Merge tag 'x86_sgx_for_v6.0-2022-08-03.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 SGX updates from Dave Hansen:
 "A set of x86/sgx changes focused on implementing the "SGX2" features,
  plus a minor cleanup:

   - SGX2 ISA support which makes enclave memory management much more
     dynamic. For instance, enclaves can now change enclave page
     permissions on the fly.

   - Removal of an unused structure member"

* tag 'x86_sgx_for_v6.0-2022-08-03.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits)
  x86/sgx: Drop 'page_index' from sgx_backing
  selftests/sgx: Page removal stress test
  selftests/sgx: Test reclaiming of untouched page
  selftests/sgx: Test invalid access to removed enclave page
  selftests/sgx: Test faulty enclave behavior
  selftests/sgx: Test complete changing of page type flow
  selftests/sgx: Introduce TCS initialization enclave operation
  selftests/sgx: Introduce dynamic entry point
  selftests/sgx: Test two different SGX2 EAUG flows
  selftests/sgx: Add test for TCS page permission changes
  selftests/sgx: Add test for EPCM permission changes
  Documentation/x86: Introduce enclave runtime management section
  x86/sgx: Free up EPC pages directly to support large page ranges
  x86/sgx: Support complete page removal
  x86/sgx: Support modifying SGX page type
  x86/sgx: Tighten accessible memory range after enclave initialization
  x86/sgx: Support adding of pages to an initialized enclave
  x86/sgx: Support restricting of enclave page permissions
  x86/sgx: Support VA page allocation without reclaiming
  x86/sgx: Export sgx_encl_page_alloc()
  ...

8 files changed, 1038 insertions, 130 deletions

diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h
index 3f9334ef67cd..eae20fa52b93 100644
--- a/arch/x86/include/asm/sgx.h
+++ b/arch/x86/include/asm/sgx.h
@@ -65,17 +65,22 @@ enum sgx_encls_function {
 
 /**
  * enum sgx_return_code - The return code type for ENCLS, ENCLU and ENCLV
+ * %SGX_EPC_PAGE_CONFLICT:	Page is being written by other ENCLS function.
  * %SGX_NOT_TRACKED:		Previous ETRACK's shootdown sequence has not
  *				been completed yet.
  * %SGX_CHILD_PRESENT		SECS has child pages present in the EPC.
  * %SGX_INVALID_EINITTOKEN:	EINITTOKEN is invalid and enclave signer's
  *				public key does not match IA32_SGXLEPUBKEYHASH.
+ * %SGX_PAGE_NOT_MODIFIABLE:	The EPC page cannot be modified because it
+ *				is in the PENDING or MODIFIED state.
  * %SGX_UNMASKED_EVENT:		An unmasked event, e.g. INTR, was received
  */
 enum sgx_return_code {
+	SGX_EPC_PAGE_CONFLICT		= 7,
 	SGX_NOT_TRACKED			= 11,
 	SGX_CHILD_PRESENT		= 13,
 	SGX_INVALID_EINITTOKEN		= 16,
+	SGX_PAGE_NOT_MODIFIABLE		= 20,
 	SGX_UNMASKED_EVENT		= 128,
 };
 
@@ -234,6 +239,9 @@ struct sgx_pageinfo {
  * %SGX_PAGE_TYPE_REG:	a regular page
  * %SGX_PAGE_TYPE_VA:	a VA page
  * %SGX_PAGE_TYPE_TRIM:	a page in trimmed state
+ *
+ * Make sure when making changes to this enum that its values can still fit
+ * in the bitfield within &struct sgx_encl_page
  */
 enum sgx_page_type {
 	SGX_PAGE_TYPE_SECS,
diff --git a/arch/x86/include/uapi/asm/sgx.h b/arch/x86/include/uapi/asm/sgx.h
index f4b81587e90b..2dd35bbdc822 100644
--- a/arch/x86/include/uapi/asm/sgx.h
+++ b/arch/x86/include/uapi/asm/sgx.h
@@ -29,6 +29,12 @@ enum sgx_page_flags {
 	_IOW(SGX_MAGIC, 0x03, struct sgx_enclave_provision)
 #define SGX_IOC_VEPC_REMOVE_ALL \
 	_IO(SGX_MAGIC, 0x04)
+#define SGX_IOC_ENCLAVE_RESTRICT_PERMISSIONS \
+	_IOWR(SGX_MAGIC, 0x05, struct sgx_enclave_restrict_permissions)
+#define SGX_IOC_ENCLAVE_MODIFY_TYPES \
+	_IOWR(SGX_MAGIC, 0x06, struct sgx_enclave_modify_types)
+#define SGX_IOC_ENCLAVE_REMOVE_PAGES \
+	_IOWR(SGX_MAGIC, 0x07, struct sgx_enclave_remove_pages)
 
 /**
  * struct sgx_enclave_create - parameter structure for the
@@ -76,6 +82,62 @@ struct sgx_enclave_provision {
 	__u64 fd;
 };
 
+/**
+ * struct sgx_enclave_restrict_permissions - parameters for ioctl
+ *                                        %SGX_IOC_ENCLAVE_RESTRICT_PERMISSIONS
+ * @offset:	starting page offset (page aligned relative to enclave base
+ *		address defined in SECS)
+ * @length:	length of memory (multiple of the page size)
+ * @permissions:new permission bits for pages in range described by @offset
+ *              and @length
+ * @result:	(output) SGX result code of ENCLS[EMODPR] function
+ * @count:	(output) bytes successfully changed (multiple of page size)
+ */
+struct sgx_enclave_restrict_permissions {
+	__u64 offset;
+	__u64 length;
+	__u64 permissions;
+	__u64 result;
+	__u64 count;
+};
+
+/**
+ * struct sgx_enclave_modify_types - parameters for ioctl
+ *                                   %SGX_IOC_ENCLAVE_MODIFY_TYPES
+ * @offset:	starting page offset (page aligned relative to enclave base
+ *		address defined in SECS)
+ * @length:	length of memory (multiple of the page size)
+ * @page_type:	new type for pages in range described by @offset and @length
+ * @result:	(output) SGX result code of ENCLS[EMODT] function
+ * @count:	(output) bytes successfully changed (multiple of page size)
+ */
+struct sgx_enclave_modify_types {
+	__u64 offset;
+	__u64 length;
+	__u64 page_type;
+	__u64 result;
+	__u64 count;
+};
+
+/**
+ * struct sgx_enclave_remove_pages - %SGX_IOC_ENCLAVE_REMOVE_PAGES parameters
+ * @offset:	starting page offset (page aligned relative to enclave base
+ *		address defined in SECS)
+ * @length:	length of memory (multiple of the page size)
+ * @count:	(output) bytes successfully changed (multiple of page size)
+ *
+ * Regular (PT_REG) or TCS (PT_TCS) can be removed from an initialized
+ * enclave if the system supports SGX2. First, the %SGX_IOC_ENCLAVE_MODIFY_TYPES
+ * ioctl() should be used to change the page type to PT_TRIM. After that
+ * succeeds ENCLU[EACCEPT] should be run from within the enclave and then
+ * %SGX_IOC_ENCLAVE_REMOVE_PAGES can be used to complete the page removal.
+ */
+struct sgx_enclave_remove_pages {
+	__u64 offset;
+	__u64 length;
+	__u64 count;
+};
+
 struct sgx_enclave_run;
 
 /**
diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c
index 19876ebfb504..24c1bb8eb196 100644
--- a/arch/x86/kernel/cpu/sgx/encl.c
+++ b/arch/x86/kernel/cpu/sgx/encl.c
@@ -232,25 +232,10 @@ static struct sgx_epc_page *sgx_encl_eldu(struct sgx_encl_page *encl_page,
 	return epc_page;
 }
 
-static struct sgx_encl_page *sgx_encl_load_page(struct sgx_encl *encl,
-						unsigned long addr,
-						unsigned long vm_flags)
+static struct sgx_encl_page *__sgx_encl_load_page(struct sgx_encl *encl,
+						  struct sgx_encl_page *entry)
 {
-	unsigned long vm_prot_bits = vm_flags & (VM_READ | VM_WRITE | VM_EXEC);
 	struct sgx_epc_page *epc_page;
-	struct sgx_encl_page *entry;
-
-	entry = xa_load(&encl->page_array, PFN_DOWN(addr));
-	if (!entry)
-		return ERR_PTR(-EFAULT);
-
-	/*
-	 * Verify that the faulted page has equal or higher build time
-	 * permissions than the VMA permissions (i.e. the subset of {VM_READ,
-	 * VM_WRITE, VM_EXECUTE} in vma->vm_flags).
-	 */
-	if ((entry->vm_max_prot_bits & vm_prot_bits) != vm_prot_bits)
-		return ERR_PTR(-EFAULT);
 
 	/* Entry successfully located. */
 	if (entry->epc_page) {
@@ -276,6 +261,146 @@ static struct sgx_encl_page *sgx_encl_load_page(struct sgx_encl *encl,
 	return entry;
 }
 
+static struct sgx_encl_page *sgx_encl_load_page_in_vma(struct sgx_encl *encl,
+						       unsigned long addr,
+						       unsigned long vm_flags)
+{
+	unsigned long vm_prot_bits = vm_flags & (VM_READ | VM_WRITE | VM_EXEC);
+	struct sgx_encl_page *entry;
+
+	entry = xa_load(&encl->page_array, PFN_DOWN(addr));
+	if (!entry)
+		return ERR_PTR(-EFAULT);
+
+	/*
+	 * Verify that the page has equal or higher build time
+	 * permissions than the VMA permissions (i.e. the subset of {VM_READ,
+	 * VM_WRITE, VM_EXECUTE} in vma->vm_flags).
+	 */
+	if ((entry->vm_max_prot_bits & vm_prot_bits) != vm_prot_bits)
+		return ERR_PTR(-EFAULT);
+
+	return __sgx_encl_load_page(encl, entry);
+}
+
+struct sgx_encl_page *sgx_encl_load_page(struct sgx_encl *encl,
+					 unsigned long addr)
+{
+	struct sgx_encl_page *entry;
+
+	entry = xa_load(&encl->page_array, PFN_DOWN(addr));
+	if (!entry)
+		return ERR_PTR(-EFAULT);
+
+	return __sgx_encl_load_page(encl, entry);
+}
+
+/**
+ * sgx_encl_eaug_page() - Dynamically add page to initialized enclave
+ * @vma:	VMA obtained from fault info from where page is accessed
+ * @encl:	enclave accessing the page
+ * @addr:	address that triggered the page fault
+ *
+ * When an initialized enclave accesses a page with no backing EPC page
+ * on a SGX2 system then the EPC can be added dynamically via the SGX2
+ * ENCLS[EAUG] instruction.
+ *
+ * Returns: Appropriate vm_fault_t: VM_FAULT_NOPAGE when PTE was installed
+ * successfully, VM_FAULT_SIGBUS or VM_FAULT_OOM as error otherwise.
+ */
+static vm_fault_t sgx_encl_eaug_page(struct vm_area_struct *vma,
+				     struct sgx_encl *encl, unsigned long addr)
+{
+	vm_fault_t vmret = VM_FAULT_SIGBUS;
+	struct sgx_pageinfo pginfo = {0};
+	struct sgx_encl_page *encl_page;
+	struct sgx_epc_page *epc_page;
+	struct sgx_va_page *va_page;
+	unsigned long phys_addr;
+	u64 secinfo_flags;
+	int ret;
+
+	if (!test_bit(SGX_ENCL_INITIALIZED, &encl->flags))
+		return VM_FAULT_SIGBUS;
+
+	/*
+	 * Ignore internal permission checking for dynamically added pages.
+	 * They matter only for data added during the pre-initialization
+	 * phase. The enclave decides the permissions by the means of
+	 * EACCEPT, EACCEPTCOPY and EMODPE.
+	 */
+	secinfo_flags = SGX_SECINFO_R | SGX_SECINFO_W | SGX_SECINFO_X;
+	encl_page = sgx_encl_page_alloc(encl, addr - encl->base, secinfo_flags);
+	if (IS_ERR(encl_page))
+		return VM_FAULT_OOM;
+
+	mutex_lock(&encl->lock);
+
+	epc_page = sgx_alloc_epc_page(encl_page, false);
+	if (IS_ERR(epc_page)) {
+		if (PTR_ERR(epc_page) == -EBUSY)
+			vmret =  VM_FAULT_NOPAGE;
+		goto err_out_unlock;
+	}
+
+	va_page = sgx_encl_grow(encl, false);
+	if (IS_ERR(va_page))
+		goto err_out_epc;
+
+	if (va_page)
+		list_add(&va_page->list, &encl->va_pages);
+
+	ret = xa_insert(&encl->page_array, PFN_DOWN(encl_page->desc),
+			encl_page, GFP_KERNEL);
+	/*
+	 * If ret == -EBUSY then page was created in another flow while
+	 * running without encl->lock
+	 */
+	if (ret)
+		goto err_out_shrink;
+
+	pginfo.secs = (unsigned long)sgx_get_epc_virt_addr(encl->secs.epc_page);
+	pginfo.addr = encl_page->desc & PAGE_MASK;
+	pginfo.metadata = 0;
+
+	ret = __eaug(&pginfo, sgx_get_epc_virt_addr(epc_page));
+	if (ret)
+		goto err_out;
+
+	encl_page->encl = encl;
+	encl_page->epc_page = epc_page;
+	encl_page->type = SGX_PAGE_TYPE_REG;
+	encl->secs_child_cnt++;
+
+	sgx_mark_page_reclaimable(encl_page->epc_page);
+
+	phys_addr = sgx_get_epc_phys_addr(epc_page);
+	/*
+	 * Do not undo everything when creating PTE entry fails - next #PF
+	 * would find page ready for a PTE.
+	 */
+	vmret = vmf_insert_pfn(vma, addr, PFN_DOWN(phys_addr));
+	if (vmret != VM_FAULT_NOPAGE) {
+		mutex_unlock(&encl->lock);
+		return VM_FAULT_SIGBUS;
+	}
+	mutex_unlock(&encl->lock);
+	return VM_FAULT_NOPAGE;
+
+err_out:
+	xa_erase(&encl->page_array, PFN_DOWN(encl_page->desc));
+
+err_out_shrink:
+	sgx_encl_shrink(encl, va_page);
+err_out_epc:
+	sgx_encl_free_epc_page(epc_page);
+err_out_unlock:
+	mutex_unlock(&encl->lock);
+	kfree(encl_page);
+
+	return vmret;
+}
+
 static vm_fault_t sgx_vma_fault(struct vm_fault *vmf)
 {
 	unsigned long addr = (unsigned long)vmf->address;
@@ -295,9 +420,20 @@ static vm_fault_t sgx_vma_fault(struct vm_fault *vmf)
 	if (unlikely(!encl))
 		return VM_FAULT_SIGBUS;
 
+	/*
+	 * The page_array keeps track of all enclave pages, whether they
+	 * are swapped out or not. If there is no entry for this page and
+	 * the system supports SGX2 then it is possible to dynamically add
+	 * a new enclave page. This is only possible for an initialized
+	 * enclave that will be checked for right away.
+	 */
+	if (cpu_feature_enabled(X86_FEATURE_SGX2) &&
+	    (!xa_load(&encl->page_array, PFN_DOWN(addr))))
+		return sgx_encl_eaug_page(vma, encl, addr);
+
 	mutex_lock(&encl->lock);
 
-	entry = sgx_encl_load_page(encl, addr, vma->vm_flags);
+	entry = sgx_encl_load_page_in_vma(encl, addr, vma->vm_flags);
 	if (IS_ERR(entry)) {
 		mutex_unlock(&encl->lock);
 
@@ -367,6 +503,11 @@ int sgx_encl_may_map(struct sgx_encl *encl, unsigned long start,
 
 	XA_STATE(xas, &encl->page_array, PFN_DOWN(start));
 
+	/* Disallow mapping outside enclave's address range. */
+	if (test_bit(SGX_ENCL_INITIALIZED, &encl->flags) &&
+	    (start < encl->base || end > encl->base + encl->size))
+		return -EACCES;
+
 	/*
 	 * Disallow READ_IMPLIES_EXEC tasks as their VMA permissions might
 	 * conflict with the enclave page permissions.
@@ -445,7 +586,7 @@ static struct sgx_encl_page *sgx_encl_reserve_page(struct sgx_encl *encl,
 	for ( ; ; ) {
 		mutex_lock(&encl->lock);
 
-		entry = sgx_encl_load_page(encl, addr, vm_flags);
+		entry = sgx_encl_load_page_in_vma(encl, addr, vm_flags);
 		if (PTR_ERR(entry) != -EBUSY)
 			break;
 
@@ -687,7 +828,7 @@ int sgx_encl_mm_add(struct sgx_encl *encl, struct mm_struct *mm)
 
 	spin_lock(&encl->mm_lock);
 	list_add_rcu(&encl_mm->list, &encl->mm_list);
-	/* Pairs with smp_rmb() in sgx_reclaimer_block(). */
+	/* Pairs with smp_rmb() in sgx_zap_enclave_ptes(). */
 	smp_wmb();
 	encl->mm_list_version++;
 	spin_unlock(&encl->mm_lock);
@@ -695,6 +836,73 @@ int sgx_encl_mm_add(struct sgx_encl *encl, struct mm_struct *mm)
 	return 0;
 }
 
+/**
+ * sgx_encl_cpumask() - Query which CPUs might be accessing the enclave
+ * @encl: the enclave
+ *
+ * Some SGX functions require that no cached linear-to-physical address
+ * mappings are present before they can succeed. For example, ENCLS[EWB]
+ * copies a page from the enclave page cache to regular main memory but
+ * it fails if it cannot ensure that there are no cached
+ * linear-to-physical address mappings referring to the page.
+ *
+ * SGX hardware flushes all cached linear-to-physical mappings on a CPU
+ * when an enclave is exited via ENCLU[EEXIT] or an Asynchronous Enclave
+ * Exit (AEX). Exiting an enclave will thus ensure cached linear-to-physical
+ * address mappings are cleared but coordination with the tracking done within
+ * the SGX hardware is needed to support the SGX functions that depend on this
+ * cache clearing.
+ *
+ * When the ENCLS[ETRACK] function is issued on an enclave the hardware
+ * tracks threads operating inside the enclave at that time. The SGX
+ * hardware tracking require that all the identified threads must have
+ * exited the enclave in order to flush the mappings before a function such
+ * as ENCLS[EWB] will be permitted
+ *
+ * The following flow is used to support SGX functions that require that
+ * no cached linear-to-physical address mappings are present:
+ * 1) Execute ENCLS[ETRACK] to initiate hardware tracking.
+ * 2) Use this function (sgx_encl_cpumask()) to query which CPUs might be
+ *    accessing the enclave.
+ * 3) Send IPI to identified CPUs, kicking them out of the enclave and
+ *    thus flushing all locally cached linear-to-physical address mappings.
+ * 4) Execute SGX function.
+ *
+ * Context: It is required to call this function after ENCLS[ETRACK].
+ *          This will ensure that if any new mm appears (racing with
+ *          sgx_encl_mm_add()) then the new mm will enter into the
+ *          enclave with fresh linear-to-physical address mappings.
+ *
+ *          It is required that all IPIs are completed before a new
+ *          ENCLS[ETRACK] is issued so be sure to protect steps 1 to 3
+ *          of the above flow with the enclave's mutex.
+ *
+ * Return: cpumask of CPUs that might be accessing @encl
+ */
+const cpumask_t *sgx_encl_cpumask(struct sgx_encl *encl)
+{
+	cpumask_t *cpumask = &encl->cpumask;
+	struct sgx_encl_mm *encl_mm;
+	int idx;
+
+	cpumask_clear(cpumask);
+
+	idx = srcu_read_lock(&encl->srcu);
+
+	list_for_each_entry_rcu(encl_mm, &encl->mm_list, list) {
+		if (!mmget_not_zero(encl_mm->mm))
+			continue;
+
+		cpumask_or(cpumask, cpumask, mm_cpumask(encl_mm->mm));
+
+		mmput_async(encl_mm->mm);
+	}
+
+	srcu_read_unlock(&encl->srcu, idx);
+
+	return cpumask;
+}
+
 static struct page *sgx_encl_get_backing_page(struct sgx_encl *encl,
 					      pgoff_t index)
 {
@@ -735,7 +943,6 @@ static int sgx_encl_get_backing(struct sgx_encl *encl, unsigned long page_index,
 		return PTR_ERR(pcmd);
 	}
 
-	backing->page_index = page_index;
 	backing->contents = contents;
 	backing->pcmd = pcmd;
 	backing->pcmd_offset = page_pcmd_off & (PAGE_SIZE - 1);
@@ -902,8 +1109,85 @@ int sgx_encl_test_and_clear_young(struct mm_struct *mm,
 	return ret;
 }
 
+struct sgx_encl_page *sgx_encl_page_alloc(struct sgx_encl *encl,
+					  unsigned long offset,
+					  u64 secinfo_flags)
+{
+	struct sgx_encl_page *encl_page;
+	unsigned long prot;
+
+	encl_page = kzalloc(sizeof(*encl_page), GFP_KERNEL);
+	if (!encl_page)
+		return ERR_PTR(-ENOMEM);
+
+	encl_page->desc = encl->base + offset;
+	encl_page->encl = encl;
+
+	prot = _calc_vm_trans(secinfo_flags, SGX_SECINFO_R, PROT_READ)  |
+	       _calc_vm_trans(secinfo_flags, SGX_SECINFO_W, PROT_WRITE) |
+	       _calc_vm_trans(secinfo_flags, SGX_SECINFO_X, PROT_EXEC);
+
+	/*
+	 * TCS pages must always RW set for CPU access while the SECINFO
+	 * permissions are *always* zero - the CPU ignores the user provided
+	 * values and silently overwrites them with zero permissions.
+	 */
+	if ((secinfo_flags & SGX_SECINFO_PAGE_TYPE_MASK) == SGX_SECINFO_TCS)
+		prot |= PROT_READ | PROT_WRITE;
+
+	/* Calculate maximum of the VM flags for the page. */
+	encl_page->vm_max_prot_bits = calc_vm_prot_bits(prot, 0);
+
+	return encl_page;
+}
+
+/**
+ * sgx_zap_enclave_ptes() - remove PTEs mapping the address from enclave
+ * @encl: the enclave
+ * @addr: page aligned pointer to single page for which PTEs will be removed
+ *
+ * Multiple VMAs may have an enclave page mapped. Remove the PTE mapping
+ * @addr from each VMA. Ensure that page fault handler is ready to handle
+ * new mappings of @addr before calling this function.
+ */
+void sgx_zap_enclave_ptes(struct sgx_encl *encl, unsigned long addr)
+{
+	unsigned long mm_list_version;
+	struct sgx_encl_mm *encl_mm;
+	struct vm_area_struct *vma;
+	int idx, ret;
+
+	do {
+		mm_list_version = encl->mm_list_version;
+
+		/* Pairs with smp_wmb() in sgx_encl_mm_add(). */
+		smp_rmb();
+
+		idx = srcu_read_lock(&encl->srcu);
+
+		list_for_each_entry_rcu(encl_mm, &encl->mm_list, list) {
+			if (!mmget_not_zero(encl_mm->mm))
+				continue;
+
+			mmap_read_lock(encl_mm->mm);
+
+			ret = sgx_encl_find(encl_mm->mm, addr, &vma);
+			if (!ret && encl == vma->vm_private_data)
+				zap_vma_ptes(vma, addr, PAGE_SIZE);
+
+			mmap_read_unlock(encl_mm->mm);
+
+			mmput_async(encl_mm->mm);
+		}
+
+		srcu_read_unlock(&encl->srcu, idx);
+	} while (unlikely(encl->mm_list_version != mm_list_version));
+}
+
 /**
  * sgx_alloc_va_page() - Allocate a Version Array (VA) page
+ * @reclaim: Reclaim EPC pages directly if none available. Enclave
+ *           mutex should not be held if this is set.
  *
  * Allocate a free EPC page and convert it to a Version Array (VA) page.
  *
@@ -911,12 +1195,12 @@ int sgx_encl_test_and_clear_young(struct mm_struct *mm,
  *   a VA page,
  *   -errno otherwise
  */
-struct sgx_epc_page *sgx_alloc_va_page(void)
+struct sgx_epc_page *sgx_alloc_va_page(bool reclaim)
 {
 	struct sgx_epc_page *epc_page;
 	int ret;
 
-	epc_page = sgx_alloc_epc_page(NULL, true);
+	epc_page = sgx_alloc_epc_page(NULL, reclaim);
 	if (IS_ERR(epc_page))
 		return ERR_CAST(epc_page);
 
diff --git a/arch/x86/kernel/cpu/sgx/encl.h b/arch/x86/kernel/cpu/sgx/encl.h
index 332ef3568267..a65a952116fd 100644
--- a/arch/x86/kernel/cpu/sgx/encl.h
+++ b/arch/x86/kernel/cpu/sgx/encl.h
@@ -27,7 +27,8 @@
 
 struct sgx_encl_page {
 	unsigned long desc;
-	unsigned long vm_max_prot_bits;
+	unsigned long vm_max_prot_bits:8;
+	enum sgx_page_type type:16;
 	struct sgx_epc_page *epc_page;
 	struct sgx_encl *encl;
 	struct sgx_va_page *va_page;
@@ -78,7 +79,6 @@ struct sgx_va_page {
 };
 
 struct sgx_backing {
-	pgoff_t page_index;
 	struct page *contents;
 	struct page *pcmd;
 	unsigned long pcmd_offset;
@@ -106,6 +106,7 @@ int sgx_encl_may_map(struct sgx_encl *encl, unsigned long start,
 bool current_is_ksgxd(void);
 void sgx_encl_release(struct kref *ref);
 int sgx_encl_mm_add(struct sgx_encl *encl, struct mm_struct *mm);
+const cpumask_t *sgx_encl_cpumask(struct sgx_encl *encl);
 int sgx_encl_lookup_backing(struct sgx_encl *encl, unsigned long page_index,
 			    struct sgx_backing *backing);
 int sgx_encl_alloc_backing(struct sgx_encl *encl, unsigned long page_index,
@@ -113,11 +114,18 @@ int sgx_encl_alloc_backing(struct sgx_encl *encl, unsigned long page_index,
 void sgx_encl_put_backing(struct sgx_backing *backing);
 int sgx_encl_test_and_clear_young(struct mm_struct *mm,
 				  struct sgx_encl_page *page);
-
-struct sgx_epc_page *sgx_alloc_va_page(void);
+struct sgx_encl_page *sgx_encl_page_alloc(struct sgx_encl *encl,
+					  unsigned long offset,
+					  u64 secinfo_flags);
+void sgx_zap_enclave_ptes(struct sgx_encl *encl, unsigned long addr);
+struct sgx_epc_page *sgx_alloc_va_page(bool reclaim);
 unsigned int sgx_alloc_va_slot(struct sgx_va_page *va_page);
 void sgx_free_va_slot(struct sgx_va_page *va_page, unsigned int offset);
 bool sgx_va_page_full(struct sgx_va_page *va_page);
 void sgx_encl_free_epc_page(struct sgx_epc_page *page);
+struct sgx_encl_page *sgx_encl_load_page(struct sgx_encl *encl,
+					 unsigned long addr);
+struct sgx_va_page *sgx_encl_grow(struct sgx_encl *encl, bool reclaim);
+void sgx_encl_shrink(struct sgx_encl *encl, struct sgx_va_page *va_page);
 
 #endif /* _X86_ENCL_H */
diff --git a/arch/x86/kernel/cpu/sgx/encls.h b/arch/x86/kernel/cpu/sgx/encls.h
index fa04a73daf9c..99004b02e2ed 100644
--- a/arch/x86/kernel/cpu/sgx/encls.h
+++ b/arch/x86/kernel/cpu/sgx/encls.h
@@ -136,57 +136,71 @@ static inline bool encls_failed(int ret)
 	ret;						\
 	})
 
+/* Initialize an EPC page into an SGX Enclave Control Structure (SECS) page. */
 static inline int __ecreate(struct sgx_pageinfo *pginfo, void *secs)
 {
 	return __encls_2(ECREATE, pginfo, secs);
 }
 
+/* Hash a 256 byte region of an enclave page to SECS:MRENCLAVE. */
 static inline int __eextend(void *secs, void *addr)
 {
 	return __encls_2(EEXTEND, secs, addr);
 }
 
+/*
+ * Associate an EPC page to an enclave either as a REG or TCS page
+ * populated with the provided data.
+ */
 static inline int __eadd(struct sgx_pageinfo *pginfo, void *addr)
 {
 	return __encls_2(EADD, pginfo, addr);
 }
 
+/* Finalize enclave build, initialize enclave for user code execution. */
 static inline int __einit(void *sigstruct, void *token, void *secs)
 {
 	return __encls_ret_3(EINIT, sigstruct, secs, token);
 }
 
+/* Disassociate EPC page from its enclave and mark it as unused. */
 static inline int __eremove(void *addr)
 {
 	return __encls_ret_1(EREMOVE, addr);
 }
 
+/* Copy data to an EPC page belonging to a debug enclave. */
 static inline int __edbgwr(void *addr, unsigned long *data)
 {
 	return __encls_2(EDGBWR, *data, addr);
 }
 
+/* Copy data from an EPC page belonging to a debug enclave. */
 static inline int __edbgrd(void *addr, unsigned long *data)
 {
 	return __encls_1_1(EDGBRD, *data, addr);
 }
 
+/* Track that software has completed the required TLB address clears. */
 static inline int __etrack(void *addr)
 {
 	return __encls_ret_1(ETRACK, addr);
 }
 
+/* Load, verify, and unblock an EPC page. */
 static inline int __eldu(struct sgx_pageinfo *pginfo, void *addr,
 			 void *va)
 {
 	return __encls_ret_3(ELDU, pginfo, addr, va);
 }
 
+/* Make EPC page inaccessible to enclave, ready to be written to memory. */
 static inline int __eblock(void *addr)
 {
 	return __encls_ret_1(EBLOCK, addr);
 }
 
+/* Initialize an EPC page into a Version Array (VA) page. */
 static inline int __epa(void *addr)
 {
 	unsigned long rbx = SGX_PAGE_TYPE_VA;
@@ -194,10 +208,29 @@ static inline int __epa(void *addr)
 	return __encls_2(EPA, rbx, addr);
 }
 
+/* Invalidate an EPC page and write it out to main memory. */
 static inline int __ewb(struct sgx_pageinfo *pginfo, void *addr,
 			void *va)
 {
 	return __encls_ret_3(EWB, pginfo, addr, va);
 }
 
+/* Restrict the EPCM permissions of an EPC page. */
+static inline int __emodpr(struct sgx_secinfo *secinfo, void *addr)
+{
+	return __encls_ret_2(EMODPR, secinfo, addr);
+}
+
+/* Change the type of an EPC page. */
+static inline int __emodt(struct sgx_secinfo *secinfo, void *addr)
+{
+	return __encls_ret_2(EMODT, secinfo, addr);
+}
+
+/* Zero a page of EPC memory and add it to an initialized enclave. */
+static inline int __eaug(struct sgx_pageinfo *pginfo, void *addr)
+{
+	return __encls_2(EAUG, pginfo, addr);
+}
+
 #endif /* _X86_ENCLS_H */
diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c
index 83df20e3e633..ebe79d60619f 100644
--- a/arch/x86/kernel/cpu/sgx/ioctl.c
+++ b/arch/x86/kernel/cpu/sgx/ioctl.c
@@ -17,7 +17,7 @@
 #include "encl.h"
 #include "encls.h"
 
-static struct sgx_va_page *sgx_encl_grow(struct sgx_encl *encl)
+struct sgx_va_page *sgx_encl_grow(struct sgx_encl *encl, bool reclaim)
 {
 	struct sgx_va_page *va_page = NULL;
 	void *err;
@@ -30,7 +30,7 @@ static struct sgx_va_page *sgx_encl_grow(struct sgx_encl *encl)
 		if (!va_page)
 			return ERR_PTR(-ENOMEM);
 
-		va_page->epc_page = sgx_alloc_va_page();
+		va_page->epc_page = sgx_alloc_va_page(reclaim);
 		if (IS_ERR(va_page->epc_page)) {
 			err = ERR_CAST(va_page->epc_page);
 			kfree(va_page);
@@ -43,7 +43,7 @@ static struct sgx_va_page *sgx_encl_grow(struct sgx_encl *encl)
 	return va_page;
 }
 
-static void sgx_encl_shrink(struct sgx_encl *encl, struct sgx_va_page *va_page)
+void sgx_encl_shrink(struct sgx_encl *encl, struct sgx_va_page *va_page)
 {
 	encl->page_cnt--;
 
@@ -64,7 +64,7 @@ static int sgx_encl_create(struct sgx_encl *encl, struct sgx_secs *secs)
 	struct file *backing;
 	long ret;
 
-	va_page = sgx_encl_grow(encl);
+	va_page = sgx_encl_grow(encl, true);
 	if (IS_ERR(va_page))
 		return PTR_ERR(va_page);
 	else if (va_page)
@@ -107,6 +107,7 @@ static int sgx_encl_create(struct sgx_encl *encl, struct sgx_secs *secs)
 		set_bit(SGX_ENCL_DEBUG, &encl->flags);
 
 	encl->secs.encl = encl;
+	encl->secs.type = SGX_PAGE_TYPE_SECS;
 	encl->base = secs->base;
 	encl->size = secs->size;
 	encl->attributes = secs->attributes;
@@ -168,38 +169,6 @@ static long sgx_ioc_enclave_create(struct sgx_encl *encl, void __user *arg)
 	return ret;
 }
 
-static struct sgx_encl_page *sgx_encl_page_alloc(struct sgx_encl *encl,
-						 unsigned long offset,
-						 u64 secinfo_flags)
-{
-	struct sgx_encl_page *encl_page;
-	unsigned long prot;
-
-	encl_page = kzalloc(sizeof(*encl_page), GFP_KERNEL);
-	if (!encl_page)
-		return ERR_PTR(-ENOMEM);
-
-	encl_page->desc = encl->base + offset;
-	encl_page->encl = encl;
-
-	prot = _calc_vm_trans(secinfo_flags, SGX_SECINFO_R, PROT_READ)  |
-	       _calc_vm_trans(secinfo_flags, SGX_SECINFO_W, PROT_WRITE) |
-	       _calc_vm_trans(secinfo_flags, SGX_SECINFO_X, PROT_EXEC);
-
-	/*
-	 * TCS pages must always RW set for CPU access while the SECINFO
-	 * permissions are *always* zero - the CPU ignores the user provided
-	 * values and silently overwrites them with zero permissions.
-	 */
-	if ((secinfo_flags & SGX_SECINFO_PAGE_TYPE_MASK) == SGX_SECINFO_TCS)
-		prot |= PROT_READ | PROT_WRITE;
-
-	/* Calculate maximum of the VM flags for the page. */
-	encl_page->vm_max_prot_bits = calc_vm_prot_bits(prot, 0);
-
-	return encl_page;
-}
-
 static int sgx_validate_secinfo(struct sgx_secinfo *secinfo)
 {
 	u64 perm = secinfo->flags & SGX_SECINFO_PERMISSION_MASK;
@@ -306,7 +275,7 @@ static int sgx_encl_add_page(struct sgx_encl *encl, unsigned long src,
 		return PTR_ERR(epc_page);
 	}
 
-	va_page = sgx_encl_grow(encl);
+	va_page = sgx_encl_grow(encl, true);
 	if (IS_ERR(va_page)) {
 		ret = PTR_ERR(va_page);
 		goto err_out_free;
@@ -344,6 +313,7 @@ static int sgx_encl_add_page(struct sgx_encl *encl, unsigned long src,
 	 */
 	encl_page->encl = encl;
 	encl_page->epc_page = epc_page;
+	encl_page->type = (secinfo->flags & SGX_SECINFO_PAGE_TYPE_MASK) >> 8;
 	encl->secs_child_cnt++;
 
 	if (flags & SGX_PAGE_MEASURE) {
@@ -372,6 +342,26 @@ err_out_free:
 	return ret;
 }
 
+/*
+ * Ensure user provided offset and length values are valid for
+ * an enclave.
+ */
+static int sgx_validate_offset_length(struct sgx_encl *encl,
+				      unsigned long offset,
+				      unsigned long length)
+{
+	if (!IS_ALIGNED(offset, PAGE_SIZE))
+		return -EINVAL;
+
+	if (!length || !IS_ALIGNED(length, PAGE_SIZE))
+		return -EINVAL;
+
+	if (offset + length - PAGE_SIZE >= encl->size)
+		return -EINVAL;
+
+	return 0;
+}
+
 /**
  * sgx_ioc_enclave_add_pages() - The handler for %SGX_IOC_ENCLAVE_ADD_PAGES
  * @encl:       an enclave pointer
@@ -425,14 +415,10 @@ static long sgx_ioc_enclave_add_pages(struct sgx_encl *encl, void __user *arg)
 	if (copy_from_user(&add_arg, arg, sizeof(add_arg)))
 		return -EFAULT;
 
-	if (!IS_ALIGNED(add_arg.offset, PAGE_SIZE) ||
-	    !IS_ALIGNED(add_arg.src, PAGE_SIZE))
-		return -EINVAL;
-
-	if (!add_arg.length || add_arg.length & (PAGE_SIZE - 1))
+	if (!IS_ALIGNED(add_arg.src, PAGE_SIZE))
 		return -EINVAL;
 
-	if (add_arg.offset + add_arg.length - PAGE_SIZE >= encl->size)
+	if (sgx_validate_offset_length(encl, add_arg.offset, add_arg.length))
 		return -EINVAL;
 
 	if (copy_from_user(&secinfo, (void __user *)add_arg.secinfo,
@@ -674,6 +660,565 @@ static long sgx_ioc_enclave_provision(struct sgx_encl *encl, void __user *arg)
 	return sgx_set_attribute(&encl->attributes_mask, params.fd);
 }
 
+/*
+ * Ensure enclave is ready for SGX2 functions. Readiness is checked
+ * by ensuring the hardware supports SGX2 and the enclave is initialized
+ * and thus able to handle requests to modify pages within it.
+ */
+static int sgx_ioc_sgx2_ready(struct sgx_encl *encl)
+{
+	if (!(cpu_feature_enabled(X86_FEATURE_SGX2)))
+		return -ENODEV;
+
+	if (!test_bit(SGX_ENCL_INITIALIZED, &encl->flags))
+		return -EINVAL;
+
+	return 0;
+}
+
+/*
+ * Some SGX functions require that no cached linear-to-physical address
+ * mappings are present before they can succeed. Collaborate with
+ * hardware via ENCLS[ETRACK] to ensure that all cached
+ * linear-to-physical address mappings belonging to all threads of
+ * the enclave are cleared. See sgx_encl_cpumask() for details.
+ *
+ * Must be called with enclave's mutex held from the time the
+ * SGX function requiring that no cached linear-to-physical mappings
+ * are present is executed until this ETRACK flow is complete.
+ */
+static int sgx_enclave_etrack(struct sgx_encl *encl)
+{
+	void *epc_virt;
+	int ret;
+
+	epc_virt = sgx_get_epc_virt_addr(encl->secs.epc_page);
+	ret = __etrack(epc_virt);
+	if (ret) {
+		/*
+		 * ETRACK only fails when there is an OS issue. For
+		 * example, two consecutive ETRACK was sent without
+		 * completed IPI between.
+		 */
+		pr_err_once("ETRACK returned %d (0x%x)", ret, ret);
+		/*
+		 * Send IPIs to kick CPUs out of the enclave and
+		 * try ETRACK again.
+		 */
+		on_each_cpu_mask(sgx_encl_cpumask(encl), sgx_ipi_cb, NULL, 1);
+		ret = __etrack(epc_virt);
+		if (ret) {
+			pr_err_once("ETRACK repeat returned %d (0x%x)",
+				    ret, ret);
+			return -EFAULT;
+		}
+	}
+	on_each_cpu_mask(sgx_encl_cpumask(encl), sgx_ipi_cb, NULL, 1);
+
+	return 0;
+}
+
+/**
+ * sgx_enclave_restrict_permissions() - Restrict EPCM permissions
+ * @encl:	Enclave to which the pages belong.
+ * @modp:	Checked parameters from user on which pages need modifying and
+ *              their new permissions.
+ *
+ * Return:
+ * - 0:		Success.
+ * - -errno:	Otherwise.
+ */
+static long
+sgx_enclave_restrict_permissions(struct sgx_encl *encl,
+				 struct sgx_enclave_restrict_permissions *modp)
+{
+	struct sgx_encl_page *entry;
+	struct sgx_secinfo secinfo;
+	unsigned long addr;
+	unsigned long c;
+	void *epc_virt;
+	int ret;
+
+	memset(&secinfo, 0, sizeof(secinfo));
+	secinfo.flags = modp->permissions & SGX_SECINFO_PERMISSION_MASK;
+
+	for (c = 0 ; c < modp->length; c += PAGE_SIZE) {
+		addr = encl->base + modp->offset + c;
+
+		sgx_reclaim_direct();
+
+		mutex_lock(&encl->lock);
+
+		entry = sgx_encl_load_page(encl, addr);
+		if (IS_ERR(entry)) {
+			ret = PTR_ERR(entry) == -EBUSY ? -EAGAIN : -EFAULT;
+			goto out_unlock;
+		}
+
+		/*
+		 * Changing EPCM permissions is only supported on regular
+		 * SGX pages. Attempting this change on other pages will
+		 * result in #PF.
+		 */
+		if (entry->type != SGX_PAGE_TYPE_REG) {
+			ret = -EINVAL;
+			goto out_unlock;
+		}
+
+		/*
+		 * Apart from ensuring that read-access remains, do not verify
+		 * the permission bits requested. Kernel has no control over
+		 * how EPCM permissions can be relaxed from within the enclave.
+		 * ENCLS[EMODPR] can only remove existing EPCM permissions,
+		 * attempting to set new permissions will be ignored by the
+		 * hardware.
+		 */
+
+		/* Change EPCM permissions. */
+		epc_virt = sgx_get_epc_virt_addr(entry->epc_page);
+		ret = __emodpr(&secinfo, epc_virt);
+		if (encls_faulted(ret)) {
+			/*
+			 * All possible faults should be avoidable:
+			 * parameters have been checked, will only change
+			 * permissions of a regular page, and no concurrent
+			 * SGX1/SGX2 ENCLS instructions since these
+			 * are protected with mutex.
+			 */
+			pr_err_once("EMODPR encountered exception %d\n",
+				    ENCLS_TRAPNR(ret));
+			ret = -EFAULT;
+			goto out_unlock;
+		}
+		if (encls_failed(ret)) {
+			modp->result = ret;
+			ret = -EFAULT;
+			goto out_unlock;
+		}
+
+		ret = sgx_enclave_etrack(encl);
+		if (ret) {
+			ret = -EFAULT;
+			goto out_unlock;
+		}
+
+		mutex_unlock(&encl->lock);
+	}
+
+	ret = 0;
+	goto out;
+
+out_unlock:
+	mutex_unlock(&encl->lock);
+out:
+	modp->count = c;
+
+	return ret;
+}
+
+/**
+ * sgx_ioc_enclave_restrict_permissions() - handler for
+ *                                        %SGX_IOC_ENCLAVE_RESTRICT_PERMISSIONS
+ * @encl:	an enclave pointer
+ * @arg:	userspace pointer to a &struct sgx_enclave_restrict_permissions
+ *		instance
+ *
+ * SGX2 distinguishes between relaxing and restricting the enclave page
+ * permissions maintained by the hardware (EPCM permissions) of pages
+ * belonging to an initialized enclave (after SGX_IOC_ENCLAVE_INIT).
+ *
+ * EPCM permissions cannot be restricted from within the enclave, the enclave
+ * requires the kernel to run the privileged level 0 instructions ENCLS[EMODPR]
+ * and ENCLS[ETRACK]. An attempt to relax EPCM permissions with this call
+ * will be ignored by the hardware.
+ *
+ * Return:
+ * - 0:		Success
+ * - -errno:	Otherwise
+ */
+static long sgx_ioc_enclave_restrict_permissions(struct sgx_encl *encl,
+						 void __user *arg)
+{
+	struct sgx_enclave_restrict_permissions params;
+	long ret;
+
+	ret = sgx_ioc_sgx2_ready(encl);
+	if (ret)
+		return ret;
+
+	if (copy_from_user(&params, arg, sizeof(params)))
+		return -EFAULT;
+
+	if (sgx_validate_offset_length(encl, params.offset, params.length))
+		return -EINVAL;
+
+	if (params.permissions & ~SGX_SECINFO_PERMISSION_MASK)
+		return -EINVAL;
+
+	/*
+	 * Fail early if invalid permissions requested to prevent ENCLS[EMODPR]
+	 * from faulting later when the CPU does the same check.
+	 */
+	if ((params.permissions & SGX_SECINFO_W) &&
+	    !(params.permissions & SGX_SECINFO_R))
+		return -EINVAL;
+
+	if (params.result || params.count)
+		return -EINVAL;
+
+	ret = sgx_enclave_restrict_permissions(encl, &params);
+
+	if (copy_to_user(arg, &params, sizeof(params)))
+		return -EFAULT;
+
+	return ret;
+}
+
+/**
+ * sgx_enclave_modify_types() - Modify type of SGX enclave pages
+ * @encl:	Enclave to which the pages belong.
+ * @modt:	Checked parameters from user about which pages need modifying
+ *              and their new page type.
+ *
+ * Return:
+ * - 0:		Success
+ * - -errno:	Otherwise
+ */
+static long sgx_enclave_modify_types(struct sgx_encl *encl,
+				     struct sgx_enclave_modify_types *modt)
+{
+	unsigned long max_prot_restore;
+	enum sgx_page_type page_type;
+	struct sgx_encl_page *entry;
+	struct sgx_secinfo secinfo;
+	unsigned long prot;
+	unsigned long addr;
+	unsigned long c;
+	void *epc_virt;
+	int ret;
+
+	page_type = modt->page_type & SGX_PAGE_TYPE_MASK;
+
+	/*
+	 * The only new page types allowed by hardware are PT_TCS and PT_TRIM.
+	 */
+	if (page_type != SGX_PAGE_TYPE_TCS && page_type != SGX_PAGE_TYPE_TRIM)
+		return -EINVAL;
+
+	memset(&secinfo, 0, sizeof(secinfo));
+
+	secinfo.flags = page_type << 8;
+
+	for (c = 0 ; c < modt->length; c += PAGE_SIZE) {
+		addr = encl->base + modt->offset + c;
+
+		sgx_reclaim_direct();
+
+		mutex_lock(&encl->lock);
+
+		entry = sgx_encl_load_page(encl, addr);
+		if (IS_ERR(entry)) {
+			ret = PTR_ERR(entry) == -EBUSY ? -EAGAIN : -EFAULT;
+			goto out_unlock;
+		}
+
+		/*
+		 * Borrow the logic from the Intel SDM. Regular pages
+		 * (SGX_PAGE_TYPE_REG) can change type to SGX_PAGE_TYPE_TCS
+		 * or SGX_PAGE_TYPE_TRIM but TCS pages can only be trimmed.
+		 * CET pages not supported yet.
+		 */
+		if (!(entry->type == SGX_PAGE_TYPE_REG ||
+		      (entry->type == SGX_PAGE_TYPE_TCS &&
+		       page_type == SGX_PAGE_TYPE_TRIM))) {
+			ret = -EINVAL;
+			goto out_unlock;
+		}
+
+		max_prot_restore = entry->vm_max_prot_bits;
+
+		/*
+		 * Once a regular page becomes a TCS page it cannot be
+		 * changed back. So the maximum allowed protection reflects
+		 * the TCS page that is always RW from kernel perspective but
+		 * will be inaccessible from within enclave. Before doing
+		 * so, do make sure that the new page type continues to
+		 * respect the originally vetted page permissions.
+		 */
+		if (entry->type == SGX_PAGE_TYPE_REG &&
+		    page_type == SGX_PAGE_TYPE_TCS) {
+			if (~entry->vm_max_prot_bits & (VM_READ | VM_WRITE)) {
+				ret = -EPERM;
+				goto out_unlock;
+			}
+			prot = PROT_READ | PROT_WRITE;
+			entry->vm_max_prot_bits = calc_vm_prot_bits(prot, 0);
+
+			/*
+			 * Prevent page from being reclaimed while mutex
+			 * is released.
+			 */
+			if (sgx_unmark_page_reclaimable(entry->epc_page)) {
+				ret = -EAGAIN;
+				goto out_entry_changed;
+			}
+
+			/*
+			 * Do not keep encl->lock because of dependency on
+			 * mmap_lock acquired in sgx_zap_enclave_ptes().
+			 */
+			mutex_unlock(&encl->lock);
+
+			sgx_zap_enclave_ptes(encl, addr);
+
+			mutex_lock(&encl->lock);
+
+			sgx_mark_page_reclaimable(entry->epc_page);
+		}
+
+		/* Change EPC type */
+		epc_virt = sgx_get_epc_virt_addr(entry->epc_page);
+		ret = __emodt(&secinfo, epc_virt);
+		if (encls_faulted(ret)) {
+			/*
+			 * All possible faults should be avoidable:
+			 * parameters have been checked, will only change
+			 * valid page types, and no concurrent
+			 * SGX1/SGX2 ENCLS instructions since these are
+			 * protected with mutex.
+			 */
+			pr_err_once("EMODT encountered exception %d\n",
+				    ENCLS_TRAPNR(ret));
+			ret = -EFAULT;
+			goto out_entry_changed;
+		}
+		if (encls_failed(ret)) {
+			modt->result = ret;
+			ret = -EFAULT;
+			goto out_entry_changed;
+		}
+
+		ret = sgx_enclave_etrack(encl);
+		if (ret) {
+			ret = -EFAULT;
+			goto out_unlock;
+		}
+
+		entry->type = page_type;
+
+		mutex_unlock(&encl->lock);
+	}
+
+	ret = 0;
+	goto out;
+
+out_entry_changed:
+	entry->vm_max_prot_bits = max_prot_restore;
+out_unlock:
+	mutex_unlock(&encl->lock);
+out:
+	modt->count = c;
+
+	return ret;
+}
+
+/**
+ * sgx_ioc_enclave_modify_types() - handler for %SGX_IOC_ENCLAVE_MODIFY_TYPES
+ * @encl:	an enclave pointer
+ * @arg:	userspace pointer to a &struct sgx_enclave_modify_types instance
+ *
+ * Ability to change the enclave page type supports the following use cases:
+ *
+ * * It is possible to add TCS pages to an enclave by changing the type of
+ *   regular pages (%SGX_PAGE_TYPE_REG) to TCS (%SGX_PAGE_TYPE_TCS) pages.
+ *   With this support the number of threads supported by an initialized
+ *   enclave can be increased dynamically.
+ *
+ * * Regular or TCS pages can dynamically be removed from an initialized
+ *   enclave by changing the page type to %SGX_PAGE_TYPE_TRIM. Changing the
+ *   page type to %SGX_PAGE_TYPE_TRIM marks the page for removal with actual
+ *   removal done by handler of %SGX_IOC_ENCLAVE_REMOVE_PAGES ioctl() called
+ *   after ENCLU[EACCEPT] is run on %SGX_PAGE_TYPE_TRIM page from within the
+ *   enclave.
+ *
+ * Return:
+ * - 0:		Success
+ * - -errno:	Otherwise
+ */
+static long sgx_ioc_enclave_modify_types(struct sgx_encl *encl,
+					 void __user *arg)
+{
+	struct sgx_enclave_modify_types params;
+	long ret;
+
+	ret = sgx_ioc_sgx2_ready(encl);
+	if (ret)
+		return ret;
+
+	if (copy_from_user(&params, arg, sizeof(params)))
+		return -EFAULT;
+
+	if (sgx_validate_offset_length(encl, params.offset, params.length))
+		return -EINVAL;
+
+	if (params.page_type & ~SGX_PAGE_TYPE_MASK)
+		return -EINVAL;
+
+	if (params.result || params.count)
+		return -EINVAL;
+
+	ret = sgx_enclave_modify_types(encl, &params);
+
+	if (copy_to_user(arg, &params, sizeof(params)))
+		return -EFAULT;
+
+	return ret;
+}
+
+/**
+ * sgx_encl_remove_pages() - Remove trimmed pages from SGX enclave
+ * @encl:	Enclave to which the pages belong
+ * @params:	Checked parameters from user on which pages need to be removed
+ *
+ * Return:
+ * - 0:		Success.
+ * - -errno:	Otherwise.
+ */
+static long sgx_encl_remove_pages(struct sgx_encl *encl,
+				  struct sgx_enclave_remove_pages *params)
+{
+	struct sgx_encl_page *entry;
+	struct sgx_secinfo secinfo;
+	unsigned long addr;
+	unsigned long c;
+	void *epc_virt;
+	int ret;
+
+	memset(&secinfo, 0, sizeof(secinfo));
+	secinfo.flags = SGX_SECINFO_R | SGX_SECINFO_W | SGX_SECINFO_X;
+
+	for (c = 0 ; c < params->length; c += PAGE_SIZE) {
+		addr = encl->base + params->offset + c;
+
+		sgx_reclaim_direct();
+
+		mutex_lock(&encl->lock);
+
+		entry = sgx_encl_load_page(encl, addr);
+		if (IS_ERR(entry)) {
+			ret = PTR_ERR(entry) == -EBUSY ? -EAGAIN : -EFAULT;
+			goto out_unlock;
+		}
+
+		if (entry->type != SGX_PAGE_TYPE_TRIM) {
+			ret = -EPERM;
+			goto out_unlock;
+		}
+
+		/*
+		 * ENCLS[EMODPR] is a no-op instruction used to inform if
+		 * ENCLU[EACCEPT] was run from within the enclave. If
+		 * ENCLS[EMODPR] is run with RWX on a trimmed page that is
+		 * not yet accepted then it will return
+		 * %SGX_PAGE_NOT_MODIFIABLE, after the trimmed page is
+		 * accepted the instruction will encounter a page fault.
+		 */
+		epc_virt = sgx_get_epc_virt_addr(entry->epc_page);
+		ret = __emodpr(&secinfo, epc_virt);
+		if (!encls_faulted(ret) || ENCLS_TRAPNR(ret) != X86_TRAP_PF) {
+			ret = -EPERM;
+			goto out_unlock;
+		}
+
+		if (sgx_unmark_page_reclaimable(entry->epc_page)) {
+			ret = -EBUSY;
+			goto out_unlock;
+		}
+
+		/*
+		 * Do not keep encl->lock because of dependency on
+		 * mmap_lock acquired in sgx_zap_enclave_ptes().
+		 */
+		mutex_unlock(&encl->lock);
+
+		sgx_zap_enclave_ptes(encl, addr);
+
+		mutex_lock(&encl->lock);
+
+		sgx_encl_free_epc_page(entry->epc_page);
+		encl->secs_child_cnt--;
+		entry->epc_page = NULL;
+		xa_erase(&encl->page_array, PFN_DOWN(entry->desc));
+		sgx_encl_shrink(encl, NULL);
+		kfree(entry);
+
+		mutex_unlock(&encl->lock);
+	}
+
+	ret = 0;
+	goto out;
+
+out_unlock:
+	mutex_unlock(&encl->lock);
+out:
+	params->count = c;
+
+	return ret;
+}
+
+/**
+ * sgx_ioc_enclave_remove_pages() - handler for %SGX_IOC_ENCLAVE_REMOVE_PAGES
+ * @encl:	an enclave pointer
+ * @arg:	userspace pointer to &struct sgx_enclave_remove_pages instance
+ *
+ * Final step of the flow removing pages from an initialized enclave. The
+ * complete flow is:
+ *
+ * 1) User changes the type of the pages to be removed to %SGX_PAGE_TYPE_TRIM
+ *    using the %SGX_IOC_ENCLAVE_MODIFY_TYPES ioctl().
+ * 2) User approves the page removal by running ENCLU[EACCEPT] from within
+ *    the enclave.
+ * 3) User initiates actual page removal using the
+ *    %SGX_IOC_ENCLAVE_REMOVE_PAGES ioctl() that is handled here.
+ *
+ * First remove any page table entries pointing to the page and then proceed
+ * with the actual removal of the enclave page and data in support of it.
+ *
+ * VA pages are not affected by this removal. It is thus possible that the
+ * enclave may end up with more VA pages than needed to support all its
+ * pages.
+ *
+ * Return:
+ * - 0:		Success
+ * - -errno:	Otherwise
+ */
+static long sgx_ioc_enclave_remove_pages(struct sgx_encl *encl,
+					 void __user *arg)
+{
+	struct sgx_enclave_remove_pages params;
+	long ret;
+
+	ret = sgx_ioc_sgx2_ready(encl);
+	if (ret)
+		return ret;
+
+	if (copy_from_user(&params, arg, sizeof(params)))
+		return -EFAULT;
+
+	if (sgx_validate_offset_length(encl, params.offset, params.length))
+		return -EINVAL;
+
+	if (params.count)
+		return -EINVAL;
+
+	ret = sgx_encl_remove_pages(encl, &params);
+
+	if (copy_to_user(arg, &params, sizeof(params)))
+		return -EFAULT;
+
+	return ret;
+}
+
 long sgx_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
 {
 	struct sgx_encl *encl = filep->private_data;
@@ -695,6 +1240,16 @@ long sgx_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
 	case SGX_IOC_ENCLAVE_PROVISION:
 		ret = sgx_ioc_enclave_provision(encl, (void __user *)arg);
 		break;
+	case SGX_IOC_ENCLAVE_RESTRICT_PERMISSIONS:
+		ret = sgx_ioc_enclave_restrict_permissions(encl,
+							   (void __user *)arg);
+		break;
+	case SGX_IOC_ENCLAVE_MODIFY_TYPES:
+		ret = sgx_ioc_enclave_modify_types(encl, (void __user *)arg);
+		break;
+	case SGX_IOC_ENCLAVE_REMOVE_PAGES:
+		ret = sgx_ioc_enclave_remove_pages(encl, (void __user *)arg);
+		break;
 	default:
 		ret = -ENOIOCTLCMD;
 		break;
diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
index a78652d43e61..515e2a5f25bb 100644
--- a/arch/x86/kernel/cpu/sgx/main.c
+++ b/arch/x86/kernel/cpu/sgx/main.c
@@ -137,36 +137,9 @@ static void sgx_reclaimer_block(struct sgx_epc_page *epc_page)
 	struct sgx_encl_page *page = epc_page->owner;
 	unsigned long addr = page->desc & PAGE_MASK;
 	struct sgx_encl *encl = page->encl;
-	unsigned long mm_list_version;
-	struct sgx_encl_mm *encl_mm;
-	struct vm_area_struct *vma;
-	int idx, ret;
-
-	do {
-		mm_list_version = encl->mm_list_version;
-
-		/* Pairs with smp_rmb() in sgx_encl_mm_add(). */
-		smp_rmb();
-
-		idx = srcu_read_lock(&encl->srcu);
-
-		list_for_each_entry_rcu(encl_mm, &encl->mm_list, list) {
-			if (!mmget_not_zero(encl_mm->mm))
-				continue;
-
-			mmap_read_lock(encl_mm->mm);
-
-			ret = sgx_encl_find(encl_mm->mm, addr, &vma);
-			if (!ret && encl == vma->vm_private_data)
-				zap_vma_ptes(vma, addr, PAGE_SIZE);
-
-			mmap_read_unlock(encl_mm->mm);
-
-			mmput_async(encl_mm->mm);
-		}
+	int ret;
 
-		srcu_read_unlock(&encl->srcu, idx);
-	} while (unlikely(encl->mm_list_version != mm_list_version));
+	sgx_zap_enclave_ptes(encl, addr);
 
 	mutex_lock(&encl->lock);
 
@@ -201,39 +174,10 @@ static int __sgx_encl_ewb(struct sgx_epc_page *epc_page, void *va_slot,
 	return ret;
 }
 
-static void sgx_ipi_cb(void *info)
+void sgx_ipi_cb(void *info)
 {
 }
 
-static const cpumask_t *sgx_encl_ewb_cpumask(struct sgx_encl *encl)
-{
-	cpumask_t *cpumask = &encl->cpumask;
-	struct sgx_encl_mm *encl_mm;
-	int idx;
-
-	/*
-	 * Can race with sgx_encl_mm_add(), but ETRACK has already been
-	 * executed, which means that the CPUs running in the new mm will enter
-	 * into the enclave with a fresh epoch.
-	 */
-	cpumask_clear(cpumask);
-
-	idx = srcu_read_lock(&encl->srcu);
-
-	list_for_each_entry_rcu(encl_mm, &encl->mm_list, list) {
-		if (!mmget_not_zero(encl_mm->mm))
-			continue;
-
-		cpumask_or(cpumask, cpumask, mm_cpumask(encl_mm->mm));
-
-		mmput_async(encl_mm->mm);
-	}
-
-	srcu_read_unlock(&encl->srcu, idx);
-
-	return cpumask;
-}
-
 /*
  * Swap page to the regular memory transformed to the blocked state by using
  * EBLOCK, which means that it can no longer be referenced (no new TLB entries).
@@ -280,7 +224,7 @@ static void sgx_encl_ewb(struct sgx_epc_page *epc_page,
 			 * miss cpus that entered the enclave between
 			 * generating the mask and incrementing epoch.
 			 */
-			on_each_cpu_mask(sgx_encl_ewb_cpumask(encl),
+			on_each_cpu_mask(sgx_encl_cpumask(encl),
 					 sgx_ipi_cb, NULL, 1);
 			ret = __sgx_encl_ewb(epc_page, va_slot, backing);
 		}
@@ -431,6 +375,17 @@ static bool sgx_should_reclaim(unsigned long watermark)
 	       !list_empty(&sgx_active_page_list);
 }
 
+/*
+ * sgx_reclaim_direct() should be called (without enclave's mutex held)
+ * in locations where SGX memory resources might be low and might be
+ * needed in order to make forward progress.
+ */
+void sgx_reclaim_direct(void)
+{
+	if (sgx_should_reclaim(SGX_NR_LOW_PAGES))
+		sgx_reclaim_pages();
+}
+
 static int ksgxd(void *p)
 {
 	set_freezable();
diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h
index 0f17def9fe6f..0f2020653fba 100644
--- a/arch/x86/kernel/cpu/sgx/sgx.h
+++ b/arch/x86/kernel/cpu/sgx/sgx.h
@@ -86,10 +86,13 @@ static inline void *sgx_get_epc_virt_addr(struct sgx_epc_page *page)
 struct sgx_epc_page *__sgx_alloc_epc_page(void);
 void sgx_free_epc_page(struct sgx_epc_page *page);
 
+void sgx_reclaim_direct(void);
 void sgx_mark_page_reclaimable(struct sgx_epc_page *page);
 int sgx_unmark_page_reclaimable(struct sgx_epc_page *page);
 struct sgx_epc_page *sgx_alloc_epc_page(void *owner, bool reclaim);
 
+void sgx_ipi_cb(void *info);
+
 #ifdef CONFIG_X86_SGX_KVM
 int __init sgx_vepc_init(void);
 #else