Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 mm updates from Ingo Molnar:
 "Lots of changes in this cycle:

   - Lots of CPA (change page attribute) optimizations and related
     cleanups (Thomas Gleixner, Peter Zijstra)

   - Make lazy TLB mode even lazier (Rik van Riel)

   - Fault handler cleanups and improvements (Dave Hansen)

   - kdump, vmcore: Enable kdumping encrypted memory with AMD SME
     enabled (Lianbo Jiang)

   - Clean up VM layout documentation (Baoquan He, Ingo Molnar)

   - ... plus misc other fixes and enhancements"

* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (51 commits)
  x86/stackprotector: Remove the call to boot_init_stack_canary() from cpu_startup_entry()
  x86/mm: Kill stray kernel fault handling comment
  x86/mm: Do not warn about PCI BIOS W+X mappings
  resource: Clean it up a bit
  resource: Fix find_next_iomem_res() iteration issue
  resource: Include resource end in walk_*() interfaces
  x86/kexec: Correct KEXEC_BACKUP_SRC_END off-by-one error
  x86/mm: Remove spurious fault pkey check
  x86/mm/vsyscall: Consider vsyscall page part of user address space
  x86/mm: Add vsyscall address helper
  x86/mm: Fix exception table comments
  x86/mm: Add clarifying comments for user addr space
  x86/mm: Break out user address space handling
  x86/mm: Break out kernel address space handling
  x86/mm: Clarify hardware vs. software "error_code"
  x86/mm/tlb: Make lazy TLB mode lazier
  x86/mm/tlb: Add freed_tables element to flush_tlb_info
  x86/mm/tlb: Add freed_tables argument to flush_tlb_mm_range
  smp,cpumask: introduce on_each_cpu_cond_mask
  smp: use __cpumask_set_cpu in on_each_cpu_cond
  ...

6 files changed, 763 insertions, 401 deletions

diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c
index a12afff146d1..fc37bbd23eb8 100644
--- a/arch/x86/mm/dump_pagetables.c
+++ b/arch/x86/mm/dump_pagetables.c
@@ -19,7 +19,9 @@
 #include <linux/sched.h>
 #include <linux/seq_file.h>
 #include <linux/highmem.h>
+#include <linux/pci.h>
 
+#include <asm/e820/types.h>
 #include <asm/pgtable.h>
 
 /*
@@ -241,6 +243,29 @@ static unsigned long normalize_addr(unsigned long u)
 	return (signed long)(u << shift) >> shift;
 }
 
+static void note_wx(struct pg_state *st)
+{
+	unsigned long npages;
+
+	npages = (st->current_address - st->start_address) / PAGE_SIZE;
+
+#ifdef CONFIG_PCI_BIOS
+	/*
+	 * If PCI BIOS is enabled, the PCI BIOS area is forced to WX.
+	 * Inform about it, but avoid the warning.
+	 */
+	if (pcibios_enabled && st->start_address >= PAGE_OFFSET + BIOS_BEGIN &&
+	    st->current_address <= PAGE_OFFSET + BIOS_END) {
+		pr_warn_once("x86/mm: PCI BIOS W+X mapping %lu pages\n", npages);
+		return;
+	}
+#endif
+	/* Account the WX pages */
+	st->wx_pages += npages;
+	WARN_ONCE(1, "x86/mm: Found insecure W+X mapping at address %pS\n",
+		  (void *)st->start_address);
+}
+
 /*
  * This function gets called on a break in a continuous series
  * of PTE entries; the next one is different so we need to
@@ -276,14 +301,8 @@ static void note_page(struct seq_file *m, struct pg_state *st,
 		unsigned long delta;
 		int width = sizeof(unsigned long) * 2;
 
-		if (st->check_wx && (eff & _PAGE_RW) && !(eff & _PAGE_NX)) {
-			WARN_ONCE(1,
-				  "x86/mm: Found insecure W+X mapping at address %p/%pS\n",
-				  (void *)st->start_address,
-				  (void *)st->start_address);
-			st->wx_pages += (st->current_address -
-					 st->start_address) / PAGE_SIZE;
-		}
+		if (st->check_wx && (eff & _PAGE_RW) && !(eff & _PAGE_NX))
+			note_wx(st);
 
 		/*
 		 * Now print the actual finished series
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 0d45f6debb3a..2b1519bc5381 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -851,6 +851,15 @@ show_signal_msg(struct pt_regs *regs, unsigned long error_code,
 	show_opcodes(regs, loglvl);
 }
 
+/*
+ * The (legacy) vsyscall page is the long page in the kernel portion
+ * of the address space that has user-accessible permissions.
+ */
+static bool is_vsyscall_vaddr(unsigned long vaddr)
+{
+	return unlikely((vaddr & PAGE_MASK) == VSYSCALL_ADDR);
+}
+
 static void
 __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
 		       unsigned long address, u32 *pkey, int si_code)
@@ -874,18 +883,6 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
 		if (is_errata100(regs, address))
 			return;
 
-#ifdef CONFIG_X86_64
-		/*
-		 * Instruction fetch faults in the vsyscall page might need
-		 * emulation.
-		 */
-		if (unlikely((error_code & X86_PF_INSTR) &&
-			     ((address & ~0xfff) == VSYSCALL_ADDR))) {
-			if (emulate_vsyscall(regs, address))
-				return;
-		}
-#endif
-
 		/*
 		 * To avoid leaking information about the kernel page table
 		 * layout, pretend that user-mode accesses to kernel addresses
@@ -1043,19 +1040,13 @@ mm_fault_error(struct pt_regs *regs, unsigned long error_code,
 	}
 }
 
-static int spurious_fault_check(unsigned long error_code, pte_t *pte)
+static int spurious_kernel_fault_check(unsigned long error_code, pte_t *pte)
 {
 	if ((error_code & X86_PF_WRITE) && !pte_write(*pte))
 		return 0;
 
 	if ((error_code & X86_PF_INSTR) && !pte_exec(*pte))
 		return 0;
-	/*
-	 * Note: We do not do lazy flushing on protection key
-	 * changes, so no spurious fault will ever set X86_PF_PK.
-	 */
-	if ((error_code & X86_PF_PK))
-		return 1;
 
 	return 1;
 }
@@ -1082,7 +1073,7 @@ static int spurious_fault_check(unsigned long error_code, pte_t *pte)
  * (Optional Invalidation).
  */
 static noinline int
-spurious_fault(unsigned long error_code, unsigned long address)
+spurious_kernel_fault(unsigned long error_code, unsigned long address)
 {
 	pgd_t *pgd;
 	p4d_t *p4d;
@@ -1113,27 +1104,27 @@ spurious_fault(unsigned long error_code, unsigned long address)
 		return 0;
 
 	if (p4d_large(*p4d))
-		return spurious_fault_check(error_code, (pte_t *) p4d);
+		return spurious_kernel_fault_check(error_code, (pte_t *) p4d);
 
 	pud = pud_offset(p4d, address);
 	if (!pud_present(*pud))
 		return 0;
 
 	if (pud_large(*pud))
-		return spurious_fault_check(error_code, (pte_t *) pud);
+		return spurious_kernel_fault_check(error_code, (pte_t *) pud);
 
 	pmd = pmd_offset(pud, address);
 	if (!pmd_present(*pmd))
 		return 0;
 
 	if (pmd_large(*pmd))
-		return spurious_fault_check(error_code, (pte_t *) pmd);
+		return spurious_kernel_fault_check(error_code, (pte_t *) pmd);
 
 	pte = pte_offset_kernel(pmd, address);
 	if (!pte_present(*pte))
 		return 0;
 
-	ret = spurious_fault_check(error_code, pte);
+	ret = spurious_kernel_fault_check(error_code, pte);
 	if (!ret)
 		return 0;
 
@@ -1141,12 +1132,12 @@ spurious_fault(unsigned long error_code, unsigned long address)
 	 * Make sure we have permissions in PMD.
 	 * If not, then there's a bug in the page tables:
 	 */
-	ret = spurious_fault_check(error_code, (pte_t *) pmd);
+	ret = spurious_kernel_fault_check(error_code, (pte_t *) pmd);
 	WARN_ONCE(!ret, "PMD has incorrect permission bits\n");
 
 	return ret;
 }
-NOKPROBE_SYMBOL(spurious_fault);
+NOKPROBE_SYMBOL(spurious_kernel_fault);
 
 int show_unhandled_signals = 1;
 
@@ -1193,6 +1184,14 @@ access_error(unsigned long error_code, struct vm_area_struct *vma)
 
 static int fault_in_kernel_space(unsigned long address)
 {
+	/*
+	 * On 64-bit systems, the vsyscall page is at an address above
+	 * TASK_SIZE_MAX, but is not considered part of the kernel
+	 * address space.
+	 */
+	if (IS_ENABLED(CONFIG_X86_64) && is_vsyscall_vaddr(address))
+		return false;
+
 	return address >= TASK_SIZE_MAX;
 }
 
@@ -1214,31 +1213,23 @@ static inline bool smap_violation(int error_code, struct pt_regs *regs)
 }
 
 /*
- * This routine handles page faults.  It determines the address,
- * and the problem, and then passes it off to one of the appropriate
- * routines.
+ * Called for all faults where 'address' is part of the kernel address
+ * space.  Might get called for faults that originate from *code* that
+ * ran in userspace or the kernel.
  */
-static noinline void
-__do_page_fault(struct pt_regs *regs, unsigned long error_code,
-		unsigned long address)
+static void
+do_kern_addr_fault(struct pt_regs *regs, unsigned long hw_error_code,
+		   unsigned long address)
 {
-	struct vm_area_struct *vma;
-	struct task_struct *tsk;
-	struct mm_struct *mm;
-	vm_fault_t fault, major = 0;
-	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
-	u32 pkey;
-
-	tsk = current;
-	mm = tsk->mm;
-
-	prefetchw(&mm->mmap_sem);
-
-	if (unlikely(kmmio_fault(regs, address)))
-		return;
+	/*
+	 * Protection keys exceptions only happen on user pages.  We
+	 * have no user pages in the kernel portion of the address
+	 * space, so do not expect them here.
+	 */
+	WARN_ON_ONCE(hw_error_code & X86_PF_PK);
 
 	/*
-	 * We fault-in kernel-space virtual memory on-demand. The
+	 * We can fault-in kernel-space virtual memory on-demand. The
 	 * 'reference' page table is init_mm.pgd.
 	 *
 	 * NOTE! We MUST NOT take any locks for this case. We may
@@ -1246,41 +1237,74 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code,
 	 * only copy the information from the master page table,
 	 * nothing more.
 	 *
-	 * This verifies that the fault happens in kernel space
-	 * (error_code & 4) == 0, and that the fault was not a
-	 * protection error (error_code & 9) == 0.
+	 * Before doing this on-demand faulting, ensure that the
+	 * fault is not any of the following:
+	 * 1. A fault on a PTE with a reserved bit set.
+	 * 2. A fault caused by a user-mode access.  (Do not demand-
+	 *    fault kernel memory due to user-mode accesses).
+	 * 3. A fault caused by a page-level protection violation.
+	 *    (A demand fault would be on a non-present page which
+	 *     would have X86_PF_PROT==0).
 	 */
-	if (unlikely(fault_in_kernel_space(address))) {
-		if (!(error_code & (X86_PF_RSVD | X86_PF_USER | X86_PF_PROT))) {
-			if (vmalloc_fault(address) >= 0)
-				return;
-		}
-
-		/* Can handle a stale RO->RW TLB: */
-		if (spurious_fault(error_code, address))
+	if (!(hw_error_code & (X86_PF_RSVD | X86_PF_USER | X86_PF_PROT))) {
+		if (vmalloc_fault(address) >= 0)
 			return;
+	}
 
-		/* kprobes don't want to hook the spurious faults: */
-		if (kprobes_fault(regs))
-			return;
-		/*
-		 * Don't take the mm semaphore here. If we fixup a prefetch
-		 * fault we could otherwise deadlock:
-		 */
-		bad_area_nosemaphore(regs, error_code, address, NULL);
+	/* Was the fault spurious, caused by lazy TLB invalidation? */
+	if (spurious_kernel_fault(hw_error_code, address))
+		return;
 
+	/* kprobes don't want to hook the spurious faults: */
+	if (kprobes_fault(regs))
 		return;
-	}
+
+	/*
+	 * Note, despite being a "bad area", there are quite a few
+	 * acceptable reasons to get here, such as erratum fixups
+	 * and handling kernel code that can fault, like get_user().
+	 *
+	 * Don't take the mm semaphore here. If we fixup a prefetch
+	 * fault we could otherwise deadlock:
+	 */
+	bad_area_nosemaphore(regs, hw_error_code, address, NULL);
+}
+NOKPROBE_SYMBOL(do_kern_addr_fault);
+
+/* Handle faults in the user portion of the address space */
+static inline
+void do_user_addr_fault(struct pt_regs *regs,
+			unsigned long hw_error_code,
+			unsigned long address)
+{
+	unsigned long sw_error_code;
+	struct vm_area_struct *vma;
+	struct task_struct *tsk;
+	struct mm_struct *mm;
+	vm_fault_t fault, major = 0;
+	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
+	u32 pkey;
+
+	tsk = current;
+	mm = tsk->mm;
 
 	/* kprobes don't want to hook the spurious faults: */
 	if (unlikely(kprobes_fault(regs)))
 		return;
 
-	if (unlikely(error_code & X86_PF_RSVD))
-		pgtable_bad(regs, error_code, address);
+	/*
+	 * Reserved bits are never expected to be set on
+	 * entries in the user portion of the page tables.
+	 */
+	if (unlikely(hw_error_code & X86_PF_RSVD))
+		pgtable_bad(regs, hw_error_code, address);
 
-	if (unlikely(smap_violation(error_code, regs))) {
-		bad_area_nosemaphore(regs, error_code, address, NULL);
+	/*
+	 * Check for invalid kernel (supervisor) access to user
+	 * pages in the user address space.
+	 */
+	if (unlikely(smap_violation(hw_error_code, regs))) {
+		bad_area_nosemaphore(regs, hw_error_code, address, NULL);
 		return;
 	}
 
@@ -1289,11 +1313,18 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code,
 	 * in a region with pagefaults disabled then we must not take the fault
 	 */
 	if (unlikely(faulthandler_disabled() || !mm)) {
-		bad_area_nosemaphore(regs, error_code, address, NULL);
+		bad_area_nosemaphore(regs, hw_error_code, address, NULL);
 		return;
 	}
 
 	/*
+	 * hw_error_code is literally the "page fault error code" passed to
+	 * the kernel directly from the hardware.  But, we will shortly be
+	 * modifying it in software, so give it a new name.
+	 */
+	sw_error_code = hw_error_code;
+
+	/*
 	 * It's safe to allow irq's after cr2 has been saved and the
 	 * vmalloc fault has been handled.
 	 *
@@ -1302,7 +1333,26 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code,
 	 */
 	if (user_mode(regs)) {
 		local_irq_enable();
-		error_code |= X86_PF_USER;
+		/*
+		 * Up to this point, X86_PF_USER set in hw_error_code
+		 * indicated a user-mode access.  But, after this,
+		 * X86_PF_USER in sw_error_code will indicate either
+		 * that, *or* an implicit kernel(supervisor)-mode access
+		 * which originated from user mode.
+		 */
+		if (!(hw_error_code & X86_PF_USER)) {
+			/*
+			 * The CPU was in user mode, but the CPU says
+			 * the fault was not a user-mode access.
+			 * Must be an implicit kernel-mode access,
+			 * which we do not expect to happen in the
+			 * user address space.
+			 */
+			pr_warn_once("kernel-mode error from user-mode: %lx\n",
+					hw_error_code);
+
+			sw_error_code |= X86_PF_USER;
+		}
 		flags |= FAULT_FLAG_USER;
 	} else {
 		if (regs->flags & X86_EFLAGS_IF)
@@ -1311,31 +1361,49 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code,
 
 	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
 
-	if (error_code & X86_PF_WRITE)
+	if (sw_error_code & X86_PF_WRITE)
 		flags |= FAULT_FLAG_WRITE;
-	if (error_code & X86_PF_INSTR)
+	if (sw_error_code & X86_PF_INSTR)
 		flags |= FAULT_FLAG_INSTRUCTION;
 
+#ifdef CONFIG_X86_64
 	/*
-	 * When running in the kernel we expect faults to occur only to
-	 * addresses in user space.  All other faults represent errors in
-	 * the kernel and should generate an OOPS.  Unfortunately, in the
-	 * case of an erroneous fault occurring in a code path which already
-	 * holds mmap_sem we will deadlock attempting to validate the fault
-	 * against the address space.  Luckily the kernel only validly
-	 * references user space from well defined areas of code, which are
-	 * listed in the exceptions table.
+	 * Instruction fetch faults in the vsyscall page might need
+	 * emulation.  The vsyscall page is at a high address
+	 * (>PAGE_OFFSET), but is considered to be part of the user
+	 * address space.
 	 *
-	 * As the vast majority of faults will be valid we will only perform
-	 * the source reference check when there is a possibility of a
-	 * deadlock. Attempt to lock the address space, if we cannot we then
-	 * validate the source. If this is invalid we can skip the address
-	 * space check, thus avoiding the deadlock:
+	 * The vsyscall page does not have a "real" VMA, so do this
+	 * emulation before we go searching for VMAs.
+	 */
+	if ((sw_error_code & X86_PF_INSTR) && is_vsyscall_vaddr(address)) {
+		if (emulate_vsyscall(regs, address))
+			return;
+	}
+#endif
+
+	/*
+	 * Kernel-mode access to the user address space should only occur
+	 * on well-defined single instructions listed in the exception
+	 * tables.  But, an erroneous kernel fault occurring outside one of
+	 * those areas which also holds mmap_sem might deadlock attempting
+	 * to validate the fault against the address space.
+	 *
+	 * Only do the expensive exception table search when we might be at
+	 * risk of a deadlock.  This happens if we
+	 * 1. Failed to acquire mmap_sem, and
+	 * 2. The access did not originate in userspace.  Note: either the
+	 *    hardware or earlier page fault code may set X86_PF_USER
+	 *    in sw_error_code.
 	 */
 	if (unlikely(!down_read_trylock(&mm->mmap_sem))) {
-		if (!(error_code & X86_PF_USER) &&
+		if (!(sw_error_code & X86_PF_USER) &&
 		    !search_exception_tables(regs->ip)) {
-			bad_area_nosemaphore(regs, error_code, address, NULL);
+			/*
+			 * Fault from code in kernel from
+			 * which we do not expect faults.
+			 */
+			bad_area_nosemaphore(regs, sw_error_code, address, NULL);
 			return;
 		}
 retry:
@@ -1351,16 +1419,16 @@ retry:
 
 	vma = find_vma(mm, address);
 	if (unlikely(!vma)) {
-		bad_area(regs, error_code, address);
+		bad_area(regs, sw_error_code, address);
 		return;
 	}
 	if (likely(vma->vm_start <= address))
 		goto good_area;
 	if (unlikely(!(vma->vm_flags & VM_GROWSDOWN))) {
-		bad_area(regs, error_code, address);
+		bad_area(regs, sw_error_code, address);
 		return;
 	}
-	if (error_code & X86_PF_USER) {
+	if (sw_error_code & X86_PF_USER) {
 		/*
 		 * Accessing the stack below %sp is always a bug.
 		 * The large cushion allows instructions like enter
@@ -1368,12 +1436,12 @@ retry:
 		 * 32 pointers and then decrements %sp by 65535.)
 		 */
 		if (unlikely(address + 65536 + 32 * sizeof(unsigned long) < regs->sp)) {
-			bad_area(regs, error_code, address);
+			bad_area(regs, sw_error_code, address);
 			return;
 		}
 	}
 	if (unlikely(expand_stack(vma, address))) {
-		bad_area(regs, error_code, address);
+		bad_area(regs, sw_error_code, address);
 		return;
 	}
 
@@ -1382,8 +1450,8 @@ retry:
 	 * we can handle it..
 	 */
 good_area:
-	if (unlikely(access_error(error_code, vma))) {
-		bad_area_access_error(regs, error_code, address, vma);
+	if (unlikely(access_error(sw_error_code, vma))) {
+		bad_area_access_error(regs, sw_error_code, address, vma);
 		return;
 	}
 
@@ -1425,13 +1493,13 @@ good_area:
 			return;
 
 		/* Not returning to user mode? Handle exceptions or die: */
-		no_context(regs, error_code, address, SIGBUS, BUS_ADRERR);
+		no_context(regs, sw_error_code, address, SIGBUS, BUS_ADRERR);
 		return;
 	}
 
 	up_read(&mm->mmap_sem);
 	if (unlikely(fault & VM_FAULT_ERROR)) {
-		mm_fault_error(regs, error_code, address, &pkey, fault);
+		mm_fault_error(regs, sw_error_code, address, &pkey, fault);
 		return;
 	}
 
@@ -1449,6 +1517,28 @@ good_area:
 
 	check_v8086_mode(regs, address, tsk);
 }
+NOKPROBE_SYMBOL(do_user_addr_fault);
+
+/*
+ * This routine handles page faults.  It determines the address,
+ * and the problem, and then passes it off to one of the appropriate
+ * routines.
+ */
+static noinline void
+__do_page_fault(struct pt_regs *regs, unsigned long hw_error_code,
+		unsigned long address)
+{
+	prefetchw(&current->mm->mmap_sem);
+
+	if (unlikely(kmmio_fault(regs, address)))
+		return;
+
+	/* Was the fault on kernel-controlled part of the address space? */
+	if (unlikely(fault_in_kernel_space(address)))
+		do_kern_addr_fault(regs, hw_error_code, address);
+	else
+		do_user_addr_fault(regs, hw_error_code, address);
+}
 NOKPROBE_SYMBOL(__do_page_fault);
 
 static nokprobe_inline void
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 979e0a02cbe1..142c7d9f89cc 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -923,34 +923,19 @@ static void mark_nxdata_nx(void)
 void mark_rodata_ro(void)
 {
 	unsigned long start = PFN_ALIGN(_text);
-	unsigned long size = PFN_ALIGN(_etext) - start;
+	unsigned long size = (unsigned long)__end_rodata - start;
 
 	set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
-	printk(KERN_INFO "Write protecting the kernel text: %luk\n",
+	pr_info("Write protecting kernel text and read-only data: %luk\n",
 		size >> 10);
 
 	kernel_set_to_readonly = 1;
 
 #ifdef CONFIG_CPA_DEBUG
-	printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n",
-		start, start+size);
-	set_pages_rw(virt_to_page(start), size>>PAGE_SHIFT);
-
-	printk(KERN_INFO "Testing CPA: write protecting again\n");
-	set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT);
-#endif
-
-	start += size;
-	size = (unsigned long)__end_rodata - start;
-	set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
-	printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
-		size >> 10);
-
-#ifdef CONFIG_CPA_DEBUG
-	printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, start + size);
+	pr_info("Testing CPA: Reverting %lx-%lx\n", start, start + size);
 	set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT);
 
-	printk(KERN_INFO "Testing CPA: write protecting again\n");
+	pr_info("Testing CPA: write protecting again\n");
 	set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
 #endif
 	mark_nxdata_nx();
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index c63a545ec199..24e0920a9b25 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -131,7 +131,8 @@ static void __ioremap_check_mem(resource_size_t addr, unsigned long size,
  * caller shouldn't need to know that small detail.
  */
 static void __iomem *__ioremap_caller(resource_size_t phys_addr,
-		unsigned long size, enum page_cache_mode pcm, void *caller)
+		unsigned long size, enum page_cache_mode pcm,
+		void *caller, bool encrypted)
 {
 	unsigned long offset, vaddr;
 	resource_size_t last_addr;
@@ -199,7 +200,7 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr,
 	 * resulting mapping.
 	 */
 	prot = PAGE_KERNEL_IO;
-	if (sev_active() && mem_flags.desc_other)
+	if ((sev_active() && mem_flags.desc_other) || encrypted)
 		prot = pgprot_encrypted(prot);
 
 	switch (pcm) {
@@ -291,7 +292,7 @@ void __iomem *ioremap_nocache(resource_size_t phys_addr, unsigned long size)
 	enum page_cache_mode pcm = _PAGE_CACHE_MODE_UC_MINUS;
 
 	return __ioremap_caller(phys_addr, size, pcm,
-				__builtin_return_address(0));
+				__builtin_return_address(0), false);
 }
 EXPORT_SYMBOL(ioremap_nocache);
 
@@ -324,7 +325,7 @@ void __iomem *ioremap_uc(resource_size_t phys_addr, unsigned long size)
 	enum page_cache_mode pcm = _PAGE_CACHE_MODE_UC;
 
 	return __ioremap_caller(phys_addr, size, pcm,
-				__builtin_return_address(0));
+				__builtin_return_address(0), false);
 }
 EXPORT_SYMBOL_GPL(ioremap_uc);
 
@@ -341,7 +342,7 @@ EXPORT_SYMBOL_GPL(ioremap_uc);
 void __iomem *ioremap_wc(resource_size_t phys_addr, unsigned long size)
 {
 	return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WC,
-					__builtin_return_address(0));
+					__builtin_return_address(0), false);
 }
 EXPORT_SYMBOL(ioremap_wc);
 
@@ -358,14 +359,21 @@ EXPORT_SYMBOL(ioremap_wc);
 void __iomem *ioremap_wt(resource_size_t phys_addr, unsigned long size)
 {
 	return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WT,
-					__builtin_return_address(0));
+					__builtin_return_address(0), false);
 }
 EXPORT_SYMBOL(ioremap_wt);
 
+void __iomem *ioremap_encrypted(resource_size_t phys_addr, unsigned long size)
+{
+	return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WB,
+				__builtin_return_address(0), true);
+}
+EXPORT_SYMBOL(ioremap_encrypted);
+
 void __iomem *ioremap_cache(resource_size_t phys_addr, unsigned long size)
 {
 	return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WB,
-				__builtin_return_address(0));
+				__builtin_return_address(0), false);
 }
 EXPORT_SYMBOL(ioremap_cache);
 
@@ -374,7 +382,7 @@ void __iomem *ioremap_prot(resource_size_t phys_addr, unsigned long size,
 {
 	return __ioremap_caller(phys_addr, size,
 				pgprot2cachemode(__pgprot(prot_val)),
-				__builtin_return_address(0));
+				__builtin_return_address(0), false);
 }
 EXPORT_SYMBOL(ioremap_prot);
 
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 51a5a69ecac9..62bb30b4bd2a 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -37,11 +37,20 @@ struct cpa_data {
 	unsigned long	numpages;
 	int		flags;
 	unsigned long	pfn;
-	unsigned	force_split : 1;
+	unsigned	force_split		: 1,
+			force_static_prot	: 1;
 	int		curpage;
 	struct page	**pages;
 };
 
+enum cpa_warn {
+	CPA_CONFLICT,
+	CPA_PROTECT,
+	CPA_DETECT,
+};
+
+static const int cpa_warn_level = CPA_PROTECT;
+
 /*
  * Serialize cpa() (for !DEBUG_PAGEALLOC which uses large identity mappings)
  * using cpa_lock. So that we don't allow any other cpu, with stale large tlb
@@ -94,6 +103,87 @@ void arch_report_meminfo(struct seq_file *m)
 static inline void split_page_count(int level) { }
 #endif
 
+#ifdef CONFIG_X86_CPA_STATISTICS
+
+static unsigned long cpa_1g_checked;
+static unsigned long cpa_1g_sameprot;
+static unsigned long cpa_1g_preserved;
+static unsigned long cpa_2m_checked;
+static unsigned long cpa_2m_sameprot;
+static unsigned long cpa_2m_preserved;
+static unsigned long cpa_4k_install;
+
+static inline void cpa_inc_1g_checked(void)
+{
+	cpa_1g_checked++;
+}
+
+static inline void cpa_inc_2m_checked(void)
+{
+	cpa_2m_checked++;
+}
+
+static inline void cpa_inc_4k_install(void)
+{
+	cpa_4k_install++;
+}
+
+static inline void cpa_inc_lp_sameprot(int level)
+{
+	if (level == PG_LEVEL_1G)
+		cpa_1g_sameprot++;
+	else
+		cpa_2m_sameprot++;
+}
+
+static inline void cpa_inc_lp_preserved(int level)
+{
+	if (level == PG_LEVEL_1G)
+		cpa_1g_preserved++;
+	else
+		cpa_2m_preserved++;
+}
+
+static int cpastats_show(struct seq_file *m, void *p)
+{
+	seq_printf(m, "1G pages checked:     %16lu\n", cpa_1g_checked);
+	seq_printf(m, "1G pages sameprot:    %16lu\n", cpa_1g_sameprot);
+	seq_printf(m, "1G pages preserved:   %16lu\n", cpa_1g_preserved);
+	seq_printf(m, "2M pages checked:     %16lu\n", cpa_2m_checked);
+	seq_printf(m, "2M pages sameprot:    %16lu\n", cpa_2m_sameprot);
+	seq_printf(m, "2M pages preserved:   %16lu\n", cpa_2m_preserved);
+	seq_printf(m, "4K pages set-checked: %16lu\n", cpa_4k_install);
+	return 0;
+}
+
+static int cpastats_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, cpastats_show, NULL);
+}
+
+static const struct file_operations cpastats_fops = {
+	.open		= cpastats_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static int __init cpa_stats_init(void)
+{
+	debugfs_create_file("cpa_stats", S_IRUSR, arch_debugfs_dir, NULL,
+			    &cpastats_fops);
+	return 0;
+}
+late_initcall(cpa_stats_init);
+#else
+static inline void cpa_inc_1g_checked(void) { }
+static inline void cpa_inc_2m_checked(void) { }
+static inline void cpa_inc_4k_install(void) { }
+static inline void cpa_inc_lp_sameprot(int level) { }
+static inline void cpa_inc_lp_preserved(int level) { }
+#endif
+
+
 static inline int
 within(unsigned long addr, unsigned long start, unsigned long end)
 {
@@ -195,14 +285,20 @@ static void cpa_flush_all(unsigned long cache)
 	on_each_cpu(__cpa_flush_all, (void *) cache, 1);
 }
 
-static void __cpa_flush_range(void *arg)
+static bool __cpa_flush_range(unsigned long start, int numpages, int cache)
 {
-	/*
-	 * We could optimize that further and do individual per page
-	 * tlb invalidates for a low number of pages. Caveat: we must
-	 * flush the high aliases on 64bit as well.
-	 */
-	__flush_tlb_all();
+	BUG_ON(irqs_disabled() && !early_boot_irqs_disabled);
+
+	WARN_ON(PAGE_ALIGN(start) != start);
+
+	if (cache && !static_cpu_has(X86_FEATURE_CLFLUSH)) {
+		cpa_flush_all(cache);
+		return true;
+	}
+
+	flush_tlb_kernel_range(start, start + PAGE_SIZE * numpages);
+
+	return !cache;
 }
 
 static void cpa_flush_range(unsigned long start, int numpages, int cache)
@@ -210,12 +306,7 @@ static void cpa_flush_range(unsigned long start, int numpages, int cache)
 	unsigned int i, level;
 	unsigned long addr;
 
-	BUG_ON(irqs_disabled() && !early_boot_irqs_disabled);
-	WARN_ON(PAGE_ALIGN(start) != start);
-
-	on_each_cpu(__cpa_flush_range, NULL, 1);
-
-	if (!cache)
+	if (__cpa_flush_range(start, numpages, cache))
 		return;
 
 	/*
@@ -235,30 +326,13 @@ static void cpa_flush_range(unsigned long start, int numpages, int cache)
 	}
 }
 
-static void cpa_flush_array(unsigned long *start, int numpages, int cache,
+static void cpa_flush_array(unsigned long baddr, unsigned long *start,
+			    int numpages, int cache,
 			    int in_flags, struct page **pages)
 {
 	unsigned int i, level;
-#ifdef CONFIG_PREEMPT
-	/*
-	 * Avoid wbinvd() because it causes latencies on all CPUs,
-	 * regardless of any CPU isolation that may be in effect.
-	 *
-	 * This should be extended for CAT enabled systems independent of
-	 * PREEMPT because wbinvd() does not respect the CAT partitions and
-	 * this is exposed to unpriviledged users through the graphics
-	 * subsystem.
-	 */
-	unsigned long do_wbinvd = 0;
-#else
-	unsigned long do_wbinvd = cache && numpages >= 1024; /* 4M threshold */
-#endif
-
-	BUG_ON(irqs_disabled() && !early_boot_irqs_disabled);
 
-	on_each_cpu(__cpa_flush_all, (void *) do_wbinvd, 1);
-
-	if (!cache || do_wbinvd)
+	if (__cpa_flush_range(baddr, numpages, cache))
 		return;
 
 	/*
@@ -286,84 +360,179 @@ static void cpa_flush_array(unsigned long *start, int numpages, int cache,
 	}
 }
 
-/*
- * Certain areas of memory on x86 require very specific protection flags,
- * for example the BIOS area or kernel text. Callers don't always get this
- * right (again, ioremap() on BIOS memory is not uncommon) so this function
- * checks and fixes these known static required protection bits.
- */
-static inline pgprot_t static_protections(pgprot_t prot, unsigned long address,
-				   unsigned long pfn)
+static bool overlaps(unsigned long r1_start, unsigned long r1_end,
+		     unsigned long r2_start, unsigned long r2_end)
 {
-	pgprot_t forbidden = __pgprot(0);
+	return (r1_start <= r2_end && r1_end >= r2_start) ||
+		(r2_start <= r1_end && r2_end >= r1_start);
+}
 
-	/*
-	 * The BIOS area between 640k and 1Mb needs to be executable for
-	 * PCI BIOS based config access (CONFIG_PCI_GOBIOS) support.
-	 */
 #ifdef CONFIG_PCI_BIOS
-	if (pcibios_enabled && within(pfn, BIOS_BEGIN >> PAGE_SHIFT, BIOS_END >> PAGE_SHIFT))
-		pgprot_val(forbidden) |= _PAGE_NX;
+/*
+ * The BIOS area between 640k and 1Mb needs to be executable for PCI BIOS
+ * based config access (CONFIG_PCI_GOBIOS) support.
+ */
+#define BIOS_PFN	PFN_DOWN(BIOS_BEGIN)
+#define BIOS_PFN_END	PFN_DOWN(BIOS_END - 1)
+
+static pgprotval_t protect_pci_bios(unsigned long spfn, unsigned long epfn)
+{
+	if (pcibios_enabled && overlaps(spfn, epfn, BIOS_PFN, BIOS_PFN_END))
+		return _PAGE_NX;
+	return 0;
+}
+#else
+static pgprotval_t protect_pci_bios(unsigned long spfn, unsigned long epfn)
+{
+	return 0;
+}
 #endif
 
-	/*
-	 * The kernel text needs to be executable for obvious reasons
-	 * Does not cover __inittext since that is gone later on. On
-	 * 64bit we do not enforce !NX on the low mapping
-	 */
-	if (within(address, (unsigned long)_text, (unsigned long)_etext))
-		pgprot_val(forbidden) |= _PAGE_NX;
+/*
+ * The .rodata section needs to be read-only. Using the pfn catches all
+ * aliases.  This also includes __ro_after_init, so do not enforce until
+ * kernel_set_to_readonly is true.
+ */
+static pgprotval_t protect_rodata(unsigned long spfn, unsigned long epfn)
+{
+	unsigned long epfn_ro, spfn_ro = PFN_DOWN(__pa_symbol(__start_rodata));
 
 	/*
-	 * The .rodata section needs to be read-only. Using the pfn
-	 * catches all aliases.  This also includes __ro_after_init,
-	 * so do not enforce until kernel_set_to_readonly is true.
+	 * Note: __end_rodata is at page aligned and not inclusive, so
+	 * subtract 1 to get the last enforced PFN in the rodata area.
 	 */
-	if (kernel_set_to_readonly &&
-	    within(pfn, __pa_symbol(__start_rodata) >> PAGE_SHIFT,
-		   __pa_symbol(__end_rodata) >> PAGE_SHIFT))
-		pgprot_val(forbidden) |= _PAGE_RW;
+	epfn_ro = PFN_DOWN(__pa_symbol(__end_rodata)) - 1;
+
+	if (kernel_set_to_readonly && overlaps(spfn, epfn, spfn_ro, epfn_ro))
+		return _PAGE_RW;
+	return 0;
+}
+
+/*
+ * Protect kernel text against becoming non executable by forbidding
+ * _PAGE_NX.  This protects only the high kernel mapping (_text -> _etext)
+ * out of which the kernel actually executes.  Do not protect the low
+ * mapping.
+ *
+ * This does not cover __inittext since that is gone after boot.
+ */
+static pgprotval_t protect_kernel_text(unsigned long start, unsigned long end)
+{
+	unsigned long t_end = (unsigned long)_etext - 1;
+	unsigned long t_start = (unsigned long)_text;
+
+	if (overlaps(start, end, t_start, t_end))
+		return _PAGE_NX;
+	return 0;
+}
 
 #if defined(CONFIG_X86_64)
+/*
+ * Once the kernel maps the text as RO (kernel_set_to_readonly is set),
+ * kernel text mappings for the large page aligned text, rodata sections
+ * will be always read-only. For the kernel identity mappings covering the
+ * holes caused by this alignment can be anything that user asks.
+ *
+ * This will preserve the large page mappings for kernel text/data at no
+ * extra cost.
+ */
+static pgprotval_t protect_kernel_text_ro(unsigned long start,
+					  unsigned long end)
+{
+	unsigned long t_end = (unsigned long)__end_rodata_hpage_align - 1;
+	unsigned long t_start = (unsigned long)_text;
+	unsigned int level;
+
+	if (!kernel_set_to_readonly || !overlaps(start, end, t_start, t_end))
+		return 0;
 	/*
-	 * Once the kernel maps the text as RO (kernel_set_to_readonly is set),
-	 * kernel text mappings for the large page aligned text, rodata sections
-	 * will be always read-only. For the kernel identity mappings covering
-	 * the holes caused by this alignment can be anything that user asks.
+	 * Don't enforce the !RW mapping for the kernel text mapping, if
+	 * the current mapping is already using small page mapping.  No
+	 * need to work hard to preserve large page mappings in this case.
 	 *
-	 * This will preserve the large page mappings for kernel text/data
-	 * at no extra cost.
+	 * This also fixes the Linux Xen paravirt guest boot failure caused
+	 * by unexpected read-only mappings for kernel identity
+	 * mappings. In this paravirt guest case, the kernel text mapping
+	 * and the kernel identity mapping share the same page-table pages,
+	 * so the protections for kernel text and identity mappings have to
+	 * be the same.
 	 */
-	if (kernel_set_to_readonly &&
-	    within(address, (unsigned long)_text,
-		   (unsigned long)__end_rodata_hpage_align)) {
-		unsigned int level;
-
-		/*
-		 * Don't enforce the !RW mapping for the kernel text mapping,
-		 * if the current mapping is already using small page mapping.
-		 * No need to work hard to preserve large page mappings in this
-		 * case.
-		 *
-		 * This also fixes the Linux Xen paravirt guest boot failure
-		 * (because of unexpected read-only mappings for kernel identity
-		 * mappings). In this paravirt guest case, the kernel text
-		 * mapping and the kernel identity mapping share the same
-		 * page-table pages. Thus we can't really use different
-		 * protections for the kernel text and identity mappings. Also,
-		 * these shared mappings are made of small page mappings.
-		 * Thus this don't enforce !RW mapping for small page kernel
-		 * text mapping logic will help Linux Xen parvirt guest boot
-		 * as well.
-		 */
-		if (lookup_address(address, &level) && (level != PG_LEVEL_4K))
-			pgprot_val(forbidden) |= _PAGE_RW;
-	}
+	if (lookup_address(start, &level) && (level != PG_LEVEL_4K))
+		return _PAGE_RW;
+	return 0;
+}
+#else
+static pgprotval_t protect_kernel_text_ro(unsigned long start,
+					  unsigned long end)
+{
+	return 0;
+}
 #endif
 
-	prot = __pgprot(pgprot_val(prot) & ~pgprot_val(forbidden));
+static inline bool conflicts(pgprot_t prot, pgprotval_t val)
+{
+	return (pgprot_val(prot) & ~val) != pgprot_val(prot);
+}
 
-	return prot;
+static inline void check_conflict(int warnlvl, pgprot_t prot, pgprotval_t val,
+				  unsigned long start, unsigned long end,
+				  unsigned long pfn, const char *txt)
+{
+	static const char *lvltxt[] = {
+		[CPA_CONFLICT]	= "conflict",
+		[CPA_PROTECT]	= "protect",
+		[CPA_DETECT]	= "detect",
+	};
+
+	if (warnlvl > cpa_warn_level || !conflicts(prot, val))
+		return;
+
+	pr_warn("CPA %8s %10s: 0x%016lx - 0x%016lx PFN %lx req %016llx prevent %016llx\n",
+		lvltxt[warnlvl], txt, start, end, pfn, (unsigned long long)pgprot_val(prot),
+		(unsigned long long)val);
+}
+
+/*
+ * Certain areas of memory on x86 require very specific protection flags,
+ * for example the BIOS area or kernel text. Callers don't always get this
+ * right (again, ioremap() on BIOS memory is not uncommon) so this function
+ * checks and fixes these known static required protection bits.
+ */
+static inline pgprot_t static_protections(pgprot_t prot, unsigned long start,
+					  unsigned long pfn, unsigned long npg,
+					  int warnlvl)
+{
+	pgprotval_t forbidden, res;
+	unsigned long end;
+
+	/*
+	 * There is no point in checking RW/NX conflicts when the requested
+	 * mapping is setting the page !PRESENT.
+	 */
+	if (!(pgprot_val(prot) & _PAGE_PRESENT))
+		return prot;
+
+	/* Operate on the virtual address */
+	end = start + npg * PAGE_SIZE - 1;
+
+	res = protect_kernel_text(start, end);
+	check_conflict(warnlvl, prot, res, start, end, pfn, "Text NX");
+	forbidden = res;
+
+	res = protect_kernel_text_ro(start, end);
+	check_conflict(warnlvl, prot, res, start, end, pfn, "Text RO");
+	forbidden |= res;
+
+	/* Check the PFN directly */
+	res = protect_pci_bios(pfn, pfn + npg - 1);
+	check_conflict(warnlvl, prot, res, start, end, pfn, "PCIBIOS NX");
+	forbidden |= res;
+
+	res = protect_rodata(pfn, pfn + npg - 1);
+	check_conflict(warnlvl, prot, res, start, end, pfn, "Rodata RO");
+	forbidden |= res;
+
+	return __pgprot(pgprot_val(prot) & ~forbidden);
 }
 
 /*
@@ -421,18 +590,18 @@ pte_t *lookup_address_in_pgd(pgd_t *pgd, unsigned long address,
  */
 pte_t *lookup_address(unsigned long address, unsigned int *level)
 {
-        return lookup_address_in_pgd(pgd_offset_k(address), address, level);
+	return lookup_address_in_pgd(pgd_offset_k(address), address, level);
 }
 EXPORT_SYMBOL_GPL(lookup_address);
 
 static pte_t *_lookup_address_cpa(struct cpa_data *cpa, unsigned long address,
 				  unsigned int *level)
 {
-        if (cpa->pgd)
+	if (cpa->pgd)
 		return lookup_address_in_pgd(cpa->pgd + pgd_index(address),
 					       address, level);
 
-        return lookup_address(address, level);
+	return lookup_address(address, level);
 }
 
 /*
@@ -549,40 +718,35 @@ static pgprot_t pgprot_clear_protnone_bits(pgprot_t prot)
 	return prot;
 }
 
-static int
-try_preserve_large_page(pte_t *kpte, unsigned long address,
-			struct cpa_data *cpa)
+static int __should_split_large_page(pte_t *kpte, unsigned long address,
+				     struct cpa_data *cpa)
 {
-	unsigned long nextpage_addr, numpages, pmask, psize, addr, pfn, old_pfn;
+	unsigned long numpages, pmask, psize, lpaddr, pfn, old_pfn;
+	pgprot_t old_prot, new_prot, req_prot, chk_prot;
 	pte_t new_pte, old_pte, *tmp;
-	pgprot_t old_prot, new_prot, req_prot;
-	int i, do_split = 1;
 	enum pg_level level;
 
-	if (cpa->force_split)
-		return 1;
-
-	spin_lock(&pgd_lock);
 	/*
 	 * Check for races, another CPU might have split this page
 	 * up already:
 	 */
 	tmp = _lookup_address_cpa(cpa, address, &level);
 	if (tmp != kpte)
-		goto out_unlock;
+		return 1;
 
 	switch (level) {
 	case PG_LEVEL_2M:
 		old_prot = pmd_pgprot(*(pmd_t *)kpte);
 		old_pfn = pmd_pfn(*(pmd_t *)kpte);
+		cpa_inc_2m_checked();
 		break;
 	case PG_LEVEL_1G:
 		old_prot = pud_pgprot(*(pud_t *)kpte);
 		old_pfn = pud_pfn(*(pud_t *)kpte);
+		cpa_inc_1g_checked();
 		break;
 	default:
-		do_split = -EINVAL;
-		goto out_unlock;
+		return -EINVAL;
 	}
 
 	psize = page_level_size(level);
@@ -592,8 +756,8 @@ try_preserve_large_page(pte_t *kpte, unsigned long address,
 	 * Calculate the number of pages, which fit into this large
 	 * page starting at address:
 	 */
-	nextpage_addr = (address + psize) & pmask;
-	numpages = (nextpage_addr - address) >> PAGE_SHIFT;
+	lpaddr = (address + psize) & pmask;
+	numpages = (lpaddr - address) >> PAGE_SHIFT;
 	if (numpages < cpa->numpages)
 		cpa->numpages = numpages;
 
@@ -620,71 +784,142 @@ try_preserve_large_page(pte_t *kpte, unsigned long address,
 		pgprot_val(req_prot) |= _PAGE_PSE;
 
 	/*
-	 * old_pfn points to the large page base pfn. So we need
-	 * to add the offset of the virtual address:
+	 * old_pfn points to the large page base pfn. So we need to add the
+	 * offset of the virtual address:
 	 */
 	pfn = old_pfn + ((address & (psize - 1)) >> PAGE_SHIFT);
 	cpa->pfn = pfn;
 
-	new_prot = static_protections(req_prot, address, pfn);
+	/*
+	 * Calculate the large page base address and the number of 4K pages
+	 * in the large page
+	 */
+	lpaddr = address & pmask;
+	numpages = psize >> PAGE_SHIFT;
 
 	/*
-	 * We need to check the full range, whether
-	 * static_protection() requires a different pgprot for one of
-	 * the pages in the range we try to preserve:
+	 * Sanity check that the existing mapping is correct versus the static
+	 * protections. static_protections() guards against !PRESENT, so no
+	 * extra conditional required here.
 	 */
-	addr = address & pmask;
-	pfn = old_pfn;
-	for (i = 0; i < (psize >> PAGE_SHIFT); i++, addr += PAGE_SIZE, pfn++) {
-		pgprot_t chk_prot = static_protections(req_prot, addr, pfn);
+	chk_prot = static_protections(old_prot, lpaddr, old_pfn, numpages,
+				      CPA_CONFLICT);
 
-		if (pgprot_val(chk_prot) != pgprot_val(new_prot))
-			goto out_unlock;
+	if (WARN_ON_ONCE(pgprot_val(chk_prot) != pgprot_val(old_prot))) {
+		/*
+		 * Split the large page and tell the split code to
+		 * enforce static protections.
+		 */
+		cpa->force_static_prot = 1;
+		return 1;
 	}
 
 	/*
-	 * If there are no changes, return. maxpages has been updated
-	 * above:
+	 * Optimization: If the requested pgprot is the same as the current
+	 * pgprot, then the large page can be preserved and no updates are
+	 * required independent of alignment and length of the requested
+	 * range. The above already established that the current pgprot is
+	 * correct, which in consequence makes the requested pgprot correct
+	 * as well if it is the same. The static protection scan below will
+	 * not come to a different conclusion.
 	 */
-	if (pgprot_val(new_prot) == pgprot_val(old_prot)) {
-		do_split = 0;
-		goto out_unlock;
+	if (pgprot_val(req_prot) == pgprot_val(old_prot)) {
+		cpa_inc_lp_sameprot(level);
+		return 0;
 	}
 
 	/*
-	 * We need to change the attributes. Check, whether we can
-	 * change the large page in one go. We request a split, when
-	 * the address is not aligned and the number of pages is
-	 * smaller than the number of pages in the large page. Note
-	 * that we limited the number of possible pages already to
-	 * the number of pages in the large page.
+	 * If the requested range does not cover the full page, split it up
 	 */
-	if (address == (address & pmask) && cpa->numpages == (psize >> PAGE_SHIFT)) {
-		/*
-		 * The address is aligned and the number of pages
-		 * covers the full page.
-		 */
-		new_pte = pfn_pte(old_pfn, new_prot);
-		__set_pmd_pte(kpte, address, new_pte);
-		cpa->flags |= CPA_FLUSHTLB;
-		do_split = 0;
-	}
+	if (address != lpaddr || cpa->numpages != numpages)
+		return 1;
 
-out_unlock:
+	/*
+	 * Check whether the requested pgprot is conflicting with a static
+	 * protection requirement in the large page.
+	 */
+	new_prot = static_protections(req_prot, lpaddr, old_pfn, numpages,
+				      CPA_DETECT);
+
+	/*
+	 * If there is a conflict, split the large page.
+	 *
+	 * There used to be a 4k wise evaluation trying really hard to
+	 * preserve the large pages, but experimentation has shown, that this
+	 * does not help at all. There might be corner cases which would
+	 * preserve one large page occasionally, but it's really not worth the
+	 * extra code and cycles for the common case.
+	 */
+	if (pgprot_val(req_prot) != pgprot_val(new_prot))
+		return 1;
+
+	/* All checks passed. Update the large page mapping. */
+	new_pte = pfn_pte(old_pfn, new_prot);
+	__set_pmd_pte(kpte, address, new_pte);
+	cpa->flags |= CPA_FLUSHTLB;
+	cpa_inc_lp_preserved(level);
+	return 0;
+}
+
+static int should_split_large_page(pte_t *kpte, unsigned long address,
+				   struct cpa_data *cpa)
+{
+	int do_split;
+
+	if (cpa->force_split)
+		return 1;
+
+	spin_lock(&pgd_lock);
+	do_split = __should_split_large_page(kpte, address, cpa);
 	spin_unlock(&pgd_lock);
 
 	return do_split;
 }
 
+static void split_set_pte(struct cpa_data *cpa, pte_t *pte, unsigned long pfn,
+			  pgprot_t ref_prot, unsigned long address,
+			  unsigned long size)
+{
+	unsigned int npg = PFN_DOWN(size);
+	pgprot_t prot;
+
+	/*
+	 * If should_split_large_page() discovered an inconsistent mapping,
+	 * remove the invalid protection in the split mapping.
+	 */
+	if (!cpa->force_static_prot)
+		goto set;
+
+	prot = static_protections(ref_prot, address, pfn, npg, CPA_PROTECT);
+
+	if (pgprot_val(prot) == pgprot_val(ref_prot))
+		goto set;
+
+	/*
+	 * If this is splitting a PMD, fix it up. PUD splits cannot be
+	 * fixed trivially as that would require to rescan the newly
+	 * installed PMD mappings after returning from split_large_page()
+	 * so an eventual further split can allocate the necessary PTE
+	 * pages. Warn for now and revisit it in case this actually
+	 * happens.
+	 */
+	if (size == PAGE_SIZE)
+		ref_prot = prot;
+	else
+		pr_warn_once("CPA: Cannot fixup static protections for PUD split\n");
+set:
+	set_pte(pte, pfn_pte(pfn, ref_prot));
+}
+
 static int
 __split_large_page(struct cpa_data *cpa, pte_t *kpte, unsigned long address,
 		   struct page *base)
 {
+	unsigned long lpaddr, lpinc, ref_pfn, pfn, pfninc = 1;
 	pte_t *pbase = (pte_t *)page_address(base);
-	unsigned long ref_pfn, pfn, pfninc = 1;
 	unsigned int i, level;
-	pte_t *tmp;
 	pgprot_t ref_prot;
+	pte_t *tmp;
 
 	spin_lock(&pgd_lock);
 	/*
@@ -707,15 +942,17 @@ __split_large_page(struct cpa_data *cpa, pte_t *kpte, unsigned long address,
 		 * PAT bit to correct position.
 		 */
 		ref_prot = pgprot_large_2_4k(ref_prot);
-
 		ref_pfn = pmd_pfn(*(pmd_t *)kpte);
+		lpaddr = address & PMD_MASK;
+		lpinc = PAGE_SIZE;
 		break;
 
 	case PG_LEVEL_1G:
 		ref_prot = pud_pgprot(*(pud_t *)kpte);
 		ref_pfn = pud_pfn(*(pud_t *)kpte);
 		pfninc = PMD_PAGE_SIZE >> PAGE_SHIFT;
-
+		lpaddr = address & PUD_MASK;
+		lpinc = PMD_SIZE;
 		/*
 		 * Clear the PSE flags if the PRESENT flag is not set
 		 * otherwise pmd_present/pmd_huge will return true
@@ -736,8 +973,8 @@ __split_large_page(struct cpa_data *cpa, pte_t *kpte, unsigned long address,
 	 * Get the target pfn from the original entry:
 	 */
 	pfn = ref_pfn;
-	for (i = 0; i < PTRS_PER_PTE; i++, pfn += pfninc)
-		set_pte(&pbase[i], pfn_pte(pfn, ref_prot));
+	for (i = 0; i < PTRS_PER_PTE; i++, pfn += pfninc, lpaddr += lpinc)
+		split_set_pte(cpa, pbase + i, pfn, ref_prot, lpaddr, lpinc);
 
 	if (virt_addr_valid(address)) {
 		unsigned long pfn = PFN_DOWN(__pa(address));
@@ -756,14 +993,24 @@ __split_large_page(struct cpa_data *cpa, pte_t *kpte, unsigned long address,
 	__set_pmd_pte(kpte, address, mk_pte(base, __pgprot(_KERNPG_TABLE)));
 
 	/*
-	 * Intel Atom errata AAH41 workaround.
+	 * Do a global flush tlb after splitting the large page
+	 * and before we do the actual change page attribute in the PTE.
+	 *
+	 * Without this, we violate the TLB application note, that says:
+	 * "The TLBs may contain both ordinary and large-page
+	 *  translations for a 4-KByte range of linear addresses. This
+	 *  may occur if software modifies the paging structures so that
+	 *  the page size used for the address range changes. If the two
+	 *  translations differ with respect to page frame or attributes
+	 *  (e.g., permissions), processor behavior is undefined and may
+	 *  be implementation-specific."
 	 *
-	 * The real fix should be in hw or in a microcode update, but
-	 * we also probabilistically try to reduce the window of having
-	 * a large TLB mixed with 4K TLBs while instruction fetches are
-	 * going on.
+	 * We do this global tlb flush inside the cpa_lock, so that we
+	 * don't allow any other cpu, with stale tlb entries change the
+	 * page attribute in parallel, that also falls into the
+	 * just split large page entry.
 	 */
-	__flush_tlb_all();
+	flush_tlb_all();
 	spin_unlock(&pgd_lock);
 
 	return 0;
@@ -1247,7 +1494,9 @@ repeat:
 		pgprot_val(new_prot) &= ~pgprot_val(cpa->mask_clr);
 		pgprot_val(new_prot) |= pgprot_val(cpa->mask_set);
 
-		new_prot = static_protections(new_prot, address, pfn);
+		cpa_inc_4k_install();
+		new_prot = static_protections(new_prot, address, pfn, 1,
+					      CPA_PROTECT);
 
 		new_prot = pgprot_clear_protnone_bits(new_prot);
 
@@ -1273,7 +1522,7 @@ repeat:
 	 * Check, whether we can keep the large page intact
 	 * and just change the pte:
 	 */
-	do_split = try_preserve_large_page(kpte, address, cpa);
+	do_split = should_split_large_page(kpte, address, cpa);
 	/*
 	 * When the range fits into the existing large page,
 	 * return. cp->numpages and cpa->tlbflush have been updated in
@@ -1286,28 +1535,8 @@ repeat:
 	 * We have to split the large page:
 	 */
 	err = split_large_page(cpa, kpte, address);
-	if (!err) {
-		/*
-	 	 * Do a global flush tlb after splitting the large page
-	 	 * and before we do the actual change page attribute in the PTE.
-	 	 *
-	 	 * With out this, we violate the TLB application note, that says
-	 	 * "The TLBs may contain both ordinary and large-page
-		 *  translations for a 4-KByte range of linear addresses. This
-		 *  may occur if software modifies the paging structures so that
-		 *  the page size used for the address range changes. If the two
-		 *  translations differ with respect to page frame or attributes
-		 *  (e.g., permissions), processor behavior is undefined and may
-		 *  be implementation-specific."
-	 	 *
-	 	 * We do this global tlb flush inside the cpa_lock, so that we
-		 * don't allow any other cpu, with stale tlb entries change the
-		 * page attribute in parallel, that also falls into the
-		 * just split large page entry.
-	 	 */
-		flush_tlb_all();
+	if (!err)
 		goto repeat;
-	}
 
 	return err;
 }
@@ -1529,19 +1758,19 @@ static int change_page_attr_set_clr(unsigned long *addr, int numpages,
 	cache = !!pgprot2cachemode(mask_set);
 
 	/*
-	 * On success we use CLFLUSH, when the CPU supports it to
-	 * avoid the WBINVD. If the CPU does not support it and in the
-	 * error case we fall back to cpa_flush_all (which uses
-	 * WBINVD):
+	 * On error; flush everything to be sure.
 	 */
-	if (!ret && boot_cpu_has(X86_FEATURE_CLFLUSH)) {
-		if (cpa.flags & (CPA_PAGES_ARRAY | CPA_ARRAY)) {
-			cpa_flush_array(addr, numpages, cache,
-					cpa.flags, pages);
-		} else
-			cpa_flush_range(baddr, numpages, cache);
-	} else
+	if (ret) {
 		cpa_flush_all(cache);
+		goto out;
+	}
+
+	if (cpa.flags & (CPA_PAGES_ARRAY | CPA_ARRAY)) {
+		cpa_flush_array(baddr, addr, numpages, cache,
+				cpa.flags, pages);
+	} else {
+		cpa_flush_range(baddr, numpages, cache);
+	}
 
 out:
 	return ret;
@@ -1856,10 +2085,7 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
 	/*
 	 * Before changing the encryption attribute, we need to flush caches.
 	 */
-	if (static_cpu_has(X86_FEATURE_CLFLUSH))
-		cpa_flush_range(start, numpages, 1);
-	else
-		cpa_flush_all(1);
+	cpa_flush_range(start, numpages, 1);
 
 	ret = __change_page_attr_set_clr(&cpa, 1);
 
@@ -1870,10 +2096,7 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
 	 * in case TLB flushing gets optimized in the cpa_flush_range()
 	 * path use the same logic as above.
 	 */
-	if (static_cpu_has(X86_FEATURE_CLFLUSH))
-		cpa_flush_range(start, numpages, 0);
-	else
-		cpa_flush_all(0);
+	cpa_flush_range(start, numpages, 0);
 
 	return ret;
 }
diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
index e96b99eb800c..7d68489cfdb1 100644
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -185,8 +185,11 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
 {
 	struct mm_struct *real_prev = this_cpu_read(cpu_tlbstate.loaded_mm);
 	u16 prev_asid = this_cpu_read(cpu_tlbstate.loaded_mm_asid);
+	bool was_lazy = this_cpu_read(cpu_tlbstate.is_lazy);
 	unsigned cpu = smp_processor_id();
 	u64 next_tlb_gen;
+	bool need_flush;
+	u16 new_asid;
 
 	/*
 	 * NB: The scheduler will call us with prev == next when switching
@@ -240,20 +243,41 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
 			   next->context.ctx_id);
 
 		/*
-		 * We don't currently support having a real mm loaded without
-		 * our cpu set in mm_cpumask().  We have all the bookkeeping
-		 * in place to figure out whether we would need to flush
-		 * if our cpu were cleared in mm_cpumask(), but we don't
-		 * currently use it.
+		 * Even in lazy TLB mode, the CPU should stay set in the
+		 * mm_cpumask. The TLB shootdown code can figure out from
+		 * from cpu_tlbstate.is_lazy whether or not to send an IPI.
 		 */
 		if (WARN_ON_ONCE(real_prev != &init_mm &&
 				 !cpumask_test_cpu(cpu, mm_cpumask(next))))
 			cpumask_set_cpu(cpu, mm_cpumask(next));
 
-		return;
+		/*
+		 * If the CPU is not in lazy TLB mode, we are just switching
+		 * from one thread in a process to another thread in the same
+		 * process. No TLB flush required.
+		 */
+		if (!was_lazy)
+			return;
+
+		/*
+		 * Read the tlb_gen to check whether a flush is needed.
+		 * If the TLB is up to date, just use it.
+		 * The barrier synchronizes with the tlb_gen increment in
+		 * the TLB shootdown code.
+		 */
+		smp_mb();
+		next_tlb_gen = atomic64_read(&next->context.tlb_gen);
+		if (this_cpu_read(cpu_tlbstate.ctxs[prev_asid].tlb_gen) ==
+				next_tlb_gen)
+			return;
+
+		/*
+		 * TLB contents went out of date while we were in lazy
+		 * mode. Fall through to the TLB switching code below.
+		 */
+		new_asid = prev_asid;
+		need_flush = true;
 	} else {
-		u16 new_asid;
-		bool need_flush;
 		u64 last_ctx_id = this_cpu_read(cpu_tlbstate.last_ctx_id);
 
 		/*
@@ -308,46 +332,48 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
 		/* Let nmi_uaccess_okay() know that we're changing CR3. */
 		this_cpu_write(cpu_tlbstate.loaded_mm, LOADED_MM_SWITCHING);
 		barrier();
+	}
 
-		if (need_flush) {
-			this_cpu_write(cpu_tlbstate.ctxs[new_asid].ctx_id, next->context.ctx_id);
-			this_cpu_write(cpu_tlbstate.ctxs[new_asid].tlb_gen, next_tlb_gen);
-			load_new_mm_cr3(next->pgd, new_asid, true);
-
-			/*
-			 * NB: This gets called via leave_mm() in the idle path
-			 * where RCU functions differently.  Tracing normally
-			 * uses RCU, so we need to use the _rcuidle variant.
-			 *
-			 * (There is no good reason for this.  The idle code should
-			 *  be rearranged to call this before rcu_idle_enter().)
-			 */
-			trace_tlb_flush_rcuidle(TLB_FLUSH_ON_TASK_SWITCH, TLB_FLUSH_ALL);
-		} else {
-			/* The new ASID is already up to date. */
-			load_new_mm_cr3(next->pgd, new_asid, false);
-
-			/* See above wrt _rcuidle. */
-			trace_tlb_flush_rcuidle(TLB_FLUSH_ON_TASK_SWITCH, 0);
-		}
+	if (need_flush) {
+		this_cpu_write(cpu_tlbstate.ctxs[new_asid].ctx_id, next->context.ctx_id);
+		this_cpu_write(cpu_tlbstate.ctxs[new_asid].tlb_gen, next_tlb_gen);
+		load_new_mm_cr3(next->pgd, new_asid, true);
 
 		/*
-		 * Record last user mm's context id, so we can avoid
-		 * flushing branch buffer with IBPB if we switch back
-		 * to the same user.
+		 * NB: This gets called via leave_mm() in the idle path
+		 * where RCU functions differently.  Tracing normally
+		 * uses RCU, so we need to use the _rcuidle variant.
+		 *
+		 * (There is no good reason for this.  The idle code should
+		 *  be rearranged to call this before rcu_idle_enter().)
 		 */
-		if (next != &init_mm)
-			this_cpu_write(cpu_tlbstate.last_ctx_id, next->context.ctx_id);
-
-		/* Make sure we write CR3 before loaded_mm. */
-		barrier();
+		trace_tlb_flush_rcuidle(TLB_FLUSH_ON_TASK_SWITCH, TLB_FLUSH_ALL);
+	} else {
+		/* The new ASID is already up to date. */
+		load_new_mm_cr3(next->pgd, new_asid, false);
 
-		this_cpu_write(cpu_tlbstate.loaded_mm, next);
-		this_cpu_write(cpu_tlbstate.loaded_mm_asid, new_asid);
+		/* See above wrt _rcuidle. */
+		trace_tlb_flush_rcuidle(TLB_FLUSH_ON_TASK_SWITCH, 0);
 	}
 
-	load_mm_cr4(next);
-	switch_ldt(real_prev, next);
+	/*
+	 * Record last user mm's context id, so we can avoid
+	 * flushing branch buffer with IBPB if we switch back
+	 * to the same user.
+	 */
+	if (next != &init_mm)
+		this_cpu_write(cpu_tlbstate.last_ctx_id, next->context.ctx_id);
+
+	/* Make sure we write CR3 before loaded_mm. */
+	barrier();
+
+	this_cpu_write(cpu_tlbstate.loaded_mm, next);
+	this_cpu_write(cpu_tlbstate.loaded_mm_asid, new_asid);
+
+	if (next != real_prev) {
+		load_mm_cr4(next);
+		switch_ldt(real_prev, next);
+	}
 }
 
 /*
@@ -368,20 +394,7 @@ void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
 	if (this_cpu_read(cpu_tlbstate.loaded_mm) == &init_mm)
 		return;
 
-	if (tlb_defer_switch_to_init_mm()) {
-		/*
-		 * There's a significant optimization that may be possible
-		 * here.  We have accurate enough TLB flush tracking that we
-		 * don't need to maintain coherence of TLB per se when we're
-		 * lazy.  We do, however, need to maintain coherence of
-		 * paging-structure caches.  We could, in principle, leave our
-		 * old mm loaded and only switch to init_mm when
-		 * tlb_remove_page() happens.
-		 */
-		this_cpu_write(cpu_tlbstate.is_lazy, true);
-	} else {
-		switch_mm(NULL, &init_mm, NULL);
-	}
+	this_cpu_write(cpu_tlbstate.is_lazy, true);
 }
 
 /*
@@ -468,6 +481,9 @@ static void flush_tlb_func_common(const struct flush_tlb_info *f,
 		 * paging-structure cache to avoid speculatively reading
 		 * garbage into our TLB.  Since switching to init_mm is barely
 		 * slower than a minimal flush, just switch to init_mm.
+		 *
+		 * This should be rare, with native_flush_tlb_others skipping
+		 * IPIs to lazy TLB mode CPUs.
 		 */
 		switch_mm_irqs_off(NULL, &init_mm, NULL);
 		return;
@@ -528,17 +544,16 @@ static void flush_tlb_func_common(const struct flush_tlb_info *f,
 	    f->new_tlb_gen == local_tlb_gen + 1 &&
 	    f->new_tlb_gen == mm_tlb_gen) {
 		/* Partial flush */
-		unsigned long addr;
-		unsigned long nr_pages = (f->end - f->start) >> PAGE_SHIFT;
+		unsigned long nr_invalidate = (f->end - f->start) >> f->stride_shift;
+		unsigned long addr = f->start;
 
-		addr = f->start;
 		while (addr < f->end) {
 			__flush_tlb_one_user(addr);
-			addr += PAGE_SIZE;
+			addr += 1UL << f->stride_shift;
 		}
 		if (local)
-			count_vm_tlb_events(NR_TLB_LOCAL_FLUSH_ONE, nr_pages);
-		trace_tlb_flush(reason, nr_pages);
+			count_vm_tlb_events(NR_TLB_LOCAL_FLUSH_ONE, nr_invalidate);
+		trace_tlb_flush(reason, nr_invalidate);
 	} else {
 		/* Full flush. */
 		local_flush_tlb();
@@ -571,6 +586,11 @@ static void flush_tlb_func_remote(void *info)
 	flush_tlb_func_common(f, false, TLB_REMOTE_SHOOTDOWN);
 }
 
+static bool tlb_is_not_lazy(int cpu, void *data)
+{
+	return !per_cpu(cpu_tlbstate.is_lazy, cpu);
+}
+
 void native_flush_tlb_others(const struct cpumask *cpumask,
 			     const struct flush_tlb_info *info)
 {
@@ -606,8 +626,23 @@ void native_flush_tlb_others(const struct cpumask *cpumask,
 					       (void *)info, 1);
 		return;
 	}
-	smp_call_function_many(cpumask, flush_tlb_func_remote,
+
+	/*
+	 * If no page tables were freed, we can skip sending IPIs to
+	 * CPUs in lazy TLB mode. They will flush the CPU themselves
+	 * at the next context switch.
+	 *
+	 * However, if page tables are getting freed, we need to send the
+	 * IPI everywhere, to prevent CPUs in lazy TLB mode from tripping
+	 * up on the new contents of what used to be page tables, while
+	 * doing a speculative memory access.
+	 */
+	if (info->freed_tables)
+		smp_call_function_many(cpumask, flush_tlb_func_remote,
 			       (void *)info, 1);
+	else
+		on_each_cpu_cond_mask(tlb_is_not_lazy, flush_tlb_func_remote,
+				(void *)info, 1, GFP_ATOMIC, cpumask);
 }
 
 /*
@@ -623,12 +658,15 @@ void native_flush_tlb_others(const struct cpumask *cpumask,
 static unsigned long tlb_single_page_flush_ceiling __read_mostly = 33;
 
 void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
-				unsigned long end, unsigned long vmflag)
+				unsigned long end, unsigned int stride_shift,
+				bool freed_tables)
 {
 	int cpu;
 
 	struct flush_tlb_info info __aligned(SMP_CACHE_BYTES) = {
 		.mm = mm,
+		.stride_shift = stride_shift,
+		.freed_tables = freed_tables,
 	};
 
 	cpu = get_cpu();
@@ -638,8 +676,7 @@ void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
 
 	/* Should we flush just the requested range? */
 	if ((end != TLB_FLUSH_ALL) &&
-	    !(vmflag & VM_HUGETLB) &&
-	    ((end - start) >> PAGE_SHIFT) <= tlb_single_page_flush_ceiling) {
+	    ((end - start) >> stride_shift) <= tlb_single_page_flush_ceiling) {
 		info.start = start;
 		info.end = end;
 	} else {