From 51ab30eb2ad4c4a61f827dc18863cd70dc46dc32 Mon Sep 17 00:00:00 2001
From: Jarkko Sakkinen
Date: Thu, 18 Mar 2021 01:53:30 +0200
Subject: x86/sgx: Replace section->init_laundry_list with sgx_dirty_page_list

During normal runtime, the "ksgxd" daemon behaves like a version of
kswapd just for SGX. But, before it starts acting like kswapd, its first
job is to initialize enclave memory.

Currently, the SGX boot code places each enclave page on a
epc_section->init_laundry_list. Once it starts up, the ksgxd code walks
over that list and populates the actual SGX page allocator.

However, the per-section structures are going away to make way for the
SGX NUMA allocator. There's also little need to have a per-section
structure; the enclave pages are all treated identically, and they can
be placed on the correct allocator list from metadata stored in the
enclave page (struct sgx_epc_page) itself.

Modify sgx_sanitize_section() to take a single page list instead of
taking a section and deriving the list from there.

Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lkml.kernel.org/r/20210317235332.362001-1-jarkko.sakkinen@intel.com
---
 arch/x86/kernel/cpu/sgx/main.c | 54 +++++++++++++++++++-----------------------
 arch/x86/kernel/cpu/sgx/sgx.h  |  7 ------
 2 files changed, 25 insertions(+), 36 deletions(-)

diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
index 8df81a3ed945..f3a5cd2d27ef 100644
--- a/arch/x86/kernel/cpu/sgx/main.c
+++ b/arch/x86/kernel/cpu/sgx/main.c
@@ -26,39 +26,43 @@ static LIST_HEAD(sgx_active_page_list);
 
 static DEFINE_SPINLOCK(sgx_reclaimer_lock);
 
+static LIST_HEAD(sgx_dirty_page_list);
+
 /*
- * Reset dirty EPC pages to uninitialized state. Laundry can be left with SECS
- * pages whose child pages blocked EREMOVE.
+ * Reset post-kexec EPC pages to the uninitialized state. The pages are removed
+ * from the input list, and made available for the page allocator. SECS pages
+ * prepending their children in the input list are left intact.
  */
-static void sgx_sanitize_section(struct sgx_epc_section *section)
+static void __sgx_sanitize_pages(struct list_head *dirty_page_list)
 {
 	struct sgx_epc_page *page;
 	LIST_HEAD(dirty);
 	int ret;
 
-	/* init_laundry_list is thread-local, no need for a lock: */
-	while (!list_empty(&section->init_laundry_list)) {
+	/* dirty_page_list is thread-local, no need for a lock: */
+	while (!list_empty(dirty_page_list)) {
 		if (kthread_should_stop())
 			return;
 
-		/* needed for access to ->page_list: */
-		spin_lock(&section->lock);
-
-		page = list_first_entry(&section->init_laundry_list,
-					struct sgx_epc_page, list);
+		page = list_first_entry(dirty_page_list, struct sgx_epc_page, list);
 
 		ret = __eremove(sgx_get_epc_virt_addr(page));
-		if (!ret)
-			list_move(&page->list, &section->page_list);
-		else
+		if (!ret) {
+			/*
+			 * page is now sanitized.  Make it available via the SGX
+			 * page allocator:
+			 */
+			list_del(&page->list);
+			sgx_free_epc_page(page);
+		} else {
+			/* The page is not yet clean - move to the dirty list. */
 			list_move_tail(&page->list, &dirty);
-
-		spin_unlock(&section->lock);
+		}
 
 		cond_resched();
 	}
 
-	list_splice(&dirty, &section->init_laundry_list);
+	list_splice(&dirty, dirty_page_list);
 }
 
 static bool sgx_reclaimer_age(struct sgx_epc_page *epc_page)
@@ -405,24 +409,17 @@ static bool sgx_should_reclaim(unsigned long watermark)
 
 static int ksgxd(void *p)
 {
-	int i;
-
 	set_freezable();
 
 	/*
 	 * Sanitize pages in order to recover from kexec(). The 2nd pass is
 	 * required for SECS pages, whose child pages blocked EREMOVE.
 	 */
-	for (i = 0; i < sgx_nr_epc_sections; i++)
-		sgx_sanitize_section(&sgx_epc_sections[i]);
-
-	for (i = 0; i < sgx_nr_epc_sections; i++) {
-		sgx_sanitize_section(&sgx_epc_sections[i]);
+	__sgx_sanitize_pages(&sgx_dirty_page_list);
+	__sgx_sanitize_pages(&sgx_dirty_page_list);
 
-		/* Should never happen. */
-		if (!list_empty(&sgx_epc_sections[i].init_laundry_list))
-			WARN(1, "EPC section %d has unsanitized pages.\n", i);
-	}
+	/* sanity check: */
+	WARN_ON(!list_empty(&sgx_dirty_page_list));
 
 	while (!kthread_should_stop()) {
 		if (try_to_freeze())
@@ -637,13 +634,12 @@ static bool __init sgx_setup_epc_section(u64 phys_addr, u64 size,
 	section->phys_addr = phys_addr;
 	spin_lock_init(&section->lock);
 	INIT_LIST_HEAD(&section->page_list);
-	INIT_LIST_HEAD(&section->init_laundry_list);
 
 	for (i = 0; i < nr_pages; i++) {
 		section->pages[i].section = index;
 		section->pages[i].flags = 0;
 		section->pages[i].owner = NULL;
-		list_add_tail(&section->pages[i].list, &section->init_laundry_list);
+		list_add_tail(&section->pages[i].list, &sgx_dirty_page_list);
 	}
 
 	section->free_cnt = nr_pages;
diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h
index 5fa42d143feb..bc8af0428640 100644
--- a/arch/x86/kernel/cpu/sgx/sgx.h
+++ b/arch/x86/kernel/cpu/sgx/sgx.h
@@ -45,13 +45,6 @@ struct sgx_epc_section {
 	spinlock_t lock;
 	struct list_head page_list;
 	unsigned long free_cnt;
-
-	/*
-	 * Pages which need EREMOVE run on them before they can be
-	 * used.  Only safe to be accessed in ksgxd and init code.
-	 * Not protected by locks.
-	 */
-	struct list_head init_laundry_list;
 };
 
 extern struct sgx_epc_section sgx_epc_sections[SGX_MAX_EPC_SECTIONS];
-- 
cgit v1.2.3


From 901ddbb9ecf5425183ea0c09d10c2fd7868dce54 Mon Sep 17 00:00:00 2001
From: Jarkko Sakkinen
Date: Thu, 18 Mar 2021 01:53:31 +0200
Subject: x86/sgx: Add a basic NUMA allocation scheme to sgx_alloc_epc_page()

Background
==========

SGX enclave memory is enumerated by the processor in contiguous physical
ranges called Enclave Page Cache (EPC) sections.  Currently, there is a
free list per section, but allocations simply target the lowest-numbered
sections.  This is functional, but has no NUMA awareness.

Fortunately, EPC sections are covered by entries in the ACPI SRAT table.
These entries allow each EPC section to be associated with a NUMA node,
just like normal RAM.

Solution
========

Implement a NUMA-aware enclave page allocator.  Mirror the buddy allocator
and maintain a list of enclave pages for each NUMA node.  Attempt to
allocate enclave memory first from local nodes, then fall back to other
nodes.

Note that the fallback is not as sophisticated as the buddy allocator
and is itself not aware of NUMA distances.  When a node's free list is
empty, it searches for the next-highest node with enclave pages (and
will wrap if necessary).  This could be improved in the future.

Other
=====

NUMA_KEEP_MEMINFO dependency is required for phys_to_target_node().

 [ Kai Huang: Do not return NULL from __sgx_alloc_epc_page() because
   callers do not expect that and that leads to a NULL ptr deref. ]

 [ dhansen: Fix an uninitialized 'nid' variable in
   __sgx_alloc_epc_page() as

   Reported-by: kernel test robot <lkp@intel.com>

   to avoid any potential allocations from the wrong NUMA node or even
   premature allocation failures. ]

Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/lkml/158188326978.894464.217282995221175417.stgit@dwillia2-desk3.amr.corp.intel.com/
Link: https://lkml.kernel.org/r/20210319040602.178558-1-kai.huang@intel.com
Link: https://lkml.kernel.org/r/20210318214933.29341-1-dave.hansen@intel.com
Link: https://lkml.kernel.org/r/20210317235332.362001-2-jarkko.sakkinen@intel.com
---
 arch/x86/Kconfig               |   1 +
 arch/x86/kernel/cpu/sgx/main.c | 119 ++++++++++++++++++++++++++---------------
 arch/x86/kernel/cpu/sgx/sgx.h  |  16 +++---
 3 files changed, 88 insertions(+), 48 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 2792879d398e..35391e94bd22 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1931,6 +1931,7 @@ config X86_SGX
 	depends on CRYPTO_SHA256=y
 	select SRCU
 	select MMU_NOTIFIER
+	select NUMA_KEEP_MEMINFO if NUMA
 	help
 	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
 	  that can be used by applications to set aside private regions of code
diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
index f3a5cd2d27ef..13a7599ce7d4 100644
--- a/arch/x86/kernel/cpu/sgx/main.c
+++ b/arch/x86/kernel/cpu/sgx/main.c
@@ -23,9 +23,21 @@ static DECLARE_WAIT_QUEUE_HEAD(ksgxd_waitq);
  * with sgx_reclaimer_lock acquired.
  */
 static LIST_HEAD(sgx_active_page_list);
-
 static DEFINE_SPINLOCK(sgx_reclaimer_lock);
 
+/* The free page list lock protected variables prepend the lock. */
+static unsigned long sgx_nr_free_pages;
+
+/* Nodes with one or more EPC sections. */
+static nodemask_t sgx_numa_mask;
+
+/*
+ * Array with one list_head for each possible NUMA node.  Each
+ * list contains all the sgx_epc_section's which are on that
+ * node.
+ */
+static struct sgx_numa_node *sgx_numa_nodes;
+
 static LIST_HEAD(sgx_dirty_page_list);
 
 /*
@@ -312,6 +324,7 @@ static void sgx_reclaim_pages(void)
 	struct sgx_epc_section *section;
 	struct sgx_encl_page *encl_page;
 	struct sgx_epc_page *epc_page;
+	struct sgx_numa_node *node;
 	pgoff_t page_index;
 	int cnt = 0;
 	int ret;
@@ -383,28 +396,18 @@ skip:
 		epc_page->flags &= ~SGX_EPC_PAGE_RECLAIMER_TRACKED;
 
 		section = &sgx_epc_sections[epc_page->section];
-		spin_lock(&section->lock);
-		list_add_tail(&epc_page->list, &section->page_list);
-		section->free_cnt++;
-		spin_unlock(&section->lock);
-	}
-}
-
-static unsigned long sgx_nr_free_pages(void)
-{
-	unsigned long cnt = 0;
-	int i;
-
-	for (i = 0; i < sgx_nr_epc_sections; i++)
-		cnt += sgx_epc_sections[i].free_cnt;
+		node = section->node;
 
-	return cnt;
+		spin_lock(&node->lock);
+		list_add_tail(&epc_page->list, &node->free_page_list);
+		sgx_nr_free_pages++;
+		spin_unlock(&node->lock);
+	}
 }
 
 static bool sgx_should_reclaim(unsigned long watermark)
 {
-	return sgx_nr_free_pages() < watermark &&
-	       !list_empty(&sgx_active_page_list);
+	return sgx_nr_free_pages < watermark && !list_empty(&sgx_active_page_list);
 }
 
 static int ksgxd(void *p)
@@ -451,45 +454,56 @@ static bool __init sgx_page_reclaimer_init(void)
 	return true;
 }
 
-static struct sgx_epc_page *__sgx_alloc_epc_page_from_section(struct sgx_epc_section *section)
+static struct sgx_epc_page *__sgx_alloc_epc_page_from_node(int nid)
 {
-	struct sgx_epc_page *page;
+	struct sgx_numa_node *node = &sgx_numa_nodes[nid];
+	struct sgx_epc_page *page = NULL;
 
-	spin_lock(&section->lock);
+	spin_lock(&node->lock);
 
-	if (list_empty(&section->page_list)) {
-		spin_unlock(&section->lock);
+	if (list_empty(&node->free_page_list)) {
+		spin_unlock(&node->lock);
 		return NULL;
 	}
 
-	page = list_first_entry(&section->page_list, struct sgx_epc_page, list);
+	page = list_first_entry(&node->free_page_list, struct sgx_epc_page, list);
 	list_del_init(&page->list);
-	section->free_cnt--;
+	sgx_nr_free_pages--;
+
+	spin_unlock(&node->lock);
 
-	spin_unlock(&section->lock);
 	return page;
 }
 
 /**
  * __sgx_alloc_epc_page() - Allocate an EPC page
  *
- * Iterate through EPC sections and borrow a free EPC page to the caller. When a
- * page is no longer needed it must be released with sgx_free_epc_page().
+ * Iterate through NUMA nodes and reserve ia free EPC page to the caller. Start
+ * from the NUMA node, where the caller is executing.
  *
  * Return:
- *   an EPC page,
- *   -errno on error
+ * - an EPC page:	A borrowed EPC pages were available.
+ * - NULL:		Out of EPC pages.
  */
 struct sgx_epc_page *__sgx_alloc_epc_page(void)
 {
-	struct sgx_epc_section *section;
 	struct sgx_epc_page *page;
-	int i;
+	int nid_of_current = numa_node_id();
+	int nid = nid_of_current;
 
-	for (i = 0; i < sgx_nr_epc_sections; i++) {
-		section = &sgx_epc_sections[i];
+	if (node_isset(nid_of_current, sgx_numa_mask)) {
+		page = __sgx_alloc_epc_page_from_node(nid_of_current);
+		if (page)
+			return page;
+	}
+
+	/* Fall back to the non-local NUMA nodes: */
+	while (true) {
+		nid = next_node_in(nid, sgx_numa_mask);
+		if (nid == nid_of_current)
+			break;
 
-		page = __sgx_alloc_epc_page_from_section(section);
+		page = __sgx_alloc_epc_page_from_node(nid);
 		if (page)
 			return page;
 	}
@@ -600,6 +614,7 @@ struct sgx_epc_page *sgx_alloc_epc_page(void *owner, bool reclaim)
 void sgx_free_epc_page(struct sgx_epc_page *page)
 {
 	struct sgx_epc_section *section = &sgx_epc_sections[page->section];
+	struct sgx_numa_node *node = section->node;
 	int ret;
 
 	WARN_ON_ONCE(page->flags & SGX_EPC_PAGE_RECLAIMER_TRACKED);
@@ -608,10 +623,12 @@ void sgx_free_epc_page(struct sgx_epc_page *page)
 	if (WARN_ONCE(ret, "EREMOVE returned %d (0x%x)", ret, ret))
 		return;
 
-	spin_lock(&section->lock);
-	list_add_tail(&page->list, &section->page_list);
-	section->free_cnt++;
-	spin_unlock(&section->lock);
+	spin_lock(&node->lock);
+
+	list_add_tail(&page->list, &node->free_page_list);
+	sgx_nr_free_pages++;
+
+	spin_unlock(&node->lock);
 }
 
 static bool __init sgx_setup_epc_section(u64 phys_addr, u64 size,
@@ -632,8 +649,6 @@ static bool __init sgx_setup_epc_section(u64 phys_addr, u64 size,
 	}
 
 	section->phys_addr = phys_addr;
-	spin_lock_init(&section->lock);
-	INIT_LIST_HEAD(&section->page_list);
 
 	for (i = 0; i < nr_pages; i++) {
 		section->pages[i].section = index;
@@ -642,7 +657,7 @@ static bool __init sgx_setup_epc_section(u64 phys_addr, u64 size,
 		list_add_tail(&section->pages[i].list, &sgx_dirty_page_list);
 	}
 
-	section->free_cnt = nr_pages;
+	sgx_nr_free_pages += nr_pages;
 	return true;
 }
 
@@ -661,8 +676,13 @@ static bool __init sgx_page_cache_init(void)
 {
 	u32 eax, ebx, ecx, edx, type;
 	u64 pa, size;
+	int nid;
 	int i;
 
+	sgx_numa_nodes = kmalloc_array(num_possible_nodes(), sizeof(*sgx_numa_nodes), GFP_KERNEL);
+	if (!sgx_numa_nodes)
+		return false;
+
 	for (i = 0; i < ARRAY_SIZE(sgx_epc_sections); i++) {
 		cpuid_count(SGX_CPUID, i + SGX_CPUID_EPC, &eax, &ebx, &ecx, &edx);
 
@@ -685,6 +705,21 @@ static bool __init sgx_page_cache_init(void)
 			break;
 		}
 
+		nid = numa_map_to_online_node(phys_to_target_node(pa));
+		if (nid == NUMA_NO_NODE) {
+			/* The physical address is already printed above. */
+			pr_warn(FW_BUG "Unable to map EPC section to online node. Fallback to the NUMA node 0.\n");
+			nid = 0;
+		}
+
+		if (!node_isset(nid, sgx_numa_mask)) {
+			spin_lock_init(&sgx_numa_nodes[nid].lock);
+			INIT_LIST_HEAD(&sgx_numa_nodes[nid].free_page_list);
+			node_set(nid, sgx_numa_mask);
+		}
+
+		sgx_epc_sections[i].node =  &sgx_numa_nodes[nid];
+
 		sgx_nr_epc_sections++;
 	}
 
diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h
index bc8af0428640..653af8ca1a25 100644
--- a/arch/x86/kernel/cpu/sgx/sgx.h
+++ b/arch/x86/kernel/cpu/sgx/sgx.h
@@ -29,22 +29,26 @@ struct sgx_epc_page {
 	struct list_head list;
 };
 
+/*
+ * Contains the tracking data for NUMA nodes having EPC pages. Most importantly,
+ * the free page list local to the node is stored here.
+ */
+struct sgx_numa_node {
+	struct list_head free_page_list;
+	spinlock_t lock;
+};
+
 /*
  * The firmware can define multiple chunks of EPC to the different areas of the
  * physical memory e.g. for memory areas of the each node. This structure is
  * used to store EPC pages for one EPC section and virtual memory area where
  * the pages have been mapped.
- *
- * 'lock' must be held before accessing 'page_list' or 'free_cnt'.
  */
 struct sgx_epc_section {
 	unsigned long phys_addr;
 	void *virt_addr;
 	struct sgx_epc_page *pages;
-
-	spinlock_t lock;
-	struct list_head page_list;
-	unsigned long free_cnt;
+	struct sgx_numa_node *node;
 };
 
 extern struct sgx_epc_section sgx_epc_sections[SGX_MAX_EPC_SECTIONS];
-- 
cgit v1.2.3


From 4284f7acb78bfb0e0c26a2b78e2b2c3d68fccd6f Mon Sep 17 00:00:00 2001
From: Dave Hansen
Date: Thu, 18 Mar 2021 12:43:01 -0700
Subject: selftests/sgx: Improve error detection and messages

The SGX device file (/dev/sgx_enclave) is unusual in that it requires
execute permissions.  It has to be both "chmod +x" *and* be on a
filesystem without 'noexec'.

In the future, udev and systemd should get updates to set up systems
automatically.  But, for now, nobody's systems do this automatically,
and everybody gets error messages like this when running ./test_sgx:

	0x0000000000000000 0x0000000000002000 0x03
	0x0000000000002000 0x0000000000001000 0x05
	0x0000000000003000 0x0000000000003000 0x03
	mmap() failed, errno=1.

That isn't very user friendly, even for forgetful kernel developers.

Further, the test case is rather haphazard about its use of fprintf()
versus perror().

Improve the error messages.  Use perror() where possible.  Lastly,
do some sanity checks on opening and mmap()ing the device file so
that we can get a decent error message out to the user.

Now, if your user doesn't have permission, you'll get the following:

	$ ls -l /dev/sgx_enclave
	crw------- 1 root root 10, 126 Mar 18 11:29 /dev/sgx_enclave
	$ ./test_sgx
	Unable to open /dev/sgx_enclave: Permission denied

If you then 'chown dave:dave /dev/sgx_enclave' (or whatever), but
you leave execute permissions off, you'll get:

	$ ls -l /dev/sgx_enclave
	crw------- 1 dave dave 10, 126 Mar 18 11:29 /dev/sgx_enclave
	$ ./test_sgx
	no execute permissions on device file

If you fix that with "chmod ug+x /dev/sgx" but you leave /dev as
noexec, you'll get this:

	$ mount | grep "/dev .*noexec"
	udev on /dev type devtmpfs (rw,nosuid,noexec,...)
	$ ./test_sgx
	ERROR: mmap for exec: Operation not permitted
	mmap() succeeded for PROT_READ, but failed for PROT_EXEC
	check that user has execute permissions on /dev/sgx_enclave and
	that /dev does not have noexec set: 'mount | grep "/dev .*noexec"'

That can be fixed with:

	mount -o remount,noexec /devESC

Hopefully, the combination of better error messages and the search
engines indexing this message will help people fix their systems
until we do this properly.

 [ bp: Improve error messages more. ]

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lore.kernel.org/r/20210318194301.11D9A984@viggo.jf.intel.com
---
 tools/testing/selftests/sgx/load.c | 69 ++++++++++++++++++++++++++++++--------
 tools/testing/selftests/sgx/main.c |  2 +-
 2 files changed, 56 insertions(+), 15 deletions(-)

diff --git a/tools/testing/selftests/sgx/load.c b/tools/testing/selftests/sgx/load.c
index 9d43b75aaa55..f441ac34b4d4 100644
--- a/tools/testing/selftests/sgx/load.c
+++ b/tools/testing/selftests/sgx/load.c
@@ -45,19 +45,19 @@ static bool encl_map_bin(const char *path, struct encl *encl)
 
 	fd = open(path, O_RDONLY);
 	if (fd == -1)  {
-		perror("open()");
+		perror("enclave executable open()");
 		return false;
 	}
 
 	ret = stat(path, &sb);
 	if (ret) {
-		perror("stat()");
+		perror("enclave executable stat()");
 		goto err;
 	}
 
 	bin = mmap(NULL, sb.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
 	if (bin == MAP_FAILED) {
-		perror("mmap()");
+		perror("enclave executable mmap()");
 		goto err;
 	}
 
@@ -90,8 +90,7 @@ static bool encl_ioc_create(struct encl *encl)
 	ioc.src = (unsigned long)secs;
 	rc = ioctl(encl->fd, SGX_IOC_ENCLAVE_CREATE, &ioc);
 	if (rc) {
-		fprintf(stderr, "SGX_IOC_ENCLAVE_CREATE failed: errno=%d\n",
-			errno);
+		perror("SGX_IOC_ENCLAVE_CREATE failed");
 		munmap((void *)secs->base, encl->encl_size);
 		return false;
 	}
@@ -116,31 +115,72 @@ static bool encl_ioc_add_pages(struct encl *encl, struct encl_segment *seg)
 
 	rc = ioctl(encl->fd, SGX_IOC_ENCLAVE_ADD_PAGES, &ioc);
 	if (rc < 0) {
-		fprintf(stderr, "SGX_IOC_ENCLAVE_ADD_PAGES failed: errno=%d.\n",
-			errno);
+		perror("SGX_IOC_ENCLAVE_ADD_PAGES failed");
 		return false;
 	}
 
 	return true;
 }
 
+
+
 bool encl_load(const char *path, struct encl *encl)
 {
+	const char device_path[] = "/dev/sgx_enclave";
 	Elf64_Phdr *phdr_tbl;
 	off_t src_offset;
 	Elf64_Ehdr *ehdr;
+	struct stat sb;
+	void *ptr;
 	int i, j;
 	int ret;
+	int fd = -1;
 
 	memset(encl, 0, sizeof(*encl));
 
-	ret = open("/dev/sgx_enclave", O_RDWR);
-	if (ret < 0) {
-		fprintf(stderr, "Unable to open /dev/sgx_enclave\n");
+	fd = open(device_path, O_RDWR);
+	if (fd < 0) {
+		perror("Unable to open /dev/sgx_enclave");
+		goto err;
+	}
+
+	ret = stat(device_path, &sb);
+	if (ret) {
+		perror("device file stat()");
+		goto err;
+	}
+
+	/*
+	 * This just checks if the /dev file has these permission
+	 * bits set.  It does not check that the current user is
+	 * the owner or in the owning group.
+	 */
+	if (!(sb.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))) {
+		fprintf(stderr, "no execute permissions on device file %s\n", device_path);
+		goto err;
+	}
+
+	ptr = mmap(NULL, PAGE_SIZE, PROT_READ, MAP_SHARED, fd, 0);
+	if (ptr == (void *)-1) {
+		perror("mmap for read");
+		goto err;
+	}
+	munmap(ptr, PAGE_SIZE);
+
+#define ERR_MSG \
+"mmap() succeeded for PROT_READ, but failed for PROT_EXEC.\n" \
+" Check that current user has execute permissions on %s and \n" \
+" that /dev does not have noexec set: mount | grep \"/dev .*noexec\"\n" \
+" If so, remount it executable: mount -o remount,exec /dev\n\n"
+
+	ptr = mmap(NULL, PAGE_SIZE, PROT_EXEC, MAP_SHARED, fd, 0);
+	if (ptr == (void *)-1) {
+		fprintf(stderr, ERR_MSG, device_path);
 		goto err;
 	}
+	munmap(ptr, PAGE_SIZE);
 
-	encl->fd = ret;
+	encl->fd = fd;
 
 	if (!encl_map_bin(path, encl))
 		goto err;
@@ -217,6 +257,8 @@ bool encl_load(const char *path, struct encl *encl)
 	return true;
 
 err:
+	if (fd != -1)
+		close(fd);
 	encl_delete(encl);
 	return false;
 }
@@ -229,7 +271,7 @@ static bool encl_map_area(struct encl *encl)
 	area = mmap(NULL, encl_size * 2, PROT_NONE,
 		    MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 	if (area == MAP_FAILED) {
-		perror("mmap");
+		perror("reservation mmap()");
 		return false;
 	}
 
@@ -268,8 +310,7 @@ bool encl_build(struct encl *encl)
 	ioc.sigstruct = (uint64_t)&encl->sigstruct;
 	ret = ioctl(encl->fd, SGX_IOC_ENCLAVE_INIT, &ioc);
 	if (ret) {
-		fprintf(stderr, "SGX_IOC_ENCLAVE_INIT failed: errno=%d\n",
-			errno);
+		perror("SGX_IOC_ENCLAVE_INIT failed");
 		return false;
 	}
 
diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c
index 724cec700926..b117bb86a73f 100644
--- a/tools/testing/selftests/sgx/main.c
+++ b/tools/testing/selftests/sgx/main.c
@@ -195,7 +195,7 @@ int main(int argc, char *argv[], char *envp[])
 		addr = mmap((void *)encl.encl_base + seg->offset, seg->size,
 			    seg->prot, MAP_SHARED | MAP_FIXED, encl.fd, 0);
 		if (addr == MAP_FAILED) {
-			fprintf(stderr, "mmap() failed, errno=%d.\n", errno);
+			perror("mmap() segment failed");
 			exit(KSFT_FAIL);
 		}
 	}
-- 
cgit v1.2.3


From f33dece70e11ce82a09cb1ea2d7c32347b82c67e Mon Sep 17 00:00:00 2001
From: Tianjia Zhang
Date: Sun, 14 Mar 2021 19:16:21 +0800
Subject: selftests/sgx: Use getauxval() to simplify test code

Use the library function getauxval() instead of a custom function to get
the base address of the vDSO.

 [ bp: Massage commit message. ]

Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Link: https://lkml.kernel.org/r/20210314111621.68428-1-tianjia.zhang@linux.alibaba.com
---
 tools/testing/selftests/sgx/main.c | 24 ++++--------------------
 1 file changed, 4 insertions(+), 20 deletions(-)

diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c
index b117bb86a73f..d304a4044eb9 100644
--- a/tools/testing/selftests/sgx/main.c
+++ b/tools/testing/selftests/sgx/main.c
@@ -15,6 +15,7 @@
 #include <sys/stat.h>
 #include <sys/time.h>
 #include <sys/types.h>
+#include <sys/auxv.h>
 #include "defines.h"
 #include "main.h"
 #include "../kselftest.h"
@@ -28,24 +29,6 @@ struct vdso_symtab {
 	Elf64_Word *elf_hashtab;
 };
 
-static void *vdso_get_base_addr(char *envp[])
-{
-	Elf64_auxv_t *auxv;
-	int i;
-
-	for (i = 0; envp[i]; i++)
-		;
-
-	auxv = (Elf64_auxv_t *)&envp[i + 1];
-
-	for (i = 0; auxv[i].a_type != AT_NULL; i++) {
-		if (auxv[i].a_type == AT_SYSINFO_EHDR)
-			return (void *)auxv[i].a_un.a_val;
-	}
-
-	return NULL;
-}
-
 static Elf64_Dyn *vdso_get_dyntab(void *addr)
 {
 	Elf64_Ehdr *ehdr = addr;
@@ -162,7 +145,7 @@ static int user_handler(long rdi, long rsi, long rdx, long ursp, long r8, long r
 	return 0;
 }
 
-int main(int argc, char *argv[], char *envp[])
+int main(int argc, char *argv[])
 {
 	struct sgx_enclave_run run;
 	struct vdso_symtab symtab;
@@ -203,7 +186,8 @@ int main(int argc, char *argv[], char *envp[])
 	memset(&run, 0, sizeof(run));
 	run.tcs = encl.encl_base;
 
-	addr = vdso_get_base_addr(envp);
+	/* Get vDSO base address */
+	addr = (void *)getauxval(AT_SYSINFO_EHDR);
 	if (!addr)
 		goto err;
 
-- 
cgit v1.2.3


From 633b0616cfe085679471a4c0fae02e8c3a1a9866 Mon Sep 17 00:00:00 2001
From: Ira Weiny
Date: Wed, 24 Mar 2021 11:22:46 -0700
Subject: x86/sgx: Remove unnecessary kmap() from sgx_ioc_enclave_init()

kmap() is inefficient and is being replaced by kmap_local_page(), if
possible. There is no readily apparent reason why initp_page needs to be
allocated and kmap'ed() except that 'sigstruct' needs to be page-aligned
and 'token' 512 byte-aligned.

Rather than change it to kmap_local_page(), use kmalloc() instead
because kmalloc() can give this alignment when allocating PAGE_SIZE
bytes.

Remove the alloc_page()/kmap() and replace with kmalloc(PAGE_SIZE, ...)
to get a page aligned kernel address.

In addition, add a comment to document the alignment requirements so that
others don't attempt to 'fix' this again.

 [ bp: Massage commit message. ]

Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210324182246.2484875-1-ira.weiny@intel.com
---
 arch/x86/kernel/cpu/sgx/ioctl.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c
index 90a5caf76939..2e10367ea66c 100644
--- a/arch/x86/kernel/cpu/sgx/ioctl.c
+++ b/arch/x86/kernel/cpu/sgx/ioctl.c
@@ -604,7 +604,6 @@ static long sgx_ioc_enclave_init(struct sgx_encl *encl, void __user *arg)
 {
 	struct sgx_sigstruct *sigstruct;
 	struct sgx_enclave_init init_arg;
-	struct page *initp_page;
 	void *token;
 	int ret;
 
@@ -615,11 +614,15 @@ static long sgx_ioc_enclave_init(struct sgx_encl *encl, void __user *arg)
 	if (copy_from_user(&init_arg, arg, sizeof(init_arg)))
 		return -EFAULT;
 
-	initp_page = alloc_page(GFP_KERNEL);
-	if (!initp_page)
+	/*
+	 * 'sigstruct' must be on a page boundary and 'token' on a 512 byte
+	 * boundary.  kmalloc() will give this alignment when allocating
+	 * PAGE_SIZE bytes.
+	 */
+	sigstruct = kmalloc(PAGE_SIZE, GFP_KERNEL);
+	if (!sigstruct)
 		return -ENOMEM;
 
-	sigstruct = kmap(initp_page);
 	token = (void *)((unsigned long)sigstruct + PAGE_SIZE / 2);
 	memset(token, 0, SGX_LAUNCH_TOKEN_SIZE);
 
@@ -645,8 +648,7 @@ static long sgx_ioc_enclave_init(struct sgx_encl *encl, void __user *arg)
 	ret = sgx_encl_init(encl, sigstruct, token);
 
 out:
-	kunmap(initp_page);
-	__free_page(initp_page);
+	kfree(sigstruct);
 	return ret;
 }
 
-- 
cgit v1.2.3


From e9a15a40e857fc6ccfbb05fec7b184e9003057df Mon Sep 17 00:00:00 2001
From: Kai Huang
Date: Fri, 19 Mar 2021 20:22:17 +1300
Subject: x86/cpufeatures: Make SGX_LC feature bit depend on SGX bit

Move SGX_LC feature bit to CPUID dependency table to make clearing all
SGX feature bits easier. Also remove clear_sgx_caps() since it is just
a wrapper of setup_clear_cpu_cap(X86_FEATURE_SGX) now.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lkml.kernel.org/r/5d4220fd0a39f52af024d3fa166231c1d498dd10.1616136308.git.kai.huang@intel.com
---
 arch/x86/kernel/cpu/cpuid-deps.c |  1 +
 arch/x86/kernel/cpu/feat_ctl.c   | 12 +++---------
 2 files changed, 4 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kernel/cpu/cpuid-deps.c b/arch/x86/kernel/cpu/cpuid-deps.c
index 42af31b64c2c..d40f8e0a54ce 100644
--- a/arch/x86/kernel/cpu/cpuid-deps.c
+++ b/arch/x86/kernel/cpu/cpuid-deps.c
@@ -72,6 +72,7 @@ static const struct cpuid_dep cpuid_deps[] = {
 	{ X86_FEATURE_AVX512_FP16,		X86_FEATURE_AVX512BW  },
 	{ X86_FEATURE_ENQCMD,			X86_FEATURE_XSAVES    },
 	{ X86_FEATURE_PER_THREAD_MBA,		X86_FEATURE_MBA       },
+	{ X86_FEATURE_SGX_LC,			X86_FEATURE_SGX	      },
 	{}
 };
 
diff --git a/arch/x86/kernel/cpu/feat_ctl.c b/arch/x86/kernel/cpu/feat_ctl.c
index 3b1b01f2b248..27533a6e04fa 100644
--- a/arch/x86/kernel/cpu/feat_ctl.c
+++ b/arch/x86/kernel/cpu/feat_ctl.c
@@ -93,15 +93,9 @@ static void init_vmx_capabilities(struct cpuinfo_x86 *c)
 }
 #endif /* CONFIG_X86_VMX_FEATURE_NAMES */
 
-static void clear_sgx_caps(void)
-{
-	setup_clear_cpu_cap(X86_FEATURE_SGX);
-	setup_clear_cpu_cap(X86_FEATURE_SGX_LC);
-}
-
 static int __init nosgx(char *str)
 {
-	clear_sgx_caps();
+	setup_clear_cpu_cap(X86_FEATURE_SGX);
 
 	return 0;
 }
@@ -116,7 +110,7 @@ void init_ia32_feat_ctl(struct cpuinfo_x86 *c)
 
 	if (rdmsrl_safe(MSR_IA32_FEAT_CTL, &msr)) {
 		clear_cpu_cap(c, X86_FEATURE_VMX);
-		clear_sgx_caps();
+		clear_cpu_cap(c, X86_FEATURE_SGX);
 		return;
 	}
 
@@ -177,6 +171,6 @@ update_sgx:
 	    !(msr & FEAT_CTL_SGX_LC_ENABLED) || !enable_sgx) {
 		if (enable_sgx)
 			pr_err_once("SGX disabled by BIOS\n");
-		clear_sgx_caps();
+		clear_cpu_cap(c, X86_FEATURE_SGX);
 	}
 }
-- 
cgit v1.2.3


From b8921dccf3b25798409d35155b5d127085de72c2 Mon Sep 17 00:00:00 2001
From: Sean Christopherson
Date: Fri, 19 Mar 2021 20:22:18 +1300
Subject: x86/cpufeatures: Add SGX1 and SGX2 sub-features

Add SGX1 and SGX2 feature flags, via CPUID.0x12.0x0.EAX, as scattered
features, since adding a new leaf for only two bits would be wasteful.
As part of virtualizing SGX, KVM will expose the SGX CPUID leafs to its
guest, and to do so correctly needs to query hardware and kernel support
for SGX1 and SGX2.

Suppress both SGX1 and SGX2 from /proc/cpuinfo. SGX1 basically means
SGX, and for SGX2 there is no concrete use case of using it in
/proc/cpuinfo.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lkml.kernel.org/r/d787827dbfca6b3210ac3e432e3ac1202727e786.1616136308.git.kai.huang@intel.com
---
 arch/x86/include/asm/cpufeatures.h | 2 ++
 arch/x86/kernel/cpu/cpuid-deps.c   | 2 ++
 arch/x86/kernel/cpu/scattered.c    | 2 ++
 3 files changed, 6 insertions(+)

diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index cc96e26d69f7..1f918f5e0055 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -290,6 +290,8 @@
 #define X86_FEATURE_FENCE_SWAPGS_KERNEL	(11*32+ 5) /* "" LFENCE in kernel entry SWAPGS path */
 #define X86_FEATURE_SPLIT_LOCK_DETECT	(11*32+ 6) /* #AC for split lock */
 #define X86_FEATURE_PER_THREAD_MBA	(11*32+ 7) /* "" Per-thread Memory Bandwidth Allocation */
+#define X86_FEATURE_SGX1		(11*32+ 8) /* "" Basic SGX */
+#define X86_FEATURE_SGX2		(11*32+ 9) /* "" SGX Enclave Dynamic Memory Management (EDMM) */
 
 /* Intel-defined CPU features, CPUID level 0x00000007:1 (EAX), word 12 */
 #define X86_FEATURE_AVX_VNNI		(12*32+ 4) /* AVX VNNI instructions */
diff --git a/arch/x86/kernel/cpu/cpuid-deps.c b/arch/x86/kernel/cpu/cpuid-deps.c
index d40f8e0a54ce..defda61f372d 100644
--- a/arch/x86/kernel/cpu/cpuid-deps.c
+++ b/arch/x86/kernel/cpu/cpuid-deps.c
@@ -73,6 +73,8 @@ static const struct cpuid_dep cpuid_deps[] = {
 	{ X86_FEATURE_ENQCMD,			X86_FEATURE_XSAVES    },
 	{ X86_FEATURE_PER_THREAD_MBA,		X86_FEATURE_MBA       },
 	{ X86_FEATURE_SGX_LC,			X86_FEATURE_SGX	      },
+	{ X86_FEATURE_SGX1,			X86_FEATURE_SGX       },
+	{ X86_FEATURE_SGX2,			X86_FEATURE_SGX1      },
 	{}
 };
 
diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c
index 972ec3bfa9c0..21d1f062895a 100644
--- a/arch/x86/kernel/cpu/scattered.c
+++ b/arch/x86/kernel/cpu/scattered.c
@@ -36,6 +36,8 @@ static const struct cpuid_bit cpuid_bits[] = {
 	{ X86_FEATURE_CDP_L2,		CPUID_ECX,  2, 0x00000010, 2 },
 	{ X86_FEATURE_MBA,		CPUID_EBX,  3, 0x00000010, 0 },
 	{ X86_FEATURE_PER_THREAD_MBA,	CPUID_ECX,  0, 0x00000010, 3 },
+	{ X86_FEATURE_SGX1,		CPUID_EAX,  0, 0x00000012, 0 },
+	{ X86_FEATURE_SGX2,		CPUID_EAX,  1, 0x00000012, 0 },
 	{ X86_FEATURE_HW_PSTATE,	CPUID_EDX,  7, 0x80000007, 0 },
 	{ X86_FEATURE_CPB,		CPUID_EDX,  9, 0x80000007, 0 },
 	{ X86_FEATURE_PROC_FEEDBACK,    CPUID_EDX, 11, 0x80000007, 0 },
-- 
cgit v1.2.3


From b0c7459be0670fabe080e30906ba9fe62df5e02c Mon Sep 17 00:00:00 2001
From: Kai Huang
Date: Thu, 25 Mar 2021 22:30:57 +1300
Subject: x86/sgx: Wipe out EREMOVE from sgx_free_epc_page()

EREMOVE takes a page and removes any association between that page and
an enclave. It must be run on a page before it can be added into another
enclave. Currently, EREMOVE is run as part of pages being freed into the
SGX page allocator. It is not expected to fail, as it would indicate a
use-after-free of EPC pages. Rather than add the page back to the pool
of available EPC pages, the kernel intentionally leaks the page to avoid
additional errors in the future.

However, KVM does not track how guest pages are used, which means that
SGX virtualization use of EREMOVE might fail. Specifically, it is
legitimate that EREMOVE returns SGX_CHILD_PRESENT for EPC assigned to
KVM guest, because KVM/kernel doesn't track SECS pages.

To allow SGX/KVM to introduce a more permissive EREMOVE helper and
to let the SGX virtualization code use the allocator directly, break
out the EREMOVE call from the SGX page allocator. Rename the original
sgx_free_epc_page() to sgx_encl_free_epc_page(), indicating that
it is used to free an EPC page assigned to a host enclave. Replace
sgx_free_epc_page() with sgx_encl_free_epc_page() in all call sites so
there's no functional change.

At the same time, improve the error message when EREMOVE fails, and
add documentation to explain to the user what that failure means and
to suggest to the user what to do when this bug happens in the case it
happens.

 [ bp: Massage commit message, fix typos and sanitize text, simplify. ]

Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lkml.kernel.org/r/20210325093057.122834-1-kai.huang@intel.com
---
 Documentation/x86/sgx.rst       | 25 +++++++++++++++++++++++++
 arch/x86/kernel/cpu/sgx/encl.c  | 31 ++++++++++++++++++++++++++-----
 arch/x86/kernel/cpu/sgx/encl.h  |  1 +
 arch/x86/kernel/cpu/sgx/ioctl.c |  6 +++---
 arch/x86/kernel/cpu/sgx/main.c  | 14 +++++---------
 arch/x86/kernel/cpu/sgx/sgx.h   |  4 ++++
 6 files changed, 64 insertions(+), 17 deletions(-)

diff --git a/Documentation/x86/sgx.rst b/Documentation/x86/sgx.rst
index eaee1368b4fd..f90076e67cde 100644
--- a/Documentation/x86/sgx.rst
+++ b/Documentation/x86/sgx.rst
@@ -209,3 +209,28 @@ An application may be loaded into a container enclave which is specially
 configured with a library OS and run-time which permits the application to run.
 The enclave run-time and library OS work together to execute the application
 when a thread enters the enclave.
+
+Impact of Potential Kernel SGX Bugs
+===================================
+
+EPC leaks
+---------
+
+When EPC page leaks happen, a WARNING like this is shown in dmesg:
+
+"EREMOVE returned ... and an EPC page was leaked.  SGX may become unusable..."
+
+This is effectively a kernel use-after-free of an EPC page, and due
+to the way SGX works, the bug is detected at freeing. Rather than
+adding the page back to the pool of available EPC pages, the kernel
+intentionally leaks the page to avoid additional errors in the future.
+
+When this happens, the kernel will likely soon leak more EPC pages, and
+SGX will likely become unusable because the memory available to SGX is
+limited. However, while this may be fatal to SGX, the rest of the kernel
+is unlikely to be impacted and should continue to work.
+
+As a result, when this happpens, user should stop running any new
+SGX workloads, (or just any new workloads), and migrate all valuable
+workloads. Although a machine reboot can recover all EPC memory, the bug
+should be reported to Linux developers.
diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c
index 7449ef33f081..d25f2a245e1d 100644
--- a/arch/x86/kernel/cpu/sgx/encl.c
+++ b/arch/x86/kernel/cpu/sgx/encl.c
@@ -78,7 +78,7 @@ static struct sgx_epc_page *sgx_encl_eldu(struct sgx_encl_page *encl_page,
 
 	ret = __sgx_encl_eldu(encl_page, epc_page, secs_page);
 	if (ret) {
-		sgx_free_epc_page(epc_page);
+		sgx_encl_free_epc_page(epc_page);
 		return ERR_PTR(ret);
 	}
 
@@ -404,7 +404,7 @@ void sgx_encl_release(struct kref *ref)
 			if (sgx_unmark_page_reclaimable(entry->epc_page))
 				continue;
 
-			sgx_free_epc_page(entry->epc_page);
+			sgx_encl_free_epc_page(entry->epc_page);
 			encl->secs_child_cnt--;
 			entry->epc_page = NULL;
 		}
@@ -415,7 +415,7 @@ void sgx_encl_release(struct kref *ref)
 	xa_destroy(&encl->page_array);
 
 	if (!encl->secs_child_cnt && encl->secs.epc_page) {
-		sgx_free_epc_page(encl->secs.epc_page);
+		sgx_encl_free_epc_page(encl->secs.epc_page);
 		encl->secs.epc_page = NULL;
 	}
 
@@ -423,7 +423,7 @@ void sgx_encl_release(struct kref *ref)
 		va_page = list_first_entry(&encl->va_pages, struct sgx_va_page,
 					   list);
 		list_del(&va_page->list);
-		sgx_free_epc_page(va_page->epc_page);
+		sgx_encl_free_epc_page(va_page->epc_page);
 		kfree(va_page);
 	}
 
@@ -686,7 +686,7 @@ struct sgx_epc_page *sgx_alloc_va_page(void)
 	ret = __epa(sgx_get_epc_virt_addr(epc_page));
 	if (ret) {
 		WARN_ONCE(1, "EPA returned %d (0x%x)", ret, ret);
-		sgx_free_epc_page(epc_page);
+		sgx_encl_free_epc_page(epc_page);
 		return ERR_PTR(-EFAULT);
 	}
 
@@ -735,3 +735,24 @@ bool sgx_va_page_full(struct sgx_va_page *va_page)
 
 	return slot == SGX_VA_SLOT_COUNT;
 }
+
+/**
+ * sgx_encl_free_epc_page - free an EPC page assigned to an enclave
+ * @page:	EPC page to be freed
+ *
+ * Free an EPC page assigned to an enclave. It does EREMOVE for the page, and
+ * only upon success, it puts the page back to free page list.  Otherwise, it
+ * gives a WARNING to indicate page is leaked.
+ */
+void sgx_encl_free_epc_page(struct sgx_epc_page *page)
+{
+	int ret;
+
+	WARN_ON_ONCE(page->flags & SGX_EPC_PAGE_RECLAIMER_TRACKED);
+
+	ret = __eremove(sgx_get_epc_virt_addr(page));
+	if (WARN_ONCE(ret, EREMOVE_ERROR_MESSAGE, ret, ret))
+		return;
+
+	sgx_free_epc_page(page);
+}
diff --git a/arch/x86/kernel/cpu/sgx/encl.h b/arch/x86/kernel/cpu/sgx/encl.h
index d8d30ccbef4c..6e74f85b6264 100644
--- a/arch/x86/kernel/cpu/sgx/encl.h
+++ b/arch/x86/kernel/cpu/sgx/encl.h
@@ -115,5 +115,6 @@ struct sgx_epc_page *sgx_alloc_va_page(void);
 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);
 
 #endif /* _X86_ENCL_H */
diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c
index 2e10367ea66c..354e309fcdb7 100644
--- a/arch/x86/kernel/cpu/sgx/ioctl.c
+++ b/arch/x86/kernel/cpu/sgx/ioctl.c
@@ -47,7 +47,7 @@ static void sgx_encl_shrink(struct sgx_encl *encl, struct sgx_va_page *va_page)
 	encl->page_cnt--;
 
 	if (va_page) {
-		sgx_free_epc_page(va_page->epc_page);
+		sgx_encl_free_epc_page(va_page->epc_page);
 		list_del(&va_page->list);
 		kfree(va_page);
 	}
@@ -117,7 +117,7 @@ static int sgx_encl_create(struct sgx_encl *encl, struct sgx_secs *secs)
 	return 0;
 
 err_out:
-	sgx_free_epc_page(encl->secs.epc_page);
+	sgx_encl_free_epc_page(encl->secs.epc_page);
 	encl->secs.epc_page = NULL;
 
 err_out_backing:
@@ -365,7 +365,7 @@ err_out_unlock:
 	mmap_read_unlock(current->mm);
 
 err_out_free:
-	sgx_free_epc_page(epc_page);
+	sgx_encl_free_epc_page(epc_page);
 	kfree(encl_page);
 
 	return ret;
diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
index 13a7599ce7d4..b227629b1e9c 100644
--- a/arch/x86/kernel/cpu/sgx/main.c
+++ b/arch/x86/kernel/cpu/sgx/main.c
@@ -294,7 +294,7 @@ static void sgx_reclaimer_write(struct sgx_epc_page *epc_page,
 
 		sgx_encl_ewb(encl->secs.epc_page, &secs_backing);
 
-		sgx_free_epc_page(encl->secs.epc_page);
+		sgx_encl_free_epc_page(encl->secs.epc_page);
 		encl->secs.epc_page = NULL;
 
 		sgx_encl_put_backing(&secs_backing, true);
@@ -609,19 +609,15 @@ struct sgx_epc_page *sgx_alloc_epc_page(void *owner, bool reclaim)
  * sgx_free_epc_page() - Free an EPC page
  * @page:	an EPC page
  *
- * Call EREMOVE for an EPC page and insert it back to the list of free pages.
+ * Put the EPC page back to the list of free pages. It's the caller's
+ * responsibility to make sure that the page is in uninitialized state. In other
+ * words, do EREMOVE, EWB or whatever operation is necessary before calling
+ * this function.
  */
 void sgx_free_epc_page(struct sgx_epc_page *page)
 {
 	struct sgx_epc_section *section = &sgx_epc_sections[page->section];
 	struct sgx_numa_node *node = section->node;
-	int ret;
-
-	WARN_ON_ONCE(page->flags & SGX_EPC_PAGE_RECLAIMER_TRACKED);
-
-	ret = __eremove(sgx_get_epc_virt_addr(page));
-	if (WARN_ONCE(ret, "EREMOVE returned %d (0x%x)", ret, ret))
-		return;
 
 	spin_lock(&node->lock);
 
diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h
index 653af8ca1a25..4aa40c627819 100644
--- a/arch/x86/kernel/cpu/sgx/sgx.h
+++ b/arch/x86/kernel/cpu/sgx/sgx.h
@@ -13,6 +13,10 @@
 #undef pr_fmt
 #define pr_fmt(fmt) "sgx: " fmt
 
+#define EREMOVE_ERROR_MESSAGE \
+	"EREMOVE returned %d (0x%x) and an EPC page was leaked. SGX may become unusable. " \
+	"Refer to Documentation/x86/sgx.rst for more information."
+
 #define SGX_MAX_EPC_SECTIONS		8
 #define SGX_EEXTEND_BLOCK_SIZE		256
 #define SGX_NR_TO_SCAN			16
-- 
cgit v1.2.3


From 231d3dbdda192e3b3c7b79f4c3b0616f6c7f31b7 Mon Sep 17 00:00:00 2001
From: Sean Christopherson
Date: Fri, 19 Mar 2021 20:22:20 +1300
Subject: x86/sgx: Add SGX_CHILD_PRESENT hardware error code

SGX driver can accurately track how enclave pages are used.  This
enables SECS to be specifically targeted and EREMOVE'd only after all
child pages have been EREMOVE'd.  This ensures that SGX driver will
never encounter SGX_CHILD_PRESENT in normal operation.

Virtual EPC is different.  The host does not track how EPC pages are
used by the guest, so it cannot guarantee EREMOVE success.  It might,
for instance, encounter a SECS with a non-zero child count.

Add a definition of SGX_CHILD_PRESENT.  It will be used exclusively by
the SGX virtualization driver to handle recoverable EREMOVE errors when
saniziting EPC pages after they are freed.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lkml.kernel.org/r/050b198e882afde7e6eba8e6a0d4da39161dbb5a.1616136308.git.kai.huang@intel.com
---
 arch/x86/kernel/cpu/sgx/arch.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/kernel/cpu/sgx/arch.h b/arch/x86/kernel/cpu/sgx/arch.h
index dd7602c44c72..abf99bb71fdc 100644
--- a/arch/x86/kernel/cpu/sgx/arch.h
+++ b/arch/x86/kernel/cpu/sgx/arch.h
@@ -26,12 +26,14 @@
  * enum sgx_return_code - The return code type for ENCLS, ENCLU and ENCLV
  * %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_UNMASKED_EVENT:		An unmasked event, e.g. INTR, was received
  */
 enum sgx_return_code {
 	SGX_NOT_TRACKED			= 11,
+	SGX_CHILD_PRESENT		= 13,
 	SGX_INVALID_EINITTOKEN		= 16,
 	SGX_UNMASKED_EVENT		= 128,
 };
-- 
cgit v1.2.3


From 540745ddbc70eabdc7dbd3fcc00fe4fb17cd59ba Mon Sep 17 00:00:00 2001
From: Sean Christopherson
Date: Fri, 19 Mar 2021 20:22:21 +1300
Subject: x86/sgx: Introduce virtual EPC for use by KVM guests

Add a misc device /dev/sgx_vepc to allow userspace to allocate "raw"
Enclave Page Cache (EPC) without an associated enclave. The intended
and only known use case for raw EPC allocation is to expose EPC to a
KVM guest, hence the 'vepc' moniker, virt.{c,h} files and X86_SGX_KVM
Kconfig.

The SGX driver uses the misc device /dev/sgx_enclave to support
userspace in creating an enclave. Each file descriptor returned from
opening /dev/sgx_enclave represents an enclave. Unlike the SGX driver,
KVM doesn't control how the guest uses the EPC, therefore EPC allocated
to a KVM guest is not associated with an enclave, and /dev/sgx_enclave
is not suitable for allocating EPC for a KVM guest.

Having separate device nodes for the SGX driver and KVM virtual EPC also
allows separate permission control for running host SGX enclaves and KVM
SGX guests.

To use /dev/sgx_vepc to allocate a virtual EPC instance with particular
size, the hypervisor opens /dev/sgx_vepc, and uses mmap() with the
intended size to get an address range of virtual EPC. Then it may use
the address range to create one KVM memory slot as virtual EPC for
a guest.

Implement the "raw" EPC allocation in the x86 core-SGX subsystem via
/dev/sgx_vepc rather than in KVM. Doing so has two major advantages:

  - Does not require changes to KVM's uAPI, e.g. EPC gets handled as
    just another memory backend for guests.

  - EPC management is wholly contained in the SGX subsystem, e.g. SGX
    does not have to export any symbols, changes to reclaim flows don't
    need to be routed through KVM, SGX's dirty laundry doesn't have to
    get aired out for the world to see, and so on and so forth.

The virtual EPC pages allocated to guests are currently not reclaimable.
Reclaiming an EPC page used by enclave requires a special reclaim
mechanism separate from normal page reclaim, and that mechanism is not
supported for virutal EPC pages. Due to the complications of handling
reclaim conflicts between guest and host, reclaiming virtual EPC pages
is significantly more complex than basic support for SGX virtualization.

 [ bp:
   - Massage commit message and comments
   - use cpu_feature_enabled()
   - vertically align struct members init
   - massage Virtual EPC clarification text
   - move Kconfig prompt to Virtualization ]

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Co-developed-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lkml.kernel.org/r/0c38ced8c8e5a69872db4d6a1c0dabd01e07cad7.1616136308.git.kai.huang@intel.com
---
 Documentation/x86/sgx.rst        |  16 +++
 arch/x86/kernel/cpu/sgx/Makefile |   1 +
 arch/x86/kernel/cpu/sgx/sgx.h    |   9 ++
 arch/x86/kernel/cpu/sgx/virt.c   | 259 +++++++++++++++++++++++++++++++++++++++
 arch/x86/kvm/Kconfig             |  12 ++
 5 files changed, 297 insertions(+)
 create mode 100644 arch/x86/kernel/cpu/sgx/virt.c

diff --git a/Documentation/x86/sgx.rst b/Documentation/x86/sgx.rst
index f90076e67cde..dd0ac96ff9ef 100644
--- a/Documentation/x86/sgx.rst
+++ b/Documentation/x86/sgx.rst
@@ -234,3 +234,19 @@ As a result, when this happpens, user should stop running any new
 SGX workloads, (or just any new workloads), and migrate all valuable
 workloads. Although a machine reboot can recover all EPC memory, the bug
 should be reported to Linux developers.
+
+
+Virtual EPC
+===========
+
+The implementation has also a virtual EPC driver to support SGX enclaves
+in guests. Unlike the SGX driver, an EPC page allocated by the virtual
+EPC driver doesn't have a specific enclave associated with it. This is
+because KVM doesn't track how a guest uses EPC pages.
+
+As a result, the SGX core page reclaimer doesn't support reclaiming EPC
+pages allocated to KVM guests through the virtual EPC driver. If the
+user wants to deploy SGX applications both on the host and in guests
+on the same machine, the user should reserve enough EPC (by taking out
+total virtual EPC size of all SGX VMs from the physical EPC size) for
+host SGX applications so they can run with acceptable performance.
diff --git a/arch/x86/kernel/cpu/sgx/Makefile b/arch/x86/kernel/cpu/sgx/Makefile
index 91d3dc784a29..9c1656779b2a 100644
--- a/arch/x86/kernel/cpu/sgx/Makefile
+++ b/arch/x86/kernel/cpu/sgx/Makefile
@@ -3,3 +3,4 @@ obj-y += \
 	encl.o \
 	ioctl.o \
 	main.o
+obj-$(CONFIG_X86_SGX_KVM)	+= virt.o
diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h
index 4aa40c627819..4854f3980edd 100644
--- a/arch/x86/kernel/cpu/sgx/sgx.h
+++ b/arch/x86/kernel/cpu/sgx/sgx.h
@@ -84,4 +84,13 @@ 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);
 
+#ifdef CONFIG_X86_SGX_KVM
+int __init sgx_vepc_init(void);
+#else
+static inline int __init sgx_vepc_init(void)
+{
+	return -ENODEV;
+}
+#endif
+
 #endif /* _X86_SGX_H */
diff --git a/arch/x86/kernel/cpu/sgx/virt.c b/arch/x86/kernel/cpu/sgx/virt.c
new file mode 100644
index 000000000000..259cc46ad78c
--- /dev/null
+++ b/arch/x86/kernel/cpu/sgx/virt.c
@@ -0,0 +1,259 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Device driver to expose SGX enclave memory to KVM guests.
+ *
+ * Copyright(c) 2021 Intel Corporation.
+ */
+
+#include <linux/miscdevice.h>
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/sched/mm.h>
+#include <linux/sched/signal.h>
+#include <linux/slab.h>
+#include <linux/xarray.h>
+#include <asm/sgx.h>
+#include <uapi/asm/sgx.h>
+
+#include "encls.h"
+#include "sgx.h"
+
+struct sgx_vepc {
+	struct xarray page_array;
+	struct mutex lock;
+};
+
+/*
+ * Temporary SECS pages that cannot be EREMOVE'd due to having child in other
+ * virtual EPC instances, and the lock to protect it.
+ */
+static struct mutex zombie_secs_pages_lock;
+static struct list_head zombie_secs_pages;
+
+static int __sgx_vepc_fault(struct sgx_vepc *vepc,
+			    struct vm_area_struct *vma, unsigned long addr)
+{
+	struct sgx_epc_page *epc_page;
+	unsigned long index, pfn;
+	int ret;
+
+	WARN_ON(!mutex_is_locked(&vepc->lock));
+
+	/* Calculate index of EPC page in virtual EPC's page_array */
+	index = vma->vm_pgoff + PFN_DOWN(addr - vma->vm_start);
+
+	epc_page = xa_load(&vepc->page_array, index);
+	if (epc_page)
+		return 0;
+
+	epc_page = sgx_alloc_epc_page(vepc, false);
+	if (IS_ERR(epc_page))
+		return PTR_ERR(epc_page);
+
+	ret = xa_err(xa_store(&vepc->page_array, index, epc_page, GFP_KERNEL));
+	if (ret)
+		goto err_free;
+
+	pfn = PFN_DOWN(sgx_get_epc_phys_addr(epc_page));
+
+	ret = vmf_insert_pfn(vma, addr, pfn);
+	if (ret != VM_FAULT_NOPAGE) {
+		ret = -EFAULT;
+		goto err_delete;
+	}
+
+	return 0;
+
+err_delete:
+	xa_erase(&vepc->page_array, index);
+err_free:
+	sgx_free_epc_page(epc_page);
+	return ret;
+}
+
+static vm_fault_t sgx_vepc_fault(struct vm_fault *vmf)
+{
+	struct vm_area_struct *vma = vmf->vma;
+	struct sgx_vepc *vepc = vma->vm_private_data;
+	int ret;
+
+	mutex_lock(&vepc->lock);
+	ret = __sgx_vepc_fault(vepc, vma, vmf->address);
+	mutex_unlock(&vepc->lock);
+
+	if (!ret)
+		return VM_FAULT_NOPAGE;
+
+	if (ret == -EBUSY && (vmf->flags & FAULT_FLAG_ALLOW_RETRY)) {
+		mmap_read_unlock(vma->vm_mm);
+		return VM_FAULT_RETRY;
+	}
+
+	return VM_FAULT_SIGBUS;
+}
+
+const struct vm_operations_struct sgx_vepc_vm_ops = {
+	.fault = sgx_vepc_fault,
+};
+
+static int sgx_vepc_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	struct sgx_vepc *vepc = file->private_data;
+
+	if (!(vma->vm_flags & VM_SHARED))
+		return -EINVAL;
+
+	vma->vm_ops = &sgx_vepc_vm_ops;
+	/* Don't copy VMA in fork() */
+	vma->vm_flags |= VM_PFNMAP | VM_IO | VM_DONTDUMP | VM_DONTCOPY;
+	vma->vm_private_data = vepc;
+
+	return 0;
+}
+
+static int sgx_vepc_free_page(struct sgx_epc_page *epc_page)
+{
+	int ret;
+
+	/*
+	 * Take a previously guest-owned EPC page and return it to the
+	 * general EPC page pool.
+	 *
+	 * Guests can not be trusted to have left this page in a good
+	 * state, so run EREMOVE on the page unconditionally.  In the
+	 * case that a guest properly EREMOVE'd this page, a superfluous
+	 * EREMOVE is harmless.
+	 */
+	ret = __eremove(sgx_get_epc_virt_addr(epc_page));
+	if (ret) {
+		/*
+		 * Only SGX_CHILD_PRESENT is expected, which is because of
+		 * EREMOVE'ing an SECS still with child, in which case it can
+		 * be handled by EREMOVE'ing the SECS again after all pages in
+		 * virtual EPC have been EREMOVE'd. See comments in below in
+		 * sgx_vepc_release().
+		 *
+		 * The user of virtual EPC (KVM) needs to guarantee there's no
+		 * logical processor is still running in the enclave in guest,
+		 * otherwise EREMOVE will get SGX_ENCLAVE_ACT which cannot be
+		 * handled here.
+		 */
+		WARN_ONCE(ret != SGX_CHILD_PRESENT, EREMOVE_ERROR_MESSAGE,
+			  ret, ret);
+		return ret;
+	}
+
+	sgx_free_epc_page(epc_page);
+
+	return 0;
+}
+
+static int sgx_vepc_release(struct inode *inode, struct file *file)
+{
+	struct sgx_vepc *vepc = file->private_data;
+	struct sgx_epc_page *epc_page, *tmp, *entry;
+	unsigned long index;
+
+	LIST_HEAD(secs_pages);
+
+	xa_for_each(&vepc->page_array, index, entry) {
+		/*
+		 * Remove all normal, child pages.  sgx_vepc_free_page()
+		 * will fail if EREMOVE fails, but this is OK and expected on
+		 * SECS pages.  Those can only be EREMOVE'd *after* all their
+		 * child pages. Retries below will clean them up.
+		 */
+		if (sgx_vepc_free_page(entry))
+			continue;
+
+		xa_erase(&vepc->page_array, index);
+	}
+
+	/*
+	 * Retry EREMOVE'ing pages.  This will clean up any SECS pages that
+	 * only had children in this 'epc' area.
+	 */
+	xa_for_each(&vepc->page_array, index, entry) {
+		epc_page = entry;
+		/*
+		 * An EREMOVE failure here means that the SECS page still
+		 * has children.  But, since all children in this 'sgx_vepc'
+		 * have been removed, the SECS page must have a child on
+		 * another instance.
+		 */
+		if (sgx_vepc_free_page(epc_page))
+			list_add_tail(&epc_page->list, &secs_pages);
+
+		xa_erase(&vepc->page_array, index);
+	}
+
+	/*
+	 * SECS pages are "pinned" by child pages, and "unpinned" once all
+	 * children have been EREMOVE'd.  A child page in this instance
+	 * may have pinned an SECS page encountered in an earlier release(),
+	 * creating a zombie.  Since some children were EREMOVE'd above,
+	 * try to EREMOVE all zombies in the hopes that one was unpinned.
+	 */
+	mutex_lock(&zombie_secs_pages_lock);
+	list_for_each_entry_safe(epc_page, tmp, &zombie_secs_pages, list) {
+		/*
+		 * Speculatively remove the page from the list of zombies,
+		 * if the page is successfully EREMOVE'd it will be added to
+		 * the list of free pages.  If EREMOVE fails, throw the page
+		 * on the local list, which will be spliced on at the end.
+		 */
+		list_del(&epc_page->list);
+
+		if (sgx_vepc_free_page(epc_page))
+			list_add_tail(&epc_page->list, &secs_pages);
+	}
+
+	if (!list_empty(&secs_pages))
+		list_splice_tail(&secs_pages, &zombie_secs_pages);
+	mutex_unlock(&zombie_secs_pages_lock);
+
+	kfree(vepc);
+
+	return 0;
+}
+
+static int sgx_vepc_open(struct inode *inode, struct file *file)
+{
+	struct sgx_vepc *vepc;
+
+	vepc = kzalloc(sizeof(struct sgx_vepc), GFP_KERNEL);
+	if (!vepc)
+		return -ENOMEM;
+	mutex_init(&vepc->lock);
+	xa_init(&vepc->page_array);
+
+	file->private_data = vepc;
+
+	return 0;
+}
+
+static const struct file_operations sgx_vepc_fops = {
+	.owner		= THIS_MODULE,
+	.open		= sgx_vepc_open,
+	.release	= sgx_vepc_release,
+	.mmap		= sgx_vepc_mmap,
+};
+
+static struct miscdevice sgx_vepc_dev = {
+	.minor		= MISC_DYNAMIC_MINOR,
+	.name		= "sgx_vepc",
+	.nodename	= "sgx_vepc",
+	.fops		= &sgx_vepc_fops,
+};
+
+int __init sgx_vepc_init(void)
+{
+	/* SGX virtualization requires KVM to work */
+	if (!cpu_feature_enabled(X86_FEATURE_VMX))
+		return -ENODEV;
+
+	INIT_LIST_HEAD(&zombie_secs_pages);
+	mutex_init(&zombie_secs_pages_lock);
+
+	return misc_register(&sgx_vepc_dev);
+}
diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
index a788d5120d4d..f6b93a35ce14 100644
--- a/arch/x86/kvm/Kconfig
+++ b/arch/x86/kvm/Kconfig
@@ -84,6 +84,18 @@ config KVM_INTEL
 	  To compile this as a module, choose M here: the module
 	  will be called kvm-intel.
 
+config X86_SGX_KVM
+	bool "Software Guard eXtensions (SGX) Virtualization"
+	depends on X86_SGX && KVM_INTEL
+	help
+
+	  Enables KVM guests to create SGX enclaves.
+
+	  This includes support to expose "raw" unreclaimable enclave memory to
+	  guests via a device node, e.g. /dev/sgx_vepc.
+
+	  If unsure, say N.
+
 config KVM_AMD
 	tristate "KVM for AMD processors support"
 	depends on KVM
-- 
cgit v1.2.3


From 332bfc7becf479de8a55864cc5ed0024baea28aa Mon Sep 17 00:00:00 2001
From: Sean Christopherson
Date: Fri, 19 Mar 2021 20:22:58 +1300
Subject: x86/cpu/intel: Allow SGX virtualization without Launch Control
 support

The kernel will currently disable all SGX support if the hardware does
not support launch control.  Make it more permissive to allow SGX
virtualization on systems without Launch Control support.  This will
allow KVM to expose SGX to guests that have less-strict requirements on
the availability of flexible launch control.

Improve error message to distinguish between three cases.  There are two
cases where SGX support is completely disabled:
1) SGX has been disabled completely by the BIOS
2) SGX LC is locked by the BIOS.  Bare-metal support is disabled because
   of LC unavailability.  SGX virtualization is unavailable (because of
   Kconfig).
One where it is partially available:
3) SGX LC is locked by the BIOS.  Bare-metal support is disabled because
   of LC unavailability.  SGX virtualization is supported.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Co-developed-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Link: https://lkml.kernel.org/r/b3329777076509b3b601550da288c8f3c406a865.1616136308.git.kai.huang@intel.com
---
 arch/x86/kernel/cpu/feat_ctl.c | 59 +++++++++++++++++++++++++++++++-----------
 1 file changed, 44 insertions(+), 15 deletions(-)

diff --git a/arch/x86/kernel/cpu/feat_ctl.c b/arch/x86/kernel/cpu/feat_ctl.c
index 27533a6e04fa..da696eb4821a 100644
--- a/arch/x86/kernel/cpu/feat_ctl.c
+++ b/arch/x86/kernel/cpu/feat_ctl.c
@@ -104,8 +104,9 @@ early_param("nosgx", nosgx);
 
 void init_ia32_feat_ctl(struct cpuinfo_x86 *c)
 {
+	bool enable_sgx_kvm = false, enable_sgx_driver = false;
 	bool tboot = tboot_enabled();
-	bool enable_sgx;
+	bool enable_vmx;
 	u64 msr;
 
 	if (rdmsrl_safe(MSR_IA32_FEAT_CTL, &msr)) {
@@ -114,13 +115,19 @@ void init_ia32_feat_ctl(struct cpuinfo_x86 *c)
 		return;
 	}
 
-	/*
-	 * Enable SGX if and only if the kernel supports SGX and Launch Control
-	 * is supported, i.e. disable SGX if the LE hash MSRs can't be written.
-	 */
-	enable_sgx = cpu_has(c, X86_FEATURE_SGX) &&
-		     cpu_has(c, X86_FEATURE_SGX_LC) &&
-		     IS_ENABLED(CONFIG_X86_SGX);
+	enable_vmx = cpu_has(c, X86_FEATURE_VMX) &&
+		     IS_ENABLED(CONFIG_KVM_INTEL);
+
+	if (cpu_has(c, X86_FEATURE_SGX) && IS_ENABLED(CONFIG_X86_SGX)) {
+		/*
+		 * Separate out SGX driver enabling from KVM.  This allows KVM
+		 * guests to use SGX even if the kernel SGX driver refuses to
+		 * use it.  This happens if flexible Launch Control is not
+		 * available.
+		 */
+		enable_sgx_driver = cpu_has(c, X86_FEATURE_SGX_LC);
+		enable_sgx_kvm = enable_vmx && IS_ENABLED(CONFIG_X86_SGX_KVM);
+	}
 
 	if (msr & FEAT_CTL_LOCKED)
 		goto update_caps;
@@ -136,15 +143,18 @@ void init_ia32_feat_ctl(struct cpuinfo_x86 *c)
 	 * i.e. KVM is enabled, to avoid unnecessarily adding an attack vector
 	 * for the kernel, e.g. using VMX to hide malicious code.
 	 */
-	if (cpu_has(c, X86_FEATURE_VMX) && IS_ENABLED(CONFIG_KVM_INTEL)) {
+	if (enable_vmx) {
 		msr |= FEAT_CTL_VMX_ENABLED_OUTSIDE_SMX;
 
 		if (tboot)
 			msr |= FEAT_CTL_VMX_ENABLED_INSIDE_SMX;
 	}
 
-	if (enable_sgx)
-		msr |= FEAT_CTL_SGX_ENABLED | FEAT_CTL_SGX_LC_ENABLED;
+	if (enable_sgx_kvm || enable_sgx_driver) {
+		msr |= FEAT_CTL_SGX_ENABLED;
+		if (enable_sgx_driver)
+			msr |= FEAT_CTL_SGX_LC_ENABLED;
+	}
 
 	wrmsrl(MSR_IA32_FEAT_CTL, msr);
 
@@ -167,10 +177,29 @@ update_caps:
 	}
 
 update_sgx:
-	if (!(msr & FEAT_CTL_SGX_ENABLED) ||
-	    !(msr & FEAT_CTL_SGX_LC_ENABLED) || !enable_sgx) {
-		if (enable_sgx)
-			pr_err_once("SGX disabled by BIOS\n");
+	if (!(msr & FEAT_CTL_SGX_ENABLED)) {
+		if (enable_sgx_kvm || enable_sgx_driver)
+			pr_err_once("SGX disabled by BIOS.\n");
 		clear_cpu_cap(c, X86_FEATURE_SGX);
+		return;
+	}
+
+	/*
+	 * VMX feature bit may be cleared due to being disabled in BIOS,
+	 * in which case SGX virtualization cannot be supported either.
+	 */
+	if (!cpu_has(c, X86_FEATURE_VMX) && enable_sgx_kvm) {
+		pr_err_once("SGX virtualization disabled due to lack of VMX.\n");
+		enable_sgx_kvm = 0;
+	}
+
+	if (!(msr & FEAT_CTL_SGX_LC_ENABLED) && enable_sgx_driver) {
+		if (!enable_sgx_kvm) {
+			pr_err_once("SGX Launch Control is locked. Disable SGX.\n");
+			clear_cpu_cap(c, X86_FEATURE_SGX);
+		} else {
+			pr_err_once("SGX Launch Control is locked. Support SGX virtualization only.\n");
+			clear_cpu_cap(c, X86_FEATURE_SGX_LC);
+		}
 	}
 }
-- 
cgit v1.2.3


From faa7d3e6f3b983a28bf0f88f82dcb1c162e61105 Mon Sep 17 00:00:00 2001
From: Kai Huang
Date: Fri, 19 Mar 2021 20:23:02 +1300
Subject: x86/sgx: Initialize virtual EPC driver even when SGX driver is
 disabled

Modify sgx_init() to always try to initialize the virtual EPC driver,
even if the SGX driver is disabled.  The SGX driver might be disabled
if SGX Launch Control is in locked mode, or not supported in the
hardware at all.  This allows (non-Linux) guests that support non-LC
configurations to use SGX.

 [ bp: De-silli-fy the test. ]

Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Link: https://lkml.kernel.org/r/d35d17a02bbf8feef83a536cec8b43746d4ea557.1616136308.git.kai.huang@intel.com
---
 arch/x86/kernel/cpu/sgx/main.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
index b227629b1e9c..1c8a228b0104 100644
--- a/arch/x86/kernel/cpu/sgx/main.c
+++ b/arch/x86/kernel/cpu/sgx/main.c
@@ -743,8 +743,17 @@ static int __init sgx_init(void)
 		goto err_page_cache;
 	}
 
+	/*
+	 * Always try to initialize the native *and* KVM drivers.
+	 * The KVM driver is less picky than the native one and
+	 * can function if the native one is not supported on the
+	 * current system or fails to initialize.
+	 *
+	 * Error out only if both fail to initialize.
+	 */
 	ret = sgx_drv_init();
-	if (ret)
+
+	if (sgx_vepc_init() && ret)
 		goto err_kthread;
 
 	return 0;
-- 
cgit v1.2.3


From 8ca52cc38dc8fdcbdbd0c23eafb19db5e5f5c8d0 Mon Sep 17 00:00:00 2001
From: Sean Christopherson
Date: Fri, 19 Mar 2021 20:23:03 +1300
Subject: x86/sgx: Expose SGX architectural definitions to the kernel

Expose SGX architectural structures, as KVM will use many of the
architectural constants and structs to virtualize SGX.

Name the new header file as asm/sgx.h, rather than asm/sgx_arch.h, to
have single header to provide SGX facilities to share with other kernel
componments. Also update MAINTAINERS to include asm/sgx.h.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Co-developed-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Link: https://lkml.kernel.org/r/6bf47acd91ab4d709e66ad1692c7803e4c9063a0.1616136308.git.kai.huang@intel.com
---
 MAINTAINERS                           |   1 +
 arch/x86/include/asm/sgx.h            | 350 ++++++++++++++++++++++++++++++++++
 arch/x86/kernel/cpu/sgx/arch.h        | 340 ---------------------------------
 arch/x86/kernel/cpu/sgx/encl.c        |   2 +-
 arch/x86/kernel/cpu/sgx/sgx.h         |   2 +-
 tools/testing/selftests/sgx/defines.h |   2 +-
 6 files changed, 354 insertions(+), 343 deletions(-)
 create mode 100644 arch/x86/include/asm/sgx.h
 delete mode 100644 arch/x86/kernel/cpu/sgx/arch.h

diff --git a/MAINTAINERS b/MAINTAINERS
index aa84121c5611..0cb606aeba5e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9274,6 +9274,7 @@ Q:	https://patchwork.kernel.org/project/intel-sgx/list/
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/sgx
 F:	Documentation/x86/sgx.rst
 F:	arch/x86/entry/vdso/vsgx.S
+F:	arch/x86/include/asm/sgx.h
 F:	arch/x86/include/uapi/asm/sgx.h
 F:	arch/x86/kernel/cpu/sgx/*
 F:	tools/testing/selftests/sgx/*
diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h
new file mode 100644
index 000000000000..14bb5f7e221c
--- /dev/null
+++ b/arch/x86/include/asm/sgx.h
@@ -0,0 +1,350 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/**
+ * Copyright(c) 2016-20 Intel Corporation.
+ *
+ * Intel Software Guard Extensions (SGX) support.
+ */
+#ifndef _ASM_X86_SGX_H
+#define _ASM_X86_SGX_H
+
+#include <linux/bits.h>
+#include <linux/types.h>
+
+/*
+ * This file contains both data structures defined by SGX architecture and Linux
+ * defined software data structures and functions.  The two should not be mixed
+ * together for better readibility.  The architectural definitions come first.
+ */
+
+/* The SGX specific CPUID function. */
+#define SGX_CPUID		0x12
+/* EPC enumeration. */
+#define SGX_CPUID_EPC		2
+/* An invalid EPC section, i.e. the end marker. */
+#define SGX_CPUID_EPC_INVALID	0x0
+/* A valid EPC section. */
+#define SGX_CPUID_EPC_SECTION	0x1
+/* The bitmask for the EPC section type. */
+#define SGX_CPUID_EPC_MASK	GENMASK(3, 0)
+
+/**
+ * enum sgx_return_code - The return code type for ENCLS, ENCLU and ENCLV
+ * %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_UNMASKED_EVENT:		An unmasked event, e.g. INTR, was received
+ */
+enum sgx_return_code {
+	SGX_NOT_TRACKED			= 11,
+	SGX_CHILD_PRESENT		= 13,
+	SGX_INVALID_EINITTOKEN		= 16,
+	SGX_UNMASKED_EVENT		= 128,
+};
+
+/* The modulus size for 3072-bit RSA keys. */
+#define SGX_MODULUS_SIZE 384
+
+/**
+ * enum sgx_miscselect - additional information to an SSA frame
+ * %SGX_MISC_EXINFO:	Report #PF or #GP to the SSA frame.
+ *
+ * Save State Area (SSA) is a stack inside the enclave used to store processor
+ * state when an exception or interrupt occurs. This enum defines additional
+ * information stored to an SSA frame.
+ */
+enum sgx_miscselect {
+	SGX_MISC_EXINFO		= BIT(0),
+};
+
+#define SGX_MISC_RESERVED_MASK	GENMASK_ULL(63, 1)
+
+#define SGX_SSA_GPRS_SIZE		184
+#define SGX_SSA_MISC_EXINFO_SIZE	16
+
+/**
+ * enum sgx_attributes - the attributes field in &struct sgx_secs
+ * %SGX_ATTR_INIT:		Enclave can be entered (is initialized).
+ * %SGX_ATTR_DEBUG:		Allow ENCLS(EDBGRD) and ENCLS(EDBGWR).
+ * %SGX_ATTR_MODE64BIT:		Tell that this a 64-bit enclave.
+ * %SGX_ATTR_PROVISIONKEY:      Allow to use provisioning keys for remote
+ *				attestation.
+ * %SGX_ATTR_KSS:		Allow to use key separation and sharing (KSS).
+ * %SGX_ATTR_EINITTOKENKEY:	Allow to use token signing key that is used to
+ *				sign cryptographic tokens that can be passed to
+ *				EINIT as an authorization to run an enclave.
+ */
+enum sgx_attribute {
+	SGX_ATTR_INIT		= BIT(0),
+	SGX_ATTR_DEBUG		= BIT(1),
+	SGX_ATTR_MODE64BIT	= BIT(2),
+	SGX_ATTR_PROVISIONKEY	= BIT(4),
+	SGX_ATTR_EINITTOKENKEY	= BIT(5),
+	SGX_ATTR_KSS		= BIT(7),
+};
+
+#define SGX_ATTR_RESERVED_MASK	(BIT_ULL(3) | BIT_ULL(6) | GENMASK_ULL(63, 8))
+
+/**
+ * struct sgx_secs - SGX Enclave Control Structure (SECS)
+ * @size:		size of the address space
+ * @base:		base address of the  address space
+ * @ssa_frame_size:	size of an SSA frame
+ * @miscselect:		additional information stored to an SSA frame
+ * @attributes:		attributes for enclave
+ * @xfrm:		XSave-Feature Request Mask (subset of XCR0)
+ * @mrenclave:		SHA256-hash of the enclave contents
+ * @mrsigner:		SHA256-hash of the public key used to sign the SIGSTRUCT
+ * @config_id:		a user-defined value that is used in key derivation
+ * @isv_prod_id:	a user-defined value that is used in key derivation
+ * @isv_svn:		a user-defined value that is used in key derivation
+ * @config_svn:		a user-defined value that is used in key derivation
+ *
+ * SGX Enclave Control Structure (SECS) is a special enclave page that is not
+ * visible in the address space. In fact, this structure defines the address
+ * range and other global attributes for the enclave and it is the first EPC
+ * page created for any enclave. It is moved from a temporary buffer to an EPC
+ * by the means of ENCLS[ECREATE] function.
+ */
+struct sgx_secs {
+	u64 size;
+	u64 base;
+	u32 ssa_frame_size;
+	u32 miscselect;
+	u8  reserved1[24];
+	u64 attributes;
+	u64 xfrm;
+	u32 mrenclave[8];
+	u8  reserved2[32];
+	u32 mrsigner[8];
+	u8  reserved3[32];
+	u32 config_id[16];
+	u16 isv_prod_id;
+	u16 isv_svn;
+	u16 config_svn;
+	u8  reserved4[3834];
+} __packed;
+
+/**
+ * enum sgx_tcs_flags - execution flags for TCS
+ * %SGX_TCS_DBGOPTIN:	If enabled allows single-stepping and breakpoints
+ *			inside an enclave. It is cleared by EADD but can
+ *			be set later with EDBGWR.
+ */
+enum sgx_tcs_flags {
+	SGX_TCS_DBGOPTIN	= 0x01,
+};
+
+#define SGX_TCS_RESERVED_MASK	GENMASK_ULL(63, 1)
+#define SGX_TCS_RESERVED_SIZE	4024
+
+/**
+ * struct sgx_tcs - Thread Control Structure (TCS)
+ * @state:		used to mark an entered TCS
+ * @flags:		execution flags (cleared by EADD)
+ * @ssa_offset:		SSA stack offset relative to the enclave base
+ * @ssa_index:		the current SSA frame index (cleard by EADD)
+ * @nr_ssa_frames:	the number of frame in the SSA stack
+ * @entry_offset:	entry point offset relative to the enclave base
+ * @exit_addr:		address outside the enclave to exit on an exception or
+ *			interrupt
+ * @fs_offset:		offset relative to the enclave base to become FS
+ *			segment inside the enclave
+ * @gs_offset:		offset relative to the enclave base to become GS
+ *			segment inside the enclave
+ * @fs_limit:		size to become a new FS-limit (only 32-bit enclaves)
+ * @gs_limit:		size to become a new GS-limit (only 32-bit enclaves)
+ *
+ * Thread Control Structure (TCS) is an enclave page visible in its address
+ * space that defines an entry point inside the enclave. A thread enters inside
+ * an enclave by supplying address of TCS to ENCLU(EENTER). A TCS can be entered
+ * by only one thread at a time.
+ */
+struct sgx_tcs {
+	u64 state;
+	u64 flags;
+	u64 ssa_offset;
+	u32 ssa_index;
+	u32 nr_ssa_frames;
+	u64 entry_offset;
+	u64 exit_addr;
+	u64 fs_offset;
+	u64 gs_offset;
+	u32 fs_limit;
+	u32 gs_limit;
+	u8  reserved[SGX_TCS_RESERVED_SIZE];
+} __packed;
+
+/**
+ * struct sgx_pageinfo - an enclave page descriptor
+ * @addr:	address of the enclave page
+ * @contents:	pointer to the page contents
+ * @metadata:	pointer either to a SECINFO or PCMD instance
+ * @secs:	address of the SECS page
+ */
+struct sgx_pageinfo {
+	u64 addr;
+	u64 contents;
+	u64 metadata;
+	u64 secs;
+} __packed __aligned(32);
+
+
+/**
+ * enum sgx_page_type - bits in the SECINFO flags defining the page type
+ * %SGX_PAGE_TYPE_SECS:	a SECS page
+ * %SGX_PAGE_TYPE_TCS:	a TCS page
+ * %SGX_PAGE_TYPE_REG:	a regular page
+ * %SGX_PAGE_TYPE_VA:	a VA page
+ * %SGX_PAGE_TYPE_TRIM:	a page in trimmed state
+ */
+enum sgx_page_type {
+	SGX_PAGE_TYPE_SECS,
+	SGX_PAGE_TYPE_TCS,
+	SGX_PAGE_TYPE_REG,
+	SGX_PAGE_TYPE_VA,
+	SGX_PAGE_TYPE_TRIM,
+};
+
+#define SGX_NR_PAGE_TYPES	5
+#define SGX_PAGE_TYPE_MASK	GENMASK(7, 0)
+
+/**
+ * enum sgx_secinfo_flags - the flags field in &struct sgx_secinfo
+ * %SGX_SECINFO_R:	allow read
+ * %SGX_SECINFO_W:	allow write
+ * %SGX_SECINFO_X:	allow execution
+ * %SGX_SECINFO_SECS:	a SECS page
+ * %SGX_SECINFO_TCS:	a TCS page
+ * %SGX_SECINFO_REG:	a regular page
+ * %SGX_SECINFO_VA:	a VA page
+ * %SGX_SECINFO_TRIM:	a page in trimmed state
+ */
+enum sgx_secinfo_flags {
+	SGX_SECINFO_R			= BIT(0),
+	SGX_SECINFO_W			= BIT(1),
+	SGX_SECINFO_X			= BIT(2),
+	SGX_SECINFO_SECS		= (SGX_PAGE_TYPE_SECS << 8),
+	SGX_SECINFO_TCS			= (SGX_PAGE_TYPE_TCS << 8),
+	SGX_SECINFO_REG			= (SGX_PAGE_TYPE_REG << 8),
+	SGX_SECINFO_VA			= (SGX_PAGE_TYPE_VA << 8),
+	SGX_SECINFO_TRIM		= (SGX_PAGE_TYPE_TRIM << 8),
+};
+
+#define SGX_SECINFO_PERMISSION_MASK	GENMASK_ULL(2, 0)
+#define SGX_SECINFO_PAGE_TYPE_MASK	(SGX_PAGE_TYPE_MASK << 8)
+#define SGX_SECINFO_RESERVED_MASK	~(SGX_SECINFO_PERMISSION_MASK | \
+					  SGX_SECINFO_PAGE_TYPE_MASK)
+
+/**
+ * struct sgx_secinfo - describes attributes of an EPC page
+ * @flags:	permissions and type
+ *
+ * Used together with ENCLS leaves that add or modify an EPC page to an
+ * enclave to define page permissions and type.
+ */
+struct sgx_secinfo {
+	u64 flags;
+	u8  reserved[56];
+} __packed __aligned(64);
+
+#define SGX_PCMD_RESERVED_SIZE 40
+
+/**
+ * struct sgx_pcmd - Paging Crypto Metadata (PCMD)
+ * @enclave_id:	enclave identifier
+ * @mac:	MAC over PCMD, page contents and isvsvn
+ *
+ * PCMD is stored for every swapped page to the regular memory. When ELDU loads
+ * the page back it recalculates the MAC by using a isvsvn number stored in a
+ * VA page. Together these two structures bring integrity and rollback
+ * protection.
+ */
+struct sgx_pcmd {
+	struct sgx_secinfo secinfo;
+	u64 enclave_id;
+	u8  reserved[SGX_PCMD_RESERVED_SIZE];
+	u8  mac[16];
+} __packed __aligned(128);
+
+#define SGX_SIGSTRUCT_RESERVED1_SIZE 84
+#define SGX_SIGSTRUCT_RESERVED2_SIZE 20
+#define SGX_SIGSTRUCT_RESERVED3_SIZE 32
+#define SGX_SIGSTRUCT_RESERVED4_SIZE 12
+
+/**
+ * struct sgx_sigstruct_header -  defines author of the enclave
+ * @header1:		constant byte string
+ * @vendor:		must be either 0x0000 or 0x8086
+ * @date:		YYYYMMDD in BCD
+ * @header2:		costant byte string
+ * @swdefined:		software defined value
+ */
+struct sgx_sigstruct_header {
+	u64 header1[2];
+	u32 vendor;
+	u32 date;
+	u64 header2[2];
+	u32 swdefined;
+	u8  reserved1[84];
+} __packed;
+
+/**
+ * struct sgx_sigstruct_body - defines contents of the enclave
+ * @miscselect:		additional information stored to an SSA frame
+ * @misc_mask:		required miscselect in SECS
+ * @attributes:		attributes for enclave
+ * @xfrm:		XSave-Feature Request Mask (subset of XCR0)
+ * @attributes_mask:	required attributes in SECS
+ * @xfrm_mask:		required XFRM in SECS
+ * @mrenclave:		SHA256-hash of the enclave contents
+ * @isvprodid:		a user-defined value that is used in key derivation
+ * @isvsvn:		a user-defined value that is used in key derivation
+ */
+struct sgx_sigstruct_body {
+	u32 miscselect;
+	u32 misc_mask;
+	u8  reserved2[20];
+	u64 attributes;
+	u64 xfrm;
+	u64 attributes_mask;
+	u64 xfrm_mask;
+	u8  mrenclave[32];
+	u8  reserved3[32];
+	u16 isvprodid;
+	u16 isvsvn;
+} __packed;
+
+/**
+ * struct sgx_sigstruct - an enclave signature
+ * @header:		defines author of the enclave
+ * @modulus:		the modulus of the public key
+ * @exponent:		the exponent of the public key
+ * @signature:		the signature calculated over the fields except modulus,
+ * @body:		defines contents of the enclave
+ * @q1:			a value used in RSA signature verification
+ * @q2:			a value used in RSA signature verification
+ *
+ * Header and body are the parts that are actual signed. The remaining fields
+ * define the signature of the enclave.
+ */
+struct sgx_sigstruct {
+	struct sgx_sigstruct_header header;
+	u8  modulus[SGX_MODULUS_SIZE];
+	u32 exponent;
+	u8  signature[SGX_MODULUS_SIZE];
+	struct sgx_sigstruct_body body;
+	u8  reserved4[12];
+	u8  q1[SGX_MODULUS_SIZE];
+	u8  q2[SGX_MODULUS_SIZE];
+} __packed;
+
+#define SGX_LAUNCH_TOKEN_SIZE 304
+
+/*
+ * Do not put any hardware-defined SGX structure representations below this
+ * comment!
+ */
+
+#endif /* _ASM_X86_SGX_H */
diff --git a/arch/x86/kernel/cpu/sgx/arch.h b/arch/x86/kernel/cpu/sgx/arch.h
deleted file mode 100644
index abf99bb71fdc..000000000000
--- a/arch/x86/kernel/cpu/sgx/arch.h
+++ /dev/null
@@ -1,340 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/**
- * Copyright(c) 2016-20 Intel Corporation.
- *
- * Contains data structures defined by the SGX architecture.  Data structures
- * defined by the Linux software stack should not be placed here.
- */
-#ifndef _ASM_X86_SGX_ARCH_H
-#define _ASM_X86_SGX_ARCH_H
-
-#include <linux/bits.h>
-#include <linux/types.h>
-
-/* The SGX specific CPUID function. */
-#define SGX_CPUID		0x12
-/* EPC enumeration. */
-#define SGX_CPUID_EPC		2
-/* An invalid EPC section, i.e. the end marker. */
-#define SGX_CPUID_EPC_INVALID	0x0
-/* A valid EPC section. */
-#define SGX_CPUID_EPC_SECTION	0x1
-/* The bitmask for the EPC section type. */
-#define SGX_CPUID_EPC_MASK	GENMASK(3, 0)
-
-/**
- * enum sgx_return_code - The return code type for ENCLS, ENCLU and ENCLV
- * %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_UNMASKED_EVENT:		An unmasked event, e.g. INTR, was received
- */
-enum sgx_return_code {
-	SGX_NOT_TRACKED			= 11,
-	SGX_CHILD_PRESENT		= 13,
-	SGX_INVALID_EINITTOKEN		= 16,
-	SGX_UNMASKED_EVENT		= 128,
-};
-
-/* The modulus size for 3072-bit RSA keys. */
-#define SGX_MODULUS_SIZE 384
-
-/**
- * enum sgx_miscselect - additional information to an SSA frame
- * %SGX_MISC_EXINFO:	Report #PF or #GP to the SSA frame.
- *
- * Save State Area (SSA) is a stack inside the enclave used to store processor
- * state when an exception or interrupt occurs. This enum defines additional
- * information stored to an SSA frame.
- */
-enum sgx_miscselect {
-	SGX_MISC_EXINFO		= BIT(0),
-};
-
-#define SGX_MISC_RESERVED_MASK	GENMASK_ULL(63, 1)
-
-#define SGX_SSA_GPRS_SIZE		184
-#define SGX_SSA_MISC_EXINFO_SIZE	16
-
-/**
- * enum sgx_attributes - the attributes field in &struct sgx_secs
- * %SGX_ATTR_INIT:		Enclave can be entered (is initialized).
- * %SGX_ATTR_DEBUG:		Allow ENCLS(EDBGRD) and ENCLS(EDBGWR).
- * %SGX_ATTR_MODE64BIT:		Tell that this a 64-bit enclave.
- * %SGX_ATTR_PROVISIONKEY:      Allow to use provisioning keys for remote
- *				attestation.
- * %SGX_ATTR_KSS:		Allow to use key separation and sharing (KSS).
- * %SGX_ATTR_EINITTOKENKEY:	Allow to use token signing key that is used to
- *				sign cryptographic tokens that can be passed to
- *				EINIT as an authorization to run an enclave.
- */
-enum sgx_attribute {
-	SGX_ATTR_INIT		= BIT(0),
-	SGX_ATTR_DEBUG		= BIT(1),
-	SGX_ATTR_MODE64BIT	= BIT(2),
-	SGX_ATTR_PROVISIONKEY	= BIT(4),
-	SGX_ATTR_EINITTOKENKEY	= BIT(5),
-	SGX_ATTR_KSS		= BIT(7),
-};
-
-#define SGX_ATTR_RESERVED_MASK	(BIT_ULL(3) | BIT_ULL(6) | GENMASK_ULL(63, 8))
-
-/**
- * struct sgx_secs - SGX Enclave Control Structure (SECS)
- * @size:		size of the address space
- * @base:		base address of the  address space
- * @ssa_frame_size:	size of an SSA frame
- * @miscselect:		additional information stored to an SSA frame
- * @attributes:		attributes for enclave
- * @xfrm:		XSave-Feature Request Mask (subset of XCR0)
- * @mrenclave:		SHA256-hash of the enclave contents
- * @mrsigner:		SHA256-hash of the public key used to sign the SIGSTRUCT
- * @config_id:		a user-defined value that is used in key derivation
- * @isv_prod_id:	a user-defined value that is used in key derivation
- * @isv_svn:		a user-defined value that is used in key derivation
- * @config_svn:		a user-defined value that is used in key derivation
- *
- * SGX Enclave Control Structure (SECS) is a special enclave page that is not
- * visible in the address space. In fact, this structure defines the address
- * range and other global attributes for the enclave and it is the first EPC
- * page created for any enclave. It is moved from a temporary buffer to an EPC
- * by the means of ENCLS[ECREATE] function.
- */
-struct sgx_secs {
-	u64 size;
-	u64 base;
-	u32 ssa_frame_size;
-	u32 miscselect;
-	u8  reserved1[24];
-	u64 attributes;
-	u64 xfrm;
-	u32 mrenclave[8];
-	u8  reserved2[32];
-	u32 mrsigner[8];
-	u8  reserved3[32];
-	u32 config_id[16];
-	u16 isv_prod_id;
-	u16 isv_svn;
-	u16 config_svn;
-	u8  reserved4[3834];
-} __packed;
-
-/**
- * enum sgx_tcs_flags - execution flags for TCS
- * %SGX_TCS_DBGOPTIN:	If enabled allows single-stepping and breakpoints
- *			inside an enclave. It is cleared by EADD but can
- *			be set later with EDBGWR.
- */
-enum sgx_tcs_flags {
-	SGX_TCS_DBGOPTIN	= 0x01,
-};
-
-#define SGX_TCS_RESERVED_MASK	GENMASK_ULL(63, 1)
-#define SGX_TCS_RESERVED_SIZE	4024
-
-/**
- * struct sgx_tcs - Thread Control Structure (TCS)
- * @state:		used to mark an entered TCS
- * @flags:		execution flags (cleared by EADD)
- * @ssa_offset:		SSA stack offset relative to the enclave base
- * @ssa_index:		the current SSA frame index (cleard by EADD)
- * @nr_ssa_frames:	the number of frame in the SSA stack
- * @entry_offset:	entry point offset relative to the enclave base
- * @exit_addr:		address outside the enclave to exit on an exception or
- *			interrupt
- * @fs_offset:		offset relative to the enclave base to become FS
- *			segment inside the enclave
- * @gs_offset:		offset relative to the enclave base to become GS
- *			segment inside the enclave
- * @fs_limit:		size to become a new FS-limit (only 32-bit enclaves)
- * @gs_limit:		size to become a new GS-limit (only 32-bit enclaves)
- *
- * Thread Control Structure (TCS) is an enclave page visible in its address
- * space that defines an entry point inside the enclave. A thread enters inside
- * an enclave by supplying address of TCS to ENCLU(EENTER). A TCS can be entered
- * by only one thread at a time.
- */
-struct sgx_tcs {
-	u64 state;
-	u64 flags;
-	u64 ssa_offset;
-	u32 ssa_index;
-	u32 nr_ssa_frames;
-	u64 entry_offset;
-	u64 exit_addr;
-	u64 fs_offset;
-	u64 gs_offset;
-	u32 fs_limit;
-	u32 gs_limit;
-	u8  reserved[SGX_TCS_RESERVED_SIZE];
-} __packed;
-
-/**
- * struct sgx_pageinfo - an enclave page descriptor
- * @addr:	address of the enclave page
- * @contents:	pointer to the page contents
- * @metadata:	pointer either to a SECINFO or PCMD instance
- * @secs:	address of the SECS page
- */
-struct sgx_pageinfo {
-	u64 addr;
-	u64 contents;
-	u64 metadata;
-	u64 secs;
-} __packed __aligned(32);
-
-
-/**
- * enum sgx_page_type - bits in the SECINFO flags defining the page type
- * %SGX_PAGE_TYPE_SECS:	a SECS page
- * %SGX_PAGE_TYPE_TCS:	a TCS page
- * %SGX_PAGE_TYPE_REG:	a regular page
- * %SGX_PAGE_TYPE_VA:	a VA page
- * %SGX_PAGE_TYPE_TRIM:	a page in trimmed state
- */
-enum sgx_page_type {
-	SGX_PAGE_TYPE_SECS,
-	SGX_PAGE_TYPE_TCS,
-	SGX_PAGE_TYPE_REG,
-	SGX_PAGE_TYPE_VA,
-	SGX_PAGE_TYPE_TRIM,
-};
-
-#define SGX_NR_PAGE_TYPES	5
-#define SGX_PAGE_TYPE_MASK	GENMASK(7, 0)
-
-/**
- * enum sgx_secinfo_flags - the flags field in &struct sgx_secinfo
- * %SGX_SECINFO_R:	allow read
- * %SGX_SECINFO_W:	allow write
- * %SGX_SECINFO_X:	allow execution
- * %SGX_SECINFO_SECS:	a SECS page
- * %SGX_SECINFO_TCS:	a TCS page
- * %SGX_SECINFO_REG:	a regular page
- * %SGX_SECINFO_VA:	a VA page
- * %SGX_SECINFO_TRIM:	a page in trimmed state
- */
-enum sgx_secinfo_flags {
-	SGX_SECINFO_R			= BIT(0),
-	SGX_SECINFO_W			= BIT(1),
-	SGX_SECINFO_X			= BIT(2),
-	SGX_SECINFO_SECS		= (SGX_PAGE_TYPE_SECS << 8),
-	SGX_SECINFO_TCS			= (SGX_PAGE_TYPE_TCS << 8),
-	SGX_SECINFO_REG			= (SGX_PAGE_TYPE_REG << 8),
-	SGX_SECINFO_VA			= (SGX_PAGE_TYPE_VA << 8),
-	SGX_SECINFO_TRIM		= (SGX_PAGE_TYPE_TRIM << 8),
-};
-
-#define SGX_SECINFO_PERMISSION_MASK	GENMASK_ULL(2, 0)
-#define SGX_SECINFO_PAGE_TYPE_MASK	(SGX_PAGE_TYPE_MASK << 8)
-#define SGX_SECINFO_RESERVED_MASK	~(SGX_SECINFO_PERMISSION_MASK | \
-					  SGX_SECINFO_PAGE_TYPE_MASK)
-
-/**
- * struct sgx_secinfo - describes attributes of an EPC page
- * @flags:	permissions and type
- *
- * Used together with ENCLS leaves that add or modify an EPC page to an
- * enclave to define page permissions and type.
- */
-struct sgx_secinfo {
-	u64 flags;
-	u8  reserved[56];
-} __packed __aligned(64);
-
-#define SGX_PCMD_RESERVED_SIZE 40
-
-/**
- * struct sgx_pcmd - Paging Crypto Metadata (PCMD)
- * @enclave_id:	enclave identifier
- * @mac:	MAC over PCMD, page contents and isvsvn
- *
- * PCMD is stored for every swapped page to the regular memory. When ELDU loads
- * the page back it recalculates the MAC by using a isvsvn number stored in a
- * VA page. Together these two structures bring integrity and rollback
- * protection.
- */
-struct sgx_pcmd {
-	struct sgx_secinfo secinfo;
-	u64 enclave_id;
-	u8  reserved[SGX_PCMD_RESERVED_SIZE];
-	u8  mac[16];
-} __packed __aligned(128);
-
-#define SGX_SIGSTRUCT_RESERVED1_SIZE 84
-#define SGX_SIGSTRUCT_RESERVED2_SIZE 20
-#define SGX_SIGSTRUCT_RESERVED3_SIZE 32
-#define SGX_SIGSTRUCT_RESERVED4_SIZE 12
-
-/**
- * struct sgx_sigstruct_header -  defines author of the enclave
- * @header1:		constant byte string
- * @vendor:		must be either 0x0000 or 0x8086
- * @date:		YYYYMMDD in BCD
- * @header2:		costant byte string
- * @swdefined:		software defined value
- */
-struct sgx_sigstruct_header {
-	u64 header1[2];
-	u32 vendor;
-	u32 date;
-	u64 header2[2];
-	u32 swdefined;
-	u8  reserved1[84];
-} __packed;
-
-/**
- * struct sgx_sigstruct_body - defines contents of the enclave
- * @miscselect:		additional information stored to an SSA frame
- * @misc_mask:		required miscselect in SECS
- * @attributes:		attributes for enclave
- * @xfrm:		XSave-Feature Request Mask (subset of XCR0)
- * @attributes_mask:	required attributes in SECS
- * @xfrm_mask:		required XFRM in SECS
- * @mrenclave:		SHA256-hash of the enclave contents
- * @isvprodid:		a user-defined value that is used in key derivation
- * @isvsvn:		a user-defined value that is used in key derivation
- */
-struct sgx_sigstruct_body {
-	u32 miscselect;
-	u32 misc_mask;
-	u8  reserved2[20];
-	u64 attributes;
-	u64 xfrm;
-	u64 attributes_mask;
-	u64 xfrm_mask;
-	u8  mrenclave[32];
-	u8  reserved3[32];
-	u16 isvprodid;
-	u16 isvsvn;
-} __packed;
-
-/**
- * struct sgx_sigstruct - an enclave signature
- * @header:		defines author of the enclave
- * @modulus:		the modulus of the public key
- * @exponent:		the exponent of the public key
- * @signature:		the signature calculated over the fields except modulus,
- * @body:		defines contents of the enclave
- * @q1:			a value used in RSA signature verification
- * @q2:			a value used in RSA signature verification
- *
- * Header and body are the parts that are actual signed. The remaining fields
- * define the signature of the enclave.
- */
-struct sgx_sigstruct {
-	struct sgx_sigstruct_header header;
-	u8  modulus[SGX_MODULUS_SIZE];
-	u32 exponent;
-	u8  signature[SGX_MODULUS_SIZE];
-	struct sgx_sigstruct_body body;
-	u8  reserved4[12];
-	u8  q1[SGX_MODULUS_SIZE];
-	u8  q2[SGX_MODULUS_SIZE];
-} __packed;
-
-#define SGX_LAUNCH_TOKEN_SIZE 304
-
-#endif /* _ASM_X86_SGX_ARCH_H */
diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c
index d25f2a245e1d..3be203297988 100644
--- a/arch/x86/kernel/cpu/sgx/encl.c
+++ b/arch/x86/kernel/cpu/sgx/encl.c
@@ -7,7 +7,7 @@
 #include <linux/shmem_fs.h>
 #include <linux/suspend.h>
 #include <linux/sched/mm.h>
-#include "arch.h"
+#include <asm/sgx.h>
 #include "encl.h"
 #include "encls.h"
 #include "sgx.h"
diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h
index 4854f3980edd..e4cbc71bf136 100644
--- a/arch/x86/kernel/cpu/sgx/sgx.h
+++ b/arch/x86/kernel/cpu/sgx/sgx.h
@@ -8,7 +8,7 @@
 #include <linux/rwsem.h>
 #include <linux/types.h>
 #include <asm/asm.h>
-#include "arch.h"
+#include <asm/sgx.h>
 
 #undef pr_fmt
 #define pr_fmt(fmt) "sgx: " fmt
diff --git a/tools/testing/selftests/sgx/defines.h b/tools/testing/selftests/sgx/defines.h
index 592c1ccf4576..0bd73428d2f3 100644
--- a/tools/testing/selftests/sgx/defines.h
+++ b/tools/testing/selftests/sgx/defines.h
@@ -14,7 +14,7 @@
 #define __aligned(x) __attribute__((__aligned__(x)))
 #define __packed __attribute__((packed))
 
-#include "../../../../arch/x86/kernel/cpu/sgx/arch.h"
+#include "../../../../arch/x86/include/asm/sgx.h"
 #include "../../../../arch/x86/include/asm/enclu.h"
 #include "../../../../arch/x86/include/uapi/asm/sgx.h"
 
-- 
cgit v1.2.3


From 9c55c78a73ce6e62a1d46ba6e4f242c23c29b812 Mon Sep 17 00:00:00 2001
From: Sean Christopherson
Date: Fri, 19 Mar 2021 20:23:04 +1300
Subject: x86/sgx: Move ENCLS leaf definitions to sgx.h

Move the ENCLS leaf definitions to sgx.h so that they can be used by
KVM.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Link: https://lkml.kernel.org/r/2e6cd7c5c1ced620cfcd292c3c6c382827fde6b2.1616136308.git.kai.huang@intel.com
---
 arch/x86/include/asm/sgx.h      | 15 +++++++++++++++
 arch/x86/kernel/cpu/sgx/encls.h | 15 ---------------
 2 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h
index 14bb5f7e221c..34f44238d1d1 100644
--- a/arch/x86/include/asm/sgx.h
+++ b/arch/x86/include/asm/sgx.h
@@ -27,6 +27,21 @@
 /* The bitmask for the EPC section type. */
 #define SGX_CPUID_EPC_MASK	GENMASK(3, 0)
 
+enum sgx_encls_function {
+	ECREATE	= 0x00,
+	EADD	= 0x01,
+	EINIT	= 0x02,
+	EREMOVE	= 0x03,
+	EDGBRD	= 0x04,
+	EDGBWR	= 0x05,
+	EEXTEND	= 0x06,
+	ELDU	= 0x08,
+	EBLOCK	= 0x09,
+	EPA	= 0x0A,
+	EWB	= 0x0B,
+	ETRACK	= 0x0C,
+};
+
 /**
  * enum sgx_return_code - The return code type for ENCLS, ENCLU and ENCLV
  * %SGX_NOT_TRACKED:		Previous ETRACK's shootdown sequence has not
diff --git a/arch/x86/kernel/cpu/sgx/encls.h b/arch/x86/kernel/cpu/sgx/encls.h
index 443188fe7e70..be5c49689980 100644
--- a/arch/x86/kernel/cpu/sgx/encls.h
+++ b/arch/x86/kernel/cpu/sgx/encls.h
@@ -11,21 +11,6 @@
 #include <asm/traps.h>
 #include "sgx.h"
 
-enum sgx_encls_function {
-	ECREATE	= 0x00,
-	EADD	= 0x01,
-	EINIT	= 0x02,
-	EREMOVE	= 0x03,
-	EDGBRD	= 0x04,
-	EDGBWR	= 0x05,
-	EEXTEND	= 0x06,
-	ELDU	= 0x08,
-	EBLOCK	= 0x09,
-	EPA	= 0x0A,
-	EWB	= 0x0B,
-	ETRACK	= 0x0C,
-};
-
 /**
  * ENCLS_FAULT_FLAG - flag signifying an ENCLS return code is a trapnr
  *
-- 
cgit v1.2.3


From 32ddda8e445df3de477db14d386fb3518042224a Mon Sep 17 00:00:00 2001
From: Sean Christopherson
Date: Fri, 19 Mar 2021 20:23:05 +1300
Subject: x86/sgx: Add SGX2 ENCLS leaf definitions (EAUG, EMODPR and EMODT)

Define the ENCLS leafs that are available with SGX2, also referred to as
Enclave Dynamic Memory Management (EDMM).  The leafs will be used by KVM
to conditionally expose SGX2 capabilities to guests.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Link: https://lkml.kernel.org/r/5f0970c251ebcc6d5add132f0d750cc753b7060f.1616136308.git.kai.huang@intel.com
---
 arch/x86/include/asm/sgx.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h
index 34f44238d1d1..3b025afec0a7 100644
--- a/arch/x86/include/asm/sgx.h
+++ b/arch/x86/include/asm/sgx.h
@@ -40,6 +40,9 @@ enum sgx_encls_function {
 	EPA	= 0x0A,
 	EWB	= 0x0B,
 	ETRACK	= 0x0C,
+	EAUG	= 0x0D,
+	EMODPR	= 0x0E,
+	EMODT	= 0x0F,
 };
 
 /**
-- 
cgit v1.2.3


From a67136b458e5e63822b19c35794451122fe2bf3e Mon Sep 17 00:00:00 2001
From: Sean Christopherson
Date: Fri, 19 Mar 2021 20:23:06 +1300
Subject: x86/sgx: Add encls_faulted() helper

Add a helper to extract the fault indicator from an encoded ENCLS return
value.  SGX virtualization will also need to detect ENCLS faults.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Link: https://lkml.kernel.org/r/c1f955898110de2f669da536fc6cf62e003dff88.1616136308.git.kai.huang@intel.com
---
 arch/x86/kernel/cpu/sgx/encls.h | 15 ++++++++++++++-
 arch/x86/kernel/cpu/sgx/ioctl.c |  2 +-
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/cpu/sgx/encls.h b/arch/x86/kernel/cpu/sgx/encls.h
index be5c49689980..9b204843b78d 100644
--- a/arch/x86/kernel/cpu/sgx/encls.h
+++ b/arch/x86/kernel/cpu/sgx/encls.h
@@ -40,6 +40,19 @@
 	} while (0);							  \
 }
 
+/*
+ * encls_faulted() - Check if an ENCLS leaf faulted given an error code
+ * @ret:	the return value of an ENCLS leaf function call
+ *
+ * Return:
+ * - true:	ENCLS leaf faulted.
+ * - false:	Otherwise.
+ */
+static inline bool encls_faulted(int ret)
+{
+	return ret & ENCLS_FAULT_FLAG;
+}
+
 /**
  * encls_failed() - Check if an ENCLS function failed
  * @ret:	the return value of an ENCLS function call
@@ -50,7 +63,7 @@
  */
 static inline bool encls_failed(int ret)
 {
-	if (ret & ENCLS_FAULT_FLAG)
+	if (encls_faulted(ret))
 		return ENCLS_TRAPNR(ret) != X86_TRAP_PF;
 
 	return !!ret;
diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c
index 354e309fcdb7..11e3f9635c24 100644
--- a/arch/x86/kernel/cpu/sgx/ioctl.c
+++ b/arch/x86/kernel/cpu/sgx/ioctl.c
@@ -568,7 +568,7 @@ static int sgx_encl_init(struct sgx_encl *encl, struct sgx_sigstruct *sigstruct,
 		}
 	}
 
-	if (ret & ENCLS_FAULT_FLAG) {
+	if (encls_faulted(ret)) {
 		if (encls_failed(ret))
 			ENCLS_WARN(ret, "EINIT");
 
-- 
cgit v1.2.3


From 73916b6a0c714258f9c2619408a66c6696a761a7 Mon Sep 17 00:00:00 2001
From: Kai Huang
Date: Fri, 19 Mar 2021 20:23:07 +1300
Subject: x86/sgx: Add helper to update SGX_LEPUBKEYHASHn MSRs

Add a helper to update SGX_LEPUBKEYHASHn MSRs.  SGX virtualization also
needs to update those MSRs based on guest's "virtual" SGX_LEPUBKEYHASHn
before EINIT from guest.

Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lkml.kernel.org/r/dfb7cd39d4dd62ea27703b64afdd8bccb579f623.1616136308.git.kai.huang@intel.com
---
 arch/x86/kernel/cpu/sgx/ioctl.c |  5 ++---
 arch/x86/kernel/cpu/sgx/main.c  | 16 ++++++++++++++++
 arch/x86/kernel/cpu/sgx/sgx.h   |  2 ++
 3 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c
index 11e3f9635c24..7be9c064a640 100644
--- a/arch/x86/kernel/cpu/sgx/ioctl.c
+++ b/arch/x86/kernel/cpu/sgx/ioctl.c
@@ -495,7 +495,7 @@ static int sgx_encl_init(struct sgx_encl *encl, struct sgx_sigstruct *sigstruct,
 			 void *token)
 {
 	u64 mrsigner[4];
-	int i, j, k;
+	int i, j;
 	void *addr;
 	int ret;
 
@@ -544,8 +544,7 @@ static int sgx_encl_init(struct sgx_encl *encl, struct sgx_sigstruct *sigstruct,
 
 			preempt_disable();
 
-			for (k = 0; k < 4; k++)
-				wrmsrl(MSR_IA32_SGXLEPUBKEYHASH0 + k, mrsigner[k]);
+			sgx_update_lepubkeyhash(mrsigner);
 
 			ret = __einit(sigstruct, token, addr);
 
diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
index 1c8a228b0104..227f1e2ad9cf 100644
--- a/arch/x86/kernel/cpu/sgx/main.c
+++ b/arch/x86/kernel/cpu/sgx/main.c
@@ -727,6 +727,22 @@ static bool __init sgx_page_cache_init(void)
 	return true;
 }
 
+/*
+ * Update the SGX_LEPUBKEYHASH MSRs to the values specified by caller.
+ * Bare-metal driver requires to update them to hash of enclave's signer
+ * before EINIT. KVM needs to update them to guest's virtual MSR values
+ * before doing EINIT from guest.
+ */
+void sgx_update_lepubkeyhash(u64 *lepubkeyhash)
+{
+	int i;
+
+	WARN_ON_ONCE(preemptible());
+
+	for (i = 0; i < 4; i++)
+		wrmsrl(MSR_IA32_SGXLEPUBKEYHASH0 + i, lepubkeyhash[i]);
+}
+
 static int __init sgx_init(void)
 {
 	int ret;
diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h
index e4cbc71bf136..4628acec0009 100644
--- a/arch/x86/kernel/cpu/sgx/sgx.h
+++ b/arch/x86/kernel/cpu/sgx/sgx.h
@@ -93,4 +93,6 @@ static inline int __init sgx_vepc_init(void)
 }
 #endif
 
+void sgx_update_lepubkeyhash(u64 *lepubkeyhash);
+
 #endif /* _X86_SGX_H */
-- 
cgit v1.2.3


From d155030b1e7c0e448aab22a803f7a71ea2e117d7 Mon Sep 17 00:00:00 2001
From: Sean Christopherson
Date: Fri, 19 Mar 2021 20:23:08 +1300
Subject: x86/sgx: Add helpers to expose ECREATE and EINIT to KVM

The host kernel must intercept ECREATE to impose policies on guests, and
intercept EINIT to be able to write guest's virtual SGX_LEPUBKEYHASH MSR
values to hardware before running guest's EINIT so it can run correctly
according to hardware behavior.

Provide wrappers around __ecreate() and __einit() to hide the ugliness
of overloading the ENCLS return value to encode multiple error formats
in a single int.  KVM will trap-and-execute ECREATE and EINIT as part
of SGX virtualization, and reflect ENCLS execution result to guest by
setting up guest's GPRs, or on an exception, injecting the correct fault
based on return value of __ecreate() and __einit().

Use host userspace addresses (provided by KVM based on guest physical
address of ENCLS parameters) to execute ENCLS/EINIT when possible.
Accesses to both EPC and memory originating from ENCLS are subject to
segmentation and paging mechanisms.  It's also possible to generate
kernel mappings for ENCLS parameters by resolving PFN but using
__uaccess_xx() is simpler.

 [ bp: Return early if the __user memory accesses fail, use
   cpu_feature_enabled(). ]

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lkml.kernel.org/r/20e09daf559aa5e9e680a0b4b5fba940f1bad86e.1616136308.git.kai.huang@intel.com
---
 arch/x86/include/asm/sgx.h     |   7 +++
 arch/x86/kernel/cpu/sgx/virt.c | 117 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 124 insertions(+)

diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h
index 3b025afec0a7..954042e04102 100644
--- a/arch/x86/include/asm/sgx.h
+++ b/arch/x86/include/asm/sgx.h
@@ -365,4 +365,11 @@ struct sgx_sigstruct {
  * comment!
  */
 
+#ifdef CONFIG_X86_SGX_KVM
+int sgx_virt_ecreate(struct sgx_pageinfo *pageinfo, void __user *secs,
+		     int *trapnr);
+int sgx_virt_einit(void __user *sigstruct, void __user *token,
+		   void __user *secs, u64 *lepubkeyhash, int *trapnr);
+#endif
+
 #endif /* _ASM_X86_SGX_H */
diff --git a/arch/x86/kernel/cpu/sgx/virt.c b/arch/x86/kernel/cpu/sgx/virt.c
index 259cc46ad78c..7d221eac716a 100644
--- a/arch/x86/kernel/cpu/sgx/virt.c
+++ b/arch/x86/kernel/cpu/sgx/virt.c
@@ -257,3 +257,120 @@ int __init sgx_vepc_init(void)
 
 	return misc_register(&sgx_vepc_dev);
 }
+
+/**
+ * sgx_virt_ecreate() - Run ECREATE on behalf of guest
+ * @pageinfo:	Pointer to PAGEINFO structure
+ * @secs:	Userspace pointer to SECS page
+ * @trapnr:	trap number injected to guest in case of ECREATE error
+ *
+ * Run ECREATE on behalf of guest after KVM traps ECREATE for the purpose
+ * of enforcing policies of guest's enclaves, and return the trap number
+ * which should be injected to guest in case of any ECREATE error.
+ *
+ * Return:
+ * -  0:	ECREATE was successful.
+ * - <0:	on error.
+ */
+int sgx_virt_ecreate(struct sgx_pageinfo *pageinfo, void __user *secs,
+		     int *trapnr)
+{
+	int ret;
+
+	/*
+	 * @secs is an untrusted, userspace-provided address.  It comes from
+	 * KVM and is assumed to be a valid pointer which points somewhere in
+	 * userspace.  This can fault and call SGX or other fault handlers when
+	 * userspace mapping @secs doesn't exist.
+	 *
+	 * Add a WARN() to make sure @secs is already valid userspace pointer
+	 * from caller (KVM), who should already have handled invalid pointer
+	 * case (for instance, made by malicious guest).  All other checks,
+	 * such as alignment of @secs, are deferred to ENCLS itself.
+	 */
+	if (WARN_ON_ONCE(!access_ok(secs, PAGE_SIZE)))
+		return -EINVAL;
+
+	__uaccess_begin();
+	ret = __ecreate(pageinfo, (void *)secs);
+	__uaccess_end();
+
+	if (encls_faulted(ret)) {
+		*trapnr = ENCLS_TRAPNR(ret);
+		return -EFAULT;
+	}
+
+	/* ECREATE doesn't return an error code, it faults or succeeds. */
+	WARN_ON_ONCE(ret);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(sgx_virt_ecreate);
+
+static int __sgx_virt_einit(void __user *sigstruct, void __user *token,
+			    void __user *secs)
+{
+	int ret;
+
+	/*
+	 * Make sure all userspace pointers from caller (KVM) are valid.
+	 * All other checks deferred to ENCLS itself.  Also see comment
+	 * for @secs in sgx_virt_ecreate().
+	 */
+#define SGX_EINITTOKEN_SIZE	304
+	if (WARN_ON_ONCE(!access_ok(sigstruct, sizeof(struct sgx_sigstruct)) ||
+			 !access_ok(token, SGX_EINITTOKEN_SIZE) ||
+			 !access_ok(secs, PAGE_SIZE)))
+		return -EINVAL;
+
+	__uaccess_begin();
+	ret = __einit((void *)sigstruct, (void *)token, (void *)secs);
+	__uaccess_end();
+
+	return ret;
+}
+
+/**
+ * sgx_virt_einit() - Run EINIT on behalf of guest
+ * @sigstruct:		Userspace pointer to SIGSTRUCT structure
+ * @token:		Userspace pointer to EINITTOKEN structure
+ * @secs:		Userspace pointer to SECS page
+ * @lepubkeyhash:	Pointer to guest's *virtual* SGX_LEPUBKEYHASH MSR values
+ * @trapnr:		trap number injected to guest in case of EINIT error
+ *
+ * Run EINIT on behalf of guest after KVM traps EINIT. If SGX_LC is available
+ * in host, SGX driver may rewrite the hardware values at wish, therefore KVM
+ * needs to update hardware values to guest's virtual MSR values in order to
+ * ensure EINIT is executed with expected hardware values.
+ *
+ * Return:
+ * -  0:	EINIT was successful.
+ * - <0:	on error.
+ */
+int sgx_virt_einit(void __user *sigstruct, void __user *token,
+		   void __user *secs, u64 *lepubkeyhash, int *trapnr)
+{
+	int ret;
+
+	if (!cpu_feature_enabled(X86_FEATURE_SGX_LC)) {
+		ret = __sgx_virt_einit(sigstruct, token, secs);
+	} else {
+		preempt_disable();
+
+		sgx_update_lepubkeyhash(lepubkeyhash);
+
+		ret = __sgx_virt_einit(sigstruct, token, secs);
+		preempt_enable();
+	}
+
+	/* Propagate up the error from the WARN_ON_ONCE in __sgx_virt_einit() */
+	if (ret == -EINVAL)
+		return ret;
+
+	if (encls_faulted(ret)) {
+		*trapnr = ENCLS_TRAPNR(ret);
+		return -EFAULT;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(sgx_virt_einit);
-- 
cgit v1.2.3


From b3754e5d3da320af2bebb7a690002685c7f5c15c Mon Sep 17 00:00:00 2001
From: Sean Christopherson
Date: Fri, 19 Mar 2021 20:23:09 +1300
Subject: x86/sgx: Move provisioning device creation out of SGX driver

And extract sgx_set_attribute() out of sgx_ioc_enclave_provision() and
export it as symbol for KVM to use.

The provisioning key is sensitive. The SGX driver only allows to create
an enclave which can access the provisioning key when the enclave
creator has permission to open /dev/sgx_provision. It should apply to
a VM as well, as the provisioning key is platform-specific, thus an
unrestricted VM can also potentially compromise the provisioning key.

Move the provisioning device creation out of sgx_drv_init() to
sgx_init() as a preparation for adding SGX virtualization support,
so that even if the SGX driver is not enabled due to flexible launch
control not being available, SGX virtualization can still be enabled,
and use it to restrict a VM's capability of being able to access the
provisioning key.

 [ bp: Massage commit message. ]

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Link: https://lkml.kernel.org/r/0f4d044d621561f26d5f4ef73e8dc6cd18cc7e79.1616136308.git.kai.huang@intel.com
---
 arch/x86/include/asm/sgx.h       |  3 +++
 arch/x86/kernel/cpu/sgx/driver.c | 17 ------------
 arch/x86/kernel/cpu/sgx/ioctl.c  | 16 ++---------
 arch/x86/kernel/cpu/sgx/main.c   | 57 +++++++++++++++++++++++++++++++++++++++-
 4 files changed, 61 insertions(+), 32 deletions(-)

diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h
index 954042e04102..a16e2c9154a3 100644
--- a/arch/x86/include/asm/sgx.h
+++ b/arch/x86/include/asm/sgx.h
@@ -372,4 +372,7 @@ int sgx_virt_einit(void __user *sigstruct, void __user *token,
 		   void __user *secs, u64 *lepubkeyhash, int *trapnr);
 #endif
 
+int sgx_set_attribute(unsigned long *allowed_attributes,
+		      unsigned int attribute_fd);
+
 #endif /* _ASM_X86_SGX_H */
diff --git a/arch/x86/kernel/cpu/sgx/driver.c b/arch/x86/kernel/cpu/sgx/driver.c
index 8ce6d8371cfb..aa9b8b868867 100644
--- a/arch/x86/kernel/cpu/sgx/driver.c
+++ b/arch/x86/kernel/cpu/sgx/driver.c
@@ -136,10 +136,6 @@ static const struct file_operations sgx_encl_fops = {
 	.get_unmapped_area	= sgx_get_unmapped_area,
 };
 
-const struct file_operations sgx_provision_fops = {
-	.owner			= THIS_MODULE,
-};
-
 static struct miscdevice sgx_dev_enclave = {
 	.minor = MISC_DYNAMIC_MINOR,
 	.name = "sgx_enclave",
@@ -147,13 +143,6 @@ static struct miscdevice sgx_dev_enclave = {
 	.fops = &sgx_encl_fops,
 };
 
-static struct miscdevice sgx_dev_provision = {
-	.minor = MISC_DYNAMIC_MINOR,
-	.name = "sgx_provision",
-	.nodename = "sgx_provision",
-	.fops = &sgx_provision_fops,
-};
-
 int __init sgx_drv_init(void)
 {
 	unsigned int eax, ebx, ecx, edx;
@@ -187,11 +176,5 @@ int __init sgx_drv_init(void)
 	if (ret)
 		return ret;
 
-	ret = misc_register(&sgx_dev_provision);
-	if (ret) {
-		misc_deregister(&sgx_dev_enclave);
-		return ret;
-	}
-
 	return 0;
 }
diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c
index 7be9c064a640..83df20e3e633 100644
--- a/arch/x86/kernel/cpu/sgx/ioctl.c
+++ b/arch/x86/kernel/cpu/sgx/ioctl.c
@@ -2,6 +2,7 @@
 /*  Copyright(c) 2016-20 Intel Corporation. */
 
 #include <asm/mman.h>
+#include <asm/sgx.h>
 #include <linux/mman.h>
 #include <linux/delay.h>
 #include <linux/file.h>
@@ -666,24 +667,11 @@ out:
 static long sgx_ioc_enclave_provision(struct sgx_encl *encl, void __user *arg)
 {
 	struct sgx_enclave_provision params;
-	struct file *file;
 
 	if (copy_from_user(&params, arg, sizeof(params)))
 		return -EFAULT;
 
-	file = fget(params.fd);
-	if (!file)
-		return -EINVAL;
-
-	if (file->f_op != &sgx_provision_fops) {
-		fput(file);
-		return -EINVAL;
-	}
-
-	encl->attributes_mask |= SGX_ATTR_PROVISIONKEY;
-
-	fput(file);
-	return 0;
+	return sgx_set_attribute(&encl->attributes_mask, params.fd);
 }
 
 long sgx_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
index 227f1e2ad9cf..92cb11dffd4c 100644
--- a/arch/x86/kernel/cpu/sgx/main.c
+++ b/arch/x86/kernel/cpu/sgx/main.c
@@ -1,14 +1,17 @@
 // SPDX-License-Identifier: GPL-2.0
 /*  Copyright(c) 2016-20 Intel Corporation. */
 
+#include <linux/file.h>
 #include <linux/freezer.h>
 #include <linux/highmem.h>
 #include <linux/kthread.h>
+#include <linux/miscdevice.h>
 #include <linux/pagemap.h>
 #include <linux/ratelimit.h>
 #include <linux/sched/mm.h>
 #include <linux/sched/signal.h>
 #include <linux/slab.h>
+#include <asm/sgx.h>
 #include "driver.h"
 #include "encl.h"
 #include "encls.h"
@@ -743,6 +746,51 @@ void sgx_update_lepubkeyhash(u64 *lepubkeyhash)
 		wrmsrl(MSR_IA32_SGXLEPUBKEYHASH0 + i, lepubkeyhash[i]);
 }
 
+const struct file_operations sgx_provision_fops = {
+	.owner			= THIS_MODULE,
+};
+
+static struct miscdevice sgx_dev_provision = {
+	.minor = MISC_DYNAMIC_MINOR,
+	.name = "sgx_provision",
+	.nodename = "sgx_provision",
+	.fops = &sgx_provision_fops,
+};
+
+/**
+ * sgx_set_attribute() - Update allowed attributes given file descriptor
+ * @allowed_attributes:		Pointer to allowed enclave attributes
+ * @attribute_fd:		File descriptor for specific attribute
+ *
+ * Append enclave attribute indicated by file descriptor to allowed
+ * attributes. Currently only SGX_ATTR_PROVISIONKEY indicated by
+ * /dev/sgx_provision is supported.
+ *
+ * Return:
+ * -0:		SGX_ATTR_PROVISIONKEY is appended to allowed_attributes
+ * -EINVAL:	Invalid, or not supported file descriptor
+ */
+int sgx_set_attribute(unsigned long *allowed_attributes,
+		      unsigned int attribute_fd)
+{
+	struct file *file;
+
+	file = fget(attribute_fd);
+	if (!file)
+		return -EINVAL;
+
+	if (file->f_op != &sgx_provision_fops) {
+		fput(file);
+		return -EINVAL;
+	}
+
+	*allowed_attributes |= SGX_ATTR_PROVISIONKEY;
+
+	fput(file);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(sgx_set_attribute);
+
 static int __init sgx_init(void)
 {
 	int ret;
@@ -759,6 +807,10 @@ static int __init sgx_init(void)
 		goto err_page_cache;
 	}
 
+	ret = misc_register(&sgx_dev_provision);
+	if (ret)
+		goto err_kthread;
+
 	/*
 	 * Always try to initialize the native *and* KVM drivers.
 	 * The KVM driver is less picky than the native one and
@@ -770,10 +822,13 @@ static int __init sgx_init(void)
 	ret = sgx_drv_init();
 
 	if (sgx_vepc_init() && ret)
-		goto err_kthread;
+		goto err_provision;
 
 	return 0;
 
+err_provision:
+	misc_deregister(&sgx_dev_provision);
+
 err_kthread:
 	kthread_stop(ksgxd_tsk);
 
-- 
cgit v1.2.3


From ae40aaf6bdbf0354a75b8284a0de453fcf5f4d32 Mon Sep 17 00:00:00 2001
From: Jarkko Sakkinen
Date: Thu, 8 Apr 2021 12:29:24 +0300
Subject: x86/sgx: Do not update sgx_nr_free_pages in sgx_setup_epc_section()

The commit in Fixes: changed the SGX EPC page sanitization to end up in
sgx_free_epc_page() which puts clean and sanitized pages on the free
list.

This was done for the reason that it is best to keep the logic to assign
available-for-use EPC pages to the correct NUMA lists in a single
location.

sgx_nr_free_pages is also incremented by sgx_free_epc_pages() but those
pages which are being added there per EPC section do not belong to the
free list yet because they haven't been sanitized yet - they land on the
dirty list first and the sanitization happens later when ksgxd starts
massaging them.

So remove that addition there and have sgx_free_epc_page() do that
solely.

 [ bp: Sanitize commit message too. ]

Fixes: 51ab30eb2ad4 ("x86/sgx: Replace section->init_laundry_list with sgx_dirty_page_list")
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210408092924.7032-1-jarkko@kernel.org
---
 arch/x86/kernel/cpu/sgx/main.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
index 92cb11dffd4c..ad904747419e 100644
--- a/arch/x86/kernel/cpu/sgx/main.c
+++ b/arch/x86/kernel/cpu/sgx/main.c
@@ -656,7 +656,6 @@ static bool __init sgx_setup_epc_section(u64 phys_addr, u64 size,
 		list_add_tail(&section->pages[i].list, &sgx_dirty_page_list);
 	}
 
-	sgx_nr_free_pages += nr_pages;
 	return true;
 }
 
-- 
cgit v1.2.3


From 523caed9efbb049339706b124185c9358c1b6477 Mon Sep 17 00:00:00 2001
From: Wei Yongjun
Date: Mon, 12 Apr 2021 16:00:23 +0000
Subject: x86/sgx: Mark sgx_vepc_vm_ops static

Fix the following sparse warning:

  arch/x86/kernel/cpu/sgx/virt.c:95:35: warning:
    symbol 'sgx_vepc_vm_ops' was not declared. Should it be static?

This symbol is not used outside of virt.c so mark it static.

 [ bp: Massage commit message. ]

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210412160023.193850-1-weiyongjun1@huawei.com
---
 arch/x86/kernel/cpu/sgx/virt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/sgx/virt.c b/arch/x86/kernel/cpu/sgx/virt.c
index 7d221eac716a..6ad165a5c0cc 100644
--- a/arch/x86/kernel/cpu/sgx/virt.c
+++ b/arch/x86/kernel/cpu/sgx/virt.c
@@ -92,7 +92,7 @@ static vm_fault_t sgx_vepc_fault(struct vm_fault *vmf)
 	return VM_FAULT_SIGBUS;
 }
 
-const struct vm_operations_struct sgx_vepc_vm_ops = {
+static const struct vm_operations_struct sgx_vepc_vm_ops = {
 	.fault = sgx_vepc_fault,
 };
 
-- 
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