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:

 - Extend the memmap= boot parameter syntax to allow the redeclaration
   and dropping of existing ranges, and to support all e820 range types
   (Jan H. Schönherr)

 - Improve the W+X boot time security checks to remove false positive
   warnings on Xen (Jan Beulich)

 - Support booting as Xen PVH guest (Juergen Gross)

 - Improved 5-level paging (LA57) support, in particular it's possible
   now to have a single kernel image for both 4-level and 5-level
   hardware (Kirill A. Shutemov)

 - AMD hardware RAM encryption support (SME/SEV) fixes (Tom Lendacky)

 - Preparatory commits for hardware-encrypted RAM support on Intel CPUs.
   (Kirill A. Shutemov)

 - Improved Intel-MID support (Andy Shevchenko)

 - Show EFI page tables in page_tables debug files (Andy Lutomirski)

 - ... plus misc fixes and smaller cleanups

* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (56 commits)
  x86/cpu/tme: Fix spelling: "configuation" -> "configuration"
  x86/boot: Fix SEV boot failure from change to __PHYSICAL_MASK_SHIFT
  x86/mm: Update comment in detect_tme() regarding x86_phys_bits
  x86/mm/32: Remove unused node_memmap_size_bytes() & CONFIG_NEED_NODE_MEMMAP_SIZE logic
  x86/mm: Remove pointless checks in vmalloc_fault
  x86/platform/intel-mid: Add special handling for ACPI HW reduced platforms
  ACPI, x86/boot: Introduce the ->reduced_hw_early_init() ACPI callback
  ACPI, x86/boot: Split out acpi_generic_reduce_hw_init() and export
  x86/pconfig: Provide defines and helper to run MKTME_KEY_PROG leaf
  x86/pconfig: Detect PCONFIG targets
  x86/tme: Detect if TME and MKTME is activated by BIOS
  x86/boot/compressed/64: Handle 5-level paging boot if kernel is above 4G
  x86/boot/compressed/64: Use page table in trampoline memory
  x86/boot/compressed/64: Use stack from trampoline memory
  x86/boot/compressed/64: Make sure we have a 32-bit code segment
  x86/mm: Do not use paravirtualized calls in native_set_p4d()
  kdump, vmcoreinfo: Export pgtable_l5_enabled value
  x86/boot/compressed/64: Prepare new top-level page table for trampoline
  x86/boot/compressed/64: Set up trampoline memory
  x86/boot/compressed/64: Save and restore trampoline memory
  ...

Documentation/admin-guide/kernel-parameters.txt

@@ -2248,6 +2248,15 @@
 			The memory region may be marked as e820 type 12 (0xc)
 			and is NVDIMM or ADR memory.
 
+	memmap=<size>%<offset>-<oldtype>+<newtype>
+			[KNL,ACPI] Convert memory within the specified region
+			from <oldtype> to <newtype>. If "-<oldtype>" is left
+			out, the whole region will be marked as <newtype>,
+			even if previously unavailable. If "+<newtype>" is left
+			out, matching memory will be removed. Types are
+			specified as e820 types, e.g., 1 = RAM, 2 = reserved,
+			3 = ACPI, 12 = PRAM.
+
 	memory_corruption_check=0/1 [X86]
 			Some BIOSes seem to corrupt the first 64k of
 			memory when doing things like suspend/resume.

Documentation/x86/x86_64/5level-paging.txt

@@ -20,12 +20,9 @@ Documentation/x86/x86_64/mm.txt
 
 CONFIG_X86_5LEVEL=y enables the feature.
 
-So far, a kernel compiled with the option enabled will be able to boot
-only on machines that supports the feature -- see for 'la57' flag in
-/proc/cpuinfo.
-
-The plan is to implement boot-time switching between 4- and 5-level paging
-in the future.
+Kernel with CONFIG_X86_5LEVEL=y still able to boot on 4-level hardware.
+In this case additional page table level -- p4d -- will be folded at
+runtime.
 
 == User-space and large virtual address space ==
 

arch/x86/Kconfig

@@ -1461,6 +1461,8 @@ config X86_PAE
 
 config X86_5LEVEL
 	bool "Enable 5-level page tables support"
+	select DYNAMIC_MEMORY_LAYOUT
+	select SPARSEMEM_VMEMMAP
 	depends on X86_64
 	---help---
 	  5-level paging enables access to larger address space:
@@ -1469,8 +1471,8 @@ config X86_5LEVEL
 
 	  It will be supported by future Intel CPUs.
 
-	  Note: a kernel with this option enabled can only be booted
-	  on machines that support the feature.
+	  A kernel with the option enabled can be booted on machines that
+	  support 4- or 5-level paging.
 
 	  See Documentation/x86/x86_64/5level-paging.txt for more
 	  information.
@@ -1595,10 +1597,6 @@ config ARCH_HAVE_MEMORY_PRESENT
 	def_bool y
 	depends on X86_32 && DISCONTIGMEM
 
-config NEED_NODE_MEMMAP_SIZE
-	def_bool y
-	depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
-
 config ARCH_FLATMEM_ENABLE
 	def_bool y
 	depends on X86_32 && !NUMA
@@ -2174,10 +2172,17 @@ config PHYSICAL_ALIGN
 
 	  Don't change this unless you know what you are doing.
 
+config DYNAMIC_MEMORY_LAYOUT
+	bool
+	---help---
+	  This option makes base addresses of vmalloc and vmemmap as well as
+	  __PAGE_OFFSET movable during boot.
+
 config RANDOMIZE_MEMORY
 	bool "Randomize the kernel memory sections"
 	depends on X86_64
 	depends on RANDOMIZE_BASE
+	select DYNAMIC_MEMORY_LAYOUT
 	default RANDOMIZE_BASE
 	---help---
 	   Randomizes the base virtual address of kernel memory sections

arch/x86/boot/compressed/Makefile

@@ -78,7 +78,7 @@ vmlinux-objs-y := $(obj)/vmlinux.lds $(obj)/head_$(BITS).o $(obj)/misc.o \
 vmlinux-objs-$(CONFIG_EARLY_PRINTK) += $(obj)/early_serial_console.o
 vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/kaslr.o
 ifdef CONFIG_X86_64
-	vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/pagetable.o
+	vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/kaslr_64.o
 	vmlinux-objs-y += $(obj)/mem_encrypt.o
 	vmlinux-objs-y += $(obj)/pgtable_64.o
 endif

arch/x86/boot/compressed/head_64.S

@@ -33,6 +33,7 @@
 #include <asm/processor-flags.h>
 #include <asm/asm-offsets.h>
 #include <asm/bootparam.h>
+#include "pgtable.h"
 
 /*
  * Locally defined symbols should be marked hidden:
@@ -304,55 +305,77 @@ ENTRY(startup_64)
 	/* Set up the stack */
 	leaq	boot_stack_end(%rbx), %rsp
 
-#ifdef CONFIG_X86_5LEVEL
 	/*
-	 * Check if we need to enable 5-level paging.
-	 * RSI holds real mode data and need to be preserved across
-	 * a function call.
+	 * At this point we are in long mode with 4-level paging enabled,
+	 * but we might want to enable 5-level paging or vice versa.
+	 *
+	 * The problem is that we cannot do it directly. Setting or clearing
+	 * CR4.LA57 in long mode would trigger #GP. So we need to switch off
+	 * long mode and paging first.
+	 *
+	 * We also need a trampoline in lower memory to switch over from
+	 * 4- to 5-level paging for cases when the bootloader puts the kernel
+	 * above 4G, but didn't enable 5-level paging for us.
+	 *
+	 * The same trampoline can be used to switch from 5- to 4-level paging
+	 * mode, like when starting 4-level paging kernel via kexec() when
+	 * original kernel worked in 5-level paging mode.
+	 *
+	 * For the trampoline, we need the top page table to reside in lower
+	 * memory as we don't have a way to load 64-bit values into CR3 in
+	 * 32-bit mode.
+	 *
+	 * We go though the trampoline even if we don't have to: if we're
+	 * already in a desired paging mode. This way the trampoline code gets
+	 * tested on every boot.
 	 */
-	pushq	%rsi
-	call	l5_paging_required
-	popq	%rsi
 
-	/* If l5_paging_required() returned zero, we're done here. */
-	cmpq	$0, %rax
-	je	lvl5
+	/* Make sure we have GDT with 32-bit code segment */
+	leaq	gdt(%rip), %rax
+	movq	%rax, gdt64+2(%rip)
+	lgdt	gdt64(%rip)
 
 	/*
-	 * At this point we are in long mode with 4-level paging enabled,
-	 * but we want to enable 5-level paging.
+	 * paging_prepare() sets up the trampoline and checks if we need to
+	 * enable 5-level paging.
 	 *
-	 * The problem is that we cannot do it directly. Setting LA57 in
-	 * long mode would trigger #GP. So we need to switch off long mode
-	 * first.
+	 * Address of the trampoline is returned in RAX.
+	 * Non zero RDX on return means we need to enable 5-level paging.
 	 *
-	 * NOTE: This is not going to work if bootloader put us above 4G
-	 * limit.
-	 *
-	 * The first step is go into compatibility mode.
+	 * RSI holds real mode data and needs to be preserved across
+	 * this function call.
 	 */
+	pushq	%rsi
+	call	paging_prepare
+	popq	%rsi
 
-	/* Clear additional page table */
-	leaq	lvl5_pgtable(%rbx), %rdi
-	xorq	%rax, %rax
-	movq	$(PAGE_SIZE/8), %rcx
-	rep	stosq
+	/* Save the trampoline address in RCX */
+	movq	%rax, %rcx
 
 	/*
-	 * Setup current CR3 as the first and only entry in a new top level
-	 * page table.
+	 * Load the address of trampoline_return() into RDI.
+	 * It will be used by the trampoline to return to the main code.
 	 */
-	movq	%cr3, %rdi
-	leaq	0x7 (%rdi), %rax
-	movq	%rax, lvl5_pgtable(%rbx)
+	leaq	trampoline_return(%rip), %rdi
 
 	/* Switch to compatibility mode (CS.L = 0 CS.D = 1) via far return */
 	pushq	$__KERNEL32_CS
-	leaq	compatible_mode(%rip), %rax
+	leaq	TRAMPOLINE_32BIT_CODE_OFFSET(%rax), %rax
 	pushq	%rax
 	lretq
-lvl5:
-#endif
+trampoline_return:
+	/* Restore the stack, the 32-bit trampoline uses its own stack */
+	leaq	boot_stack_end(%rbx), %rsp
+
+	/*
+	 * cleanup_trampoline() would restore trampoline memory.
+	 *
+	 * RSI holds real mode data and needs to be preserved across
+	 * this function call.
+	 */
+	pushq	%rsi
+	call	cleanup_trampoline
+	popq	%rsi
 
 	/* Zero EFLAGS */
 	pushq	$0
@@ -490,46 +513,82 @@ relocated:
 	jmp	*%rax
 
 	.code32
-#ifdef CONFIG_X86_5LEVEL
-compatible_mode:
-	/* Setup data and stack segments */
+/*
+ * This is the 32-bit trampoline that will be copied over to low memory.
+ *
+ * RDI contains the return address (might be above 4G).
+ * ECX contains the base address of the trampoline memory.
+ * Non zero RDX on return means we need to enable 5-level paging.
+ */
+ENTRY(trampoline_32bit_src)
+	/* Set up data and stack segments */
 	movl	$__KERNEL_DS, %eax
 	movl	%eax, %ds
 	movl	%eax, %ss
 
+	/* Set up new stack */
+	leal	TRAMPOLINE_32BIT_STACK_END(%ecx), %esp
+
 	/* Disable paging */
 	movl	%cr0, %eax
 	btrl	$X86_CR0_PG_BIT, %eax
 	movl	%eax, %cr0
 
-	/* Point CR3 to 5-level paging */
-	leal	lvl5_pgtable(%ebx), %eax
-	movl	%eax, %cr3
+	/* Check what paging mode we want to be in after the trampoline */
+	cmpl	$0, %edx
+	jz	1f
 
-	/* Enable PAE and LA57 mode */
+	/* We want 5-level paging: don't touch CR3 if it already points to 5-level page tables */
+	movl	%cr4, %eax
+	testl	$X86_CR4_LA57, %eax
+	jnz	3f
+	jmp	2f
+1:
+	/* We want 4-level paging: don't touch CR3 if it already points to 4-level page tables */
 	movl	%cr4, %eax
-	orl	$(X86_CR4_PAE | X86_CR4_LA57), %eax
+	testl	$X86_CR4_LA57, %eax
+	jz	3f
+2:
+	/* Point CR3 to the trampoline's new top level page table */
+	leal	TRAMPOLINE_32BIT_PGTABLE_OFFSET(%ecx), %eax
+	movl	%eax, %cr3
+3:
+	/* Enable PAE and LA57 (if required) paging modes */
+	movl	$X86_CR4_PAE, %eax
+	cmpl	$0, %edx
+	jz	1f
+	orl	$X86_CR4_LA57, %eax
+1:
 	movl	%eax, %cr4
 
-	/* Calculate address we are running at */
-	call	1f
-1:	popl	%edi
-	subl	$1b, %edi
+	/* Calculate address of paging_enabled() once we are executing in the trampoline */
+	leal	paging_enabled - trampoline_32bit_src + TRAMPOLINE_32BIT_CODE_OFFSET(%ecx), %eax
 
-	/* Prepare stack for far return to Long Mode */
+	/* Prepare the stack for far return to Long Mode */
 	pushl	$__KERNEL_CS
-	leal	lvl5(%edi), %eax
-	push	%eax
+	pushl	%eax
 
-	/* Enable paging back */
+	/* Enable paging again */
 	movl	$(X86_CR0_PG | X86_CR0_PE), %eax
 	movl	%eax, %cr0
 
 	lret
-#endif
 
+	.code64
+paging_enabled:
+	/* Return from the trampoline */
+	jmp	*%rdi
+
+	/*
+         * The trampoline code has a size limit.
+         * Make sure we fail to compile if the trampoline code grows
+         * beyond TRAMPOLINE_32BIT_CODE_SIZE bytes.
+	 */
+	.org	trampoline_32bit_src + TRAMPOLINE_32BIT_CODE_SIZE
+
+	.code32
 no_longmode:
-	/* This isn't an x86-64 CPU so hang */
+	/* This isn't an x86-64 CPU, so hang intentionally, we cannot continue */
 1:
 	hlt
 	jmp     1b
@@ -537,6 +596,11 @@ no_longmode:
 #include "../../kernel/verify_cpu.S"
 
 	.data
+gdt64:
+	.word	gdt_end - gdt
+	.long	0
+	.word	0
+	.quad   0
 gdt:
 	.word	gdt_end - gdt
 	.long	gdt
@@ -585,7 +649,3 @@ boot_stack_end:
 	.balign 4096
 pgtable:
 	.fill BOOT_PGT_SIZE, 1, 0
-#ifdef CONFIG_X86_5LEVEL
-lvl5_pgtable:
-	.fill PAGE_SIZE, 1, 0
-#endif

arch/x86/boot/compressed/kaslr.c

@@ -46,6 +46,12 @@
 #define STATIC
 #include <linux/decompress/mm.h>
 
+#ifdef CONFIG_X86_5LEVEL
+unsigned int pgtable_l5_enabled __ro_after_init;
+unsigned int pgdir_shift __ro_after_init = 39;
+unsigned int ptrs_per_p4d __ro_after_init = 1;
+#endif
+
 extern unsigned long get_cmd_line_ptr(void);
 
 /* Simplified build-specific string for starting entropy. */
@@ -723,6 +729,14 @@ void choose_random_location(unsigned long input,
 		return;
 	}
 
+#ifdef CONFIG_X86_5LEVEL
+	if (__read_cr4() & X86_CR4_LA57) {
+		pgtable_l5_enabled = 1;
+		pgdir_shift = 48;
+		ptrs_per_p4d = 512;
+	}
+#endif
+
 	boot_params->hdr.loadflags |= KASLR_FLAG;
 
 	/* Prepare to add new identity pagetables on demand. */

arch/x86/boot/compressed/pagetable.c → arch/x86/boot/compressed/kaslr_64.c

@@ -16,13 +16,6 @@
 #define __pa(x)  ((unsigned long)(x))
 #define __va(x)  ((void *)((unsigned long)(x)))
 
-/*
- * The pgtable.h and mm/ident_map.c includes make use of the SME related
- * information which is not used in the compressed image support. Un-define
- * the SME support to avoid any compile and link errors.
- */
-#undef CONFIG_AMD_MEM_ENCRYPT
-
 /* No PAGE_TABLE_ISOLATION support needed either: */
 #undef CONFIG_PAGE_TABLE_ISOLATION
 
@@ -85,13 +78,14 @@ static struct x86_mapping_info mapping_info;
 /* Locates and clears a region for a new top level page table. */
 void initialize_identity_maps(void)
 {
-	unsigned long sev_me_mask = get_sev_encryption_mask();
+	/* If running as an SEV guest, the encryption mask is required. */
+	set_sev_encryption_mask();
 
 	/* Init mapping_info with run-time function/buffer pointers. */
 	mapping_info.alloc_pgt_page = alloc_pgt_page;
 	mapping_info.context = &pgt_data;
-	mapping_info.page_flag = __PAGE_KERNEL_LARGE_EXEC | sev_me_mask;
-	mapping_info.kernpg_flag = _KERNPG_TABLE | sev_me_mask;
+	mapping_info.page_flag = __PAGE_KERNEL_LARGE_EXEC | sme_me_mask;
+	mapping_info.kernpg_flag = _KERNPG_TABLE;
 
 	/*
 	 * It should be impossible for this not to already be true,

arch/x86/boot/compressed/mem_encrypt.S

@@ -88,9 +88,7 @@ ENTRY(get_sev_encryption_bit)
 ENDPROC(get_sev_encryption_bit)
 
 	.code64
-ENTRY(get_sev_encryption_mask)
-	xor	%rax, %rax
-
+ENTRY(set_sev_encryption_mask)
 #ifdef CONFIG_AMD_MEM_ENCRYPT
 	push	%rbp
 	push	%rdx
@@ -101,9 +99,7 @@ ENTRY(get_sev_encryption_mask)
 	testl	%eax, %eax
 	jz	.Lno_sev_mask
 
-	xor	%rdx, %rdx
-	bts	%rax, %rdx		/* Create the encryption mask */
-	mov	%rdx, %rax		/* ... and return it */
+	bts	%rax, sme_me_mask(%rip)	/* Create the encryption mask */
 
 .Lno_sev_mask:
 	movq	%rbp, %rsp		/* Restore original stack pointer */
@@ -112,9 +108,16 @@ ENTRY(get_sev_encryption_mask)
 	pop	%rbp
 #endif
 
+	xor	%rax, %rax
 	ret
-ENDPROC(get_sev_encryption_mask)
+ENDPROC(set_sev_encryption_mask)
 
 	.data
 enc_bit:
 	.int	0xffffffff
+
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+	.balign	8
+GLOBAL(sme_me_mask)
+	.quad	0
+#endif

arch/x86/boot/compressed/misc.c

@@ -14,6 +14,7 @@
 
 #include "misc.h"
 #include "error.h"
+#include "pgtable.h"
 #include "../string.h"
 #include "../voffset.h"
 
@@ -169,16 +170,6 @@ void __puthex(unsigned long value)
 	}
 }
 
-static bool l5_supported(void)
-{
-	/* Check if leaf 7 is supported. */
-	if (native_cpuid_eax(0) < 7)
-		return 0;
-
-	/* Check if la57 is supported. */
-	return native_cpuid_ecx(7) & (1 << (X86_FEATURE_LA57 & 31));
-}
-
 #if CONFIG_X86_NEED_RELOCS
 static void handle_relocations(void *output, unsigned long output_len,
 			       unsigned long virt_addr)
@@ -376,12 +367,6 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap,
 	console_init();
 	debug_putstr("early console in extract_kernel\n");
 
-	if (IS_ENABLED(CONFIG_X86_5LEVEL) && !l5_supported()) {
-		error("This linux kernel as configured requires 5-level paging\n"
-			"This CPU does not support the required 'cr4.la57' feature\n"
-			"Unable to boot - please use a kernel appropriate for your CPU\n");
-	}
-
 	free_mem_ptr     = heap;	/* Heap */
 	free_mem_end_ptr = heap + BOOT_HEAP_SIZE;
 
@@ -392,6 +377,11 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap,
 	debug_putaddr(output_len);
 	debug_putaddr(kernel_total_size);
 
+#ifdef CONFIG_X86_64
+	/* Report address of 32-bit trampoline */
+	debug_putaddr(trampoline_32bit);
+#endif
+
 	/*
 	 * The memory hole needed for the kernel is the larger of either
 	 * the entire decompressed kernel plus relocation table, or the

arch/x86/boot/compressed/misc.h

@@ -12,6 +12,11 @@
 #undef CONFIG_PARAVIRT_SPINLOCKS
 #undef CONFIG_KASAN
 
+#ifdef CONFIG_X86_5LEVEL
+/* cpu_feature_enabled() cannot be used that early */
+#define pgtable_l5_enabled __pgtable_l5_enabled
+#endif
+
 #include <linux/linkage.h>
 #include <linux/screen_info.h>
 #include <linux/elf.h>
@@ -109,6 +114,6 @@ static inline void console_init(void)
 { }
 #endif
 
-unsigned long get_sev_encryption_mask(void);
+void set_sev_encryption_mask(void);
 
 #endif

arch/x86/boot/compressed/pgtable.h

+#ifndef BOOT_COMPRESSED_PAGETABLE_H
+#define BOOT_COMPRESSED_PAGETABLE_H
+
+#define TRAMPOLINE_32BIT_SIZE		(2 * PAGE_SIZE)
+
+#define TRAMPOLINE_32BIT_PGTABLE_OFFSET	0
+
+#define TRAMPOLINE_32BIT_CODE_OFFSET	PAGE_SIZE
+#define TRAMPOLINE_32BIT_CODE_SIZE	0x60
+
+#define TRAMPOLINE_32BIT_STACK_END	TRAMPOLINE_32BIT_SIZE
+
+#ifndef __ASSEMBLER__
+
+extern unsigned long *trampoline_32bit;
+
+extern void trampoline_32bit_src(void *return_ptr);
+
+#endif /* __ASSEMBLER__ */
+#endif /* BOOT_COMPRESSED_PAGETABLE_H */

arch/x86/boot/compressed/pgtable_64.c

 #include <asm/processor.h>
+#include "pgtable.h"
+#include "../string.h"
 
 /*
  * __force_order is used by special_insns.h asm code to force instruction
@@ -9,20 +11,144 @@
  */
 unsigned long __force_order;
 
-int l5_paging_required(void)
+#define BIOS_START_MIN		0x20000U	/* 128K, less than this is insane */
+#define BIOS_START_MAX		0x9f000U	/* 640K, absolute maximum */
+
+struct paging_config {
+	unsigned long trampoline_start;
+	unsigned long l5_required;
+};
+
+/* Buffer to preserve trampoline memory */
+static char trampoline_save[TRAMPOLINE_32BIT_SIZE];
+
+/*
+ * The page table is going to be used instead of page table in the trampoline
+ * memory.
+ *
+ * It must not be in BSS as BSS is cleared after cleanup_trampoline().
+ */
+static char top_pgtable[PAGE_SIZE] __aligned(PAGE_SIZE) __section(.data);
+
+/*
+ * Trampoline address will be printed by extract_kernel() for debugging
+ * purposes.
+ *
+ * Avoid putting the pointer into .bss as it will be cleared between
+ * paging_prepare() and extract_kernel().
+ */
+unsigned long *trampoline_32bit __section(.data);
+
+struct paging_config paging_prepare(void)
 {
-	/* Check if leaf 7 is supported. */
+	struct paging_config paging_config = {};
+	unsigned long bios_start, ebda_start;
+
+	/*
+	 * Check if LA57 is desired and supported.
+	 *
+	 * There are two parts to the check:
+	 *   - if the kernel supports 5-level paging: CONFIG_X86_5LEVEL=y
+	 *   - if the machine supports 5-level paging:
+	 *     + CPUID leaf 7 is supported
+	 *     + the leaf has the feature bit set
+	 *
+	 * That's substitute for boot_cpu_has() in early boot code.
+	 */
+	if (IS_ENABLED(CONFIG_X86_5LEVEL) &&
+			native_cpuid_eax(0) >= 7 &&
+			(native_cpuid_ecx(7) & (1 << (X86_FEATURE_LA57 & 31)))) {
+		paging_config.l5_required = 1;
+	}
+
+	/*
+	 * Find a suitable spot for the trampoline.
+	 * This code is based on reserve_bios_regions().
+	 */
+
+	ebda_start = *(unsigned short *)0x40e << 4;
+	bios_start = *(unsigned short *)0x413 << 10;
 
-	if (native_cpuid_eax(0) < 7)
-		return 0;
+	if (bios_start < BIOS_START_MIN || bios_start > BIOS_START_MAX)
+		bios_start = BIOS_START_MAX;
+
+	if (ebda_start > BIOS_START_MIN && ebda_start < bios_start)
+		bios_start = ebda_start;
+
+	/* Place the trampoline just below the end of low memory, aligned to 4k */
+	paging_config.trampoline_start = bios_start - TRAMPOLINE_32BIT_SIZE;
+	paging_config.trampoline_start = round_down(paging_config.trampoline_start, PAGE_SIZE);
+
+	trampoline_32bit = (unsigned long *)paging_config.trampoline_start;
+
+	/* Preserve trampoline memory */
+	memcpy(trampoline_save, trampoline_32bit, TRAMPOLINE_32BIT_SIZE);
+
+	/* Clear trampoline memory first */
+	memset(trampoline_32bit, 0, TRAMPOLINE_32BIT_SIZE);
+
+	/* Copy trampoline code in place */
+	memcpy(trampoline_32bit + TRAMPOLINE_32BIT_CODE_OFFSET / sizeof(unsigned long),
+			&trampoline_32bit_src, TRAMPOLINE_32BIT_CODE_SIZE);
+
+	/*
+	 * The code below prepares page table in trampoline memory.
+	 *
+	 * The new page table will be used by trampoline code for switching
+	 * from 4- to 5-level paging or vice versa.
+	 *
+	 * If switching is not required, the page table is unused: trampoline
+	 * code wouldn't touch CR3.
+	 */
+
+	/*
+	 * We are not going to use the page table in trampoline memory if we
+	 * are already in the desired paging mode.
+	 */
+	if (paging_config.l5_required == !!(native_read_cr4() & X86_CR4_LA57))
+		goto out;
+
+	if (paging_config.l5_required) {
+		/*
+		 * For 4- to 5-level paging transition, set up current CR3 as
+		 * the first and the only entry in a new top-level page table.
+		 */
+		trampoline_32bit[TRAMPOLINE_32BIT_PGTABLE_OFFSET] = __native_read_cr3() | _PAGE_TABLE_NOENC;
+	} else {
+		unsigned long src;
+
+		/*
+		 * For 5- to 4-level paging transition, copy page table pointed
+		 * by first entry in the current top-level page table as our
+		 * new top-level page table.
+		 *
+		 * We cannot just point to the page table from trampoline as it
+		 * may be above 4G.
+		 */
+		src = *(unsigned long *)__native_read_cr3() & PAGE_MASK;
+		memcpy(trampoline_32bit + TRAMPOLINE_32BIT_PGTABLE_OFFSET / sizeof(unsigned long),
+		       (void *)src, PAGE_SIZE);
+	}
+
+out:
+	return paging_config;
+}
+
+void cleanup_trampoline(void)
+{
+	void *trampoline_pgtable;
 
-	/* Check if la57 is supported. */
-	if (!(native_cpuid_ecx(7) & (1 << (X86_FEATURE_LA57 & 31))))
-		return 0;
+	trampoline_pgtable = trampoline_32bit + TRAMPOLINE_32BIT_PGTABLE_OFFSET;
 
-	/* Check if 5-level paging has already been enabled. */
-	if (native_read_cr4() & X86_CR4_LA57)
-		return 0;
+	/*
+	 * Move the top level page table out of trampoline memory,
+	 * if it's there.
+	 */
+	if ((void *)__native_read_cr3() == trampoline_pgtable) {
+		memcpy(top_pgtable, trampoline_pgtable, PAGE_SIZE);
+		native_write_cr3((unsigned long)top_pgtable);
+	}
 
-	return 1;
+	/* Restore trampoline memory */
+	memcpy(trampoline_32bit, trampoline_save, TRAMPOLINE_32BIT_SIZE);
 }

arch/x86/entry/entry_64.S

@@ -260,8 +260,13 @@ GLOBAL(entry_SYSCALL_64_after_hwframe)
 	 * Change top bits to match most significant bit (47th or 56th bit
 	 * depending on paging mode) in the address.
 	 */
+#ifdef CONFIG_X86_5LEVEL
+	ALTERNATIVE "shl $(64 - 48), %rcx; sar $(64 - 48), %rcx", \
+		"shl $(64 - 57), %rcx; sar $(64 - 57), %rcx", X86_FEATURE_LA57
+#else
 	shl	$(64 - (__VIRTUAL_MASK_SHIFT+1)), %rcx
 	sar	$(64 - (__VIRTUAL_MASK_SHIFT+1)), %rcx
+#endif
 
 	/* If this changed %rcx, it was not canonical */
 	cmpq	%rcx, %r11

arch/x86/include/asm/acpi.h

@@ -31,6 +31,7 @@
 #include <asm/mmu.h>
 #include <asm/mpspec.h>
 #include <asm/realmode.h>
+#include <asm/x86_init.h>
 
 #ifdef CONFIG_ACPI_APEI
 # include <asm/pgtable_types.h>
@@ -133,6 +134,14 @@ static inline bool acpi_has_cpu_in_madt(void)
 	return !!acpi_lapic;
 }
 
+#define ACPI_HAVE_ARCH_GET_ROOT_POINTER
+static inline u64 acpi_arch_get_root_pointer(void)
+{
+	return x86_init.acpi.get_root_pointer();
+}
+
+void acpi_generic_reduced_hw_init(void);
+
 #else /* !CONFIG_ACPI */
 
 #define acpi_lapic 0
@@ -142,6 +151,8 @@ static inline void acpi_noirq_set(void) { }
 static inline void acpi_disable_pci(void) { }
 static inline void disable_acpi(void) { }
 
+static inline void acpi_generic_reduced_hw_init(void) { }
+
 #endif /* !CONFIG_ACPI */
 
 #define ARCH_HAS_POWER_INIT	1

arch/x86/include/asm/intel_pconfig.h

+#ifndef	_ASM_X86_INTEL_PCONFIG_H
+#define	_ASM_X86_INTEL_PCONFIG_H
+
+#include <asm/asm.h>
+#include <asm/processor.h>
+
+enum pconfig_target {
+	INVALID_TARGET	= 0,
+	MKTME_TARGET	= 1,
+	PCONFIG_TARGET_NR
+};
+
+int pconfig_target_supported(enum pconfig_target target);
+
+enum pconfig_leaf {
+	MKTME_KEY_PROGRAM	= 0,
+	PCONFIG_LEAF_INVALID,
+};
+
+#define PCONFIG ".byte 0x0f, 0x01, 0xc5"
+
+/* Defines and structure for MKTME_KEY_PROGRAM of PCONFIG instruction */
+
+/* mktme_key_program::keyid_ctrl COMMAND, bits [7:0] */
+#define MKTME_KEYID_SET_KEY_DIRECT	0
+#define MKTME_KEYID_SET_KEY_RANDOM	1
+#define MKTME_KEYID_CLEAR_KEY		2
+#define MKTME_KEYID_NO_ENCRYPT		3
+
+/* mktme_key_program::keyid_ctrl ENC_ALG, bits [23:8] */
+#define MKTME_AES_XTS_128	(1 << 8)
+
+/* Return codes from the PCONFIG MKTME_KEY_PROGRAM */
+#define MKTME_PROG_SUCCESS	0
+#define MKTME_INVALID_PROG_CMD	1
+#define MKTME_ENTROPY_ERROR	2
+#define MKTME_INVALID_KEYID	3
+#define MKTME_INVALID_ENC_ALG	4
+#define MKTME_DEVICE_BUSY	5
+
+/* Hardware requires the structure to be 256 byte alinged. Otherwise #GP(0). */
+struct mktme_key_program {
+	u16 keyid;
+	u32 keyid_ctrl;
+	u8 __rsvd[58];
+	u8 key_field_1[64];
+	u8 key_field_2[64];
+} __packed __aligned(256);
+
+static inline int mktme_key_program(struct mktme_key_program *key_program)
+{
+	unsigned long rax = MKTME_KEY_PROGRAM;
+
+	if (!pconfig_target_supported(MKTME_TARGET))
+		return -ENXIO;
+
+	asm volatile(PCONFIG
+		: "=a" (rax), "=b" (key_program)
+		: "0" (rax), "1" (key_program)
+		: "memory", "cc");
+
+	return rax;
+}
+
+#endif	/* _ASM_X86_INTEL_PCONFIG_H */

arch/x86/include/asm/kaslr.h

@@ -5,10 +5,6 @@
 unsigned long kaslr_get_random_long(const char *purpose);
 
 #ifdef CONFIG_RANDOMIZE_MEMORY
-extern unsigned long page_offset_base;
-extern unsigned long vmalloc_base;
-extern unsigned long vmemmap_base;
-
 void kernel_randomize_memory(void);
 #else
 static inline void kernel_randomize_memory(void) { }

arch/x86/include/asm/mem_encrypt.h

@@ -22,6 +22,7 @@
 #ifdef CONFIG_AMD_MEM_ENCRYPT
 
 extern u64 sme_me_mask;
+extern bool sev_enabled;
 
 void sme_encrypt_execute(unsigned long encrypted_kernel_vaddr,
 			 unsigned long decrypted_kernel_vaddr,

arch/x86/include/asm/page_64.h

@@ -11,6 +11,10 @@
 extern unsigned long max_pfn;
 extern unsigned long phys_base;
 
+extern unsigned long page_offset_base;
+extern unsigned long vmalloc_base;
+extern unsigned long vmemmap_base;
+
 static inline unsigned long __phys_addr_nodebug(unsigned long x)
 {
 	unsigned long y = x - __START_KERNEL_map;

arch/x86/include/asm/page_64_types.h

@@ -37,26 +37,24 @@
  * hypervisor to fit.  Choosing 16 slots here is arbitrary, but it's
  * what Xen requires.
  */
-#ifdef CONFIG_X86_5LEVEL
-#define __PAGE_OFFSET_BASE      _AC(0xff10000000000000, UL)
-#else
-#define __PAGE_OFFSET_BASE      _AC(0xffff880000000000, UL)
-#endif
+#define __PAGE_OFFSET_BASE_L5	_AC(0xff10000000000000, UL)
+#define __PAGE_OFFSET_BASE_L4	_AC(0xffff880000000000, UL)
 
-#ifdef CONFIG_RANDOMIZE_MEMORY
+#ifdef CONFIG_DYNAMIC_MEMORY_LAYOUT
 #define __PAGE_OFFSET           page_offset_base
 #else
-#define __PAGE_OFFSET           __PAGE_OFFSET_BASE
-#endif /* CONFIG_RANDOMIZE_MEMORY */
+#define __PAGE_OFFSET           __PAGE_OFFSET_BASE_L4
+#endif /* CONFIG_DYNAMIC_MEMORY_LAYOUT */
 
 #define __START_KERNEL_map	_AC(0xffffffff80000000, UL)
 
 /* See Documentation/x86/x86_64/mm.txt for a description of the memory map. */
-#ifdef CONFIG_X86_5LEVEL
+
 #define __PHYSICAL_MASK_SHIFT	52
-#define __VIRTUAL_MASK_SHIFT	56
+
+#ifdef CONFIG_X86_5LEVEL
+#define __VIRTUAL_MASK_SHIFT	(pgtable_l5_enabled ? 56 : 47)
 #else
-#define __PHYSICAL_MASK_SHIFT	46
 #define __VIRTUAL_MASK_SHIFT	47
 #endif
 

arch/x86/include/asm/paravirt.h

@@ -568,17 +568,22 @@ static inline p4dval_t p4d_val(p4d_t p4d)
 	return PVOP_CALLEE1(p4dval_t, pv_mmu_ops.p4d_val, p4d.p4d);
 }
 
-static inline void set_pgd(pgd_t *pgdp, pgd_t pgd)
+static inline void __set_pgd(pgd_t *pgdp, pgd_t pgd)
 {
-	pgdval_t val = native_pgd_val(pgd);
-
-	PVOP_VCALL2(pv_mmu_ops.set_pgd, pgdp, val);
+	PVOP_VCALL2(pv_mmu_ops.set_pgd, pgdp, native_pgd_val(pgd));
 }
 
-static inline void pgd_clear(pgd_t *pgdp)
-{
-	set_pgd(pgdp, __pgd(0));
-}
+#define set_pgd(pgdp, pgdval) do {					\
+	if (pgtable_l5_enabled)						\
+		__set_pgd(pgdp, pgdval);				\
+	else								\
+		set_p4d((p4d_t *)(pgdp), (p4d_t) { (pgdval).pgd });	\
+} while (0)
+
+#define pgd_clear(pgdp) do {						\
+	if (pgtable_l5_enabled)						\
+		set_pgd(pgdp, __pgd(0));				\
+} while (0)
 
 #endif  /* CONFIG_PGTABLE_LEVELS == 5 */
 

arch/x86/include/asm/pgalloc.h

@@ -167,6 +167,8 @@ static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pud,
 #if CONFIG_PGTABLE_LEVELS > 4
 static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, p4d_t *p4d)
 {
+	if (!pgtable_l5_enabled)
+		return;
 	paravirt_alloc_p4d(mm, __pa(p4d) >> PAGE_SHIFT);
 	set_pgd(pgd, __pgd(_PAGE_TABLE | __pa(p4d)));
 }
@@ -191,7 +193,8 @@ extern void ___p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d);
 static inline void __p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d,
 				  unsigned long address)
 {
-	___p4d_free_tlb(tlb, p4d);
+	if (pgtable_l5_enabled)
+		___p4d_free_tlb(tlb, p4d);
 }
 
 #endif	/* CONFIG_PGTABLE_LEVELS > 4 */

arch/x86/include/asm/pgtable-3level_types.h

@@ -44,5 +44,6 @@ typedef union {
  */
 #define PTRS_PER_PTE	512
 
+#define MAX_POSSIBLE_PHYSMEM_BITS	36
 
 #endif /* _ASM_X86_PGTABLE_3LEVEL_DEFS_H */

arch/x86/include/asm/pgtable.h

@@ -65,7 +65,7 @@ extern pmdval_t early_pmd_flags;
 
 #ifndef __PAGETABLE_P4D_FOLDED
 #define set_pgd(pgdp, pgd)		native_set_pgd(pgdp, pgd)
-#define pgd_clear(pgd)			native_pgd_clear(pgd)
+#define pgd_clear(pgd)			(pgtable_l5_enabled ? native_pgd_clear(pgd) : 0)
 #endif
 
 #ifndef set_p4d
@@ -859,6 +859,8 @@ static inline unsigned long p4d_index(unsigned long address)
 #if CONFIG_PGTABLE_LEVELS > 4
 static inline int pgd_present(pgd_t pgd)
 {
+	if (!pgtable_l5_enabled)
+		return 1;
 	return pgd_flags(pgd) & _PAGE_PRESENT;
 }
 
@@ -876,6 +878,8 @@ static inline unsigned long pgd_page_vaddr(pgd_t pgd)
 /* to find an entry in a page-table-directory. */
 static inline p4d_t *p4d_offset(pgd_t *pgd, unsigned long address)
 {
+	if (!pgtable_l5_enabled)
+		return (p4d_t *)pgd;
 	return (p4d_t *)pgd_page_vaddr(*pgd) + p4d_index(address);
 }
 
@@ -883,6 +887,9 @@ static inline int pgd_bad(pgd_t pgd)
 {
 	unsigned long ignore_flags = _PAGE_USER;
 
+	if (!pgtable_l5_enabled)
+		return 0;
+
 	if (IS_ENABLED(CONFIG_PAGE_TABLE_ISOLATION))
 		ignore_flags |= _PAGE_NX;
 
@@ -891,6 +898,8 @@ static inline int pgd_bad(pgd_t pgd)
 
 static inline int pgd_none(pgd_t pgd)
 {
+	if (!pgtable_l5_enabled)
+		return 0;
 	/*
 	 * There is no need to do a workaround for the KNL stray
 	 * A/D bit erratum here.  PGDs only point to page tables

arch/x86/include/asm/pgtable_32.h

@@ -34,6 +34,8 @@ static inline void check_pgt_cache(void) { }
 void paging_init(void);
 void sync_initial_page_table(void);
 
+static inline int pgd_large(pgd_t pgd) { return 0; }
+
 /*
  * Define this if things work differently on an i386 and an i486:
  * it will (on an i486) warn about kernel memory accesses that are

arch/x86/include/asm/pgtable_32_types.h

@@ -15,6 +15,8 @@
 # include <asm/pgtable-2level_types.h>
 #endif
 
+#define pgtable_l5_enabled 0
+
 #define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
 #define PGDIR_MASK	(~(PGDIR_SIZE - 1))
 

arch/x86/include/asm/pgtable_64.h

@@ -218,29 +218,26 @@ static inline pgd_t pti_set_user_pgd(pgd_t *pgdp, pgd_t pgd)
 
 static inline void native_set_p4d(p4d_t *p4dp, p4d_t p4d)
 {
-#if defined(CONFIG_PAGE_TABLE_ISOLATION) && !defined(CONFIG_X86_5LEVEL)
-	p4dp->pgd = pti_set_user_pgd(&p4dp->pgd, p4d.pgd);
-#else
-	*p4dp = p4d;
-#endif
+	pgd_t pgd;
+
+	if (pgtable_l5_enabled || !IS_ENABLED(CONFIG_PAGE_TABLE_ISOLATION)) {
+		*p4dp = p4d;
+		return;
+	}
+
+	pgd = native_make_pgd(native_p4d_val(p4d));
+	pgd = pti_set_user_pgd((pgd_t *)p4dp, pgd);
+	*p4dp = native_make_p4d(native_pgd_val(pgd));
 }
 
 static inline void native_p4d_clear(p4d_t *p4d)
 {
-#ifdef CONFIG_X86_5LEVEL
 	native_set_p4d(p4d, native_make_p4d(0));
-#else
-	native_set_p4d(p4d, (p4d_t) { .pgd = native_make_pgd(0)});
-#endif
 }
 
 static inline void native_set_pgd(pgd_t *pgdp, pgd_t pgd)
 {
-#ifdef CONFIG_PAGE_TABLE_ISOLATION
 	*pgdp = pti_set_user_pgd(pgdp, pgd);
-#else
-	*pgdp = pgd;
-#endif
 }
 
 static inline void native_pgd_clear(pgd_t *pgd)

arch/x86/include/asm/pgtable_64_types.h

@@ -20,6 +20,18 @@ typedef unsigned long	pgprotval_t;
 
 typedef struct { pteval_t pte; } pte_t;
 
+#ifdef CONFIG_X86_5LEVEL
+extern unsigned int __pgtable_l5_enabled;
+#ifndef pgtable_l5_enabled
+#define pgtable_l5_enabled cpu_feature_enabled(X86_FEATURE_LA57)
+#endif
+#else
+#define pgtable_l5_enabled 0
+#endif
+
+extern unsigned int pgdir_shift;
+extern unsigned int ptrs_per_p4d;
+
 #endif	/* !__ASSEMBLY__ */
 
 #define SHARED_KERNEL_PMD	0
@@ -29,24 +41,28 @@ typedef struct { pteval_t pte; } pte_t;
 /*
  * PGDIR_SHIFT determines what a top-level page table entry can map
  */
-#define PGDIR_SHIFT	48
+#define PGDIR_SHIFT	pgdir_shift
 #define PTRS_PER_PGD	512
 
 /*
  * 4th level page in 5-level paging case
  */
-#define P4D_SHIFT	39
-#define PTRS_PER_P4D	512
-#define P4D_SIZE	(_AC(1, UL) << P4D_SHIFT)
-#define P4D_MASK	(~(P4D_SIZE - 1))
+#define P4D_SHIFT		39
+#define MAX_PTRS_PER_P4D	512
+#define PTRS_PER_P4D		ptrs_per_p4d
+#define P4D_SIZE		(_AC(1, UL) << P4D_SHIFT)
+#define P4D_MASK		(~(P4D_SIZE - 1))
+
+#define MAX_POSSIBLE_PHYSMEM_BITS	52
 
 #else /* CONFIG_X86_5LEVEL */
 
 /*
  * PGDIR_SHIFT determines what a top-level page table entry can map
  */
-#define PGDIR_SHIFT	39
-#define PTRS_PER_PGD	512
+#define PGDIR_SHIFT		39
+#define PTRS_PER_PGD		512
+#define MAX_PTRS_PER_P4D	1
 
 #endif /* CONFIG_X86_5LEVEL */
 
@@ -82,31 +98,33 @@ typedef struct { pteval_t pte; } pte_t;
  * range must not overlap with anything except the KASAN shadow area, which
  * is correct as KASAN disables KASLR.
  */
-#define MAXMEM			_AC(__AC(1, UL) << MAX_PHYSMEM_BITS, UL)
+#define MAXMEM			(1UL << MAX_PHYSMEM_BITS)
 
-#ifdef CONFIG_X86_5LEVEL
-# define VMALLOC_SIZE_TB	_AC(12800, UL)
-# define __VMALLOC_BASE		_AC(0xffa0000000000000, UL)
-# define __VMEMMAP_BASE		_AC(0xffd4000000000000, UL)
-# define LDT_PGD_ENTRY		_AC(-112, UL)
-# define LDT_BASE_ADDR		(LDT_PGD_ENTRY << PGDIR_SHIFT)
-#else
-# define VMALLOC_SIZE_TB	_AC(32, UL)
-# define __VMALLOC_BASE		_AC(0xffffc90000000000, UL)
-# define __VMEMMAP_BASE		_AC(0xffffea0000000000, UL)
-# define LDT_PGD_ENTRY		_AC(-3, UL)
-# define LDT_BASE_ADDR		(LDT_PGD_ENTRY << PGDIR_SHIFT)
-#endif
+#define LDT_PGD_ENTRY_L4	-3UL
+#define LDT_PGD_ENTRY_L5	-112UL
+#define LDT_PGD_ENTRY		(pgtable_l5_enabled ? LDT_PGD_ENTRY_L5 : LDT_PGD_ENTRY_L4)
+#define LDT_BASE_ADDR		(LDT_PGD_ENTRY << PGDIR_SHIFT)
+
+#define __VMALLOC_BASE_L4	0xffffc90000000000
+#define __VMALLOC_BASE_L5 	0xffa0000000000000
+
+#define VMALLOC_SIZE_TB_L4	32UL
+#define VMALLOC_SIZE_TB_L5	12800UL
+
+#define __VMEMMAP_BASE_L4	0xffffea0000000000
+#define __VMEMMAP_BASE_L5	0xffd4000000000000
 
-#ifdef CONFIG_RANDOMIZE_MEMORY
+#ifdef CONFIG_DYNAMIC_MEMORY_LAYOUT
 # define VMALLOC_START		vmalloc_base
+# define VMALLOC_SIZE_TB	(pgtable_l5_enabled ? VMALLOC_SIZE_TB_L5 : VMALLOC_SIZE_TB_L4)
 # define VMEMMAP_START		vmemmap_base
 #else
-# define VMALLOC_START		__VMALLOC_BASE
-# define VMEMMAP_START		__VMEMMAP_BASE
-#endif /* CONFIG_RANDOMIZE_MEMORY */
+# define VMALLOC_START		__VMALLOC_BASE_L4
+# define VMALLOC_SIZE_TB	VMALLOC_SIZE_TB_L4
+# define VMEMMAP_START		__VMEMMAP_BASE_L4
+#endif /* CONFIG_DYNAMIC_MEMORY_LAYOUT */
 
-#define VMALLOC_END		(VMALLOC_START + _AC((VMALLOC_SIZE_TB << 40) - 1, UL))
+#define VMALLOC_END		(VMALLOC_START + (VMALLOC_SIZE_TB << 40) - 1)
 
 #define MODULES_VADDR		(__START_KERNEL_map + KERNEL_IMAGE_SIZE)
 /* The module sections ends with the start of the fixmap */

arch/x86/include/asm/required-features.h

@@ -53,12 +53,6 @@
 # define NEED_MOVBE	0
 #endif
 
-#ifdef CONFIG_X86_5LEVEL
-# define NEED_LA57	(1<<(X86_FEATURE_LA57 & 31))
-#else
-# define NEED_LA57	0
-#endif
-
 #ifdef CONFIG_X86_64
 #ifdef CONFIG_PARAVIRT
 /* Paravirtualized systems may not have PSE or PGE available */
@@ -104,7 +98,7 @@
 #define REQUIRED_MASK13	0
 #define REQUIRED_MASK14	0
 #define REQUIRED_MASK15	0
-#define REQUIRED_MASK16	(NEED_LA57)
+#define REQUIRED_MASK16	0
 #define REQUIRED_MASK17	0
 #define REQUIRED_MASK18	0
 #define REQUIRED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 19)

arch/x86/include/asm/sparsemem.h

@@ -27,13 +27,8 @@
 # endif
 #else /* CONFIG_X86_32 */
 # define SECTION_SIZE_BITS	27 /* matt - 128 is convenient right now */
-# ifdef CONFIG_X86_5LEVEL
-#  define MAX_PHYSADDR_BITS	52
-#  define MAX_PHYSMEM_BITS	52
-# else
-#  define MAX_PHYSADDR_BITS	44
-#  define MAX_PHYSMEM_BITS	46
-# endif
+# define MAX_PHYSADDR_BITS	(pgtable_l5_enabled ? 52 : 44)
+# define MAX_PHYSMEM_BITS	(pgtable_l5_enabled ? 52 : 46)
 #endif
 
 #endif /* CONFIG_SPARSEMEM */

arch/x86/include/asm/x86_init.h

@@ -130,6 +130,16 @@ struct x86_hyper_init {
 	void (*init_mem_mapping)(void);
 };
 
+/**
+ * struct x86_init_acpi - x86 ACPI init functions
+ * @get_root_pointer:		get RSDP address
+ * @reduced_hw_early_init:	hardware reduced platform early init
+ */
+struct x86_init_acpi {
+	u64 (*get_root_pointer)(void);
+	void (*reduced_hw_early_init)(void);
+};
+
 /**
  * struct x86_init_ops - functions for platform specific setup
  *
@@ -144,6 +154,7 @@ struct x86_init_ops {
 	struct x86_init_iommu		iommu;
 	struct x86_init_pci		pci;
 	struct x86_hyper_init		hyper;
+	struct x86_init_acpi		acpi;
 };
 
 /**

arch/x86/kernel/acpi/boot.c

@@ -1376,17 +1376,21 @@ static int __init dmi_ignore_irq0_timer_override(const struct dmi_system_id *d)
  *
  * We initialize the Hardware-reduced ACPI model here:
  */
+void __init acpi_generic_reduced_hw_init(void)
+{
+	/*
+	 * Override x86_init functions and bypass legacy PIC in
+	 * hardware reduced ACPI mode.
+	 */
+	x86_init.timers.timer_init	= x86_init_noop;
+	x86_init.irqs.pre_vector_init	= x86_init_noop;
+	legacy_pic			= &null_legacy_pic;
+}
+
 static void __init acpi_reduced_hw_init(void)
 {
-	if (acpi_gbl_reduced_hardware) {
-		/*
-		 * Override x86_init functions and bypass legacy pic
-		 * in Hardware-reduced ACPI mode
-		 */
-		x86_init.timers.timer_init	= x86_init_noop;
-		x86_init.irqs.pre_vector_init	= x86_init_noop;
-		legacy_pic			= &null_legacy_pic;
-	}
+	if (acpi_gbl_reduced_hardware)
+		x86_init.acpi.reduced_hw_early_init();
 }
 
 /*

arch/x86/kernel/cpu/Makefile

@@ -28,7 +28,7 @@ obj-y			+= cpuid-deps.o
 obj-$(CONFIG_PROC_FS)	+= proc.o
 obj-$(CONFIG_X86_FEATURE_NAMES) += capflags.o powerflags.o
 
-obj-$(CONFIG_CPU_SUP_INTEL)		+= intel.o
+obj-$(CONFIG_CPU_SUP_INTEL)		+= intel.o intel_pconfig.o
 obj-$(CONFIG_CPU_SUP_AMD)		+= amd.o
 obj-$(CONFIG_CPU_SUP_CYRIX_32)		+= cyrix.o
 obj-$(CONFIG_CPU_SUP_CENTAUR)		+= centaur.o

arch/x86/kernel/cpu/intel.c

@@ -509,6 +509,90 @@ static void detect_vmx_virtcap(struct cpuinfo_x86 *c)
 	}
 }
 
+#define MSR_IA32_TME_ACTIVATE		0x982
+
+/* Helpers to access TME_ACTIVATE MSR */
+#define TME_ACTIVATE_LOCKED(x)		(x & 0x1)
+#define TME_ACTIVATE_ENABLED(x)		(x & 0x2)
+
+#define TME_ACTIVATE_POLICY(x)		((x >> 4) & 0xf)	/* Bits 7:4 */
+#define TME_ACTIVATE_POLICY_AES_XTS_128	0
+
+#define TME_ACTIVATE_KEYID_BITS(x)	((x >> 32) & 0xf)	/* Bits 35:32 */
+
+#define TME_ACTIVATE_CRYPTO_ALGS(x)	((x >> 48) & 0xffff)	/* Bits 63:48 */
+#define TME_ACTIVATE_CRYPTO_AES_XTS_128	1
+
+/* Values for mktme_status (SW only construct) */
+#define MKTME_ENABLED			0
+#define MKTME_DISABLED			1
+#define MKTME_UNINITIALIZED		2
+static int mktme_status = MKTME_UNINITIALIZED;
+
+static void detect_tme(struct cpuinfo_x86 *c)
+{
+	u64 tme_activate, tme_policy, tme_crypto_algs;
+	int keyid_bits = 0, nr_keyids = 0;
+	static u64 tme_activate_cpu0 = 0;
+
+	rdmsrl(MSR_IA32_TME_ACTIVATE, tme_activate);
+
+	if (mktme_status != MKTME_UNINITIALIZED) {
+		if (tme_activate != tme_activate_cpu0) {
+			/* Broken BIOS? */
+			pr_err_once("x86/tme: configuration is inconsistent between CPUs\n");
+			pr_err_once("x86/tme: MKTME is not usable\n");
+			mktme_status = MKTME_DISABLED;
+
+			/* Proceed. We may need to exclude bits from x86_phys_bits. */
+		}
+	} else {
+		tme_activate_cpu0 = tme_activate;
+	}
+
+	if (!TME_ACTIVATE_LOCKED(tme_activate) || !TME_ACTIVATE_ENABLED(tme_activate)) {
+		pr_info_once("x86/tme: not enabled by BIOS\n");
+		mktme_status = MKTME_DISABLED;
+		return;
+	}
+
+	if (mktme_status != MKTME_UNINITIALIZED)
+		goto detect_keyid_bits;
+
+	pr_info("x86/tme: enabled by BIOS\n");
+
+	tme_policy = TME_ACTIVATE_POLICY(tme_activate);
+	if (tme_policy != TME_ACTIVATE_POLICY_AES_XTS_128)
+		pr_warn("x86/tme: Unknown policy is active: %#llx\n", tme_policy);
+
+	tme_crypto_algs = TME_ACTIVATE_CRYPTO_ALGS(tme_activate);
+	if (!(tme_crypto_algs & TME_ACTIVATE_CRYPTO_AES_XTS_128)) {
+		pr_err("x86/mktme: No known encryption algorithm is supported: %#llx\n",
+				tme_crypto_algs);
+		mktme_status = MKTME_DISABLED;
+	}
+detect_keyid_bits:
+	keyid_bits = TME_ACTIVATE_KEYID_BITS(tme_activate);
+	nr_keyids = (1UL << keyid_bits) - 1;
+	if (nr_keyids) {
+		pr_info_once("x86/mktme: enabled by BIOS\n");
+		pr_info_once("x86/mktme: %d KeyIDs available\n", nr_keyids);
+	} else {
+		pr_info_once("x86/mktme: disabled by BIOS\n");
+	}
+
+	if (mktme_status == MKTME_UNINITIALIZED) {
+		/* MKTME is usable */
+		mktme_status = MKTME_ENABLED;
+	}
+
+	/*
+	 * KeyID bits effectively lower the number of physical address
+	 * bits.  Update cpuinfo_x86::x86_phys_bits accordingly.
+	 */
+	c->x86_phys_bits -= keyid_bits;
+}
+
 static void init_intel_energy_perf(struct cpuinfo_x86 *c)
 {
 	u64 epb;
@@ -679,6 +763,9 @@ static void init_intel(struct cpuinfo_x86 *c)
 	if (cpu_has(c, X86_FEATURE_VMX))
 		detect_vmx_virtcap(c);
 
+	if (cpu_has(c, X86_FEATURE_TME))
+		detect_tme(c);
+
 	init_intel_energy_perf(c);
 
 	init_intel_misc_features(c);

arch/x86/kernel/cpu/intel_pconfig.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Intel PCONFIG instruction support.
+ *
+ * Copyright (C) 2017 Intel Corporation
+ *
+ * Author:
+ *	Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
+ */
+
+#include <asm/cpufeature.h>
+#include <asm/intel_pconfig.h>
+
+#define	PCONFIG_CPUID			0x1b
+
+#define PCONFIG_CPUID_SUBLEAF_MASK	((1 << 12) - 1)
+
+/* Subleaf type (EAX) for PCONFIG CPUID leaf (0x1B) */
+enum {
+	PCONFIG_CPUID_SUBLEAF_INVALID	= 0,
+	PCONFIG_CPUID_SUBLEAF_TARGETID	= 1,
+};
+
+/* Bitmask of supported targets */
+static u64 targets_supported __read_mostly;
+
+int pconfig_target_supported(enum pconfig_target target)
+{
+	/*
+	 * We would need to re-think the implementation once we get > 64
+	 * PCONFIG targets. Spec allows up to 2^32 targets.
+	 */
+	BUILD_BUG_ON(PCONFIG_TARGET_NR >= 64);
+
+	if (WARN_ON_ONCE(target >= 64))
+		return 0;
+	return targets_supported & (1ULL << target);
+}
+
+static int __init intel_pconfig_init(void)
+{
+	int subleaf;
+
+	if (!boot_cpu_has(X86_FEATURE_PCONFIG))
+		return 0;
+
+	/*
+	 * Scan subleafs of PCONFIG CPUID leaf.
+	 *
+	 * Subleafs of the same type need not to be consecutive.
+	 *
+	 * Stop on the first invalid subleaf type. All subleafs after the first
+	 * invalid are invalid too.
+	 */
+	for (subleaf = 0; subleaf < INT_MAX; subleaf++) {
+		struct cpuid_regs regs;
+
+		cpuid_count(PCONFIG_CPUID, subleaf,
+				&regs.eax, &regs.ebx, &regs.ecx, &regs.edx);
+
+		switch (regs.eax & PCONFIG_CPUID_SUBLEAF_MASK) {
+		case PCONFIG_CPUID_SUBLEAF_INVALID:
+			/* Stop on the first invalid subleaf */
+			goto out;
+		case PCONFIG_CPUID_SUBLEAF_TARGETID:
+			/* Mark supported PCONFIG targets */
+			if (regs.ebx < 64)
+				targets_supported |= (1ULL << regs.ebx);
+			if (regs.ecx < 64)
+				targets_supported |= (1ULL << regs.ecx);
+			if (regs.edx < 64)
+				targets_supported |= (1ULL << regs.edx);
+			break;
+		default:
+			/* Unknown CPUID.PCONFIG subleaf: ignore */
+			break;
+		}
+	}
+out:
+	return 0;
+}
+arch_initcall(intel_pconfig_init);

arch/x86/kernel/cpu/mcheck/mce.c

@@ -1095,19 +1095,7 @@ static void mce_unmap_kpfn(unsigned long pfn)
 	 * a legal address.
 	 */
 
-/*
- * Build time check to see if we have a spare virtual bit. Don't want
- * to leave this until run time because most developers don't have a
- * system that can exercise this code path. This will only become a
- * problem if/when we move beyond 5-level page tables.
- *
- * Hard code "9" here because cpp doesn't grok ilog2(PTRS_PER_PGD)
- */
-#if PGDIR_SHIFT + 9 < 63
 	decoy_addr = (pfn << PAGE_SHIFT) + (PAGE_OFFSET ^ BIT(63));
-#else
-#error "no unused virtual bit available"
-#endif
 
 	if (set_memory_np(decoy_addr, 1))
 		pr_warn("Could not invalidate pfn=0x%lx from 1:1 map\n", pfn);
@@ -2357,6 +2345,12 @@ static __init int mcheck_init_device(void)
 {
 	int err;
 
+	/*
+	 * Check if we have a spare virtual bit. This will only become
+	 * a problem if/when we move beyond 5-level page tables.
+	 */
+	MAYBE_BUILD_BUG_ON(__VIRTUAL_MASK_SHIFT >= 63);
+
 	if (!mce_available(&boot_cpu_data)) {
 		err = -EIO;
 		goto err_out;

arch/x86/kernel/e820.c

@@ -924,6 +924,24 @@ static int __init parse_memmap_one(char *p)
 	} else if (*p == '!') {
 		start_at = memparse(p+1, &p);
 		e820__range_add(start_at, mem_size, E820_TYPE_PRAM);
+	} else if (*p == '%') {
+		enum e820_type from = 0, to = 0;
+
+		start_at = memparse(p + 1, &p);
+		if (*p == '-')
+			from = simple_strtoull(p + 1, &p, 0);
+		if (*p == '+')
+			to = simple_strtoull(p + 1, &p, 0);
+		if (*p != '\0')
+			return -EINVAL;
+		if (from && to)
+			e820__range_update(start_at, mem_size, from, to);
+		else if (to)
+			e820__range_add(start_at, mem_size, to);
+		else if (from)
+			e820__range_remove(start_at, mem_size, from, 1);
+		else
+			e820__range_remove(start_at, mem_size, 0, 0);
 	} else {
 		e820__range_remove(mem_size, ULLONG_MAX - mem_size, E820_TYPE_RAM, 1);
 	}

arch/x86/kernel/head64.c

@@ -32,6 +32,11 @@
 #include <asm/microcode.h>
 #include <asm/kasan.h>
 
+#ifdef CONFIG_X86_5LEVEL
+#undef pgtable_l5_enabled
+#define pgtable_l5_enabled __pgtable_l5_enabled
+#endif
+
 /*
  * Manage page tables very early on.
  */
@@ -39,6 +44,24 @@ extern pmd_t early_dynamic_pgts[EARLY_DYNAMIC_PAGE_TABLES][PTRS_PER_PMD];
 static unsigned int __initdata next_early_pgt;
 pmdval_t early_pmd_flags = __PAGE_KERNEL_LARGE & ~(_PAGE_GLOBAL | _PAGE_NX);
 
+#ifdef CONFIG_X86_5LEVEL
+unsigned int __pgtable_l5_enabled __ro_after_init;
+EXPORT_SYMBOL(__pgtable_l5_enabled);
+unsigned int pgdir_shift __ro_after_init = 39;
+EXPORT_SYMBOL(pgdir_shift);
+unsigned int ptrs_per_p4d __ro_after_init = 1;
+EXPORT_SYMBOL(ptrs_per_p4d);
+#endif
+
+#ifdef CONFIG_DYNAMIC_MEMORY_LAYOUT
+unsigned long page_offset_base __ro_after_init = __PAGE_OFFSET_BASE_L4;
+EXPORT_SYMBOL(page_offset_base);
+unsigned long vmalloc_base __ro_after_init = __VMALLOC_BASE_L4;
+EXPORT_SYMBOL(vmalloc_base);
+unsigned long vmemmap_base __ro_after_init = __VMEMMAP_BASE_L4;
+EXPORT_SYMBOL(vmemmap_base);
+#endif
+
 #define __head	__section(.head.text)
 
 static void __head *fixup_pointer(void *ptr, unsigned long physaddr)
@@ -46,6 +69,41 @@ static void __head *fixup_pointer(void *ptr, unsigned long physaddr)
 	return ptr - (void *)_text + (void *)physaddr;
 }
 
+static unsigned long __head *fixup_long(void *ptr, unsigned long physaddr)
+{
+	return fixup_pointer(ptr, physaddr);
+}
+
+#ifdef CONFIG_X86_5LEVEL
+static unsigned int __head *fixup_int(void *ptr, unsigned long physaddr)
+{
+	return fixup_pointer(ptr, physaddr);
+}
+
+static bool __head check_la57_support(unsigned long physaddr)
+{
+	if (native_cpuid_eax(0) < 7)
+		return false;
+
+	if (!(native_cpuid_ecx(7) & (1 << (X86_FEATURE_LA57 & 31))))
+		return false;
+
+	*fixup_int(&pgtable_l5_enabled, physaddr) = 1;
+	*fixup_int(&pgdir_shift, physaddr) = 48;
+	*fixup_int(&ptrs_per_p4d, physaddr) = 512;
+	*fixup_long(&page_offset_base, physaddr) = __PAGE_OFFSET_BASE_L5;
+	*fixup_long(&vmalloc_base, physaddr) = __VMALLOC_BASE_L5;
+	*fixup_long(&vmemmap_base, physaddr) = __VMEMMAP_BASE_L5;
+
+	return true;
+}
+#else
+static bool __head check_la57_support(unsigned long physaddr)
+{
+	return false;
+}
+#endif
+
 unsigned long __head __startup_64(unsigned long physaddr,
 				  struct boot_params *bp)
 {
@@ -55,9 +113,12 @@ unsigned long __head __startup_64(unsigned long physaddr,
 	p4dval_t *p4d;
 	pudval_t *pud;
 	pmdval_t *pmd, pmd_entry;
+	bool la57;
 	int i;
 	unsigned int *next_pgt_ptr;
 
+	la57 = check_la57_support(physaddr);
+
 	/* Is the address too large? */
 	if (physaddr >> MAX_PHYSMEM_BITS)
 		for (;;);
@@ -81,9 +142,14 @@ unsigned long __head __startup_64(unsigned long physaddr,
 	/* Fixup the physical addresses in the page table */
 
 	pgd = fixup_pointer(&early_top_pgt, physaddr);
-	pgd[pgd_index(__START_KERNEL_map)] += load_delta;
-
-	if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
+	p = pgd + pgd_index(__START_KERNEL_map);
+	if (la57)
+		*p = (unsigned long)level4_kernel_pgt;
+	else
+		*p = (unsigned long)level3_kernel_pgt;
+	*p += _PAGE_TABLE_NOENC - __START_KERNEL_map + load_delta;
+
+	if (la57) {
 		p4d = fixup_pointer(&level4_kernel_pgt, physaddr);
 		p4d[511] += load_delta;
 	}
@@ -108,7 +174,7 @@ unsigned long __head __startup_64(unsigned long physaddr,
 
 	pgtable_flags = _KERNPG_TABLE_NOENC + sme_get_me_mask();
 
-	if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
+	if (la57) {
 		p4d = fixup_pointer(early_dynamic_pgts[next_early_pgt++], physaddr);
 
 		i = (physaddr >> PGDIR_SHIFT) % PTRS_PER_PGD;
@@ -154,8 +220,7 @@ unsigned long __head __startup_64(unsigned long physaddr,
 	 * Fixup phys_base - remove the memory encryption mask to obtain
 	 * the true physical address.
 	 */
-	p = fixup_pointer(&phys_base, physaddr);
-	*p += load_delta - sme_get_me_mask();
+	*fixup_long(&phys_base, physaddr) += load_delta - sme_get_me_mask();
 
 	/* Encrypt the kernel and related (if SME is active) */
 	sme_encrypt_kernel(bp);
@@ -206,7 +271,7 @@ int __init __early_make_pgtable(unsigned long address, pmdval_t pmd)
 	 * critical -- __PAGE_OFFSET would point us back into the dynamic
 	 * range and we might end up looping forever...
 	 */
-	if (!IS_ENABLED(CONFIG_X86_5LEVEL))
+	if (!pgtable_l5_enabled)
 		p4d_p = pgd_p;
 	else if (pgd)
 		p4d_p = (p4dval_t *)((pgd & PTE_PFN_MASK) + __START_KERNEL_map - phys_base);
@@ -322,7 +387,7 @@ asmlinkage __visible void __init x86_64_start_kernel(char * real_mode_data)
 	BUILD_BUG_ON((__START_KERNEL_map & ~PMD_MASK) != 0);
 	BUILD_BUG_ON((MODULES_VADDR & ~PMD_MASK) != 0);
 	BUILD_BUG_ON(!(MODULES_VADDR > __START_KERNEL));
-	BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) ==
+	MAYBE_BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) ==
 				(__START_KERNEL & PGDIR_MASK)));
 	BUILD_BUG_ON(__fix_to_virt(__end_of_fixed_addresses) <= MODULES_END);
 

arch/x86/kernel/head_64.S

@@ -39,12 +39,12 @@
  *
  */
 
+#define l4_index(x)	(((x) >> 39) & 511)
 #define pud_index(x)	(((x) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
 
-#if defined(CONFIG_XEN_PV) || defined(CONFIG_XEN_PVH)
-PGD_PAGE_OFFSET = pgd_index(__PAGE_OFFSET_BASE)
-PGD_START_KERNEL = pgd_index(__START_KERNEL_map)
-#endif
+L4_PAGE_OFFSET = l4_index(__PAGE_OFFSET_BASE_L4)
+L4_START_KERNEL = l4_index(__START_KERNEL_map)
+
 L3_START_KERNEL = pud_index(__START_KERNEL_map)
 
 	.text
@@ -125,7 +125,10 @@ ENTRY(secondary_startup_64)
 	/* Enable PAE mode, PGE and LA57 */
 	movl	$(X86_CR4_PAE | X86_CR4_PGE), %ecx
 #ifdef CONFIG_X86_5LEVEL
+	testl	$1, __pgtable_l5_enabled(%rip)
+	jz	1f
 	orl	$X86_CR4_LA57, %ecx
+1:
 #endif
 	movq	%rcx, %cr4
 
@@ -374,12 +377,7 @@ GLOBAL(name)
 
 	__INITDATA
 NEXT_PGD_PAGE(early_top_pgt)
-	.fill	511,8,0
-#ifdef CONFIG_X86_5LEVEL
-	.quad	level4_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC
-#else
-	.quad	level3_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC
-#endif
+	.fill	512,8,0
 	.fill	PTI_USER_PGD_FILL,8,0
 
 NEXT_PAGE(early_dynamic_pgts)
@@ -390,9 +388,9 @@ NEXT_PAGE(early_dynamic_pgts)
 #if defined(CONFIG_XEN_PV) || defined(CONFIG_XEN_PVH)
 NEXT_PGD_PAGE(init_top_pgt)
 	.quad   level3_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE_NOENC
-	.org    init_top_pgt + PGD_PAGE_OFFSET*8, 0
+	.org    init_top_pgt + L4_PAGE_OFFSET*8, 0
 	.quad   level3_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE_NOENC
-	.org    init_top_pgt + PGD_START_KERNEL*8, 0
+	.org    init_top_pgt + L4_START_KERNEL*8, 0
 	/* (2^48-(2*1024*1024*1024))/(2^39) = 511 */
 	.quad   level3_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC
 	.fill	PTI_USER_PGD_FILL,8,0

arch/x86/kernel/machine_kexec_64.c

@@ -350,6 +350,7 @@ void arch_crash_save_vmcoreinfo(void)
 {
 	VMCOREINFO_NUMBER(phys_base);
 	VMCOREINFO_SYMBOL(init_top_pgt);
+	VMCOREINFO_NUMBER(pgtable_l5_enabled);
 
 #ifdef CONFIG_NUMA
 	VMCOREINFO_SYMBOL(node_data);

arch/x86/kernel/setup.c

@@ -189,9 +189,7 @@ struct ist_info ist_info;
 #endif
 
 #else
-struct cpuinfo_x86 boot_cpu_data __read_mostly = {
-	.x86_phys_bits = MAX_PHYSMEM_BITS,
-};
+struct cpuinfo_x86 boot_cpu_data __read_mostly;
 EXPORT_SYMBOL(boot_cpu_data);
 #endif
 
@@ -851,6 +849,7 @@ void __init setup_arch(char **cmdline_p)
 	__flush_tlb_all();
 #else
 	printk(KERN_INFO "Command line: %s\n", boot_command_line);
+	boot_cpu_data.x86_phys_bits = MAX_PHYSMEM_BITS;
 #endif
 
 	/*

arch/x86/kernel/x86_init.c

@@ -8,6 +8,7 @@
 #include <linux/export.h>
 #include <linux/pci.h>
 
+#include <asm/acpi.h>
 #include <asm/bios_ebda.h>
 #include <asm/paravirt.h>
 #include <asm/pci_x86.h>
@@ -26,10 +27,11 @@
 
 void x86_init_noop(void) { }
 void __init x86_init_uint_noop(unsigned int unused) { }
-int __init iommu_init_noop(void) { return 0; }
-void iommu_shutdown_noop(void) { }
-bool __init bool_x86_init_noop(void) { return false; }
-void x86_op_int_noop(int cpu) { }
+static int __init iommu_init_noop(void) { return 0; }
+static void iommu_shutdown_noop(void) { }
+static bool __init bool_x86_init_noop(void) { return false; }
+static void x86_op_int_noop(int cpu) { }
+static u64 u64_x86_init_noop(void) { return 0; }
 
 /*
  * The platform setup functions are preset with the default functions
@@ -91,6 +93,11 @@ struct x86_init_ops x86_init __initdata = {
 		.x2apic_available	= bool_x86_init_noop,
 		.init_mem_mapping	= x86_init_noop,
 	},
+
+	.acpi = {
+		.get_root_pointer	= u64_x86_init_noop,
+		.reduced_hw_early_init	= acpi_generic_reduced_hw_init,
+	},
 };
 
 struct x86_cpuinit_ops x86_cpuinit = {

arch/x86/mm/Makefile

 # SPDX-License-Identifier: GPL-2.0
-# Kernel does not boot with instrumentation of tlb.c and mem_encrypt.c
-KCOV_INSTRUMENT_tlb.o		:= n
-KCOV_INSTRUMENT_mem_encrypt.o	:= n
+# Kernel does not boot with instrumentation of tlb.c and mem_encrypt*.c
+KCOV_INSTRUMENT_tlb.o			:= n
+KCOV_INSTRUMENT_mem_encrypt.o		:= n
+KCOV_INSTRUMENT_mem_encrypt_identity.o	:= n
 
-KASAN_SANITIZE_mem_encrypt.o	:= n
+KASAN_SANITIZE_mem_encrypt.o		:= n
+KASAN_SANITIZE_mem_encrypt_identity.o	:= n
 
 ifdef CONFIG_FUNCTION_TRACER
-CFLAGS_REMOVE_mem_encrypt.o	= -pg
+CFLAGS_REMOVE_mem_encrypt.o		= -pg
+CFLAGS_REMOVE_mem_encrypt_identity.o	= -pg
 endif
 
 obj-y	:=  init.o init_$(BITS).o fault.o ioremap.o extable.o pageattr.o mmap.o \
@@ -16,6 +19,7 @@ obj-y	:=  init.o init_$(BITS).o fault.o ioremap.o extable.o pageattr.o mmap.o \
 nostackp := $(call cc-option, -fno-stack-protector)
 CFLAGS_physaddr.o		:= $(nostackp)
 CFLAGS_setup_nx.o		:= $(nostackp)
+CFLAGS_mem_encrypt_identity.o	:= $(nostackp)
 
 CFLAGS_fault.o := -I$(src)/../include/asm/trace
 
@@ -47,4 +51,5 @@ obj-$(CONFIG_RANDOMIZE_MEMORY)			+= kaslr.o
 obj-$(CONFIG_PAGE_TABLE_ISOLATION)		+= pti.o
 
 obj-$(CONFIG_AMD_MEM_ENCRYPT)	+= mem_encrypt.o
+obj-$(CONFIG_AMD_MEM_ENCRYPT)	+= mem_encrypt_identity.o
 obj-$(CONFIG_AMD_MEM_ENCRYPT)	+= mem_encrypt_boot.o

arch/x86/mm/debug_pagetables.c

@@ -72,6 +72,31 @@ static const struct file_operations ptdump_curusr_fops = {
 };
 #endif
 
+#if defined(CONFIG_EFI) && defined(CONFIG_X86_64)
+extern pgd_t *efi_pgd;
+static struct dentry *pe_efi;
+
+static int ptdump_show_efi(struct seq_file *m, void *v)
+{
+	if (efi_pgd)
+		ptdump_walk_pgd_level_debugfs(m, efi_pgd, false);
+	return 0;
+}
+
+static int ptdump_open_efi(struct inode *inode, struct file *filp)
+{
+	return single_open(filp, ptdump_show_efi, NULL);
+}
+
+static const struct file_operations ptdump_efi_fops = {
+	.owner		= THIS_MODULE,
+	.open		= ptdump_open_efi,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+#endif
+
 static struct dentry *dir, *pe_knl, *pe_curknl;
 
 static int __init pt_dump_debug_init(void)
@@ -96,6 +121,13 @@ static int __init pt_dump_debug_init(void)
 	if (!pe_curusr)
 		goto err;
 #endif
+
+#if defined(CONFIG_EFI) && defined(CONFIG_X86_64)
+	pe_efi = debugfs_create_file("efi", 0400, dir, NULL, &ptdump_efi_fops);
+	if (!pe_efi)
+		goto err;
+#endif
+
 	return 0;
 err:
 	debugfs_remove_recursive(dir);

arch/x86/mm/fault.c

@@ -417,11 +417,11 @@ void vmalloc_sync_all(void)
  */
 static noinline int vmalloc_fault(unsigned long address)
 {
-	pgd_t *pgd, *pgd_ref;
-	p4d_t *p4d, *p4d_ref;
-	pud_t *pud, *pud_ref;
-	pmd_t *pmd, *pmd_ref;
-	pte_t *pte, *pte_ref;
+	pgd_t *pgd, *pgd_k;
+	p4d_t *p4d, *p4d_k;
+	pud_t *pud;
+	pmd_t *pmd;
+	pte_t *pte;
 
 	/* Make sure we are in vmalloc area: */
 	if (!(address >= VMALLOC_START && address < VMALLOC_END))
@@ -435,73 +435,51 @@ static noinline int vmalloc_fault(unsigned long address)
 	 * case just flush:
 	 */
 	pgd = (pgd_t *)__va(read_cr3_pa()) + pgd_index(address);
-	pgd_ref = pgd_offset_k(address);
-	if (pgd_none(*pgd_ref))
+	pgd_k = pgd_offset_k(address);
+	if (pgd_none(*pgd_k))
 		return -1;
 
-	if (CONFIG_PGTABLE_LEVELS > 4) {
+	if (pgtable_l5_enabled) {
 		if (pgd_none(*pgd)) {
-			set_pgd(pgd, *pgd_ref);
+			set_pgd(pgd, *pgd_k);
 			arch_flush_lazy_mmu_mode();
 		} else {
-			BUG_ON(pgd_page_vaddr(*pgd) != pgd_page_vaddr(*pgd_ref));
+			BUG_ON(pgd_page_vaddr(*pgd) != pgd_page_vaddr(*pgd_k));
 		}
 	}
 
 	/* With 4-level paging, copying happens on the p4d level. */
 	p4d = p4d_offset(pgd, address);
-	p4d_ref = p4d_offset(pgd_ref, address);
-	if (p4d_none(*p4d_ref))
+	p4d_k = p4d_offset(pgd_k, address);
+	if (p4d_none(*p4d_k))
 		return -1;
 
-	if (p4d_none(*p4d) && CONFIG_PGTABLE_LEVELS == 4) {
-		set_p4d(p4d, *p4d_ref);
+	if (p4d_none(*p4d) && !pgtable_l5_enabled) {
+		set_p4d(p4d, *p4d_k);
 		arch_flush_lazy_mmu_mode();
 	} else {
-		BUG_ON(p4d_pfn(*p4d) != p4d_pfn(*p4d_ref));
+		BUG_ON(p4d_pfn(*p4d) != p4d_pfn(*p4d_k));
 	}
 
-	/*
-	 * Below here mismatches are bugs because these lower tables
-	 * are shared:
-	 */
 	BUILD_BUG_ON(CONFIG_PGTABLE_LEVELS < 4);
 
 	pud = pud_offset(p4d, address);
-	pud_ref = pud_offset(p4d_ref, address);
-	if (pud_none(*pud_ref))
+	if (pud_none(*pud))
 		return -1;
 
-	if (pud_none(*pud) || pud_pfn(*pud) != pud_pfn(*pud_ref))
-		BUG();
-
 	if (pud_large(*pud))
 		return 0;
 
 	pmd = pmd_offset(pud, address);
-	pmd_ref = pmd_offset(pud_ref, address);
-	if (pmd_none(*pmd_ref))
+	if (pmd_none(*pmd))
 		return -1;
 
-	if (pmd_none(*pmd) || pmd_pfn(*pmd) != pmd_pfn(*pmd_ref))
-		BUG();
-
 	if (pmd_large(*pmd))
 		return 0;
 
-	pte_ref = pte_offset_kernel(pmd_ref, address);
-	if (!pte_present(*pte_ref))
-		return -1;
-
 	pte = pte_offset_kernel(pmd, address);
-
-	/*
-	 * Don't use pte_page here, because the mappings can point
-	 * outside mem_map, and the NUMA hash lookup cannot handle
-	 * that:
-	 */
-	if (!pte_present(*pte) || pte_pfn(*pte) != pte_pfn(*pte_ref))
-		BUG();
+	if (!pte_present(*pte))
+		return -1;
 
 	return 0;
 }

arch/x86/mm/ident_map.c

@@ -120,7 +120,7 @@ int kernel_ident_mapping_init(struct x86_mapping_info *info, pgd_t *pgd_page,
 		result = ident_p4d_init(info, p4d, addr, next);
 		if (result)
 			return result;
-		if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
+		if (pgtable_l5_enabled) {
 			set_pgd(pgd, __pgd(__pa(p4d) | info->kernpg_flag));
 		} else {
 			/*

arch/x86/mm/init_64.c

@@ -88,12 +88,7 @@ static int __init nonx32_setup(char *str)
 }
 __setup("noexec32=", nonx32_setup);
 
-/*
- * When memory was added make sure all the processes MM have
- * suitable PGD entries in the local PGD level page.
- */
-#ifdef CONFIG_X86_5LEVEL
-void sync_global_pgds(unsigned long start, unsigned long end)
+static void sync_global_pgds_l5(unsigned long start, unsigned long end)
 {
 	unsigned long addr;
 
@@ -129,8 +124,8 @@ void sync_global_pgds(unsigned long start, unsigned long end)
 		spin_unlock(&pgd_lock);
 	}
 }
-#else
-void sync_global_pgds(unsigned long start, unsigned long end)
+
+static void sync_global_pgds_l4(unsigned long start, unsigned long end)
 {
 	unsigned long addr;
 
@@ -143,7 +138,7 @@ void sync_global_pgds(unsigned long start, unsigned long end)
 		 * With folded p4d, pgd_none() is always false, we need to
 		 * handle synchonization on p4d level.
 		 */
-		BUILD_BUG_ON(pgd_none(*pgd_ref));
+		MAYBE_BUILD_BUG_ON(pgd_none(*pgd_ref));
 		p4d_ref = p4d_offset(pgd_ref, addr);
 
 		if (p4d_none(*p4d_ref))
@@ -173,7 +168,18 @@ void sync_global_pgds(unsigned long start, unsigned long end)
 		spin_unlock(&pgd_lock);
 	}
 }
-#endif
+
+/*
+ * When memory was added make sure all the processes MM have
+ * suitable PGD entries in the local PGD level page.
+ */
+void sync_global_pgds(unsigned long start, unsigned long end)
+{
+	if (pgtable_l5_enabled)
+		sync_global_pgds_l5(start, end);
+	else
+		sync_global_pgds_l4(start, end);
+}
 
 /*
  * NOTE: This function is marked __ref because it calls __init function
@@ -632,7 +638,7 @@ phys_p4d_init(p4d_t *p4d_page, unsigned long paddr, unsigned long paddr_end,
 	unsigned long vaddr = (unsigned long)__va(paddr);
 	int i = p4d_index(vaddr);
 
-	if (!IS_ENABLED(CONFIG_X86_5LEVEL))
+	if (!pgtable_l5_enabled)
 		return phys_pud_init((pud_t *) p4d_page, paddr, paddr_end, page_size_mask);
 
 	for (; i < PTRS_PER_P4D; i++, paddr = paddr_next) {
@@ -712,7 +718,7 @@ kernel_physical_mapping_init(unsigned long paddr_start,
 					   page_size_mask);
 
 		spin_lock(&init_mm.page_table_lock);
-		if (IS_ENABLED(CONFIG_X86_5LEVEL))
+		if (pgtable_l5_enabled)
 			pgd_populate(&init_mm, pgd, p4d);
 		else
 			p4d_populate(&init_mm, p4d_offset(pgd, vaddr), (pud_t *) p4d);
@@ -1089,7 +1095,7 @@ remove_p4d_table(p4d_t *p4d_start, unsigned long addr, unsigned long end,
 		 * 5-level case we should free them. This code will have to change
 		 * to adapt for boot-time switching between 4 and 5 level page tables.
 		 */
-		if (CONFIG_PGTABLE_LEVELS == 5)
+		if (pgtable_l5_enabled)
 			free_pud_table(pud_base, p4d);
 	}
 

arch/x86/mm/kasan_init_64.c

 // SPDX-License-Identifier: GPL-2.0
 #define DISABLE_BRANCH_PROFILING
 #define pr_fmt(fmt) "kasan: " fmt
+
+#ifdef CONFIG_X86_5LEVEL
+/* Too early to use cpu_feature_enabled() */
+#define pgtable_l5_enabled __pgtable_l5_enabled
+#endif
+
 #include <linux/bootmem.h>
 #include <linux/kasan.h>
 #include <linux/kdebug.h>
@@ -19,7 +25,7 @@
 
 extern struct range pfn_mapped[E820_MAX_ENTRIES];
 
-static p4d_t tmp_p4d_table[PTRS_PER_P4D] __initdata __aligned(PAGE_SIZE);
+static p4d_t tmp_p4d_table[MAX_PTRS_PER_P4D] __initdata __aligned(PAGE_SIZE);
 
 static __init void *early_alloc(size_t size, int nid, bool panic)
 {
@@ -176,10 +182,10 @@ static void __init clear_pgds(unsigned long start,
 		 * With folded p4d, pgd_clear() is nop, use p4d_clear()
 		 * instead.
 		 */
-		if (CONFIG_PGTABLE_LEVELS < 5)
-			p4d_clear(p4d_offset(pgd, start));
-		else
+		if (pgtable_l5_enabled)
 			pgd_clear(pgd);
+		else
+			p4d_clear(p4d_offset(pgd, start));
 	}
 
 	pgd = pgd_offset_k(start);
@@ -191,7 +197,7 @@ static inline p4d_t *early_p4d_offset(pgd_t *pgd, unsigned long addr)
 {
 	unsigned long p4d;
 
-	if (!IS_ENABLED(CONFIG_X86_5LEVEL))
+	if (!pgtable_l5_enabled)
 		return (p4d_t *)pgd;
 
 	p4d = __pa_nodebug(pgd_val(*pgd)) & PTE_PFN_MASK;
@@ -272,7 +278,7 @@ void __init kasan_early_init(void)
 	for (i = 0; i < PTRS_PER_PUD; i++)
 		kasan_zero_pud[i] = __pud(pud_val);
 
-	for (i = 0; IS_ENABLED(CONFIG_X86_5LEVEL) && i < PTRS_PER_P4D; i++)
+	for (i = 0; pgtable_l5_enabled && i < PTRS_PER_P4D; i++)
 		kasan_zero_p4d[i] = __p4d(p4d_val);
 
 	kasan_map_early_shadow(early_top_pgt);
@@ -303,7 +309,7 @@ void __init kasan_init(void)
 	 * bunch of things like kernel code, modules, EFI mapping, etc.
 	 * We need to take extra steps to not overwrite them.
 	 */
-	if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
+	if (pgtable_l5_enabled) {
 		void *ptr;
 
 		ptr = (void *)pgd_page_vaddr(*pgd_offset_k(KASAN_SHADOW_END));

arch/x86/mm/kaslr.c

@@ -34,23 +34,12 @@
 #define TB_SHIFT 40
 
 /*
- * Virtual address start and end range for randomization.
- *
  * The end address could depend on more configuration options to make the
  * highest amount of space for randomization available, but that's too hard
  * to keep straight and caused issues already.
  */
-static const unsigned long vaddr_start = __PAGE_OFFSET_BASE;
 static const unsigned long vaddr_end = CPU_ENTRY_AREA_BASE;
 
-/* Default values */
-unsigned long page_offset_base = __PAGE_OFFSET_BASE;
-EXPORT_SYMBOL(page_offset_base);
-unsigned long vmalloc_base = __VMALLOC_BASE;
-EXPORT_SYMBOL(vmalloc_base);
-unsigned long vmemmap_base = __VMEMMAP_BASE;
-EXPORT_SYMBOL(vmemmap_base);
-
 /*
  * Memory regions randomized by KASLR (except modules that use a separate logic
  * earlier during boot). The list is ordered based on virtual addresses. This
@@ -60,8 +49,8 @@ static __initdata struct kaslr_memory_region {
 	unsigned long *base;
 	unsigned long size_tb;
 } kaslr_regions[] = {
-	{ &page_offset_base, 1 << (__PHYSICAL_MASK_SHIFT - TB_SHIFT) /* Maximum */ },
-	{ &vmalloc_base, VMALLOC_SIZE_TB },
+	{ &page_offset_base, 0 },
+	{ &vmalloc_base, 0 },
 	{ &vmemmap_base, 1 },
 };
 
@@ -84,11 +73,14 @@ static inline bool kaslr_memory_enabled(void)
 void __init kernel_randomize_memory(void)
 {
 	size_t i;
-	unsigned long vaddr = vaddr_start;
+	unsigned long vaddr_start, vaddr;
 	unsigned long rand, memory_tb;
 	struct rnd_state rand_state;
 	unsigned long remain_entropy;
 
+	vaddr_start = pgtable_l5_enabled ? __PAGE_OFFSET_BASE_L5 : __PAGE_OFFSET_BASE_L4;
+	vaddr = vaddr_start;
+
 	/*
 	 * These BUILD_BUG_ON checks ensure the memory layout is consistent
 	 * with the vaddr_start/vaddr_end variables. These checks are very
@@ -101,6 +93,9 @@ void __init kernel_randomize_memory(void)
 	if (!kaslr_memory_enabled())
 		return;
 
+	kaslr_regions[0].size_tb = 1 << (__PHYSICAL_MASK_SHIFT - TB_SHIFT);
+	kaslr_regions[1].size_tb = VMALLOC_SIZE_TB;
+
 	/*
 	 * Update Physical memory mapping to available and
 	 * add padding if needed (especially for memory hotplug support).
@@ -129,7 +124,7 @@ void __init kernel_randomize_memory(void)
 		 */
 		entropy = remain_entropy / (ARRAY_SIZE(kaslr_regions) - i);
 		prandom_bytes_state(&rand_state, &rand, sizeof(rand));
-		if (IS_ENABLED(CONFIG_X86_5LEVEL))
+		if (pgtable_l5_enabled)
 			entropy = (rand % (entropy + 1)) & P4D_MASK;
 		else
 			entropy = (rand % (entropy + 1)) & PUD_MASK;
@@ -141,7 +136,7 @@ void __init kernel_randomize_memory(void)
 		 * randomization alignment.
 		 */
 		vaddr += get_padding(&kaslr_regions[i]);
-		if (IS_ENABLED(CONFIG_X86_5LEVEL))
+		if (pgtable_l5_enabled)
 			vaddr = round_up(vaddr + 1, P4D_SIZE);
 		else
 			vaddr = round_up(vaddr + 1, PUD_SIZE);
@@ -217,7 +212,7 @@ void __meminit init_trampoline(void)
 		return;
 	}
 
-	if (IS_ENABLED(CONFIG_X86_5LEVEL))
+	if (pgtable_l5_enabled)
 		init_trampoline_p4d();
 	else
 		init_trampoline_pud();

arch/x86/mm/numa_32.c

@@ -60,17 +60,6 @@ void memory_present(int nid, unsigned long start, unsigned long end)
 	}
 	printk(KERN_CONT "\n");
 }
-
-unsigned long node_memmap_size_bytes(int nid, unsigned long start_pfn,
-					      unsigned long end_pfn)
-{
-	unsigned long nr_pages = end_pfn - start_pfn;
-
-	if (!nr_pages)
-		return 0;
-
-	return (nr_pages + 1) * sizeof(struct page);
-}
 #endif
 
 extern unsigned long highend_pfn, highstart_pfn;

arch/x86/mm/tlb.c

@@ -157,7 +157,7 @@ static void sync_current_stack_to_mm(struct mm_struct *mm)
 	unsigned long sp = current_stack_pointer;
 	pgd_t *pgd = pgd_offset(mm, sp);
 
-	if (CONFIG_PGTABLE_LEVELS > 4) {
+	if (pgtable_l5_enabled) {
 		if (unlikely(pgd_none(*pgd))) {
 			pgd_t *pgd_ref = pgd_offset_k(sp);
 
@@ -613,7 +613,7 @@ void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
 {
 	int cpu;
 
-	struct flush_tlb_info info = {
+	struct flush_tlb_info info __aligned(SMP_CACHE_BYTES) = {
 		.mm = mm,
 	};
 

arch/x86/platform/efi/efi_64.c

@@ -27,6 +27,7 @@
 #include <linux/ioport.h>
 #include <linux/mc146818rtc.h>
 #include <linux/efi.h>
+#include <linux/export.h>
 #include <linux/uaccess.h>
 #include <linux/io.h>
 #include <linux/reboot.h>
@@ -190,7 +191,8 @@ void __init efi_call_phys_epilog(pgd_t *save_pgd)
 	early_code_mapping_set_exec(0);
 }
 
-static pgd_t *efi_pgd;
+pgd_t *efi_pgd;
+EXPORT_SYMBOL_GPL(efi_pgd);
 
 /*
  * We need our own copy of the higher levels of the page tables
@@ -225,7 +227,7 @@ int __init efi_alloc_page_tables(void)
 
 	pud = pud_alloc(&init_mm, p4d, EFI_VA_END);
 	if (!pud) {
-		if (CONFIG_PGTABLE_LEVELS > 4)
+		if (pgtable_l5_enabled)
 			free_page((unsigned long) pgd_page_vaddr(*pgd));
 		free_pages((unsigned long)efi_pgd, PGD_ALLOCATION_ORDER);
 		return -ENOMEM;
@@ -255,8 +257,8 @@ void efi_sync_low_kernel_mappings(void)
 	 * only span a single PGD entry and that the entry also maps
 	 * other important kernel regions.
 	 */
-	BUILD_BUG_ON(pgd_index(EFI_VA_END) != pgd_index(MODULES_END));
-	BUILD_BUG_ON((EFI_VA_START & PGDIR_MASK) !=
+	MAYBE_BUILD_BUG_ON(pgd_index(EFI_VA_END) != pgd_index(MODULES_END));
+	MAYBE_BUILD_BUG_ON((EFI_VA_START & PGDIR_MASK) !=
 			(EFI_VA_END & PGDIR_MASK));
 
 	pgd_efi = efi_pgd + pgd_index(PAGE_OFFSET);

arch/x86/platform/intel-mid/intel-mid.c

@@ -199,6 +199,12 @@ void __init x86_intel_mid_early_setup(void)
 
 	legacy_pic = &null_legacy_pic;
 
+	/*
+	 * Do nothing for now as everything needed done in
+	 * x86_intel_mid_early_setup() below.
+	 */
+	x86_init.acpi.reduced_hw_early_init = x86_init_noop;
+
 	pm_power_off = intel_mid_power_off;
 	machine_ops.emergency_restart  = intel_mid_reboot;
 

arch/x86/power/hibernate_64.c

@@ -50,7 +50,7 @@ static int set_up_temporary_text_mapping(pgd_t *pgd)
 {
 	pmd_t *pmd;
 	pud_t *pud;
-	p4d_t *p4d;
+	p4d_t *p4d = NULL;
 
 	/*
 	 * The new mapping only has to cover the page containing the image
@@ -66,7 +66,7 @@ static int set_up_temporary_text_mapping(pgd_t *pgd)
 	 * tables used by the image kernel.
 	 */
 
-	if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
+	if (pgtable_l5_enabled) {
 		p4d = (p4d_t *)get_safe_page(GFP_ATOMIC);
 		if (!p4d)
 			return -ENOMEM;
@@ -84,7 +84,7 @@ static int set_up_temporary_text_mapping(pgd_t *pgd)
 		__pmd((jump_address_phys & PMD_MASK) | __PAGE_KERNEL_LARGE_EXEC));
 	set_pud(pud + pud_index(restore_jump_address),
 		__pud(__pa(pmd) | _KERNPG_TABLE));
-	if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
+	if (p4d) {
 		set_p4d(p4d + p4d_index(restore_jump_address), __p4d(__pa(pud) | _KERNPG_TABLE));
 		set_pgd(pgd + pgd_index(restore_jump_address), __pgd(__pa(p4d) | _KERNPG_TABLE));
 	} else {

arch/x86/xen/Kconfig

@@ -18,9 +18,6 @@ config XEN_PV
 	bool "Xen PV guest support"
 	default y
 	depends on XEN
-	# XEN_PV is not ready to work with 5-level paging.
-	# Changes to hypervisor are also required.
-	depends on !X86_5LEVEL
 	select XEN_HAVE_PVMMU
 	select XEN_HAVE_VPMU
 	help
@@ -79,6 +76,4 @@ config XEN_DEBUG_FS
 config XEN_PVH
 	bool "Support for running as a PVH guest"
 	depends on XEN && XEN_PVHVM && ACPI
-	# Pre-built page tables are not ready to handle 5-level paging.
-	depends on !X86_5LEVEL
 	def_bool n

arch/x86/xen/enlighten_pvh.c

@@ -6,6 +6,7 @@
 #include <asm/io_apic.h>
 #include <asm/hypervisor.h>
 #include <asm/e820/api.h>
+#include <asm/x86_init.h>
 
 #include <asm/xen/interface.h>
 #include <asm/xen/hypercall.h>
@@ -16,15 +17,20 @@
 /*
  * PVH variables.
  *
- * xen_pvh and pvh_bootparams need to live in data segment since they
- * are used after startup_{32|64}, which clear .bss, are invoked.
+ * xen_pvh pvh_bootparams and pvh_start_info need to live in data segment
+ * since they are used after startup_{32|64}, which clear .bss, are invoked.
  */
 bool xen_pvh __attribute__((section(".data"))) = 0;
 struct boot_params pvh_bootparams __attribute__((section(".data")));
+struct hvm_start_info pvh_start_info __attribute__((section(".data")));
 
-struct hvm_start_info pvh_start_info;
 unsigned int pvh_start_info_sz = sizeof(pvh_start_info);
 
+static u64 pvh_get_root_pointer(void)
+{
+	return pvh_start_info.rsdp_paddr;
+}
+
 static void __init init_pvh_bootparams(void)
 {
 	struct xen_memory_map memmap;
@@ -71,6 +77,8 @@ static void __init init_pvh_bootparams(void)
 	 */
 	pvh_bootparams.hdr.version = 0x212;
 	pvh_bootparams.hdr.type_of_loader = (9 << 4) | 0; /* Xen loader */
+
+	x86_init.acpi.get_root_pointer = pvh_get_root_pointer;
 }
 
 /*

arch/x86/xen/mmu_pv.c

@@ -538,6 +538,22 @@ static void xen_set_p4d(p4d_t *ptr, p4d_t val)
 
 	xen_mc_issue(PARAVIRT_LAZY_MMU);
 }
+
+#if CONFIG_PGTABLE_LEVELS >= 5
+__visible p4dval_t xen_p4d_val(p4d_t p4d)
+{
+	return pte_mfn_to_pfn(p4d.p4d);
+}
+PV_CALLEE_SAVE_REGS_THUNK(xen_p4d_val);
+
+__visible p4d_t xen_make_p4d(p4dval_t p4d)
+{
+	p4d = pte_pfn_to_mfn(p4d);
+
+	return native_make_p4d(p4d);
+}
+PV_CALLEE_SAVE_REGS_THUNK(xen_make_p4d);
+#endif  /* CONFIG_PGTABLE_LEVELS >= 5 */
 #endif	/* CONFIG_X86_64 */
 
 static int xen_pmd_walk(struct mm_struct *mm, pmd_t *pmd,
@@ -2411,6 +2427,11 @@ static const struct pv_mmu_ops xen_mmu_ops __initconst = {
 
 	.alloc_pud = xen_alloc_pmd_init,
 	.release_pud = xen_release_pmd_init,
+
+#if CONFIG_PGTABLE_LEVELS >= 5
+	.p4d_val = PV_CALLEE_SAVE(xen_p4d_val),
+	.make_p4d = PV_CALLEE_SAVE(xen_make_p4d),
+#endif
 #endif	/* CONFIG_X86_64 */
 
 	.activate_mm = xen_activate_mm,

drivers/acpi/osl.c

@@ -189,12 +189,15 @@ early_param("acpi_rsdp", setup_acpi_rsdp);
 
 acpi_physical_address __init acpi_os_get_root_pointer(void)
 {
-	acpi_physical_address pa = 0;
+	acpi_physical_address pa;
 
 #ifdef CONFIG_KEXEC
 	if (acpi_rsdp)
 		return acpi_rsdp;
 #endif
+	pa = acpi_arch_get_root_pointer();
+	if (pa)
+		return pa;
 
 	if (efi_enabled(EFI_CONFIG_TABLES)) {
 		if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)

include/asm-generic/5level-fixup.h

@@ -8,6 +8,7 @@
 #define P4D_SHIFT			PGDIR_SHIFT
 #define P4D_SIZE			PGDIR_SIZE
 #define P4D_MASK			PGDIR_MASK
+#define MAX_PTRS_PER_P4D		1
 #define PTRS_PER_P4D			1
 
 #define p4d_t				pgd_t

include/asm-generic/pgtable-nop4d.h

@@ -8,10 +8,11 @@
 
 typedef struct { pgd_t pgd; } p4d_t;
 
-#define P4D_SHIFT	PGDIR_SHIFT
-#define PTRS_PER_P4D	1
-#define P4D_SIZE	(1UL << P4D_SHIFT)
-#define P4D_MASK	(~(P4D_SIZE-1))
+#define P4D_SHIFT		PGDIR_SHIFT
+#define MAX_PTRS_PER_P4D	1
+#define PTRS_PER_P4D		1
+#define P4D_SIZE		(1UL << P4D_SHIFT)
+#define P4D_MASK		(~(P4D_SIZE-1))
 
 /*
  * The "pgd_xxx()" functions here are trivial for a folded two-level

include/linux/acpi.h

@@ -623,6 +623,13 @@ bool acpi_gtdt_c3stop(int type);
 int acpi_arch_timer_mem_init(struct arch_timer_mem *timer_mem, int *timer_count);
 #endif
 
+#ifndef ACPI_HAVE_ARCH_GET_ROOT_POINTER
+static inline u64 acpi_arch_get_root_pointer(void)
+{
+	return 0;
+}
+#endif
+
 #else	/* !CONFIG_ACPI */
 
 #define acpi_disabled 1

include/linux/kasan.h

@@ -18,7 +18,7 @@ extern unsigned char kasan_zero_page[PAGE_SIZE];
 extern pte_t kasan_zero_pte[PTRS_PER_PTE];
 extern pmd_t kasan_zero_pmd[PTRS_PER_PMD];
 extern pud_t kasan_zero_pud[PTRS_PER_PUD];
-extern p4d_t kasan_zero_p4d[PTRS_PER_P4D];
+extern p4d_t kasan_zero_p4d[MAX_PTRS_PER_P4D];
 
 void kasan_populate_zero_shadow(const void *shadow_start,
 				const void *shadow_end);

include/linux/mmzone.h

@@ -816,10 +816,6 @@ int local_memory_node(int node_id);
 static inline int local_memory_node(int node_id) { return node_id; };
 #endif
 
-#ifdef CONFIG_NEED_NODE_MEMMAP_SIZE
-unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
-#endif
-
 /*
  * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
  */
@@ -1289,7 +1285,6 @@ struct mminit_pfnnid_cache {
 #endif
 
 void memory_present(int nid, unsigned long start, unsigned long end);
-unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
 
 /*
  * If it is possible to have holes within a MAX_ORDER_NR_PAGES, then we

mm/kasan/kasan_init.c

@@ -31,7 +31,7 @@
 unsigned char kasan_zero_page[PAGE_SIZE] __page_aligned_bss;
 
 #if CONFIG_PGTABLE_LEVELS > 4
-p4d_t kasan_zero_p4d[PTRS_PER_P4D] __page_aligned_bss;
+p4d_t kasan_zero_p4d[MAX_PTRS_PER_P4D] __page_aligned_bss;
 #endif
 #if CONFIG_PGTABLE_LEVELS > 3
 pud_t kasan_zero_pud[PTRS_PER_PUD] __page_aligned_bss;

mm/sparse.c

@@ -235,28 +235,6 @@ void __init memory_present(int nid, unsigned long start, unsigned long end)
 	}
 }
 
-/*
- * Only used by the i386 NUMA architecures, but relatively
- * generic code.
- */
-unsigned long __init node_memmap_size_bytes(int nid, unsigned long start_pfn,
-						     unsigned long end_pfn)
-{
-	unsigned long pfn;
-	unsigned long nr_pages = 0;
-
-	mminit_validate_memmodel_limits(&start_pfn, &end_pfn);
-	for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
-		if (nid != early_pfn_to_nid(pfn))
-			continue;
-
-		if (pfn_present(pfn))
-			nr_pages += PAGES_PER_SECTION;
-	}
-
-	return nr_pages * sizeof(struct page);
-}
-
 /*
  * Subtle, we encode the real pfn into the mem_map such that
  * the identity pfn - section_mem_map will return the actual

mm/zsmalloc.c

@@ -84,18 +84,19 @@
  * This is made more complicated by various memory models and PAE.
  */
 
-#ifndef MAX_PHYSMEM_BITS
-#ifdef CONFIG_HIGHMEM64G
-#define MAX_PHYSMEM_BITS 36
-#else /* !CONFIG_HIGHMEM64G */
+#ifndef MAX_POSSIBLE_PHYSMEM_BITS
+#ifdef MAX_PHYSMEM_BITS
+#define MAX_POSSIBLE_PHYSMEM_BITS MAX_PHYSMEM_BITS
+#else
 /*
  * If this definition of MAX_PHYSMEM_BITS is used, OBJ_INDEX_BITS will just
  * be PAGE_SHIFT
  */
-#define MAX_PHYSMEM_BITS BITS_PER_LONG
+#define MAX_POSSIBLE_PHYSMEM_BITS BITS_PER_LONG
 #endif
 #endif
-#define _PFN_BITS		(MAX_PHYSMEM_BITS - PAGE_SHIFT)
+
+#define _PFN_BITS		(MAX_POSSIBLE_PHYSMEM_BITS - PAGE_SHIFT)
 
 /*
  * Memory for allocating for handle keeps object position by