xref: /linux/arch/x86/Kconfig (revision c4101e55974cc7d835fbd2d8e01553a3f61e9e75)
1# SPDX-License-Identifier: GPL-2.0
2# Select 32 or 64 bit
3config 64BIT
4	bool "64-bit kernel" if "$(ARCH)" = "x86"
5	default "$(ARCH)" != "i386"
6	help
7	  Say yes to build a 64-bit kernel - formerly known as x86_64
8	  Say no to build a 32-bit kernel - formerly known as i386
9
10config X86_32
11	def_bool y
12	depends on !64BIT
13	# Options that are inherently 32-bit kernel only:
14	select ARCH_WANT_IPC_PARSE_VERSION
15	select CLKSRC_I8253
16	select CLONE_BACKWARDS
17	select GENERIC_VDSO_32
18	select HAVE_DEBUG_STACKOVERFLOW
19	select KMAP_LOCAL
20	select MODULES_USE_ELF_REL
21	select OLD_SIGACTION
22	select ARCH_SPLIT_ARG64
23
24config X86_64
25	def_bool y
26	depends on 64BIT
27	# Options that are inherently 64-bit kernel only:
28	select ARCH_HAS_GIGANTIC_PAGE
29	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
30	select ARCH_SUPPORTS_PER_VMA_LOCK
31	select HAVE_ARCH_SOFT_DIRTY
32	select MODULES_USE_ELF_RELA
33	select NEED_DMA_MAP_STATE
34	select SWIOTLB
35	select ARCH_HAS_ELFCORE_COMPAT
36	select ZONE_DMA32
37
38config FORCE_DYNAMIC_FTRACE
39	def_bool y
40	depends on X86_32
41	depends on FUNCTION_TRACER
42	select DYNAMIC_FTRACE
43	help
44	  We keep the static function tracing (!DYNAMIC_FTRACE) around
45	  in order to test the non static function tracing in the
46	  generic code, as other architectures still use it. But we
47	  only need to keep it around for x86_64. No need to keep it
48	  for x86_32. For x86_32, force DYNAMIC_FTRACE.
49#
50# Arch settings
51#
52# ( Note that options that are marked 'if X86_64' could in principle be
53#   ported to 32-bit as well. )
54#
55config X86
56	def_bool y
57	#
58	# Note: keep this list sorted alphabetically
59	#
60	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
61	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
62	select ARCH_32BIT_OFF_T			if X86_32
63	select ARCH_CLOCKSOURCE_INIT
64	select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
65	select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION
66	select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64
67	select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG
68	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE)
69	select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE
70	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
71	select ARCH_HAS_CACHE_LINE_SIZE
72	select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
73	select ARCH_HAS_CPU_FINALIZE_INIT
74	select ARCH_HAS_CURRENT_STACK_POINTER
75	select ARCH_HAS_DEBUG_VIRTUAL
76	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
77	select ARCH_HAS_DEVMEM_IS_ALLOWED
78	select ARCH_HAS_EARLY_DEBUG		if KGDB
79	select ARCH_HAS_ELF_RANDOMIZE
80	select ARCH_HAS_FAST_MULTIPLIER
81	select ARCH_HAS_FORTIFY_SOURCE
82	select ARCH_HAS_GCOV_PROFILE_ALL
83	select ARCH_HAS_KCOV			if X86_64
84	select ARCH_HAS_MEM_ENCRYPT
85	select ARCH_HAS_MEMBARRIER_SYNC_CORE
86	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
87	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
88	select ARCH_HAS_PMEM_API		if X86_64
89	select ARCH_HAS_PTE_DEVMAP		if X86_64
90	select ARCH_HAS_PTE_SPECIAL
91	select ARCH_HAS_HW_PTE_YOUNG
92	select ARCH_HAS_NONLEAF_PMD_YOUNG	if PGTABLE_LEVELS > 2
93	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
94	select ARCH_HAS_COPY_MC			if X86_64
95	select ARCH_HAS_SET_MEMORY
96	select ARCH_HAS_SET_DIRECT_MAP
97	select ARCH_HAS_STRICT_KERNEL_RWX
98	select ARCH_HAS_STRICT_MODULE_RWX
99	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
100	select ARCH_HAS_SYSCALL_WRAPPER
101	select ARCH_HAS_UBSAN_SANITIZE_ALL
102	select ARCH_HAS_DEBUG_WX
103	select ARCH_HAS_ZONE_DMA_SET if EXPERT
104	select ARCH_HAVE_NMI_SAFE_CMPXCHG
105	select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
106	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
107	select ARCH_MIGHT_HAVE_PC_PARPORT
108	select ARCH_MIGHT_HAVE_PC_SERIO
109	select ARCH_STACKWALK
110	select ARCH_SUPPORTS_ACPI
111	select ARCH_SUPPORTS_ATOMIC_RMW
112	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
113	select ARCH_SUPPORTS_PAGE_TABLE_CHECK	if X86_64
114	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
115	select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP	if NR_CPUS <= 4096
116	select ARCH_SUPPORTS_CFI_CLANG		if X86_64
117	select ARCH_USES_CFI_TRAPS		if X86_64 && CFI_CLANG
118	select ARCH_SUPPORTS_LTO_CLANG
119	select ARCH_SUPPORTS_LTO_CLANG_THIN
120	select ARCH_USE_BUILTIN_BSWAP
121	select ARCH_USE_CMPXCHG_LOCKREF		if X86_CMPXCHG64
122	select ARCH_USE_MEMTEST
123	select ARCH_USE_QUEUED_RWLOCKS
124	select ARCH_USE_QUEUED_SPINLOCKS
125	select ARCH_USE_SYM_ANNOTATIONS
126	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
127	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
128	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
129	select ARCH_WANTS_NO_INSTR
130	select ARCH_WANT_GENERAL_HUGETLB
131	select ARCH_WANT_HUGE_PMD_SHARE
132	select ARCH_WANT_LD_ORPHAN_WARN
133	select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP	if X86_64
134	select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP	if X86_64
135	select ARCH_WANTS_THP_SWAP		if X86_64
136	select ARCH_HAS_PARANOID_L1D_FLUSH
137	select BUILDTIME_TABLE_SORT
138	select CLKEVT_I8253
139	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
140	select CLOCKSOURCE_WATCHDOG
141	# Word-size accesses may read uninitialized data past the trailing \0
142	# in strings and cause false KMSAN reports.
143	select DCACHE_WORD_ACCESS		if !KMSAN
144	select DYNAMIC_SIGFRAME
145	select EDAC_ATOMIC_SCRUB
146	select EDAC_SUPPORT
147	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
148	select GENERIC_CLOCKEVENTS_MIN_ADJUST
149	select GENERIC_CMOS_UPDATE
150	select GENERIC_CPU_AUTOPROBE
151	select GENERIC_CPU_VULNERABILITIES
152	select GENERIC_EARLY_IOREMAP
153	select GENERIC_ENTRY
154	select GENERIC_IOMAP
155	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
156	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
157	select GENERIC_IRQ_MIGRATION		if SMP
158	select GENERIC_IRQ_PROBE
159	select GENERIC_IRQ_RESERVATION_MODE
160	select GENERIC_IRQ_SHOW
161	select GENERIC_PENDING_IRQ		if SMP
162	select GENERIC_PTDUMP
163	select GENERIC_SMP_IDLE_THREAD
164	select GENERIC_TIME_VSYSCALL
165	select GENERIC_GETTIMEOFDAY
166	select GENERIC_VDSO_TIME_NS
167	select GUP_GET_PXX_LOW_HIGH		if X86_PAE
168	select HARDIRQS_SW_RESEND
169	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
170	select HAS_IOPORT
171	select HAVE_ACPI_APEI			if ACPI
172	select HAVE_ACPI_APEI_NMI		if ACPI
173	select HAVE_ALIGNED_STRUCT_PAGE
174	select HAVE_ARCH_AUDITSYSCALL
175	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
176	select HAVE_ARCH_HUGE_VMALLOC		if X86_64
177	select HAVE_ARCH_JUMP_LABEL
178	select HAVE_ARCH_JUMP_LABEL_RELATIVE
179	select HAVE_ARCH_KASAN			if X86_64
180	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
181	select HAVE_ARCH_KFENCE
182	select HAVE_ARCH_KMSAN			if X86_64
183	select HAVE_ARCH_KGDB
184	select HAVE_ARCH_MMAP_RND_BITS		if MMU
185	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
186	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
187	select HAVE_ARCH_PREL32_RELOCATIONS
188	select HAVE_ARCH_SECCOMP_FILTER
189	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
190	select HAVE_ARCH_STACKLEAK
191	select HAVE_ARCH_TRACEHOOK
192	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
193	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
194	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
195	select HAVE_ARCH_USERFAULTFD_MINOR	if X86_64 && USERFAULTFD
196	select HAVE_ARCH_VMAP_STACK		if X86_64
197	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
198	select HAVE_ARCH_WITHIN_STACK_FRAMES
199	select HAVE_ASM_MODVERSIONS
200	select HAVE_CMPXCHG_DOUBLE
201	select HAVE_CMPXCHG_LOCAL
202	select HAVE_CONTEXT_TRACKING_USER		if X86_64
203	select HAVE_CONTEXT_TRACKING_USER_OFFSTACK	if HAVE_CONTEXT_TRACKING_USER
204	select HAVE_C_RECORDMCOUNT
205	select HAVE_OBJTOOL_MCOUNT		if HAVE_OBJTOOL
206	select HAVE_OBJTOOL_NOP_MCOUNT		if HAVE_OBJTOOL_MCOUNT
207	select HAVE_BUILDTIME_MCOUNT_SORT
208	select HAVE_DEBUG_KMEMLEAK
209	select HAVE_DMA_CONTIGUOUS
210	select HAVE_DYNAMIC_FTRACE
211	select HAVE_DYNAMIC_FTRACE_WITH_REGS
212	select HAVE_DYNAMIC_FTRACE_WITH_ARGS	if X86_64
213	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
214	select HAVE_SAMPLE_FTRACE_DIRECT	if X86_64
215	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI	if X86_64
216	select HAVE_EBPF_JIT
217	select HAVE_EFFICIENT_UNALIGNED_ACCESS
218	select HAVE_EISA
219	select HAVE_EXIT_THREAD
220	select HAVE_FAST_GUP
221	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
222	select HAVE_FTRACE_MCOUNT_RECORD
223	select HAVE_FUNCTION_GRAPH_RETVAL	if HAVE_FUNCTION_GRAPH_TRACER
224	select HAVE_FUNCTION_GRAPH_TRACER	if X86_32 || (X86_64 && DYNAMIC_FTRACE)
225	select HAVE_FUNCTION_TRACER
226	select HAVE_GCC_PLUGINS
227	select HAVE_HW_BREAKPOINT
228	select HAVE_IOREMAP_PROT
229	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
230	select HAVE_IRQ_TIME_ACCOUNTING
231	select HAVE_JUMP_LABEL_HACK		if HAVE_OBJTOOL
232	select HAVE_KERNEL_BZIP2
233	select HAVE_KERNEL_GZIP
234	select HAVE_KERNEL_LZ4
235	select HAVE_KERNEL_LZMA
236	select HAVE_KERNEL_LZO
237	select HAVE_KERNEL_XZ
238	select HAVE_KERNEL_ZSTD
239	select HAVE_KPROBES
240	select HAVE_KPROBES_ON_FTRACE
241	select HAVE_FUNCTION_ERROR_INJECTION
242	select HAVE_KRETPROBES
243	select HAVE_RETHOOK
244	select HAVE_KVM
245	select HAVE_LIVEPATCH			if X86_64
246	select HAVE_MIXED_BREAKPOINTS_REGS
247	select HAVE_MOD_ARCH_SPECIFIC
248	select HAVE_MOVE_PMD
249	select HAVE_MOVE_PUD
250	select HAVE_NOINSTR_HACK		if HAVE_OBJTOOL
251	select HAVE_NMI
252	select HAVE_NOINSTR_VALIDATION		if HAVE_OBJTOOL
253	select HAVE_OBJTOOL			if X86_64
254	select HAVE_OPTPROBES
255	select HAVE_PCSPKR_PLATFORM
256	select HAVE_PERF_EVENTS
257	select HAVE_PERF_EVENTS_NMI
258	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
259	select HAVE_PCI
260	select HAVE_PERF_REGS
261	select HAVE_PERF_USER_STACK_DUMP
262	select MMU_GATHER_RCU_TABLE_FREE	if PARAVIRT
263	select MMU_GATHER_MERGE_VMAS
264	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
265	select HAVE_REGS_AND_STACK_ACCESS_API
266	select HAVE_RELIABLE_STACKTRACE		if UNWINDER_ORC || STACK_VALIDATION
267	select HAVE_FUNCTION_ARG_ACCESS_API
268	select HAVE_SETUP_PER_CPU_AREA
269	select HAVE_SOFTIRQ_ON_OWN_STACK
270	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
271	select HAVE_STACK_VALIDATION		if HAVE_OBJTOOL
272	select HAVE_STATIC_CALL
273	select HAVE_STATIC_CALL_INLINE		if HAVE_OBJTOOL
274	select HAVE_PREEMPT_DYNAMIC_CALL
275	select HAVE_RSEQ
276	select HAVE_RUST			if X86_64
277	select HAVE_SYSCALL_TRACEPOINTS
278	select HAVE_UACCESS_VALIDATION		if HAVE_OBJTOOL
279	select HAVE_UNSTABLE_SCHED_CLOCK
280	select HAVE_USER_RETURN_NOTIFIER
281	select HAVE_GENERIC_VDSO
282	select HOTPLUG_PARALLEL			if SMP && X86_64
283	select HOTPLUG_SMT			if SMP
284	select HOTPLUG_SPLIT_STARTUP		if SMP && X86_32
285	select IRQ_FORCED_THREADING
286	select LOCK_MM_AND_FIND_VMA
287	select NEED_PER_CPU_EMBED_FIRST_CHUNK
288	select NEED_PER_CPU_PAGE_FIRST_CHUNK
289	select NEED_SG_DMA_LENGTH
290	select PCI_DOMAINS			if PCI
291	select PCI_LOCKLESS_CONFIG		if PCI
292	select PERF_EVENTS
293	select RTC_LIB
294	select RTC_MC146818_LIB
295	select SPARSE_IRQ
296	select SYSCTL_EXCEPTION_TRACE
297	select THREAD_INFO_IN_TASK
298	select TRACE_IRQFLAGS_SUPPORT
299	select TRACE_IRQFLAGS_NMI_SUPPORT
300	select USER_STACKTRACE_SUPPORT
301	select HAVE_ARCH_KCSAN			if X86_64
302	select PROC_PID_ARCH_STATUS		if PROC_FS
303	select HAVE_ARCH_NODE_DEV_GROUP		if X86_SGX
304	select FUNCTION_ALIGNMENT_16B		if X86_64 || X86_ALIGNMENT_16
305	select FUNCTION_ALIGNMENT_4B
306	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
307	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
308
309config INSTRUCTION_DECODER
310	def_bool y
311	depends on KPROBES || PERF_EVENTS || UPROBES
312
313config OUTPUT_FORMAT
314	string
315	default "elf32-i386" if X86_32
316	default "elf64-x86-64" if X86_64
317
318config LOCKDEP_SUPPORT
319	def_bool y
320
321config STACKTRACE_SUPPORT
322	def_bool y
323
324config MMU
325	def_bool y
326
327config ARCH_MMAP_RND_BITS_MIN
328	default 28 if 64BIT
329	default 8
330
331config ARCH_MMAP_RND_BITS_MAX
332	default 32 if 64BIT
333	default 16
334
335config ARCH_MMAP_RND_COMPAT_BITS_MIN
336	default 8
337
338config ARCH_MMAP_RND_COMPAT_BITS_MAX
339	default 16
340
341config SBUS
342	bool
343
344config GENERIC_ISA_DMA
345	def_bool y
346	depends on ISA_DMA_API
347
348config GENERIC_CSUM
349	bool
350	default y if KMSAN || KASAN
351
352config GENERIC_BUG
353	def_bool y
354	depends on BUG
355	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
356
357config GENERIC_BUG_RELATIVE_POINTERS
358	bool
359
360config ARCH_MAY_HAVE_PC_FDC
361	def_bool y
362	depends on ISA_DMA_API
363
364config GENERIC_CALIBRATE_DELAY
365	def_bool y
366
367config ARCH_HAS_CPU_RELAX
368	def_bool y
369
370config ARCH_HIBERNATION_POSSIBLE
371	def_bool y
372
373config ARCH_SUSPEND_POSSIBLE
374	def_bool y
375
376config AUDIT_ARCH
377	def_bool y if X86_64
378
379config KASAN_SHADOW_OFFSET
380	hex
381	depends on KASAN
382	default 0xdffffc0000000000
383
384config HAVE_INTEL_TXT
385	def_bool y
386	depends on INTEL_IOMMU && ACPI
387
388config X86_64_SMP
389	def_bool y
390	depends on X86_64 && SMP
391
392config ARCH_SUPPORTS_UPROBES
393	def_bool y
394
395config FIX_EARLYCON_MEM
396	def_bool y
397
398config DYNAMIC_PHYSICAL_MASK
399	bool
400
401config PGTABLE_LEVELS
402	int
403	default 5 if X86_5LEVEL
404	default 4 if X86_64
405	default 3 if X86_PAE
406	default 2
407
408config CC_HAS_SANE_STACKPROTECTOR
409	bool
410	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) if 64BIT
411	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC) $(CLANG_FLAGS))
412	help
413	  We have to make sure stack protector is unconditionally disabled if
414	  the compiler produces broken code or if it does not let us control
415	  the segment on 32-bit kernels.
416
417menu "Processor type and features"
418
419config SMP
420	bool "Symmetric multi-processing support"
421	help
422	  This enables support for systems with more than one CPU. If you have
423	  a system with only one CPU, say N. If you have a system with more
424	  than one CPU, say Y.
425
426	  If you say N here, the kernel will run on uni- and multiprocessor
427	  machines, but will use only one CPU of a multiprocessor machine. If
428	  you say Y here, the kernel will run on many, but not all,
429	  uniprocessor machines. On a uniprocessor machine, the kernel
430	  will run faster if you say N here.
431
432	  Note that if you say Y here and choose architecture "586" or
433	  "Pentium" under "Processor family", the kernel will not work on 486
434	  architectures. Similarly, multiprocessor kernels for the "PPro"
435	  architecture may not work on all Pentium based boards.
436
437	  People using multiprocessor machines who say Y here should also say
438	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
439	  Management" code will be disabled if you say Y here.
440
441	  See also <file:Documentation/arch/x86/i386/IO-APIC.rst>,
442	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
443	  <http://www.tldp.org/docs.html#howto>.
444
445	  If you don't know what to do here, say N.
446
447config X86_X2APIC
448	bool "Support x2apic"
449	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
450	help
451	  This enables x2apic support on CPUs that have this feature.
452
453	  This allows 32-bit apic IDs (so it can support very large systems),
454	  and accesses the local apic via MSRs not via mmio.
455
456	  Some Intel systems circa 2022 and later are locked into x2APIC mode
457	  and can not fall back to the legacy APIC modes if SGX or TDX are
458	  enabled in the BIOS. They will boot with very reduced functionality
459	  without enabling this option.
460
461	  If you don't know what to do here, say N.
462
463config X86_MPPARSE
464	bool "Enable MPS table" if ACPI
465	default y
466	depends on X86_LOCAL_APIC
467	help
468	  For old smp systems that do not have proper acpi support. Newer systems
469	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
470
471config GOLDFISH
472	def_bool y
473	depends on X86_GOLDFISH
474
475config X86_CPU_RESCTRL
476	bool "x86 CPU resource control support"
477	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
478	select KERNFS
479	select PROC_CPU_RESCTRL		if PROC_FS
480	help
481	  Enable x86 CPU resource control support.
482
483	  Provide support for the allocation and monitoring of system resources
484	  usage by the CPU.
485
486	  Intel calls this Intel Resource Director Technology
487	  (Intel(R) RDT). More information about RDT can be found in the
488	  Intel x86 Architecture Software Developer Manual.
489
490	  AMD calls this AMD Platform Quality of Service (AMD QoS).
491	  More information about AMD QoS can be found in the AMD64 Technology
492	  Platform Quality of Service Extensions manual.
493
494	  Say N if unsure.
495
496if X86_32
497config X86_BIGSMP
498	bool "Support for big SMP systems with more than 8 CPUs"
499	depends on SMP
500	help
501	  This option is needed for the systems that have more than 8 CPUs.
502
503config X86_EXTENDED_PLATFORM
504	bool "Support for extended (non-PC) x86 platforms"
505	default y
506	help
507	  If you disable this option then the kernel will only support
508	  standard PC platforms. (which covers the vast majority of
509	  systems out there.)
510
511	  If you enable this option then you'll be able to select support
512	  for the following (non-PC) 32 bit x86 platforms:
513		Goldfish (Android emulator)
514		AMD Elan
515		RDC R-321x SoC
516		SGI 320/540 (Visual Workstation)
517		STA2X11-based (e.g. Northville)
518		Moorestown MID devices
519
520	  If you have one of these systems, or if you want to build a
521	  generic distribution kernel, say Y here - otherwise say N.
522endif # X86_32
523
524if X86_64
525config X86_EXTENDED_PLATFORM
526	bool "Support for extended (non-PC) x86 platforms"
527	default y
528	help
529	  If you disable this option then the kernel will only support
530	  standard PC platforms. (which covers the vast majority of
531	  systems out there.)
532
533	  If you enable this option then you'll be able to select support
534	  for the following (non-PC) 64 bit x86 platforms:
535		Numascale NumaChip
536		ScaleMP vSMP
537		SGI Ultraviolet
538
539	  If you have one of these systems, or if you want to build a
540	  generic distribution kernel, say Y here - otherwise say N.
541endif # X86_64
542# This is an alphabetically sorted list of 64 bit extended platforms
543# Please maintain the alphabetic order if and when there are additions
544config X86_NUMACHIP
545	bool "Numascale NumaChip"
546	depends on X86_64
547	depends on X86_EXTENDED_PLATFORM
548	depends on NUMA
549	depends on SMP
550	depends on X86_X2APIC
551	depends on PCI_MMCONFIG
552	help
553	  Adds support for Numascale NumaChip large-SMP systems. Needed to
554	  enable more than ~168 cores.
555	  If you don't have one of these, you should say N here.
556
557config X86_VSMP
558	bool "ScaleMP vSMP"
559	select HYPERVISOR_GUEST
560	select PARAVIRT
561	depends on X86_64 && PCI
562	depends on X86_EXTENDED_PLATFORM
563	depends on SMP
564	help
565	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
566	  supposed to run on these EM64T-based machines.  Only choose this option
567	  if you have one of these machines.
568
569config X86_UV
570	bool "SGI Ultraviolet"
571	depends on X86_64
572	depends on X86_EXTENDED_PLATFORM
573	depends on NUMA
574	depends on EFI
575	depends on KEXEC_CORE
576	depends on X86_X2APIC
577	depends on PCI
578	help
579	  This option is needed in order to support SGI Ultraviolet systems.
580	  If you don't have one of these, you should say N here.
581
582# Following is an alphabetically sorted list of 32 bit extended platforms
583# Please maintain the alphabetic order if and when there are additions
584
585config X86_GOLDFISH
586	bool "Goldfish (Virtual Platform)"
587	depends on X86_EXTENDED_PLATFORM
588	help
589	  Enable support for the Goldfish virtual platform used primarily
590	  for Android development. Unless you are building for the Android
591	  Goldfish emulator say N here.
592
593config X86_INTEL_CE
594	bool "CE4100 TV platform"
595	depends on PCI
596	depends on PCI_GODIRECT
597	depends on X86_IO_APIC
598	depends on X86_32
599	depends on X86_EXTENDED_PLATFORM
600	select X86_REBOOTFIXUPS
601	select OF
602	select OF_EARLY_FLATTREE
603	help
604	  Select for the Intel CE media processor (CE4100) SOC.
605	  This option compiles in support for the CE4100 SOC for settop
606	  boxes and media devices.
607
608config X86_INTEL_MID
609	bool "Intel MID platform support"
610	depends on X86_EXTENDED_PLATFORM
611	depends on X86_PLATFORM_DEVICES
612	depends on PCI
613	depends on X86_64 || (PCI_GOANY && X86_32)
614	depends on X86_IO_APIC
615	select I2C
616	select DW_APB_TIMER
617	select INTEL_SCU_PCI
618	help
619	  Select to build a kernel capable of supporting Intel MID (Mobile
620	  Internet Device) platform systems which do not have the PCI legacy
621	  interfaces. If you are building for a PC class system say N here.
622
623	  Intel MID platforms are based on an Intel processor and chipset which
624	  consume less power than most of the x86 derivatives.
625
626config X86_INTEL_QUARK
627	bool "Intel Quark platform support"
628	depends on X86_32
629	depends on X86_EXTENDED_PLATFORM
630	depends on X86_PLATFORM_DEVICES
631	depends on X86_TSC
632	depends on PCI
633	depends on PCI_GOANY
634	depends on X86_IO_APIC
635	select IOSF_MBI
636	select INTEL_IMR
637	select COMMON_CLK
638	help
639	  Select to include support for Quark X1000 SoC.
640	  Say Y here if you have a Quark based system such as the Arduino
641	  compatible Intel Galileo.
642
643config X86_INTEL_LPSS
644	bool "Intel Low Power Subsystem Support"
645	depends on X86 && ACPI && PCI
646	select COMMON_CLK
647	select PINCTRL
648	select IOSF_MBI
649	help
650	  Select to build support for Intel Low Power Subsystem such as
651	  found on Intel Lynxpoint PCH. Selecting this option enables
652	  things like clock tree (common clock framework) and pincontrol
653	  which are needed by the LPSS peripheral drivers.
654
655config X86_AMD_PLATFORM_DEVICE
656	bool "AMD ACPI2Platform devices support"
657	depends on ACPI
658	select COMMON_CLK
659	select PINCTRL
660	help
661	  Select to interpret AMD specific ACPI device to platform device
662	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
663	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
664	  implemented under PINCTRL subsystem.
665
666config IOSF_MBI
667	tristate "Intel SoC IOSF Sideband support for SoC platforms"
668	depends on PCI
669	help
670	  This option enables sideband register access support for Intel SoC
671	  platforms. On these platforms the IOSF sideband is used in lieu of
672	  MSR's for some register accesses, mostly but not limited to thermal
673	  and power. Drivers may query the availability of this device to
674	  determine if they need the sideband in order to work on these
675	  platforms. The sideband is available on the following SoC products.
676	  This list is not meant to be exclusive.
677	   - BayTrail
678	   - Braswell
679	   - Quark
680
681	  You should say Y if you are running a kernel on one of these SoC's.
682
683config IOSF_MBI_DEBUG
684	bool "Enable IOSF sideband access through debugfs"
685	depends on IOSF_MBI && DEBUG_FS
686	help
687	  Select this option to expose the IOSF sideband access registers (MCR,
688	  MDR, MCRX) through debugfs to write and read register information from
689	  different units on the SoC. This is most useful for obtaining device
690	  state information for debug and analysis. As this is a general access
691	  mechanism, users of this option would have specific knowledge of the
692	  device they want to access.
693
694	  If you don't require the option or are in doubt, say N.
695
696config X86_RDC321X
697	bool "RDC R-321x SoC"
698	depends on X86_32
699	depends on X86_EXTENDED_PLATFORM
700	select M486
701	select X86_REBOOTFIXUPS
702	help
703	  This option is needed for RDC R-321x system-on-chip, also known
704	  as R-8610-(G).
705	  If you don't have one of these chips, you should say N here.
706
707config X86_32_NON_STANDARD
708	bool "Support non-standard 32-bit SMP architectures"
709	depends on X86_32 && SMP
710	depends on X86_EXTENDED_PLATFORM
711	help
712	  This option compiles in the bigsmp and STA2X11 default
713	  subarchitectures.  It is intended for a generic binary
714	  kernel. If you select them all, kernel will probe it one by
715	  one and will fallback to default.
716
717# Alphabetically sorted list of Non standard 32 bit platforms
718
719config X86_SUPPORTS_MEMORY_FAILURE
720	def_bool y
721	# MCE code calls memory_failure():
722	depends on X86_MCE
723	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
724	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
725	depends on X86_64 || !SPARSEMEM
726	select ARCH_SUPPORTS_MEMORY_FAILURE
727
728config STA2X11
729	bool "STA2X11 Companion Chip Support"
730	depends on X86_32_NON_STANDARD && PCI
731	select SWIOTLB
732	select MFD_STA2X11
733	select GPIOLIB
734	help
735	  This adds support for boards based on the STA2X11 IO-Hub,
736	  a.k.a. "ConneXt". The chip is used in place of the standard
737	  PC chipset, so all "standard" peripherals are missing. If this
738	  option is selected the kernel will still be able to boot on
739	  standard PC machines.
740
741config X86_32_IRIS
742	tristate "Eurobraille/Iris poweroff module"
743	depends on X86_32
744	help
745	  The Iris machines from EuroBraille do not have APM or ACPI support
746	  to shut themselves down properly.  A special I/O sequence is
747	  needed to do so, which is what this module does at
748	  kernel shutdown.
749
750	  This is only for Iris machines from EuroBraille.
751
752	  If unused, say N.
753
754config SCHED_OMIT_FRAME_POINTER
755	def_bool y
756	prompt "Single-depth WCHAN output"
757	depends on X86
758	help
759	  Calculate simpler /proc/<PID>/wchan values. If this option
760	  is disabled then wchan values will recurse back to the
761	  caller function. This provides more accurate wchan values,
762	  at the expense of slightly more scheduling overhead.
763
764	  If in doubt, say "Y".
765
766menuconfig HYPERVISOR_GUEST
767	bool "Linux guest support"
768	help
769	  Say Y here to enable options for running Linux under various hyper-
770	  visors. This option enables basic hypervisor detection and platform
771	  setup.
772
773	  If you say N, all options in this submenu will be skipped and
774	  disabled, and Linux guest support won't be built in.
775
776if HYPERVISOR_GUEST
777
778config PARAVIRT
779	bool "Enable paravirtualization code"
780	depends on HAVE_STATIC_CALL
781	help
782	  This changes the kernel so it can modify itself when it is run
783	  under a hypervisor, potentially improving performance significantly
784	  over full virtualization.  However, when run without a hypervisor
785	  the kernel is theoretically slower and slightly larger.
786
787config PARAVIRT_XXL
788	bool
789
790config PARAVIRT_DEBUG
791	bool "paravirt-ops debugging"
792	depends on PARAVIRT && DEBUG_KERNEL
793	help
794	  Enable to debug paravirt_ops internals.  Specifically, BUG if
795	  a paravirt_op is missing when it is called.
796
797config PARAVIRT_SPINLOCKS
798	bool "Paravirtualization layer for spinlocks"
799	depends on PARAVIRT && SMP
800	help
801	  Paravirtualized spinlocks allow a pvops backend to replace the
802	  spinlock implementation with something virtualization-friendly
803	  (for example, block the virtual CPU rather than spinning).
804
805	  It has a minimal impact on native kernels and gives a nice performance
806	  benefit on paravirtualized KVM / Xen kernels.
807
808	  If you are unsure how to answer this question, answer Y.
809
810config X86_HV_CALLBACK_VECTOR
811	def_bool n
812
813source "arch/x86/xen/Kconfig"
814
815config KVM_GUEST
816	bool "KVM Guest support (including kvmclock)"
817	depends on PARAVIRT
818	select PARAVIRT_CLOCK
819	select ARCH_CPUIDLE_HALTPOLL
820	select X86_HV_CALLBACK_VECTOR
821	default y
822	help
823	  This option enables various optimizations for running under the KVM
824	  hypervisor. It includes a paravirtualized clock, so that instead
825	  of relying on a PIT (or probably other) emulation by the
826	  underlying device model, the host provides the guest with
827	  timing infrastructure such as time of day, and system time
828
829config ARCH_CPUIDLE_HALTPOLL
830	def_bool n
831	prompt "Disable host haltpoll when loading haltpoll driver"
832	help
833	  If virtualized under KVM, disable host haltpoll.
834
835config PVH
836	bool "Support for running PVH guests"
837	help
838	  This option enables the PVH entry point for guest virtual machines
839	  as specified in the x86/HVM direct boot ABI.
840
841config PARAVIRT_TIME_ACCOUNTING
842	bool "Paravirtual steal time accounting"
843	depends on PARAVIRT
844	help
845	  Select this option to enable fine granularity task steal time
846	  accounting. Time spent executing other tasks in parallel with
847	  the current vCPU is discounted from the vCPU power. To account for
848	  that, there can be a small performance impact.
849
850	  If in doubt, say N here.
851
852config PARAVIRT_CLOCK
853	bool
854
855config JAILHOUSE_GUEST
856	bool "Jailhouse non-root cell support"
857	depends on X86_64 && PCI
858	select X86_PM_TIMER
859	help
860	  This option allows to run Linux as guest in a Jailhouse non-root
861	  cell. You can leave this option disabled if you only want to start
862	  Jailhouse and run Linux afterwards in the root cell.
863
864config ACRN_GUEST
865	bool "ACRN Guest support"
866	depends on X86_64
867	select X86_HV_CALLBACK_VECTOR
868	help
869	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
870	  a flexible, lightweight reference open-source hypervisor, built with
871	  real-time and safety-criticality in mind. It is built for embedded
872	  IOT with small footprint and real-time features. More details can be
873	  found in https://projectacrn.org/.
874
875config INTEL_TDX_GUEST
876	bool "Intel TDX (Trust Domain Extensions) - Guest Support"
877	depends on X86_64 && CPU_SUP_INTEL
878	depends on X86_X2APIC
879	depends on EFI_STUB
880	select ARCH_HAS_CC_PLATFORM
881	select X86_MEM_ENCRYPT
882	select X86_MCE
883	select UNACCEPTED_MEMORY
884	help
885	  Support running as a guest under Intel TDX.  Without this support,
886	  the guest kernel can not boot or run under TDX.
887	  TDX includes memory encryption and integrity capabilities
888	  which protect the confidentiality and integrity of guest
889	  memory contents and CPU state. TDX guests are protected from
890	  some attacks from the VMM.
891
892endif # HYPERVISOR_GUEST
893
894source "arch/x86/Kconfig.cpu"
895
896config HPET_TIMER
897	def_bool X86_64
898	prompt "HPET Timer Support" if X86_32
899	help
900	  Use the IA-PC HPET (High Precision Event Timer) to manage
901	  time in preference to the PIT and RTC, if a HPET is
902	  present.
903	  HPET is the next generation timer replacing legacy 8254s.
904	  The HPET provides a stable time base on SMP
905	  systems, unlike the TSC, but it is more expensive to access,
906	  as it is off-chip.  The interface used is documented
907	  in the HPET spec, revision 1.
908
909	  You can safely choose Y here.  However, HPET will only be
910	  activated if the platform and the BIOS support this feature.
911	  Otherwise the 8254 will be used for timing services.
912
913	  Choose N to continue using the legacy 8254 timer.
914
915config HPET_EMULATE_RTC
916	def_bool y
917	depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
918
919# Mark as expert because too many people got it wrong.
920# The code disables itself when not needed.
921config DMI
922	default y
923	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
924	bool "Enable DMI scanning" if EXPERT
925	help
926	  Enabled scanning of DMI to identify machine quirks. Say Y
927	  here unless you have verified that your setup is not
928	  affected by entries in the DMI blacklist. Required by PNP
929	  BIOS code.
930
931config GART_IOMMU
932	bool "Old AMD GART IOMMU support"
933	select DMA_OPS
934	select IOMMU_HELPER
935	select SWIOTLB
936	depends on X86_64 && PCI && AMD_NB
937	help
938	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
939	  GART based hardware IOMMUs.
940
941	  The GART supports full DMA access for devices with 32-bit access
942	  limitations, on systems with more than 3 GB. This is usually needed
943	  for USB, sound, many IDE/SATA chipsets and some other devices.
944
945	  Newer systems typically have a modern AMD IOMMU, supported via
946	  the CONFIG_AMD_IOMMU=y config option.
947
948	  In normal configurations this driver is only active when needed:
949	  there's more than 3 GB of memory and the system contains a
950	  32-bit limited device.
951
952	  If unsure, say Y.
953
954config BOOT_VESA_SUPPORT
955	bool
956	help
957	  If true, at least one selected framebuffer driver can take advantage
958	  of VESA video modes set at an early boot stage via the vga= parameter.
959
960config MAXSMP
961	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
962	depends on X86_64 && SMP && DEBUG_KERNEL
963	select CPUMASK_OFFSTACK
964	help
965	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
966	  If unsure, say N.
967
968#
969# The maximum number of CPUs supported:
970#
971# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
972# and which can be configured interactively in the
973# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
974#
975# The ranges are different on 32-bit and 64-bit kernels, depending on
976# hardware capabilities and scalability features of the kernel.
977#
978# ( If MAXSMP is enabled we just use the highest possible value and disable
979#   interactive configuration. )
980#
981
982config NR_CPUS_RANGE_BEGIN
983	int
984	default NR_CPUS_RANGE_END if MAXSMP
985	default    1 if !SMP
986	default    2
987
988config NR_CPUS_RANGE_END
989	int
990	depends on X86_32
991	default   64 if  SMP &&  X86_BIGSMP
992	default    8 if  SMP && !X86_BIGSMP
993	default    1 if !SMP
994
995config NR_CPUS_RANGE_END
996	int
997	depends on X86_64
998	default 8192 if  SMP && CPUMASK_OFFSTACK
999	default  512 if  SMP && !CPUMASK_OFFSTACK
1000	default    1 if !SMP
1001
1002config NR_CPUS_DEFAULT
1003	int
1004	depends on X86_32
1005	default   32 if  X86_BIGSMP
1006	default    8 if  SMP
1007	default    1 if !SMP
1008
1009config NR_CPUS_DEFAULT
1010	int
1011	depends on X86_64
1012	default 8192 if  MAXSMP
1013	default   64 if  SMP
1014	default    1 if !SMP
1015
1016config NR_CPUS
1017	int "Maximum number of CPUs" if SMP && !MAXSMP
1018	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1019	default NR_CPUS_DEFAULT
1020	help
1021	  This allows you to specify the maximum number of CPUs which this
1022	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1023	  supported value is 8192, otherwise the maximum value is 512.  The
1024	  minimum value which makes sense is 2.
1025
1026	  This is purely to save memory: each supported CPU adds about 8KB
1027	  to the kernel image.
1028
1029config SCHED_CLUSTER
1030	bool "Cluster scheduler support"
1031	depends on SMP
1032	default y
1033	help
1034	  Cluster scheduler support improves the CPU scheduler's decision
1035	  making when dealing with machines that have clusters of CPUs.
1036	  Cluster usually means a couple of CPUs which are placed closely
1037	  by sharing mid-level caches, last-level cache tags or internal
1038	  busses.
1039
1040config SCHED_SMT
1041	def_bool y if SMP
1042
1043config SCHED_MC
1044	def_bool y
1045	prompt "Multi-core scheduler support"
1046	depends on SMP
1047	help
1048	  Multi-core scheduler support improves the CPU scheduler's decision
1049	  making when dealing with multi-core CPU chips at a cost of slightly
1050	  increased overhead in some places. If unsure say N here.
1051
1052config SCHED_MC_PRIO
1053	bool "CPU core priorities scheduler support"
1054	depends on SCHED_MC && CPU_SUP_INTEL
1055	select X86_INTEL_PSTATE
1056	select CPU_FREQ
1057	default y
1058	help
1059	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1060	  core ordering determined at manufacturing time, which allows
1061	  certain cores to reach higher turbo frequencies (when running
1062	  single threaded workloads) than others.
1063
1064	  Enabling this kernel feature teaches the scheduler about
1065	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1066	  scheduler's CPU selection logic accordingly, so that higher
1067	  overall system performance can be achieved.
1068
1069	  This feature will have no effect on CPUs without this feature.
1070
1071	  If unsure say Y here.
1072
1073config UP_LATE_INIT
1074	def_bool y
1075	depends on !SMP && X86_LOCAL_APIC
1076
1077config X86_UP_APIC
1078	bool "Local APIC support on uniprocessors" if !PCI_MSI
1079	default PCI_MSI
1080	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1081	help
1082	  A local APIC (Advanced Programmable Interrupt Controller) is an
1083	  integrated interrupt controller in the CPU. If you have a single-CPU
1084	  system which has a processor with a local APIC, you can say Y here to
1085	  enable and use it. If you say Y here even though your machine doesn't
1086	  have a local APIC, then the kernel will still run with no slowdown at
1087	  all. The local APIC supports CPU-generated self-interrupts (timer,
1088	  performance counters), and the NMI watchdog which detects hard
1089	  lockups.
1090
1091config X86_UP_IOAPIC
1092	bool "IO-APIC support on uniprocessors"
1093	depends on X86_UP_APIC
1094	help
1095	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1096	  SMP-capable replacement for PC-style interrupt controllers. Most
1097	  SMP systems and many recent uniprocessor systems have one.
1098
1099	  If you have a single-CPU system with an IO-APIC, you can say Y here
1100	  to use it. If you say Y here even though your machine doesn't have
1101	  an IO-APIC, then the kernel will still run with no slowdown at all.
1102
1103config X86_LOCAL_APIC
1104	def_bool y
1105	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1106	select IRQ_DOMAIN_HIERARCHY
1107
1108config X86_IO_APIC
1109	def_bool y
1110	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1111
1112config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1113	bool "Reroute for broken boot IRQs"
1114	depends on X86_IO_APIC
1115	help
1116	  This option enables a workaround that fixes a source of
1117	  spurious interrupts. This is recommended when threaded
1118	  interrupt handling is used on systems where the generation of
1119	  superfluous "boot interrupts" cannot be disabled.
1120
1121	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1122	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1123	  kernel does during interrupt handling). On chipsets where this
1124	  boot IRQ generation cannot be disabled, this workaround keeps
1125	  the original IRQ line masked so that only the equivalent "boot
1126	  IRQ" is delivered to the CPUs. The workaround also tells the
1127	  kernel to set up the IRQ handler on the boot IRQ line. In this
1128	  way only one interrupt is delivered to the kernel. Otherwise
1129	  the spurious second interrupt may cause the kernel to bring
1130	  down (vital) interrupt lines.
1131
1132	  Only affects "broken" chipsets. Interrupt sharing may be
1133	  increased on these systems.
1134
1135config X86_MCE
1136	bool "Machine Check / overheating reporting"
1137	select GENERIC_ALLOCATOR
1138	default y
1139	help
1140	  Machine Check support allows the processor to notify the
1141	  kernel if it detects a problem (e.g. overheating, data corruption).
1142	  The action the kernel takes depends on the severity of the problem,
1143	  ranging from warning messages to halting the machine.
1144
1145config X86_MCELOG_LEGACY
1146	bool "Support for deprecated /dev/mcelog character device"
1147	depends on X86_MCE
1148	help
1149	  Enable support for /dev/mcelog which is needed by the old mcelog
1150	  userspace logging daemon. Consider switching to the new generation
1151	  rasdaemon solution.
1152
1153config X86_MCE_INTEL
1154	def_bool y
1155	prompt "Intel MCE features"
1156	depends on X86_MCE && X86_LOCAL_APIC
1157	help
1158	  Additional support for intel specific MCE features such as
1159	  the thermal monitor.
1160
1161config X86_MCE_AMD
1162	def_bool y
1163	prompt "AMD MCE features"
1164	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1165	help
1166	  Additional support for AMD specific MCE features such as
1167	  the DRAM Error Threshold.
1168
1169config X86_ANCIENT_MCE
1170	bool "Support for old Pentium 5 / WinChip machine checks"
1171	depends on X86_32 && X86_MCE
1172	help
1173	  Include support for machine check handling on old Pentium 5 or WinChip
1174	  systems. These typically need to be enabled explicitly on the command
1175	  line.
1176
1177config X86_MCE_THRESHOLD
1178	depends on X86_MCE_AMD || X86_MCE_INTEL
1179	def_bool y
1180
1181config X86_MCE_INJECT
1182	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1183	tristate "Machine check injector support"
1184	help
1185	  Provide support for injecting machine checks for testing purposes.
1186	  If you don't know what a machine check is and you don't do kernel
1187	  QA it is safe to say n.
1188
1189source "arch/x86/events/Kconfig"
1190
1191config X86_LEGACY_VM86
1192	bool "Legacy VM86 support"
1193	depends on X86_32
1194	help
1195	  This option allows user programs to put the CPU into V8086
1196	  mode, which is an 80286-era approximation of 16-bit real mode.
1197
1198	  Some very old versions of X and/or vbetool require this option
1199	  for user mode setting.  Similarly, DOSEMU will use it if
1200	  available to accelerate real mode DOS programs.  However, any
1201	  recent version of DOSEMU, X, or vbetool should be fully
1202	  functional even without kernel VM86 support, as they will all
1203	  fall back to software emulation. Nevertheless, if you are using
1204	  a 16-bit DOS program where 16-bit performance matters, vm86
1205	  mode might be faster than emulation and you might want to
1206	  enable this option.
1207
1208	  Note that any app that works on a 64-bit kernel is unlikely to
1209	  need this option, as 64-bit kernels don't, and can't, support
1210	  V8086 mode. This option is also unrelated to 16-bit protected
1211	  mode and is not needed to run most 16-bit programs under Wine.
1212
1213	  Enabling this option increases the complexity of the kernel
1214	  and slows down exception handling a tiny bit.
1215
1216	  If unsure, say N here.
1217
1218config VM86
1219	bool
1220	default X86_LEGACY_VM86
1221
1222config X86_16BIT
1223	bool "Enable support for 16-bit segments" if EXPERT
1224	default y
1225	depends on MODIFY_LDT_SYSCALL
1226	help
1227	  This option is required by programs like Wine to run 16-bit
1228	  protected mode legacy code on x86 processors.  Disabling
1229	  this option saves about 300 bytes on i386, or around 6K text
1230	  plus 16K runtime memory on x86-64,
1231
1232config X86_ESPFIX32
1233	def_bool y
1234	depends on X86_16BIT && X86_32
1235
1236config X86_ESPFIX64
1237	def_bool y
1238	depends on X86_16BIT && X86_64
1239
1240config X86_VSYSCALL_EMULATION
1241	bool "Enable vsyscall emulation" if EXPERT
1242	default y
1243	depends on X86_64
1244	help
1245	  This enables emulation of the legacy vsyscall page.  Disabling
1246	  it is roughly equivalent to booting with vsyscall=none, except
1247	  that it will also disable the helpful warning if a program
1248	  tries to use a vsyscall.  With this option set to N, offending
1249	  programs will just segfault, citing addresses of the form
1250	  0xffffffffff600?00.
1251
1252	  This option is required by many programs built before 2013, and
1253	  care should be used even with newer programs if set to N.
1254
1255	  Disabling this option saves about 7K of kernel size and
1256	  possibly 4K of additional runtime pagetable memory.
1257
1258config X86_IOPL_IOPERM
1259	bool "IOPERM and IOPL Emulation"
1260	default y
1261	help
1262	  This enables the ioperm() and iopl() syscalls which are necessary
1263	  for legacy applications.
1264
1265	  Legacy IOPL support is an overbroad mechanism which allows user
1266	  space aside of accessing all 65536 I/O ports also to disable
1267	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1268	  capabilities and permission from potentially active security
1269	  modules.
1270
1271	  The emulation restricts the functionality of the syscall to
1272	  only allowing the full range I/O port access, but prevents the
1273	  ability to disable interrupts from user space which would be
1274	  granted if the hardware IOPL mechanism would be used.
1275
1276config TOSHIBA
1277	tristate "Toshiba Laptop support"
1278	depends on X86_32
1279	help
1280	  This adds a driver to safely access the System Management Mode of
1281	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1282	  not work on models with a Phoenix BIOS. The System Management Mode
1283	  is used to set the BIOS and power saving options on Toshiba portables.
1284
1285	  For information on utilities to make use of this driver see the
1286	  Toshiba Linux utilities web site at:
1287	  <http://www.buzzard.org.uk/toshiba/>.
1288
1289	  Say Y if you intend to run this kernel on a Toshiba portable.
1290	  Say N otherwise.
1291
1292config X86_REBOOTFIXUPS
1293	bool "Enable X86 board specific fixups for reboot"
1294	depends on X86_32
1295	help
1296	  This enables chipset and/or board specific fixups to be done
1297	  in order to get reboot to work correctly. This is only needed on
1298	  some combinations of hardware and BIOS. The symptom, for which
1299	  this config is intended, is when reboot ends with a stalled/hung
1300	  system.
1301
1302	  Currently, the only fixup is for the Geode machines using
1303	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1304
1305	  Say Y if you want to enable the fixup. Currently, it's safe to
1306	  enable this option even if you don't need it.
1307	  Say N otherwise.
1308
1309config MICROCODE
1310	def_bool y
1311	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1312
1313config MICROCODE_INITRD32
1314	def_bool y
1315	depends on MICROCODE && X86_32 && BLK_DEV_INITRD
1316
1317config MICROCODE_LATE_LOADING
1318	bool "Late microcode loading (DANGEROUS)"
1319	default n
1320	depends on MICROCODE && SMP
1321	help
1322	  Loading microcode late, when the system is up and executing instructions
1323	  is a tricky business and should be avoided if possible. Just the sequence
1324	  of synchronizing all cores and SMT threads is one fragile dance which does
1325	  not guarantee that cores might not softlock after the loading. Therefore,
1326	  use this at your own risk. Late loading taints the kernel unless the
1327	  microcode header indicates that it is safe for late loading via the
1328	  minimal revision check. This minimal revision check can be enforced on
1329	  the kernel command line with "microcode.minrev=Y".
1330
1331config MICROCODE_LATE_FORCE_MINREV
1332	bool "Enforce late microcode loading minimal revision check"
1333	default n
1334	depends on MICROCODE_LATE_LOADING
1335	help
1336	  To prevent that users load microcode late which modifies already
1337	  in use features, newer microcode patches have a minimum revision field
1338	  in the microcode header, which tells the kernel which minimum
1339	  revision must be active in the CPU to safely load that new microcode
1340	  late into the running system. If disabled the check will not
1341	  be enforced but the kernel will be tainted when the minimal
1342	  revision check fails.
1343
1344	  This minimal revision check can also be controlled via the
1345	  "microcode.minrev" parameter on the kernel command line.
1346
1347	  If unsure say Y.
1348
1349config X86_MSR
1350	tristate "/dev/cpu/*/msr - Model-specific register support"
1351	help
1352	  This device gives privileged processes access to the x86
1353	  Model-Specific Registers (MSRs).  It is a character device with
1354	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1355	  MSR accesses are directed to a specific CPU on multi-processor
1356	  systems.
1357
1358config X86_CPUID
1359	tristate "/dev/cpu/*/cpuid - CPU information support"
1360	help
1361	  This device gives processes access to the x86 CPUID instruction to
1362	  be executed on a specific processor.  It is a character device
1363	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1364	  /dev/cpu/31/cpuid.
1365
1366choice
1367	prompt "High Memory Support"
1368	default HIGHMEM4G
1369	depends on X86_32
1370
1371config NOHIGHMEM
1372	bool "off"
1373	help
1374	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1375	  However, the address space of 32-bit x86 processors is only 4
1376	  Gigabytes large. That means that, if you have a large amount of
1377	  physical memory, not all of it can be "permanently mapped" by the
1378	  kernel. The physical memory that's not permanently mapped is called
1379	  "high memory".
1380
1381	  If you are compiling a kernel which will never run on a machine with
1382	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1383	  choice and suitable for most users). This will result in a "3GB/1GB"
1384	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1385	  space and the remaining part of the 4GB virtual memory space is used
1386	  by the kernel to permanently map as much physical memory as
1387	  possible.
1388
1389	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1390	  answer "4GB" here.
1391
1392	  If more than 4 Gigabytes is used then answer "64GB" here. This
1393	  selection turns Intel PAE (Physical Address Extension) mode on.
1394	  PAE implements 3-level paging on IA32 processors. PAE is fully
1395	  supported by Linux, PAE mode is implemented on all recent Intel
1396	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1397	  then the kernel will not boot on CPUs that don't support PAE!
1398
1399	  The actual amount of total physical memory will either be
1400	  auto detected or can be forced by using a kernel command line option
1401	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1402	  your boot loader (lilo or loadlin) about how to pass options to the
1403	  kernel at boot time.)
1404
1405	  If unsure, say "off".
1406
1407config HIGHMEM4G
1408	bool "4GB"
1409	help
1410	  Select this if you have a 32-bit processor and between 1 and 4
1411	  gigabytes of physical RAM.
1412
1413config HIGHMEM64G
1414	bool "64GB"
1415	depends on X86_HAVE_PAE
1416	select X86_PAE
1417	help
1418	  Select this if you have a 32-bit processor and more than 4
1419	  gigabytes of physical RAM.
1420
1421endchoice
1422
1423choice
1424	prompt "Memory split" if EXPERT
1425	default VMSPLIT_3G
1426	depends on X86_32
1427	help
1428	  Select the desired split between kernel and user memory.
1429
1430	  If the address range available to the kernel is less than the
1431	  physical memory installed, the remaining memory will be available
1432	  as "high memory". Accessing high memory is a little more costly
1433	  than low memory, as it needs to be mapped into the kernel first.
1434	  Note that increasing the kernel address space limits the range
1435	  available to user programs, making the address space there
1436	  tighter.  Selecting anything other than the default 3G/1G split
1437	  will also likely make your kernel incompatible with binary-only
1438	  kernel modules.
1439
1440	  If you are not absolutely sure what you are doing, leave this
1441	  option alone!
1442
1443	config VMSPLIT_3G
1444		bool "3G/1G user/kernel split"
1445	config VMSPLIT_3G_OPT
1446		depends on !X86_PAE
1447		bool "3G/1G user/kernel split (for full 1G low memory)"
1448	config VMSPLIT_2G
1449		bool "2G/2G user/kernel split"
1450	config VMSPLIT_2G_OPT
1451		depends on !X86_PAE
1452		bool "2G/2G user/kernel split (for full 2G low memory)"
1453	config VMSPLIT_1G
1454		bool "1G/3G user/kernel split"
1455endchoice
1456
1457config PAGE_OFFSET
1458	hex
1459	default 0xB0000000 if VMSPLIT_3G_OPT
1460	default 0x80000000 if VMSPLIT_2G
1461	default 0x78000000 if VMSPLIT_2G_OPT
1462	default 0x40000000 if VMSPLIT_1G
1463	default 0xC0000000
1464	depends on X86_32
1465
1466config HIGHMEM
1467	def_bool y
1468	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1469
1470config X86_PAE
1471	bool "PAE (Physical Address Extension) Support"
1472	depends on X86_32 && X86_HAVE_PAE
1473	select PHYS_ADDR_T_64BIT
1474	select SWIOTLB
1475	help
1476	  PAE is required for NX support, and furthermore enables
1477	  larger swapspace support for non-overcommit purposes. It
1478	  has the cost of more pagetable lookup overhead, and also
1479	  consumes more pagetable space per process.
1480
1481config X86_5LEVEL
1482	bool "Enable 5-level page tables support"
1483	default y
1484	select DYNAMIC_MEMORY_LAYOUT
1485	select SPARSEMEM_VMEMMAP
1486	depends on X86_64
1487	help
1488	  5-level paging enables access to larger address space:
1489	  up to 128 PiB of virtual address space and 4 PiB of
1490	  physical address space.
1491
1492	  It will be supported by future Intel CPUs.
1493
1494	  A kernel with the option enabled can be booted on machines that
1495	  support 4- or 5-level paging.
1496
1497	  See Documentation/arch/x86/x86_64/5level-paging.rst for more
1498	  information.
1499
1500	  Say N if unsure.
1501
1502config X86_DIRECT_GBPAGES
1503	def_bool y
1504	depends on X86_64
1505	help
1506	  Certain kernel features effectively disable kernel
1507	  linear 1 GB mappings (even if the CPU otherwise
1508	  supports them), so don't confuse the user by printing
1509	  that we have them enabled.
1510
1511config X86_CPA_STATISTICS
1512	bool "Enable statistic for Change Page Attribute"
1513	depends on DEBUG_FS
1514	help
1515	  Expose statistics about the Change Page Attribute mechanism, which
1516	  helps to determine the effectiveness of preserving large and huge
1517	  page mappings when mapping protections are changed.
1518
1519config X86_MEM_ENCRYPT
1520	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1521	select DYNAMIC_PHYSICAL_MASK
1522	def_bool n
1523
1524config AMD_MEM_ENCRYPT
1525	bool "AMD Secure Memory Encryption (SME) support"
1526	depends on X86_64 && CPU_SUP_AMD
1527	depends on EFI_STUB
1528	select DMA_COHERENT_POOL
1529	select ARCH_USE_MEMREMAP_PROT
1530	select INSTRUCTION_DECODER
1531	select ARCH_HAS_CC_PLATFORM
1532	select X86_MEM_ENCRYPT
1533	select UNACCEPTED_MEMORY
1534	help
1535	  Say yes to enable support for the encryption of system memory.
1536	  This requires an AMD processor that supports Secure Memory
1537	  Encryption (SME).
1538
1539config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1540	bool "Activate AMD Secure Memory Encryption (SME) by default"
1541	depends on AMD_MEM_ENCRYPT
1542	help
1543	  Say yes to have system memory encrypted by default if running on
1544	  an AMD processor that supports Secure Memory Encryption (SME).
1545
1546	  If set to Y, then the encryption of system memory can be
1547	  deactivated with the mem_encrypt=off command line option.
1548
1549	  If set to N, then the encryption of system memory can be
1550	  activated with the mem_encrypt=on command line option.
1551
1552# Common NUMA Features
1553config NUMA
1554	bool "NUMA Memory Allocation and Scheduler Support"
1555	depends on SMP
1556	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1557	default y if X86_BIGSMP
1558	select USE_PERCPU_NUMA_NODE_ID
1559	select OF_NUMA if OF
1560	help
1561	  Enable NUMA (Non-Uniform Memory Access) support.
1562
1563	  The kernel will try to allocate memory used by a CPU on the
1564	  local memory controller of the CPU and add some more
1565	  NUMA awareness to the kernel.
1566
1567	  For 64-bit this is recommended if the system is Intel Core i7
1568	  (or later), AMD Opteron, or EM64T NUMA.
1569
1570	  For 32-bit this is only needed if you boot a 32-bit
1571	  kernel on a 64-bit NUMA platform.
1572
1573	  Otherwise, you should say N.
1574
1575config AMD_NUMA
1576	def_bool y
1577	prompt "Old style AMD Opteron NUMA detection"
1578	depends on X86_64 && NUMA && PCI
1579	help
1580	  Enable AMD NUMA node topology detection.  You should say Y here if
1581	  you have a multi processor AMD system. This uses an old method to
1582	  read the NUMA configuration directly from the builtin Northbridge
1583	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1584	  which also takes priority if both are compiled in.
1585
1586config X86_64_ACPI_NUMA
1587	def_bool y
1588	prompt "ACPI NUMA detection"
1589	depends on X86_64 && NUMA && ACPI && PCI
1590	select ACPI_NUMA
1591	help
1592	  Enable ACPI SRAT based node topology detection.
1593
1594config NUMA_EMU
1595	bool "NUMA emulation"
1596	depends on NUMA
1597	help
1598	  Enable NUMA emulation. A flat machine will be split
1599	  into virtual nodes when booted with "numa=fake=N", where N is the
1600	  number of nodes. This is only useful for debugging.
1601
1602config NODES_SHIFT
1603	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1604	range 1 10
1605	default "10" if MAXSMP
1606	default "6" if X86_64
1607	default "3"
1608	depends on NUMA
1609	help
1610	  Specify the maximum number of NUMA Nodes available on the target
1611	  system.  Increases memory reserved to accommodate various tables.
1612
1613config ARCH_FLATMEM_ENABLE
1614	def_bool y
1615	depends on X86_32 && !NUMA
1616
1617config ARCH_SPARSEMEM_ENABLE
1618	def_bool y
1619	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1620	select SPARSEMEM_STATIC if X86_32
1621	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1622
1623config ARCH_SPARSEMEM_DEFAULT
1624	def_bool X86_64 || (NUMA && X86_32)
1625
1626config ARCH_SELECT_MEMORY_MODEL
1627	def_bool y
1628	depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE
1629
1630config ARCH_MEMORY_PROBE
1631	bool "Enable sysfs memory/probe interface"
1632	depends on MEMORY_HOTPLUG
1633	help
1634	  This option enables a sysfs memory/probe interface for testing.
1635	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1636	  If you are unsure how to answer this question, answer N.
1637
1638config ARCH_PROC_KCORE_TEXT
1639	def_bool y
1640	depends on X86_64 && PROC_KCORE
1641
1642config ILLEGAL_POINTER_VALUE
1643	hex
1644	default 0 if X86_32
1645	default 0xdead000000000000 if X86_64
1646
1647config X86_PMEM_LEGACY_DEVICE
1648	bool
1649
1650config X86_PMEM_LEGACY
1651	tristate "Support non-standard NVDIMMs and ADR protected memory"
1652	depends on PHYS_ADDR_T_64BIT
1653	depends on BLK_DEV
1654	select X86_PMEM_LEGACY_DEVICE
1655	select NUMA_KEEP_MEMINFO if NUMA
1656	select LIBNVDIMM
1657	help
1658	  Treat memory marked using the non-standard e820 type of 12 as used
1659	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1660	  The kernel will offer these regions to the 'pmem' driver so
1661	  they can be used for persistent storage.
1662
1663	  Say Y if unsure.
1664
1665config HIGHPTE
1666	bool "Allocate 3rd-level pagetables from highmem"
1667	depends on HIGHMEM
1668	help
1669	  The VM uses one page table entry for each page of physical memory.
1670	  For systems with a lot of RAM, this can be wasteful of precious
1671	  low memory.  Setting this option will put user-space page table
1672	  entries in high memory.
1673
1674config X86_CHECK_BIOS_CORRUPTION
1675	bool "Check for low memory corruption"
1676	help
1677	  Periodically check for memory corruption in low memory, which
1678	  is suspected to be caused by BIOS.  Even when enabled in the
1679	  configuration, it is disabled at runtime.  Enable it by
1680	  setting "memory_corruption_check=1" on the kernel command
1681	  line.  By default it scans the low 64k of memory every 60
1682	  seconds; see the memory_corruption_check_size and
1683	  memory_corruption_check_period parameters in
1684	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1685
1686	  When enabled with the default parameters, this option has
1687	  almost no overhead, as it reserves a relatively small amount
1688	  of memory and scans it infrequently.  It both detects corruption
1689	  and prevents it from affecting the running system.
1690
1691	  It is, however, intended as a diagnostic tool; if repeatable
1692	  BIOS-originated corruption always affects the same memory,
1693	  you can use memmap= to prevent the kernel from using that
1694	  memory.
1695
1696config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1697	bool "Set the default setting of memory_corruption_check"
1698	depends on X86_CHECK_BIOS_CORRUPTION
1699	default y
1700	help
1701	  Set whether the default state of memory_corruption_check is
1702	  on or off.
1703
1704config MATH_EMULATION
1705	bool
1706	depends on MODIFY_LDT_SYSCALL
1707	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1708	help
1709	  Linux can emulate a math coprocessor (used for floating point
1710	  operations) if you don't have one. 486DX and Pentium processors have
1711	  a math coprocessor built in, 486SX and 386 do not, unless you added
1712	  a 487DX or 387, respectively. (The messages during boot time can
1713	  give you some hints here ["man dmesg"].) Everyone needs either a
1714	  coprocessor or this emulation.
1715
1716	  If you don't have a math coprocessor, you need to say Y here; if you
1717	  say Y here even though you have a coprocessor, the coprocessor will
1718	  be used nevertheless. (This behavior can be changed with the kernel
1719	  command line option "no387", which comes handy if your coprocessor
1720	  is broken. Try "man bootparam" or see the documentation of your boot
1721	  loader (lilo or loadlin) about how to pass options to the kernel at
1722	  boot time.) This means that it is a good idea to say Y here if you
1723	  intend to use this kernel on different machines.
1724
1725	  More information about the internals of the Linux math coprocessor
1726	  emulation can be found in <file:arch/x86/math-emu/README>.
1727
1728	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1729	  kernel, it won't hurt.
1730
1731config MTRR
1732	def_bool y
1733	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1734	help
1735	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1736	  the Memory Type Range Registers (MTRRs) may be used to control
1737	  processor access to memory ranges. This is most useful if you have
1738	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1739	  allows bus write transfers to be combined into a larger transfer
1740	  before bursting over the PCI/AGP bus. This can increase performance
1741	  of image write operations 2.5 times or more. Saying Y here creates a
1742	  /proc/mtrr file which may be used to manipulate your processor's
1743	  MTRRs. Typically the X server should use this.
1744
1745	  This code has a reasonably generic interface so that similar
1746	  control registers on other processors can be easily supported
1747	  as well:
1748
1749	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1750	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1751	  these, the ARRs are used to emulate the MTRRs.
1752	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1753	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1754	  write-combining. All of these processors are supported by this code
1755	  and it makes sense to say Y here if you have one of them.
1756
1757	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1758	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1759	  can lead to all sorts of problems, so it's good to say Y here.
1760
1761	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1762	  just add about 9 KB to your kernel.
1763
1764	  See <file:Documentation/arch/x86/mtrr.rst> for more information.
1765
1766config MTRR_SANITIZER
1767	def_bool y
1768	prompt "MTRR cleanup support"
1769	depends on MTRR
1770	help
1771	  Convert MTRR layout from continuous to discrete, so X drivers can
1772	  add writeback entries.
1773
1774	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1775	  The largest mtrr entry size for a continuous block can be set with
1776	  mtrr_chunk_size.
1777
1778	  If unsure, say Y.
1779
1780config MTRR_SANITIZER_ENABLE_DEFAULT
1781	int "MTRR cleanup enable value (0-1)"
1782	range 0 1
1783	default "0"
1784	depends on MTRR_SANITIZER
1785	help
1786	  Enable mtrr cleanup default value
1787
1788config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1789	int "MTRR cleanup spare reg num (0-7)"
1790	range 0 7
1791	default "1"
1792	depends on MTRR_SANITIZER
1793	help
1794	  mtrr cleanup spare entries default, it can be changed via
1795	  mtrr_spare_reg_nr=N on the kernel command line.
1796
1797config X86_PAT
1798	def_bool y
1799	prompt "x86 PAT support" if EXPERT
1800	depends on MTRR
1801	help
1802	  Use PAT attributes to setup page level cache control.
1803
1804	  PATs are the modern equivalents of MTRRs and are much more
1805	  flexible than MTRRs.
1806
1807	  Say N here if you see bootup problems (boot crash, boot hang,
1808	  spontaneous reboots) or a non-working video driver.
1809
1810	  If unsure, say Y.
1811
1812config ARCH_USES_PG_UNCACHED
1813	def_bool y
1814	depends on X86_PAT
1815
1816config X86_UMIP
1817	def_bool y
1818	prompt "User Mode Instruction Prevention" if EXPERT
1819	help
1820	  User Mode Instruction Prevention (UMIP) is a security feature in
1821	  some x86 processors. If enabled, a general protection fault is
1822	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1823	  executed in user mode. These instructions unnecessarily expose
1824	  information about the hardware state.
1825
1826	  The vast majority of applications do not use these instructions.
1827	  For the very few that do, software emulation is provided in
1828	  specific cases in protected and virtual-8086 modes. Emulated
1829	  results are dummy.
1830
1831config CC_HAS_IBT
1832	# GCC >= 9 and binutils >= 2.29
1833	# Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654
1834	# Clang/LLVM >= 14
1835	# https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f
1836	# https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332
1837	def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \
1838		  (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \
1839		  $(as-instr,endbr64)
1840
1841config X86_CET
1842	def_bool n
1843	help
1844	  CET features configured (Shadow stack or IBT)
1845
1846config X86_KERNEL_IBT
1847	prompt "Indirect Branch Tracking"
1848	def_bool y
1849	depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL
1850	# https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f
1851	depends on !LD_IS_LLD || LLD_VERSION >= 140000
1852	select OBJTOOL
1853	select X86_CET
1854	help
1855	  Build the kernel with support for Indirect Branch Tracking, a
1856	  hardware support course-grain forward-edge Control Flow Integrity
1857	  protection. It enforces that all indirect calls must land on
1858	  an ENDBR instruction, as such, the compiler will instrument the
1859	  code with them to make this happen.
1860
1861	  In addition to building the kernel with IBT, seal all functions that
1862	  are not indirect call targets, avoiding them ever becoming one.
1863
1864	  This requires LTO like objtool runs and will slow down the build. It
1865	  does significantly reduce the number of ENDBR instructions in the
1866	  kernel image.
1867
1868config X86_INTEL_MEMORY_PROTECTION_KEYS
1869	prompt "Memory Protection Keys"
1870	def_bool y
1871	# Note: only available in 64-bit mode
1872	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
1873	select ARCH_USES_HIGH_VMA_FLAGS
1874	select ARCH_HAS_PKEYS
1875	help
1876	  Memory Protection Keys provides a mechanism for enforcing
1877	  page-based protections, but without requiring modification of the
1878	  page tables when an application changes protection domains.
1879
1880	  For details, see Documentation/core-api/protection-keys.rst
1881
1882	  If unsure, say y.
1883
1884choice
1885	prompt "TSX enable mode"
1886	depends on CPU_SUP_INTEL
1887	default X86_INTEL_TSX_MODE_OFF
1888	help
1889	  Intel's TSX (Transactional Synchronization Extensions) feature
1890	  allows to optimize locking protocols through lock elision which
1891	  can lead to a noticeable performance boost.
1892
1893	  On the other hand it has been shown that TSX can be exploited
1894	  to form side channel attacks (e.g. TAA) and chances are there
1895	  will be more of those attacks discovered in the future.
1896
1897	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1898	  might override this decision by tsx=on the command line parameter.
1899	  Even with TSX enabled, the kernel will attempt to enable the best
1900	  possible TAA mitigation setting depending on the microcode available
1901	  for the particular machine.
1902
1903	  This option allows to set the default tsx mode between tsx=on, =off
1904	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1905	  details.
1906
1907	  Say off if not sure, auto if TSX is in use but it should be used on safe
1908	  platforms or on if TSX is in use and the security aspect of tsx is not
1909	  relevant.
1910
1911config X86_INTEL_TSX_MODE_OFF
1912	bool "off"
1913	help
1914	  TSX is disabled if possible - equals to tsx=off command line parameter.
1915
1916config X86_INTEL_TSX_MODE_ON
1917	bool "on"
1918	help
1919	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1920	  line parameter.
1921
1922config X86_INTEL_TSX_MODE_AUTO
1923	bool "auto"
1924	help
1925	  TSX is enabled on TSX capable HW that is believed to be safe against
1926	  side channel attacks- equals the tsx=auto command line parameter.
1927endchoice
1928
1929config X86_SGX
1930	bool "Software Guard eXtensions (SGX)"
1931	depends on X86_64 && CPU_SUP_INTEL && X86_X2APIC
1932	depends on CRYPTO=y
1933	depends on CRYPTO_SHA256=y
1934	select MMU_NOTIFIER
1935	select NUMA_KEEP_MEMINFO if NUMA
1936	select XARRAY_MULTI
1937	help
1938	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1939	  that can be used by applications to set aside private regions of code
1940	  and data, referred to as enclaves. An enclave's private memory can
1941	  only be accessed by code running within the enclave. Accesses from
1942	  outside the enclave, including other enclaves, are disallowed by
1943	  hardware.
1944
1945	  If unsure, say N.
1946
1947config X86_USER_SHADOW_STACK
1948	bool "X86 userspace shadow stack"
1949	depends on AS_WRUSS
1950	depends on X86_64
1951	select ARCH_USES_HIGH_VMA_FLAGS
1952	select X86_CET
1953	help
1954	  Shadow stack protection is a hardware feature that detects function
1955	  return address corruption.  This helps mitigate ROP attacks.
1956	  Applications must be enabled to use it, and old userspace does not
1957	  get protection "for free".
1958
1959	  CPUs supporting shadow stacks were first released in 2020.
1960
1961	  See Documentation/arch/x86/shstk.rst for more information.
1962
1963	  If unsure, say N.
1964
1965config INTEL_TDX_HOST
1966	bool "Intel Trust Domain Extensions (TDX) host support"
1967	depends on CPU_SUP_INTEL
1968	depends on X86_64
1969	depends on KVM_INTEL
1970	help
1971	  Intel Trust Domain Extensions (TDX) protects guest VMs from malicious
1972	  host and certain physical attacks.  This option enables necessary TDX
1973	  support in the host kernel to run confidential VMs.
1974
1975	  If unsure, say N.
1976
1977config EFI
1978	bool "EFI runtime service support"
1979	depends on ACPI
1980	select UCS2_STRING
1981	select EFI_RUNTIME_WRAPPERS
1982	select ARCH_USE_MEMREMAP_PROT
1983	select EFI_RUNTIME_MAP if KEXEC_CORE
1984	help
1985	  This enables the kernel to use EFI runtime services that are
1986	  available (such as the EFI variable services).
1987
1988	  This option is only useful on systems that have EFI firmware.
1989	  In addition, you should use the latest ELILO loader available
1990	  at <http://elilo.sourceforge.net> in order to take advantage
1991	  of EFI runtime services. However, even with this option, the
1992	  resultant kernel should continue to boot on existing non-EFI
1993	  platforms.
1994
1995config EFI_STUB
1996	bool "EFI stub support"
1997	depends on EFI
1998	select RELOCATABLE
1999	help
2000	  This kernel feature allows a bzImage to be loaded directly
2001	  by EFI firmware without the use of a bootloader.
2002
2003	  See Documentation/admin-guide/efi-stub.rst for more information.
2004
2005config EFI_HANDOVER_PROTOCOL
2006	bool "EFI handover protocol (DEPRECATED)"
2007	depends on EFI_STUB
2008	default y
2009	help
2010	  Select this in order to include support for the deprecated EFI
2011	  handover protocol, which defines alternative entry points into the
2012	  EFI stub.  This is a practice that has no basis in the UEFI
2013	  specification, and requires a priori knowledge on the part of the
2014	  bootloader about Linux/x86 specific ways of passing the command line
2015	  and initrd, and where in memory those assets may be loaded.
2016
2017	  If in doubt, say Y. Even though the corresponding support is not
2018	  present in upstream GRUB or other bootloaders, most distros build
2019	  GRUB with numerous downstream patches applied, and may rely on the
2020	  handover protocol as as result.
2021
2022config EFI_MIXED
2023	bool "EFI mixed-mode support"
2024	depends on EFI_STUB && X86_64
2025	help
2026	  Enabling this feature allows a 64-bit kernel to be booted
2027	  on a 32-bit firmware, provided that your CPU supports 64-bit
2028	  mode.
2029
2030	  Note that it is not possible to boot a mixed-mode enabled
2031	  kernel via the EFI boot stub - a bootloader that supports
2032	  the EFI handover protocol must be used.
2033
2034	  If unsure, say N.
2035
2036config EFI_FAKE_MEMMAP
2037	bool "Enable EFI fake memory map"
2038	depends on EFI
2039	help
2040	  Saying Y here will enable "efi_fake_mem" boot option.  By specifying
2041	  this parameter, you can add arbitrary attribute to specific memory
2042	  range by updating original (firmware provided) EFI memmap.  This is
2043	  useful for debugging of EFI memmap related feature, e.g., Address
2044	  Range Mirroring feature.
2045
2046config EFI_MAX_FAKE_MEM
2047	int "maximum allowable number of ranges in efi_fake_mem boot option"
2048	depends on EFI_FAKE_MEMMAP
2049	range 1 128
2050	default 8
2051	help
2052	  Maximum allowable number of ranges in efi_fake_mem boot option.
2053	  Ranges can be set up to this value using comma-separated list.
2054	  The default value is 8.
2055
2056config EFI_RUNTIME_MAP
2057	bool "Export EFI runtime maps to sysfs" if EXPERT
2058	depends on EFI
2059	help
2060	  Export EFI runtime memory regions to /sys/firmware/efi/runtime-map.
2061	  That memory map is required by the 2nd kernel to set up EFI virtual
2062	  mappings after kexec, but can also be used for debugging purposes.
2063
2064	  See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map.
2065
2066source "kernel/Kconfig.hz"
2067
2068config ARCH_SUPPORTS_KEXEC
2069	def_bool y
2070
2071config ARCH_SUPPORTS_KEXEC_FILE
2072	def_bool X86_64
2073
2074config ARCH_SELECTS_KEXEC_FILE
2075	def_bool y
2076	depends on KEXEC_FILE
2077	select HAVE_IMA_KEXEC if IMA
2078
2079config ARCH_SUPPORTS_KEXEC_PURGATORY
2080	def_bool y
2081
2082config ARCH_SUPPORTS_KEXEC_SIG
2083	def_bool y
2084
2085config ARCH_SUPPORTS_KEXEC_SIG_FORCE
2086	def_bool y
2087
2088config ARCH_SUPPORTS_KEXEC_BZIMAGE_VERIFY_SIG
2089	def_bool y
2090
2091config ARCH_SUPPORTS_KEXEC_JUMP
2092	def_bool y
2093
2094config ARCH_SUPPORTS_CRASH_DUMP
2095	def_bool X86_64 || (X86_32 && HIGHMEM)
2096
2097config ARCH_SUPPORTS_CRASH_HOTPLUG
2098	def_bool y
2099
2100config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
2101	def_bool CRASH_CORE
2102
2103config PHYSICAL_START
2104	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2105	default "0x1000000"
2106	help
2107	  This gives the physical address where the kernel is loaded.
2108
2109	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2110	  bzImage will decompress itself to above physical address and
2111	  run from there. Otherwise, bzImage will run from the address where
2112	  it has been loaded by the boot loader and will ignore above physical
2113	  address.
2114
2115	  In normal kdump cases one does not have to set/change this option
2116	  as now bzImage can be compiled as a completely relocatable image
2117	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2118	  address. This option is mainly useful for the folks who don't want
2119	  to use a bzImage for capturing the crash dump and want to use a
2120	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2121	  to be specifically compiled to run from a specific memory area
2122	  (normally a reserved region) and this option comes handy.
2123
2124	  So if you are using bzImage for capturing the crash dump,
2125	  leave the value here unchanged to 0x1000000 and set
2126	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2127	  for capturing the crash dump change this value to start of
2128	  the reserved region.  In other words, it can be set based on
2129	  the "X" value as specified in the "crashkernel=YM@XM"
2130	  command line boot parameter passed to the panic-ed
2131	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2132	  for more details about crash dumps.
2133
2134	  Usage of bzImage for capturing the crash dump is recommended as
2135	  one does not have to build two kernels. Same kernel can be used
2136	  as production kernel and capture kernel. Above option should have
2137	  gone away after relocatable bzImage support is introduced. But it
2138	  is present because there are users out there who continue to use
2139	  vmlinux for dump capture. This option should go away down the
2140	  line.
2141
2142	  Don't change this unless you know what you are doing.
2143
2144config RELOCATABLE
2145	bool "Build a relocatable kernel"
2146	default y
2147	help
2148	  This builds a kernel image that retains relocation information
2149	  so it can be loaded someplace besides the default 1MB.
2150	  The relocations tend to make the kernel binary about 10% larger,
2151	  but are discarded at runtime.
2152
2153	  One use is for the kexec on panic case where the recovery kernel
2154	  must live at a different physical address than the primary
2155	  kernel.
2156
2157	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2158	  it has been loaded at and the compile time physical address
2159	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2160
2161config RANDOMIZE_BASE
2162	bool "Randomize the address of the kernel image (KASLR)"
2163	depends on RELOCATABLE
2164	default y
2165	help
2166	  In support of Kernel Address Space Layout Randomization (KASLR),
2167	  this randomizes the physical address at which the kernel image
2168	  is decompressed and the virtual address where the kernel
2169	  image is mapped, as a security feature that deters exploit
2170	  attempts relying on knowledge of the location of kernel
2171	  code internals.
2172
2173	  On 64-bit, the kernel physical and virtual addresses are
2174	  randomized separately. The physical address will be anywhere
2175	  between 16MB and the top of physical memory (up to 64TB). The
2176	  virtual address will be randomized from 16MB up to 1GB (9 bits
2177	  of entropy). Note that this also reduces the memory space
2178	  available to kernel modules from 1.5GB to 1GB.
2179
2180	  On 32-bit, the kernel physical and virtual addresses are
2181	  randomized together. They will be randomized from 16MB up to
2182	  512MB (8 bits of entropy).
2183
2184	  Entropy is generated using the RDRAND instruction if it is
2185	  supported. If RDTSC is supported, its value is mixed into
2186	  the entropy pool as well. If neither RDRAND nor RDTSC are
2187	  supported, then entropy is read from the i8254 timer. The
2188	  usable entropy is limited by the kernel being built using
2189	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2190	  minimum of 2MB. As a result, only 10 bits of entropy are
2191	  theoretically possible, but the implementations are further
2192	  limited due to memory layouts.
2193
2194	  If unsure, say Y.
2195
2196# Relocation on x86 needs some additional build support
2197config X86_NEED_RELOCS
2198	def_bool y
2199	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2200
2201config PHYSICAL_ALIGN
2202	hex "Alignment value to which kernel should be aligned"
2203	default "0x200000"
2204	range 0x2000 0x1000000 if X86_32
2205	range 0x200000 0x1000000 if X86_64
2206	help
2207	  This value puts the alignment restrictions on physical address
2208	  where kernel is loaded and run from. Kernel is compiled for an
2209	  address which meets above alignment restriction.
2210
2211	  If bootloader loads the kernel at a non-aligned address and
2212	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2213	  address aligned to above value and run from there.
2214
2215	  If bootloader loads the kernel at a non-aligned address and
2216	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2217	  load address and decompress itself to the address it has been
2218	  compiled for and run from there. The address for which kernel is
2219	  compiled already meets above alignment restrictions. Hence the
2220	  end result is that kernel runs from a physical address meeting
2221	  above alignment restrictions.
2222
2223	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2224	  this value must be a multiple of 0x200000.
2225
2226	  Don't change this unless you know what you are doing.
2227
2228config DYNAMIC_MEMORY_LAYOUT
2229	bool
2230	help
2231	  This option makes base addresses of vmalloc and vmemmap as well as
2232	  __PAGE_OFFSET movable during boot.
2233
2234config RANDOMIZE_MEMORY
2235	bool "Randomize the kernel memory sections"
2236	depends on X86_64
2237	depends on RANDOMIZE_BASE
2238	select DYNAMIC_MEMORY_LAYOUT
2239	default RANDOMIZE_BASE
2240	help
2241	  Randomizes the base virtual address of kernel memory sections
2242	  (physical memory mapping, vmalloc & vmemmap). This security feature
2243	  makes exploits relying on predictable memory locations less reliable.
2244
2245	  The order of allocations remains unchanged. Entropy is generated in
2246	  the same way as RANDOMIZE_BASE. Current implementation in the optimal
2247	  configuration have in average 30,000 different possible virtual
2248	  addresses for each memory section.
2249
2250	  If unsure, say Y.
2251
2252config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2253	hex "Physical memory mapping padding" if EXPERT
2254	depends on RANDOMIZE_MEMORY
2255	default "0xa" if MEMORY_HOTPLUG
2256	default "0x0"
2257	range 0x1 0x40 if MEMORY_HOTPLUG
2258	range 0x0 0x40
2259	help
2260	  Define the padding in terabytes added to the existing physical
2261	  memory size during kernel memory randomization. It is useful
2262	  for memory hotplug support but reduces the entropy available for
2263	  address randomization.
2264
2265	  If unsure, leave at the default value.
2266
2267config ADDRESS_MASKING
2268	bool "Linear Address Masking support"
2269	depends on X86_64
2270	help
2271	  Linear Address Masking (LAM) modifies the checking that is applied
2272	  to 64-bit linear addresses, allowing software to use of the
2273	  untranslated address bits for metadata.
2274
2275	  The capability can be used for efficient address sanitizers (ASAN)
2276	  implementation and for optimizations in JITs.
2277
2278config HOTPLUG_CPU
2279	def_bool y
2280	depends on SMP
2281
2282config COMPAT_VDSO
2283	def_bool n
2284	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2285	depends on COMPAT_32
2286	help
2287	  Certain buggy versions of glibc will crash if they are
2288	  presented with a 32-bit vDSO that is not mapped at the address
2289	  indicated in its segment table.
2290
2291	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2292	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2293	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2294	  the only released version with the bug, but OpenSUSE 9
2295	  contains a buggy "glibc 2.3.2".
2296
2297	  The symptom of the bug is that everything crashes on startup, saying:
2298	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2299
2300	  Saying Y here changes the default value of the vdso32 boot
2301	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2302	  This works around the glibc bug but hurts performance.
2303
2304	  If unsure, say N: if you are compiling your own kernel, you
2305	  are unlikely to be using a buggy version of glibc.
2306
2307choice
2308	prompt "vsyscall table for legacy applications"
2309	depends on X86_64
2310	default LEGACY_VSYSCALL_XONLY
2311	help
2312	  Legacy user code that does not know how to find the vDSO expects
2313	  to be able to issue three syscalls by calling fixed addresses in
2314	  kernel space. Since this location is not randomized with ASLR,
2315	  it can be used to assist security vulnerability exploitation.
2316
2317	  This setting can be changed at boot time via the kernel command
2318	  line parameter vsyscall=[emulate|xonly|none].  Emulate mode
2319	  is deprecated and can only be enabled using the kernel command
2320	  line.
2321
2322	  On a system with recent enough glibc (2.14 or newer) and no
2323	  static binaries, you can say None without a performance penalty
2324	  to improve security.
2325
2326	  If unsure, select "Emulate execution only".
2327
2328	config LEGACY_VSYSCALL_XONLY
2329		bool "Emulate execution only"
2330		help
2331		  The kernel traps and emulates calls into the fixed vsyscall
2332		  address mapping and does not allow reads.  This
2333		  configuration is recommended when userspace might use the
2334		  legacy vsyscall area but support for legacy binary
2335		  instrumentation of legacy code is not needed.  It mitigates
2336		  certain uses of the vsyscall area as an ASLR-bypassing
2337		  buffer.
2338
2339	config LEGACY_VSYSCALL_NONE
2340		bool "None"
2341		help
2342		  There will be no vsyscall mapping at all. This will
2343		  eliminate any risk of ASLR bypass due to the vsyscall
2344		  fixed address mapping. Attempts to use the vsyscalls
2345		  will be reported to dmesg, so that either old or
2346		  malicious userspace programs can be identified.
2347
2348endchoice
2349
2350config CMDLINE_BOOL
2351	bool "Built-in kernel command line"
2352	help
2353	  Allow for specifying boot arguments to the kernel at
2354	  build time.  On some systems (e.g. embedded ones), it is
2355	  necessary or convenient to provide some or all of the
2356	  kernel boot arguments with the kernel itself (that is,
2357	  to not rely on the boot loader to provide them.)
2358
2359	  To compile command line arguments into the kernel,
2360	  set this option to 'Y', then fill in the
2361	  boot arguments in CONFIG_CMDLINE.
2362
2363	  Systems with fully functional boot loaders (i.e. non-embedded)
2364	  should leave this option set to 'N'.
2365
2366config CMDLINE
2367	string "Built-in kernel command string"
2368	depends on CMDLINE_BOOL
2369	default ""
2370	help
2371	  Enter arguments here that should be compiled into the kernel
2372	  image and used at boot time.  If the boot loader provides a
2373	  command line at boot time, it is appended to this string to
2374	  form the full kernel command line, when the system boots.
2375
2376	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2377	  change this behavior.
2378
2379	  In most cases, the command line (whether built-in or provided
2380	  by the boot loader) should specify the device for the root
2381	  file system.
2382
2383config CMDLINE_OVERRIDE
2384	bool "Built-in command line overrides boot loader arguments"
2385	depends on CMDLINE_BOOL && CMDLINE != ""
2386	help
2387	  Set this option to 'Y' to have the kernel ignore the boot loader
2388	  command line, and use ONLY the built-in command line.
2389
2390	  This is used to work around broken boot loaders.  This should
2391	  be set to 'N' under normal conditions.
2392
2393config MODIFY_LDT_SYSCALL
2394	bool "Enable the LDT (local descriptor table)" if EXPERT
2395	default y
2396	help
2397	  Linux can allow user programs to install a per-process x86
2398	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2399	  call.  This is required to run 16-bit or segmented code such as
2400	  DOSEMU or some Wine programs.  It is also used by some very old
2401	  threading libraries.
2402
2403	  Enabling this feature adds a small amount of overhead to
2404	  context switches and increases the low-level kernel attack
2405	  surface.  Disabling it removes the modify_ldt(2) system call.
2406
2407	  Saying 'N' here may make sense for embedded or server kernels.
2408
2409config STRICT_SIGALTSTACK_SIZE
2410	bool "Enforce strict size checking for sigaltstack"
2411	depends on DYNAMIC_SIGFRAME
2412	help
2413	  For historical reasons MINSIGSTKSZ is a constant which became
2414	  already too small with AVX512 support. Add a mechanism to
2415	  enforce strict checking of the sigaltstack size against the
2416	  real size of the FPU frame. This option enables the check
2417	  by default. It can also be controlled via the kernel command
2418	  line option 'strict_sas_size' independent of this config
2419	  switch. Enabling it might break existing applications which
2420	  allocate a too small sigaltstack but 'work' because they
2421	  never get a signal delivered.
2422
2423	  Say 'N' unless you want to really enforce this check.
2424
2425source "kernel/livepatch/Kconfig"
2426
2427endmenu
2428
2429config CC_HAS_SLS
2430	def_bool $(cc-option,-mharden-sls=all)
2431
2432config CC_HAS_RETURN_THUNK
2433	def_bool $(cc-option,-mfunction-return=thunk-extern)
2434
2435config CC_HAS_ENTRY_PADDING
2436	def_bool $(cc-option,-fpatchable-function-entry=16,16)
2437
2438config FUNCTION_PADDING_CFI
2439	int
2440	default 59 if FUNCTION_ALIGNMENT_64B
2441	default 27 if FUNCTION_ALIGNMENT_32B
2442	default 11 if FUNCTION_ALIGNMENT_16B
2443	default  3 if FUNCTION_ALIGNMENT_8B
2444	default  0
2445
2446# Basically: FUNCTION_ALIGNMENT - 5*CFI_CLANG
2447# except Kconfig can't do arithmetic :/
2448config FUNCTION_PADDING_BYTES
2449	int
2450	default FUNCTION_PADDING_CFI if CFI_CLANG
2451	default FUNCTION_ALIGNMENT
2452
2453config CALL_PADDING
2454	def_bool n
2455	depends on CC_HAS_ENTRY_PADDING && OBJTOOL
2456	select FUNCTION_ALIGNMENT_16B
2457
2458config FINEIBT
2459	def_bool y
2460	depends on X86_KERNEL_IBT && CFI_CLANG && RETPOLINE
2461	select CALL_PADDING
2462
2463config HAVE_CALL_THUNKS
2464	def_bool y
2465	depends on CC_HAS_ENTRY_PADDING && RETHUNK && OBJTOOL
2466
2467config CALL_THUNKS
2468	def_bool n
2469	select CALL_PADDING
2470
2471config PREFIX_SYMBOLS
2472	def_bool y
2473	depends on CALL_PADDING && !CFI_CLANG
2474
2475menuconfig SPECULATION_MITIGATIONS
2476	bool "Mitigations for speculative execution vulnerabilities"
2477	default y
2478	help
2479	  Say Y here to enable options which enable mitigations for
2480	  speculative execution hardware vulnerabilities.
2481
2482	  If you say N, all mitigations will be disabled. You really
2483	  should know what you are doing to say so.
2484
2485if SPECULATION_MITIGATIONS
2486
2487config PAGE_TABLE_ISOLATION
2488	bool "Remove the kernel mapping in user mode"
2489	default y
2490	depends on (X86_64 || X86_PAE)
2491	help
2492	  This feature reduces the number of hardware side channels by
2493	  ensuring that the majority of kernel addresses are not mapped
2494	  into userspace.
2495
2496	  See Documentation/arch/x86/pti.rst for more details.
2497
2498config RETPOLINE
2499	bool "Avoid speculative indirect branches in kernel"
2500	select OBJTOOL if HAVE_OBJTOOL
2501	default y
2502	help
2503	  Compile kernel with the retpoline compiler options to guard against
2504	  kernel-to-user data leaks by avoiding speculative indirect
2505	  branches. Requires a compiler with -mindirect-branch=thunk-extern
2506	  support for full protection. The kernel may run slower.
2507
2508config RETHUNK
2509	bool "Enable return-thunks"
2510	depends on RETPOLINE && CC_HAS_RETURN_THUNK
2511	select OBJTOOL if HAVE_OBJTOOL
2512	default y if X86_64
2513	help
2514	  Compile the kernel with the return-thunks compiler option to guard
2515	  against kernel-to-user data leaks by avoiding return speculation.
2516	  Requires a compiler with -mfunction-return=thunk-extern
2517	  support for full protection. The kernel may run slower.
2518
2519config CPU_UNRET_ENTRY
2520	bool "Enable UNRET on kernel entry"
2521	depends on CPU_SUP_AMD && RETHUNK && X86_64
2522	default y
2523	help
2524	  Compile the kernel with support for the retbleed=unret mitigation.
2525
2526config CALL_DEPTH_TRACKING
2527	bool "Mitigate RSB underflow with call depth tracking"
2528	depends on CPU_SUP_INTEL && HAVE_CALL_THUNKS
2529	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
2530	select CALL_THUNKS
2531	default y
2532	help
2533	  Compile the kernel with call depth tracking to mitigate the Intel
2534	  SKL Return-Speculation-Buffer (RSB) underflow issue. The
2535	  mitigation is off by default and needs to be enabled on the
2536	  kernel command line via the retbleed=stuff option. For
2537	  non-affected systems the overhead of this option is marginal as
2538	  the call depth tracking is using run-time generated call thunks
2539	  in a compiler generated padding area and call patching. This
2540	  increases text size by ~5%. For non affected systems this space
2541	  is unused. On affected SKL systems this results in a significant
2542	  performance gain over the IBRS mitigation.
2543
2544config CALL_THUNKS_DEBUG
2545	bool "Enable call thunks and call depth tracking debugging"
2546	depends on CALL_DEPTH_TRACKING
2547	select FUNCTION_ALIGNMENT_32B
2548	default n
2549	help
2550	  Enable call/ret counters for imbalance detection and build in
2551	  a noisy dmesg about callthunks generation and call patching for
2552	  trouble shooting. The debug prints need to be enabled on the
2553	  kernel command line with 'debug-callthunks'.
2554	  Only enable this when you are debugging call thunks as this
2555	  creates a noticeable runtime overhead. If unsure say N.
2556
2557config CPU_IBPB_ENTRY
2558	bool "Enable IBPB on kernel entry"
2559	depends on CPU_SUP_AMD && X86_64
2560	default y
2561	help
2562	  Compile the kernel with support for the retbleed=ibpb mitigation.
2563
2564config CPU_IBRS_ENTRY
2565	bool "Enable IBRS on kernel entry"
2566	depends on CPU_SUP_INTEL && X86_64
2567	default y
2568	help
2569	  Compile the kernel with support for the spectre_v2=ibrs mitigation.
2570	  This mitigates both spectre_v2 and retbleed at great cost to
2571	  performance.
2572
2573config CPU_SRSO
2574	bool "Mitigate speculative RAS overflow on AMD"
2575	depends on CPU_SUP_AMD && X86_64 && RETHUNK
2576	default y
2577	help
2578	  Enable the SRSO mitigation needed on AMD Zen1-4 machines.
2579
2580config SLS
2581	bool "Mitigate Straight-Line-Speculation"
2582	depends on CC_HAS_SLS && X86_64
2583	select OBJTOOL if HAVE_OBJTOOL
2584	default n
2585	help
2586	  Compile the kernel with straight-line-speculation options to guard
2587	  against straight line speculation. The kernel image might be slightly
2588	  larger.
2589
2590config GDS_FORCE_MITIGATION
2591	bool "Force GDS Mitigation"
2592	depends on CPU_SUP_INTEL
2593	default n
2594	help
2595	  Gather Data Sampling (GDS) is a hardware vulnerability which allows
2596	  unprivileged speculative access to data which was previously stored in
2597	  vector registers.
2598
2599	  This option is equivalent to setting gather_data_sampling=force on the
2600	  command line. The microcode mitigation is used if present, otherwise
2601	  AVX is disabled as a mitigation. On affected systems that are missing
2602	  the microcode any userspace code that unconditionally uses AVX will
2603	  break with this option set.
2604
2605	  Setting this option on systems not vulnerable to GDS has no effect.
2606
2607	  If in doubt, say N.
2608
2609endif
2610
2611config ARCH_HAS_ADD_PAGES
2612	def_bool y
2613	depends on ARCH_ENABLE_MEMORY_HOTPLUG
2614
2615menu "Power management and ACPI options"
2616
2617config ARCH_HIBERNATION_HEADER
2618	def_bool y
2619	depends on HIBERNATION
2620
2621source "kernel/power/Kconfig"
2622
2623source "drivers/acpi/Kconfig"
2624
2625config X86_APM_BOOT
2626	def_bool y
2627	depends on APM
2628
2629menuconfig APM
2630	tristate "APM (Advanced Power Management) BIOS support"
2631	depends on X86_32 && PM_SLEEP
2632	help
2633	  APM is a BIOS specification for saving power using several different
2634	  techniques. This is mostly useful for battery powered laptops with
2635	  APM compliant BIOSes. If you say Y here, the system time will be
2636	  reset after a RESUME operation, the /proc/apm device will provide
2637	  battery status information, and user-space programs will receive
2638	  notification of APM "events" (e.g. battery status change).
2639
2640	  If you select "Y" here, you can disable actual use of the APM
2641	  BIOS by passing the "apm=off" option to the kernel at boot time.
2642
2643	  Note that the APM support is almost completely disabled for
2644	  machines with more than one CPU.
2645
2646	  In order to use APM, you will need supporting software. For location
2647	  and more information, read <file:Documentation/power/apm-acpi.rst>
2648	  and the Battery Powered Linux mini-HOWTO, available from
2649	  <http://www.tldp.org/docs.html#howto>.
2650
2651	  This driver does not spin down disk drives (see the hdparm(8)
2652	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2653	  VESA-compliant "green" monitors.
2654
2655	  This driver does not support the TI 4000M TravelMate and the ACER
2656	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2657	  desktop machines also don't have compliant BIOSes, and this driver
2658	  may cause those machines to panic during the boot phase.
2659
2660	  Generally, if you don't have a battery in your machine, there isn't
2661	  much point in using this driver and you should say N. If you get
2662	  random kernel OOPSes or reboots that don't seem to be related to
2663	  anything, try disabling/enabling this option (or disabling/enabling
2664	  APM in your BIOS).
2665
2666	  Some other things you should try when experiencing seemingly random,
2667	  "weird" problems:
2668
2669	  1) make sure that you have enough swap space and that it is
2670	  enabled.
2671	  2) pass the "idle=poll" option to the kernel
2672	  3) switch on floating point emulation in the kernel and pass
2673	  the "no387" option to the kernel
2674	  4) pass the "floppy=nodma" option to the kernel
2675	  5) pass the "mem=4M" option to the kernel (thereby disabling
2676	  all but the first 4 MB of RAM)
2677	  6) make sure that the CPU is not over clocked.
2678	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2679	  8) disable the cache from your BIOS settings
2680	  9) install a fan for the video card or exchange video RAM
2681	  10) install a better fan for the CPU
2682	  11) exchange RAM chips
2683	  12) exchange the motherboard.
2684
2685	  To compile this driver as a module, choose M here: the
2686	  module will be called apm.
2687
2688if APM
2689
2690config APM_IGNORE_USER_SUSPEND
2691	bool "Ignore USER SUSPEND"
2692	help
2693	  This option will ignore USER SUSPEND requests. On machines with a
2694	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2695	  series notebooks, it is necessary to say Y because of a BIOS bug.
2696
2697config APM_DO_ENABLE
2698	bool "Enable PM at boot time"
2699	help
2700	  Enable APM features at boot time. From page 36 of the APM BIOS
2701	  specification: "When disabled, the APM BIOS does not automatically
2702	  power manage devices, enter the Standby State, enter the Suspend
2703	  State, or take power saving steps in response to CPU Idle calls."
2704	  This driver will make CPU Idle calls when Linux is idle (unless this
2705	  feature is turned off -- see "Do CPU IDLE calls", below). This
2706	  should always save battery power, but more complicated APM features
2707	  will be dependent on your BIOS implementation. You may need to turn
2708	  this option off if your computer hangs at boot time when using APM
2709	  support, or if it beeps continuously instead of suspending. Turn
2710	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2711	  T400CDT. This is off by default since most machines do fine without
2712	  this feature.
2713
2714config APM_CPU_IDLE
2715	depends on CPU_IDLE
2716	bool "Make CPU Idle calls when idle"
2717	help
2718	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2719	  On some machines, this can activate improved power savings, such as
2720	  a slowed CPU clock rate, when the machine is idle. These idle calls
2721	  are made after the idle loop has run for some length of time (e.g.,
2722	  333 mS). On some machines, this will cause a hang at boot time or
2723	  whenever the CPU becomes idle. (On machines with more than one CPU,
2724	  this option does nothing.)
2725
2726config APM_DISPLAY_BLANK
2727	bool "Enable console blanking using APM"
2728	help
2729	  Enable console blanking using the APM. Some laptops can use this to
2730	  turn off the LCD backlight when the screen blanker of the Linux
2731	  virtual console blanks the screen. Note that this is only used by
2732	  the virtual console screen blanker, and won't turn off the backlight
2733	  when using the X Window system. This also doesn't have anything to
2734	  do with your VESA-compliant power-saving monitor. Further, this
2735	  option doesn't work for all laptops -- it might not turn off your
2736	  backlight at all, or it might print a lot of errors to the console,
2737	  especially if you are using gpm.
2738
2739config APM_ALLOW_INTS
2740	bool "Allow interrupts during APM BIOS calls"
2741	help
2742	  Normally we disable external interrupts while we are making calls to
2743	  the APM BIOS as a measure to lessen the effects of a badly behaving
2744	  BIOS implementation.  The BIOS should reenable interrupts if it
2745	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2746	  many of the newer IBM Thinkpads.  If you experience hangs when you
2747	  suspend, try setting this to Y.  Otherwise, say N.
2748
2749endif # APM
2750
2751source "drivers/cpufreq/Kconfig"
2752
2753source "drivers/cpuidle/Kconfig"
2754
2755source "drivers/idle/Kconfig"
2756
2757endmenu
2758
2759menu "Bus options (PCI etc.)"
2760
2761choice
2762	prompt "PCI access mode"
2763	depends on X86_32 && PCI
2764	default PCI_GOANY
2765	help
2766	  On PCI systems, the BIOS can be used to detect the PCI devices and
2767	  determine their configuration. However, some old PCI motherboards
2768	  have BIOS bugs and may crash if this is done. Also, some embedded
2769	  PCI-based systems don't have any BIOS at all. Linux can also try to
2770	  detect the PCI hardware directly without using the BIOS.
2771
2772	  With this option, you can specify how Linux should detect the
2773	  PCI devices. If you choose "BIOS", the BIOS will be used,
2774	  if you choose "Direct", the BIOS won't be used, and if you
2775	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2776	  If you choose "Any", the kernel will try MMCONFIG, then the
2777	  direct access method and falls back to the BIOS if that doesn't
2778	  work. If unsure, go with the default, which is "Any".
2779
2780config PCI_GOBIOS
2781	bool "BIOS"
2782
2783config PCI_GOMMCONFIG
2784	bool "MMConfig"
2785
2786config PCI_GODIRECT
2787	bool "Direct"
2788
2789config PCI_GOOLPC
2790	bool "OLPC XO-1"
2791	depends on OLPC
2792
2793config PCI_GOANY
2794	bool "Any"
2795
2796endchoice
2797
2798config PCI_BIOS
2799	def_bool y
2800	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2801
2802# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2803config PCI_DIRECT
2804	def_bool y
2805	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2806
2807config PCI_MMCONFIG
2808	bool "Support mmconfig PCI config space access" if X86_64
2809	default y
2810	depends on PCI && (ACPI || JAILHOUSE_GUEST)
2811	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2812
2813config PCI_OLPC
2814	def_bool y
2815	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2816
2817config PCI_XEN
2818	def_bool y
2819	depends on PCI && XEN
2820
2821config MMCONF_FAM10H
2822	def_bool y
2823	depends on X86_64 && PCI_MMCONFIG && ACPI
2824
2825config PCI_CNB20LE_QUIRK
2826	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2827	depends on PCI
2828	help
2829	  Read the PCI windows out of the CNB20LE host bridge. This allows
2830	  PCI hotplug to work on systems with the CNB20LE chipset which do
2831	  not have ACPI.
2832
2833	  There's no public spec for this chipset, and this functionality
2834	  is known to be incomplete.
2835
2836	  You should say N unless you know you need this.
2837
2838config ISA_BUS
2839	bool "ISA bus support on modern systems" if EXPERT
2840	help
2841	  Expose ISA bus device drivers and options available for selection and
2842	  configuration. Enable this option if your target machine has an ISA
2843	  bus. ISA is an older system, displaced by PCI and newer bus
2844	  architectures -- if your target machine is modern, it probably does
2845	  not have an ISA bus.
2846
2847	  If unsure, say N.
2848
2849# x86_64 have no ISA slots, but can have ISA-style DMA.
2850config ISA_DMA_API
2851	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2852	default y
2853	help
2854	  Enables ISA-style DMA support for devices requiring such controllers.
2855	  If unsure, say Y.
2856
2857if X86_32
2858
2859config ISA
2860	bool "ISA support"
2861	help
2862	  Find out whether you have ISA slots on your motherboard.  ISA is the
2863	  name of a bus system, i.e. the way the CPU talks to the other stuff
2864	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2865	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2866	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2867
2868config SCx200
2869	tristate "NatSemi SCx200 support"
2870	help
2871	  This provides basic support for National Semiconductor's
2872	  (now AMD's) Geode processors.  The driver probes for the
2873	  PCI-IDs of several on-chip devices, so its a good dependency
2874	  for other scx200_* drivers.
2875
2876	  If compiled as a module, the driver is named scx200.
2877
2878config SCx200HR_TIMER
2879	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2880	depends on SCx200
2881	default y
2882	help
2883	  This driver provides a clocksource built upon the on-chip
2884	  27MHz high-resolution timer.  Its also a workaround for
2885	  NSC Geode SC-1100's buggy TSC, which loses time when the
2886	  processor goes idle (as is done by the scheduler).  The
2887	  other workaround is idle=poll boot option.
2888
2889config OLPC
2890	bool "One Laptop Per Child support"
2891	depends on !X86_PAE
2892	select GPIOLIB
2893	select OF
2894	select OF_PROMTREE
2895	select IRQ_DOMAIN
2896	select OLPC_EC
2897	help
2898	  Add support for detecting the unique features of the OLPC
2899	  XO hardware.
2900
2901config OLPC_XO1_PM
2902	bool "OLPC XO-1 Power Management"
2903	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2904	help
2905	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2906
2907config OLPC_XO1_RTC
2908	bool "OLPC XO-1 Real Time Clock"
2909	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2910	help
2911	  Add support for the XO-1 real time clock, which can be used as a
2912	  programmable wakeup source.
2913
2914config OLPC_XO1_SCI
2915	bool "OLPC XO-1 SCI extras"
2916	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2917	depends on INPUT=y
2918	select POWER_SUPPLY
2919	help
2920	  Add support for SCI-based features of the OLPC XO-1 laptop:
2921	   - EC-driven system wakeups
2922	   - Power button
2923	   - Ebook switch
2924	   - Lid switch
2925	   - AC adapter status updates
2926	   - Battery status updates
2927
2928config OLPC_XO15_SCI
2929	bool "OLPC XO-1.5 SCI extras"
2930	depends on OLPC && ACPI
2931	select POWER_SUPPLY
2932	help
2933	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2934	   - EC-driven system wakeups
2935	   - AC adapter status updates
2936	   - Battery status updates
2937
2938config ALIX
2939	bool "PCEngines ALIX System Support (LED setup)"
2940	select GPIOLIB
2941	help
2942	  This option enables system support for the PCEngines ALIX.
2943	  At present this just sets up LEDs for GPIO control on
2944	  ALIX2/3/6 boards.  However, other system specific setup should
2945	  get added here.
2946
2947	  Note: You must still enable the drivers for GPIO and LED support
2948	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2949
2950	  Note: You have to set alix.force=1 for boards with Award BIOS.
2951
2952config NET5501
2953	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2954	select GPIOLIB
2955	help
2956	  This option enables system support for the Soekris Engineering net5501.
2957
2958config GEOS
2959	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2960	select GPIOLIB
2961	depends on DMI
2962	help
2963	  This option enables system support for the Traverse Technologies GEOS.
2964
2965config TS5500
2966	bool "Technologic Systems TS-5500 platform support"
2967	depends on MELAN
2968	select CHECK_SIGNATURE
2969	select NEW_LEDS
2970	select LEDS_CLASS
2971	help
2972	  This option enables system support for the Technologic Systems TS-5500.
2973
2974endif # X86_32
2975
2976config AMD_NB
2977	def_bool y
2978	depends on CPU_SUP_AMD && PCI
2979
2980endmenu
2981
2982menu "Binary Emulations"
2983
2984config IA32_EMULATION
2985	bool "IA32 Emulation"
2986	depends on X86_64
2987	select ARCH_WANT_OLD_COMPAT_IPC
2988	select BINFMT_ELF
2989	select COMPAT_OLD_SIGACTION
2990	help
2991	  Include code to run legacy 32-bit programs under a
2992	  64-bit kernel. You should likely turn this on, unless you're
2993	  100% sure that you don't have any 32-bit programs left.
2994
2995config IA32_EMULATION_DEFAULT_DISABLED
2996	bool "IA32 emulation disabled by default"
2997	default n
2998	depends on IA32_EMULATION
2999	help
3000	  Make IA32 emulation disabled by default. This prevents loading 32-bit
3001	  processes and access to 32-bit syscalls. If unsure, leave it to its
3002	  default value.
3003
3004config X86_X32_ABI
3005	bool "x32 ABI for 64-bit mode"
3006	depends on X86_64
3007	# llvm-objcopy does not convert x86_64 .note.gnu.property or
3008	# compressed debug sections to x86_x32 properly:
3009	# https://github.com/ClangBuiltLinux/linux/issues/514
3010	# https://github.com/ClangBuiltLinux/linux/issues/1141
3011	depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm)
3012	help
3013	  Include code to run binaries for the x32 native 32-bit ABI
3014	  for 64-bit processors.  An x32 process gets access to the
3015	  full 64-bit register file and wide data path while leaving
3016	  pointers at 32 bits for smaller memory footprint.
3017
3018config COMPAT_32
3019	def_bool y
3020	depends on IA32_EMULATION || X86_32
3021	select HAVE_UID16
3022	select OLD_SIGSUSPEND3
3023
3024config COMPAT
3025	def_bool y
3026	depends on IA32_EMULATION || X86_X32_ABI
3027
3028config COMPAT_FOR_U64_ALIGNMENT
3029	def_bool y
3030	depends on COMPAT
3031
3032endmenu
3033
3034config HAVE_ATOMIC_IOMAP
3035	def_bool y
3036	depends on X86_32
3037
3038source "arch/x86/kvm/Kconfig"
3039
3040source "arch/x86/Kconfig.assembler"
3041