
+	rb_erase(&this->node, &hyp_shared_pfns);
+	kfree(this);
+	ret = kvm_call_hyp_nvhe(__pkvm_host_unshare_hyp, pfn, 1);
+unlock:
+	mutex_unlock(&hyp_shared_pfns_lock);
+
+	return ret;
+}
+
+int kvm_share_hyp(void *from, void *to)
+{
+	phys_addr_t start, end, cur;
+	u64 pfn;
 	int ret;
 
-	for (addr = ALIGN_DOWN(start, PAGE_SIZE); addr < end; addr += PAGE_SIZE) {
-		ret = kvm_call_hyp_nvhe(__pkvm_host_share_hyp,
-					__phys_to_pfn(addr));
+	if (is_kernel_in_hyp_mode())
+		return 0;
+
+	/*
+	 * The share hcall maps things in the 'fixed-offset' region of the hyp
+	 * VA space, so we can only share physically contiguous data-structures
+	 * for now.
+	 */
+	if (is_vmalloc_or_module_addr(from) || is_vmalloc_or_module_addr(to))
+		return -EINVAL;
+
+	if (kvm_host_owns_hyp_mappings())
+		return create_hyp_mappings(from, to, PAGE_HYP);
+
+	start = ALIGN_DOWN(__pa(from), PAGE_SIZE);
+	end = PAGE_ALIGN(__pa(to));
+	for (cur = start; cur < end; cur += PAGE_SIZE) {
+		pfn = __phys_to_pfn(cur);
+		ret = share_pfn_hyp(pfn);
 		if (ret)
 			return ret;
 	}
@@ -299,6 +402,22 @@ static int pkvm_share_hyp(phys_addr_t start, phys_addr_t end)
 	return 0;
 }
 
+void kvm_unshare_hyp(void *from, void *to)
+{
+	phys_addr_t start, end, cur;
+	u64 pfn;
+
+	if (is_kernel_in_hyp_mode() || kvm_host_owns_hyp_mappings() || !from)
+		return;
+
+	start = ALIGN_DOWN(__pa(from), PAGE_SIZE);
+	end = PAGE_ALIGN(__pa(to));
+	for (cur = start; cur < end; cur += PAGE_SIZE) {
+		pfn = __phys_to_pfn(cur);
+		WARN_ON(unshare_pfn_hyp(pfn));
+	}
+}
+
 /**
  * create_hyp_mappings - duplicate a kernel virtual address range in Hyp mode
  * @from:	The virtual kernel start address of the range
@@ -319,12 +438,8 @@ int create_hyp_mappings(void *from, void *to, enum kvm_pgtable_prot prot)
 	if (is_kernel_in_hyp_mode())
 		return 0;
 
-	if (!kvm_host_owns_hyp_mappings()) {
-		if (WARN_ON(prot != PAGE_HYP))
+	if (!kvm_host_owns_hyp_mappings())
 		return -EPERM;
-		return pkvm_share_hyp(kvm_kaddr_to_phys(from),
-				      kvm_kaddr_to_phys(to));
-	}
 
 	start = start & PAGE_MASK;
 	end = PAGE_ALIGN(end);

arch/arm64/kvm/reset.c

@@ -113,7 +113,7 @@ static int kvm_vcpu_finalize_sve(struct kvm_vcpu *vcpu)
 	if (!buf)
 		return -ENOMEM;
 
-	ret = create_hyp_mappings(buf, buf + reg_sz, PAGE_HYP);
+	ret = kvm_share_hyp(buf, buf + reg_sz);
 	if (ret) {
 		kfree(buf);
 		return ret;
@@ -150,7 +150,13 @@ bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu)
 
 void kvm_arm_vcpu_destroy(struct kvm_vcpu *vcpu)
 {
-	kfree(vcpu->arch.sve_state);
+	void *sve_state = vcpu->arch.sve_state;
+
+	kvm_vcpu_unshare_task_fp(vcpu);
+	kvm_unshare_hyp(vcpu, vcpu + 1);
+	if (sve_state)
+		kvm_unshare_hyp(sve_state, sve_state + vcpu_sve_state_size(vcpu));
+	kfree(sve_state);
 }
 
 static void kvm_vcpu_reset_sve(struct kvm_vcpu *vcpu)