xref: /linux/arch/s390/Kconfig (revision a6d0dbba950880e269d433222ca6d516ebe8a6ae)
1# SPDX-License-Identifier: GPL-2.0
2config MMU
3	def_bool y
4
5config CPU_BIG_ENDIAN
6	def_bool y
7
8config LOCKDEP_SUPPORT
9	def_bool y
10
11config STACKTRACE_SUPPORT
12	def_bool y
13
14config ARCH_HAS_ILOG2_U32
15	def_bool n
16
17config ARCH_HAS_ILOG2_U64
18	def_bool n
19
20config ARCH_PROC_KCORE_TEXT
21	def_bool y
22
23config GENERIC_HWEIGHT
24	def_bool !HAVE_MARCH_Z196_FEATURES
25
26config GENERIC_BUG
27	def_bool y if BUG
28
29config GENERIC_BUG_RELATIVE_POINTERS
30	def_bool y
31
32config GENERIC_LOCKBREAK
33	def_bool y if PREEMPTION
34
35config PGSTE
36	def_bool y if KVM
37
38config AUDIT_ARCH
39	def_bool y
40
41config NO_IOPORT_MAP
42	def_bool y
43
44config ARCH_SUPPORTS_UPROBES
45	def_bool y
46
47config KASAN_SHADOW_OFFSET
48	hex
49	depends on KASAN
50	default 0x1C000000000000
51
52config CC_ASM_FLAG_OUTPUT_BROKEN
53	def_bool CC_IS_GCC && GCC_VERSION < 140200
54	help
55	  GCC versions before 14.2.0 may die with an internal
56	  compiler error in some configurations if flag output
57	  operands are used within inline assemblies.
58
59config CC_HAS_ASM_AOR_FORMAT_FLAGS
60	def_bool !(CC_IS_CLANG && CLANG_VERSION < 190100)
61	help
62	  Clang versions before 19.1.0 do not support A,
63	  O, and R inline assembly format flags.
64
65config S390
66	def_bool y
67	#
68	# Note: keep this list sorted alphabetically
69	#
70	imply IMA_SECURE_AND_OR_TRUSTED_BOOT
71	select ALTERNATE_USER_ADDRESS_SPACE
72	select ARCH_32BIT_USTAT_F_TINODE
73	select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
74	select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM
75	select ARCH_ENABLE_MEMORY_HOTREMOVE
76	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
77	select ARCH_HAS_CPU_FINALIZE_INIT
78	select ARCH_HAS_CRC32
79	select ARCH_HAS_CURRENT_STACK_POINTER
80	select ARCH_HAS_DEBUG_VIRTUAL
81	select ARCH_HAS_DEBUG_VM_PGTABLE
82	select ARCH_HAS_DEBUG_WX
83	select ARCH_HAS_DEVMEM_IS_ALLOWED
84	select ARCH_HAS_DMA_OPS if PCI
85	select ARCH_HAS_ELF_RANDOMIZE
86	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
87	select ARCH_HAS_FORTIFY_SOURCE
88	select ARCH_HAS_GCOV_PROFILE_ALL
89	select ARCH_HAS_GIGANTIC_PAGE
90	select ARCH_HAS_KCOV
91	select ARCH_HAS_MEMBARRIER_SYNC_CORE
92	select ARCH_HAS_MEM_ENCRYPT
93	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
94	select ARCH_HAS_PREEMPT_LAZY
95	select ARCH_HAS_PTDUMP
96	select ARCH_HAS_PTE_SPECIAL
97	select ARCH_HAS_SCALED_CPUTIME
98	select ARCH_HAS_SET_DIRECT_MAP
99	select ARCH_HAS_SET_MEMORY
100	select ARCH_HAS_STRICT_KERNEL_RWX
101	select ARCH_HAS_STRICT_MODULE_RWX
102	select ARCH_HAS_SYSCALL_WRAPPER
103	select ARCH_HAS_UBSAN
104	select ARCH_HAS_VDSO_TIME_DATA
105	select ARCH_HAVE_NMI_SAFE_CMPXCHG
106	select ARCH_INLINE_READ_LOCK
107	select ARCH_INLINE_READ_LOCK_BH
108	select ARCH_INLINE_READ_LOCK_IRQ
109	select ARCH_INLINE_READ_LOCK_IRQSAVE
110	select ARCH_INLINE_READ_TRYLOCK
111	select ARCH_INLINE_READ_UNLOCK
112	select ARCH_INLINE_READ_UNLOCK_BH
113	select ARCH_INLINE_READ_UNLOCK_IRQ
114	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
115	select ARCH_INLINE_SPIN_LOCK
116	select ARCH_INLINE_SPIN_LOCK_BH
117	select ARCH_INLINE_SPIN_LOCK_IRQ
118	select ARCH_INLINE_SPIN_LOCK_IRQSAVE
119	select ARCH_INLINE_SPIN_TRYLOCK
120	select ARCH_INLINE_SPIN_TRYLOCK_BH
121	select ARCH_INLINE_SPIN_UNLOCK
122	select ARCH_INLINE_SPIN_UNLOCK_BH
123	select ARCH_INLINE_SPIN_UNLOCK_IRQ
124	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
125	select ARCH_INLINE_WRITE_LOCK
126	select ARCH_INLINE_WRITE_LOCK_BH
127	select ARCH_INLINE_WRITE_LOCK_IRQ
128	select ARCH_INLINE_WRITE_LOCK_IRQSAVE
129	select ARCH_INLINE_WRITE_TRYLOCK
130	select ARCH_INLINE_WRITE_UNLOCK
131	select ARCH_INLINE_WRITE_UNLOCK_BH
132	select ARCH_INLINE_WRITE_UNLOCK_IRQ
133	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
134	select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
135	select ARCH_STACKWALK
136	select ARCH_SUPPORTS_ATOMIC_RMW
137	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
138	select ARCH_SUPPORTS_HUGETLBFS
139	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && CC_IS_CLANG
140	select ARCH_SUPPORTS_NUMA_BALANCING
141	select ARCH_SUPPORTS_PER_VMA_LOCK
142	select ARCH_USE_BUILTIN_BSWAP
143	select ARCH_USE_CMPXCHG_LOCKREF
144	select ARCH_USE_SYM_ANNOTATIONS
145	select ARCH_WANTS_NO_INSTR
146	select ARCH_WANT_DEFAULT_BPF_JIT
147	select ARCH_WANT_IPC_PARSE_VERSION
148	select ARCH_WANT_KERNEL_PMD_MKWRITE
149	select ARCH_WANT_LD_ORPHAN_WARN
150	select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP
151	select BUILDTIME_TABLE_SORT
152	select CLONE_BACKWARDS2
153	select DCACHE_WORD_ACCESS if !KMSAN
154	select DYNAMIC_FTRACE if FUNCTION_TRACER
155	select FUNCTION_ALIGNMENT_8B if CC_IS_GCC
156	select FUNCTION_ALIGNMENT_16B if !CC_IS_GCC
157	select GENERIC_ALLOCATOR
158	select GENERIC_CPU_DEVICES
159	select GENERIC_CPU_AUTOPROBE
160	select GENERIC_CPU_VULNERABILITIES
161	select GENERIC_ENTRY
162	select GENERIC_GETTIMEOFDAY
163	select GENERIC_SMP_IDLE_THREAD
164	select GENERIC_TIME_VSYSCALL
165	select GENERIC_VDSO_DATA_STORE
166	select GENERIC_VDSO_TIME_NS
167	select GENERIC_IOREMAP if PCI
168	select HAVE_ALIGNED_STRUCT_PAGE
169	select HAVE_ARCH_AUDITSYSCALL
170	select HAVE_ARCH_JUMP_LABEL
171	select HAVE_ARCH_JUMP_LABEL_RELATIVE
172	select HAVE_ARCH_KASAN
173	select HAVE_ARCH_KASAN_VMALLOC
174	select HAVE_ARCH_KCSAN
175	select HAVE_ARCH_KMSAN
176	select HAVE_ARCH_KFENCE
177	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
178	select HAVE_ARCH_SECCOMP_FILTER
179	select HAVE_ARCH_SOFT_DIRTY
180	select HAVE_ARCH_STACKLEAK
181	select HAVE_ARCH_TRACEHOOK
182	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
183	select HAVE_ARCH_VMAP_STACK
184	select HAVE_ASM_MODVERSIONS
185	select HAVE_BUILDTIME_MCOUNT_SORT
186	select HAVE_CMPXCHG_DOUBLE
187	select HAVE_CMPXCHG_LOCAL
188	select HAVE_DEBUG_KMEMLEAK
189	select HAVE_DMA_CONTIGUOUS
190	select HAVE_DYNAMIC_FTRACE
191	select HAVE_DYNAMIC_FTRACE_WITH_ARGS
192	select HAVE_FTRACE_REGS_HAVING_PT_REGS
193	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
194	select HAVE_DYNAMIC_FTRACE_WITH_REGS
195	select HAVE_EBPF_JIT if HAVE_MARCH_Z196_FEATURES
196	select HAVE_EFFICIENT_UNALIGNED_ACCESS
197	select HAVE_GUP_FAST
198	select HAVE_FENTRY
199	select HAVE_FTRACE_GRAPH_FUNC
200	select HAVE_FTRACE_MCOUNT_RECORD
201	select HAVE_FUNCTION_ARG_ACCESS_API
202	select HAVE_FUNCTION_ERROR_INJECTION
203	select HAVE_FUNCTION_GRAPH_FREGS
204	select HAVE_FUNCTION_GRAPH_TRACER
205	select HAVE_FUNCTION_TRACER
206	select HAVE_GCC_PLUGINS
207	select HAVE_GENERIC_VDSO
208	select HAVE_IOREMAP_PROT if PCI
209	select HAVE_KERNEL_BZIP2
210	select HAVE_KERNEL_GZIP
211	select HAVE_KERNEL_LZ4
212	select HAVE_KERNEL_LZMA
213	select HAVE_KERNEL_LZO
214	select HAVE_KERNEL_UNCOMPRESSED
215	select HAVE_KERNEL_XZ
216	select HAVE_KERNEL_ZSTD
217	select HAVE_KPROBES
218	select HAVE_KPROBES_ON_FTRACE
219	select HAVE_KRETPROBES
220	select HAVE_LIVEPATCH
221	select HAVE_MEMBLOCK_PHYS_MAP
222	select HAVE_MOD_ARCH_SPECIFIC
223	select HAVE_NMI
224	select HAVE_NOP_MCOUNT
225	select HAVE_PAGE_SIZE_4KB
226	select HAVE_PCI
227	select HAVE_PERF_EVENTS
228	select HAVE_PERF_REGS
229	select HAVE_PERF_USER_STACK_DUMP
230	select HAVE_PREEMPT_DYNAMIC_KEY
231	select HAVE_REGS_AND_STACK_ACCESS_API
232	select HAVE_RELIABLE_STACKTRACE
233	select HAVE_RETHOOK
234	select HAVE_RSEQ
235	select HAVE_SAMPLE_FTRACE_DIRECT
236	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
237	select HAVE_SETUP_PER_CPU_AREA
238	select HAVE_SOFTIRQ_ON_OWN_STACK
239	select HAVE_SYSCALL_TRACEPOINTS
240	select HAVE_VIRT_CPU_ACCOUNTING
241	select HAVE_VIRT_CPU_ACCOUNTING_IDLE
242	select IOMMU_HELPER		if PCI
243	select IOMMU_SUPPORT		if PCI
244	select KASAN_VMALLOC if KASAN
245	select LOCK_MM_AND_FIND_VMA
246	select MMU_GATHER_MERGE_VMAS
247	select MMU_GATHER_NO_GATHER
248	select MMU_GATHER_RCU_TABLE_FREE
249	select MODULES_USE_ELF_RELA
250	select NEED_DMA_MAP_STATE	if PCI
251	select NEED_PER_CPU_EMBED_FIRST_CHUNK
252	select NEED_PROC_VMCORE_DEVICE_RAM if PROC_VMCORE
253	select NEED_SG_DMA_LENGTH	if PCI
254	select OLD_SIGACTION
255	select OLD_SIGSUSPEND3
256	select PCI_DOMAINS		if PCI
257	select PCI_MSI			if PCI
258	select PCI_MSI_ARCH_FALLBACKS	if PCI_MSI
259	select PCI_QUIRKS		if PCI
260	select SPARSE_IRQ
261	select SWIOTLB
262	select SYSCTL_EXCEPTION_TRACE
263	select THREAD_INFO_IN_TASK
264	select TRACE_IRQFLAGS_SUPPORT
265	select TTY
266	select USER_STACKTRACE_SUPPORT
267	select VDSO_GETRANDOM
268	select VIRT_CPU_ACCOUNTING
269	select VMAP_STACK
270	select ZONE_DMA
271	# Note: keep the above list sorted alphabetically
272
273config SCHED_OMIT_FRAME_POINTER
274	def_bool y
275
276config PGTABLE_LEVELS
277	int
278	default 5
279
280source "kernel/livepatch/Kconfig"
281
282config ARCH_SUPPORTS_KEXEC
283	def_bool y
284
285config ARCH_SUPPORTS_KEXEC_FILE
286	def_bool y
287
288config ARCH_SUPPORTS_KEXEC_SIG
289	def_bool MODULE_SIG_FORMAT
290
291config ARCH_SUPPORTS_KEXEC_PURGATORY
292	def_bool y
293
294config ARCH_SUPPORTS_CRASH_DUMP
295	def_bool y
296	help
297	  Refer to <file:Documentation/arch/s390/zfcpdump.rst> for more details on this.
298	  This option also enables s390 zfcpdump.
299	  See also <file:Documentation/arch/s390/zfcpdump.rst>
300
301config ARCH_DEFAULT_CRASH_DUMP
302	def_bool y
303
304menu "Processor type and features"
305
306config HAVE_MARCH_Z10_FEATURES
307	def_bool n
308
309config HAVE_MARCH_Z196_FEATURES
310	def_bool n
311	select HAVE_MARCH_Z10_FEATURES
312
313config HAVE_MARCH_ZEC12_FEATURES
314	def_bool n
315	select HAVE_MARCH_Z196_FEATURES
316
317config HAVE_MARCH_Z13_FEATURES
318	def_bool n
319	select HAVE_MARCH_ZEC12_FEATURES
320
321config HAVE_MARCH_Z14_FEATURES
322	def_bool n
323	select HAVE_MARCH_Z13_FEATURES
324
325config HAVE_MARCH_Z15_FEATURES
326	def_bool n
327	select HAVE_MARCH_Z14_FEATURES
328
329config HAVE_MARCH_Z16_FEATURES
330	def_bool n
331	select HAVE_MARCH_Z15_FEATURES
332
333choice
334	prompt "Processor type"
335	default MARCH_Z196
336
337config MARCH_Z10
338	bool "IBM System z10"
339	select HAVE_MARCH_Z10_FEATURES
340	depends on $(cc-option,-march=z10)
341	help
342	  Select this to enable optimizations for IBM System z10 (2097 and 2098
343	  series). This is the oldest machine generation currently supported.
344
345config MARCH_Z196
346	bool "IBM zEnterprise 114 and 196"
347	select HAVE_MARCH_Z196_FEATURES
348	depends on $(cc-option,-march=z196)
349	help
350	  Select this to enable optimizations for IBM zEnterprise 114 and 196
351	  (2818 and 2817 series). The kernel will be slightly faster but will
352	  not work on older machines.
353
354config MARCH_ZEC12
355	bool "IBM zBC12 and zEC12"
356	select HAVE_MARCH_ZEC12_FEATURES
357	depends on $(cc-option,-march=zEC12)
358	help
359	  Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
360	  2827 series). The kernel will be slightly faster but will not work on
361	  older machines.
362
363config MARCH_Z13
364	bool "IBM z13s and z13"
365	select HAVE_MARCH_Z13_FEATURES
366	depends on $(cc-option,-march=z13)
367	help
368	  Select this to enable optimizations for IBM z13s and z13 (2965 and
369	  2964 series). The kernel will be slightly faster but will not work on
370	  older machines.
371
372config MARCH_Z14
373	bool "IBM z14 ZR1 and z14"
374	select HAVE_MARCH_Z14_FEATURES
375	depends on $(cc-option,-march=z14)
376	help
377	  Select this to enable optimizations for IBM z14 ZR1 and z14 (3907
378	  and 3906 series). The kernel will be slightly faster but will not
379	  work on older machines.
380
381config MARCH_Z15
382	bool "IBM z15"
383	select HAVE_MARCH_Z15_FEATURES
384	depends on $(cc-option,-march=z15)
385	help
386	  Select this to enable optimizations for IBM z15 (8562
387	  and 8561 series). The kernel will be slightly faster but will not
388	  work on older machines.
389
390config MARCH_Z16
391	bool "IBM z16"
392	select HAVE_MARCH_Z16_FEATURES
393	depends on $(cc-option,-march=z16)
394	help
395	  Select this to enable optimizations for IBM z16 (3931 and
396	  3932 series).
397
398endchoice
399
400config MARCH_Z10_TUNE
401	def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
402
403config MARCH_Z196_TUNE
404	def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
405
406config MARCH_ZEC12_TUNE
407	def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
408
409config MARCH_Z13_TUNE
410	def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT
411
412config MARCH_Z14_TUNE
413	def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT
414
415config MARCH_Z15_TUNE
416	def_bool TUNE_Z15 || MARCH_Z15 && TUNE_DEFAULT
417
418config MARCH_Z16_TUNE
419	def_bool TUNE_Z16 || MARCH_Z16 && TUNE_DEFAULT
420
421choice
422	prompt "Tune code generation"
423	default TUNE_DEFAULT
424	help
425	  Cause the compiler to tune (-mtune) the generated code for a machine.
426	  This will make the code run faster on the selected machine but
427	  somewhat slower on other machines.
428	  This option only changes how the compiler emits instructions, not the
429	  selection of instructions itself, so the resulting kernel will run on
430	  all other machines.
431
432config TUNE_DEFAULT
433	bool "Default"
434	help
435	  Tune the generated code for the target processor for which the kernel
436	  will be compiled.
437
438config TUNE_Z10
439	bool "IBM System z10"
440
441config TUNE_Z196
442	bool "IBM zEnterprise 114 and 196"
443	depends on $(cc-option,-mtune=z196)
444
445config TUNE_ZEC12
446	bool "IBM zBC12 and zEC12"
447	depends on $(cc-option,-mtune=zEC12)
448
449config TUNE_Z13
450	bool "IBM z13s and z13"
451	depends on $(cc-option,-mtune=z13)
452
453config TUNE_Z14
454	bool "IBM z14 ZR1 and z14"
455	depends on $(cc-option,-mtune=z14)
456
457config TUNE_Z15
458	bool "IBM z15"
459	depends on $(cc-option,-mtune=z15)
460
461config TUNE_Z16
462	bool "IBM z16"
463	depends on $(cc-option,-mtune=z16)
464
465endchoice
466
467config 64BIT
468	def_bool y
469
470config COMMAND_LINE_SIZE
471	int "Maximum size of kernel command line"
472	default 4096
473	range 896 1048576
474	help
475	  This allows you to specify the maximum length of the kernel command
476	  line.
477
478config COMPAT
479	def_bool n
480	prompt "Kernel support for 31 bit emulation"
481	select ARCH_WANT_OLD_COMPAT_IPC
482	select COMPAT_OLD_SIGACTION
483	select HAVE_UID16
484	depends on MULTIUSER
485	depends on !CC_IS_CLANG && !LD_IS_LLD
486	help
487	  Select this option if you want to enable your system kernel to
488	  handle system-calls from ELF binaries for 31 bit ESA.  This option
489	  (and some other stuff like libraries and such) is needed for
490	  executing 31 bit applications.
491
492	  If unsure say N.
493
494config SMP
495	def_bool y
496
497config NR_CPUS
498	int "Maximum number of CPUs (2-512)"
499	range 2 512
500	default "64"
501	help
502	  This allows you to specify the maximum number of CPUs which this
503	  kernel will support. The maximum supported value is 512 and the
504	  minimum value which makes sense is 2.
505
506	  This is purely to save memory - each supported CPU adds
507	  approximately sixteen kilobytes to the kernel image.
508
509config HOTPLUG_CPU
510	def_bool y
511
512config NUMA
513	bool "NUMA support"
514	depends on SCHED_TOPOLOGY
515	default n
516	help
517	  Enable NUMA support
518
519	  This option adds NUMA support to the kernel.
520
521config NODES_SHIFT
522	int
523	depends on NUMA
524	default "1"
525
526config SCHED_SMT
527	def_bool n
528
529config SCHED_MC
530	def_bool n
531
532config SCHED_TOPOLOGY
533	def_bool y
534	prompt "Topology scheduler support"
535	select SCHED_SMT
536	select SCHED_MC
537	help
538	  Topology scheduler support improves the CPU scheduler's decision
539	  making when dealing with machines that have multi-threading,
540	  multiple cores or multiple books.
541
542config SCHED_TOPOLOGY_VERTICAL
543	def_bool y
544	bool "Use vertical CPU polarization by default"
545	depends on SCHED_TOPOLOGY
546	help
547	  Use vertical CPU polarization by default if available.
548	  The default CPU polarization is horizontal.
549
550config HIPERDISPATCH_ON
551	def_bool y
552	bool "Use hiperdispatch on vertical polarization by default"
553	depends on SCHED_TOPOLOGY
554	depends on PROC_SYSCTL
555	help
556	  Hiperdispatch aims to improve the CPU scheduler's decision
557	  making when using vertical polarization by adjusting CPU
558	  capacities dynamically. Set this option to use hiperdispatch
559	  on vertical polarization by default. This can be overwritten
560	  by sysctl's s390.hiperdispatch attribute later on.
561
562source "kernel/Kconfig.hz"
563
564config CERT_STORE
565	bool "Get user certificates via DIAG320"
566	depends on KEYS
567	select CRYPTO_LIB_SHA256
568	help
569	  Enable this option if you want to access user-provided secure boot
570	  certificates via DIAG 0x320.
571
572	  These certificates will be made available via the keyring named
573	  'cert_store'.
574
575config KERNEL_NOBP
576	def_bool n
577	prompt "Enable modified branch prediction for the kernel by default"
578	help
579	  If this option is selected the kernel will switch to a modified
580	  branch prediction mode if the firmware interface is available.
581	  The modified branch prediction mode improves the behaviour in
582	  regard to speculative execution.
583
584	  With the option enabled the kernel parameter "nobp=0" or "nospec"
585	  can be used to run the kernel in the normal branch prediction mode.
586
587	  With the option disabled the modified branch prediction mode is
588	  enabled with the "nobp=1" kernel parameter.
589
590	  If unsure, say N.
591
592config EXPOLINE
593	def_bool n
594	depends on $(cc-option,-mindirect-branch=thunk)
595	prompt "Avoid speculative indirect branches in the kernel"
596	help
597	  Compile the kernel with the expoline compiler options to guard
598	  against kernel-to-user data leaks by avoiding speculative indirect
599	  branches.
600	  Requires a compiler with -mindirect-branch=thunk support for full
601	  protection. The kernel may run slower.
602
603	  If unsure, say N.
604
605config EXPOLINE_EXTERN
606	def_bool EXPOLINE && CC_IS_GCC && GCC_VERSION >= 110200 && \
607		 $(success,$(srctree)/arch/s390/tools/gcc-thunk-extern.sh $(CC))
608	help
609	  Generate expolines as external functions if the compiler supports it.
610	  This option is required for some tooling like kpatch, if expolines
611	  are enabled. The kernel is compiled with
612	  -mindirect-branch=thunk-extern, which requires a newer compiler.
613
614choice
615	prompt "Expoline default"
616	depends on EXPOLINE
617	default EXPOLINE_FULL
618
619config EXPOLINE_OFF
620	bool "spectre_v2=off"
621
622config EXPOLINE_AUTO
623	bool "spectre_v2=auto"
624
625config EXPOLINE_FULL
626	bool "spectre_v2=on"
627
628endchoice
629
630config RELOCATABLE
631	def_bool y
632	help
633	  This builds a kernel image that retains relocation information
634	  so it can be loaded at an arbitrary address.
635	  The relocations make the kernel image about 15% larger (compressed
636	  10%), but are discarded at runtime.
637	  Note: this option exists only for documentation purposes, please do
638	  not remove it.
639
640config RANDOMIZE_BASE
641	bool "Randomize the address of the kernel image (KASLR)"
642	default y
643	help
644	  In support of Kernel Address Space Layout Randomization (KASLR),
645	  this randomizes the address at which the kernel image is loaded,
646	  as a security feature that deters exploit attempts relying on
647	  knowledge of the location of kernel internals.
648
649config RANDOMIZE_IDENTITY_BASE
650	bool "Randomize the address of the identity mapping base"
651	depends on RANDOMIZE_BASE
652	default DEBUG_VM
653	help
654	  The identity mapping base address is pinned to zero by default.
655	  Allow randomization of that base to expose otherwise missed
656	  notion of physical and virtual addresses of data structures.
657	  That does not have any impact on the base address at which the
658	  kernel image is loaded.
659
660	  If unsure, say N
661
662config KERNEL_IMAGE_BASE
663	hex "Kernel image base address"
664	range 0x100000 0x1FFFFFE0000000 if !KASAN
665	range 0x100000 0x1BFFFFE0000000 if KASAN
666	default 0x3FFE0000000 if !KASAN
667	default 0x7FFFE0000000 if KASAN
668	help
669	  This is the address at which the kernel image is loaded in case
670	  Kernel Address Space Layout Randomization (KASLR) is disabled.
671
672	  In case the Protected virtualization guest support is enabled the
673	  Ultravisor imposes a virtual address limit. If the value of this
674	  option leads to the kernel image exceeding the Ultravisor limit,
675	  this option is ignored and the image is loaded below the limit.
676
677	  If the value of this option leads to the kernel image overlapping
678	  the virtual memory where other data structures are located, this
679	  option is ignored and the image is loaded above the structures.
680
681endmenu
682
683menu "Memory setup"
684
685config ARCH_SPARSEMEM_ENABLE
686	def_bool y
687	select SPARSEMEM_VMEMMAP_ENABLE
688	select SPARSEMEM_VMEMMAP
689
690config ARCH_SPARSEMEM_DEFAULT
691	def_bool y
692
693config MAX_PHYSMEM_BITS
694	int "Maximum size of supported physical memory in bits (42-53)"
695	range 42 53
696	default "46"
697	help
698	  This option specifies the maximum supported size of physical memory
699	  in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB).
700	  Increasing the number of bits also increases the kernel image size.
701	  By default 46 bits (64TB) are supported.
702
703endmenu
704
705menu "I/O subsystem"
706
707config QDIO
708	def_tristate y
709	prompt "QDIO support"
710	help
711	  This driver provides the Queued Direct I/O base support for
712	  IBM System z.
713
714	  To compile this driver as a module, choose M here: the
715	  module will be called qdio.
716
717	  If unsure, say Y.
718
719if PCI
720
721config PCI_NR_FUNCTIONS
722	int "Maximum number of PCI functions (1-4096)"
723	range 1 4096
724	default "512"
725	help
726	  This allows you to specify the maximum number of PCI functions which
727	  this kernel will support.
728
729endif # PCI
730
731config HAS_IOMEM
732	def_bool PCI
733
734config CHSC_SCH
735	def_tristate m
736	prompt "Support for CHSC subchannels"
737	help
738	  This driver allows usage of CHSC subchannels. A CHSC subchannel
739	  is usually present on LPAR only.
740	  The driver creates a device /dev/chsc, which may be used to
741	  obtain I/O configuration information about the machine and
742	  to issue asynchronous chsc commands (DANGEROUS).
743	  You will usually only want to use this interface on a special
744	  LPAR designated for system management.
745
746	  To compile this driver as a module, choose M here: the
747	  module will be called chsc_sch.
748
749	  If unsure, say N.
750
751config SCM_BUS
752	def_bool y
753	prompt "SCM bus driver"
754	help
755	  Bus driver for Storage Class Memory.
756
757config EADM_SCH
758	def_tristate m
759	prompt "Support for EADM subchannels"
760	depends on SCM_BUS
761	help
762	  This driver allows usage of EADM subchannels. EADM subchannels act
763	  as a communication vehicle for SCM increments.
764
765	  To compile this driver as a module, choose M here: the
766	  module will be called eadm_sch.
767
768config AP
769	def_tristate y
770	prompt "Support for Adjunct Processors (ap)"
771	help
772	  This driver allows usage to Adjunct Processor (AP) devices via
773	  the ap bus, cards and queues. Supported Adjunct Processors are
774	  the CryptoExpress Cards (CEX).
775
776	  To compile this driver as a module, choose M here: the
777	  module will be called ap.
778
779	  If unsure, say Y (default).
780
781config AP_DEBUG
782	def_bool n
783	prompt "Enable debug features for Adjunct Processor (ap) devices"
784	depends on AP
785	help
786	  Say 'Y' here to enable some additional debug features for Adjunct
787	  Processor (ap) devices.
788
789	  There will be some more sysfs attributes displayed for ap queues.
790
791	  Do not enable on production level kernel build.
792
793	  If unsure, say N.
794
795config VFIO_CCW
796	def_tristate n
797	prompt "Support for VFIO-CCW subchannels"
798	depends on VFIO
799	select VFIO_MDEV
800	help
801	  This driver allows usage of I/O subchannels via VFIO-CCW.
802
803	  To compile this driver as a module, choose M here: the
804	  module will be called vfio_ccw.
805
806config VFIO_AP
807	def_tristate n
808	prompt "VFIO support for AP devices"
809	depends on KVM
810	depends on VFIO
811	depends on AP
812	select VFIO_MDEV
813	help
814	  This driver grants access to Adjunct Processor (AP) devices
815	  via the VFIO mediated device interface.
816
817	  To compile this driver as a module, choose M here: the module
818	  will be called vfio_ap.
819
820endmenu
821
822config CCW
823	def_bool y
824
825config HAVE_PNETID
826	tristate
827	default (SMC || CCWGROUP)
828
829menu "Virtualization"
830
831config PFAULT
832	def_bool y
833	prompt "Pseudo page fault support"
834	help
835	  Select this option, if you want to use PFAULT pseudo page fault
836	  handling under VM. If running native or in LPAR, this option
837	  has no effect. If your VM does not support PFAULT, PAGEEX
838	  pseudo page fault handling will be used.
839	  Note that VM 4.2 supports PFAULT but has a bug in its
840	  implementation that causes some problems.
841	  Everybody who wants to run Linux under VM != VM4.2 should select
842	  this option.
843
844config CMM
845	def_tristate n
846	prompt "Cooperative memory management"
847	help
848	  Select this option, if you want to enable the kernel interface
849	  to reduce the memory size of the system. This is accomplished
850	  by allocating pages of memory and put them "on hold". This only
851	  makes sense for a system running under VM where the unused pages
852	  will be reused by VM for other guest systems. The interface
853	  allows an external monitor to balance memory of many systems.
854	  Everybody who wants to run Linux under VM should select this
855	  option.
856
857config CMM_IUCV
858	def_bool y
859	prompt "IUCV special message interface to cooperative memory management"
860	depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
861	help
862	  Select this option to enable the special message interface to
863	  the cooperative memory management.
864
865config APPLDATA_BASE
866	def_bool n
867	prompt "Linux - VM Monitor Stream, base infrastructure"
868	depends on PROC_SYSCTL
869	help
870	  This provides a kernel interface for creating and updating z/VM APPLDATA
871	  monitor records. The monitor records are updated at certain time
872	  intervals, once the timer is started.
873	  Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
874	  i.e. enables or disables monitoring on the Linux side.
875	  A custom interval value (in seconds) can be written to
876	  /proc/appldata/interval.
877
878	  Defaults are 60 seconds interval and timer off.
879	  The /proc entries can also be read from, showing the current settings.
880
881config APPLDATA_MEM
882	def_tristate m
883	prompt "Monitor memory management statistics"
884	depends on APPLDATA_BASE && VM_EVENT_COUNTERS
885	help
886	  This provides memory management related data to the Linux - VM Monitor
887	  Stream, like paging/swapping rate, memory utilisation, etc.
888	  Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
889	  APPLDATA monitor record, i.e. enables or disables monitoring this record
890	  on the z/VM side.
891
892	  Default is disabled.
893	  The /proc entry can also be read from, showing the current settings.
894
895	  This can also be compiled as a module, which will be called
896	  appldata_mem.o.
897
898config APPLDATA_OS
899	def_tristate m
900	prompt "Monitor OS statistics"
901	depends on APPLDATA_BASE
902	help
903	  This provides OS related data to the Linux - VM Monitor Stream, like
904	  CPU utilisation, etc.
905	  Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
906	  APPLDATA monitor record, i.e. enables or disables monitoring this record
907	  on the z/VM side.
908
909	  Default is disabled.
910	  This can also be compiled as a module, which will be called
911	  appldata_os.o.
912
913config APPLDATA_NET_SUM
914	def_tristate m
915	prompt "Monitor overall network statistics"
916	depends on APPLDATA_BASE && NET
917	help
918	  This provides network related data to the Linux - VM Monitor Stream,
919	  currently there is only a total sum of network I/O statistics, no
920	  per-interface data.
921	  Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
922	  APPLDATA monitor record, i.e. enables or disables monitoring this record
923	  on the z/VM side.
924
925	  Default is disabled.
926	  This can also be compiled as a module, which will be called
927	  appldata_net_sum.o.
928
929config S390_HYPFS
930	def_bool y
931	prompt "s390 hypervisor information"
932	help
933	  This provides several binary files at (debugfs)/s390_hypfs/ to
934	  provide accounting information in an s390 hypervisor environment.
935
936config S390_HYPFS_FS
937	def_bool n
938	prompt "s390 hypervisor file system support"
939	select SYS_HYPERVISOR
940	depends on S390_HYPFS
941	help
942	  This is a virtual file system intended to provide accounting
943	  information in an s390 hypervisor environment. This file system
944	  is deprecated and should not be used.
945
946	  Say N if you are unsure.
947
948source "arch/s390/kvm/Kconfig"
949
950config S390_GUEST
951	def_bool y
952	prompt "s390 support for virtio devices"
953	select TTY
954	select VIRTUALIZATION
955	select VIRTIO
956	help
957	  Enabling this option adds support for virtio based paravirtual device
958	  drivers on s390.
959
960	  Select this option if you want to run the kernel as a guest under
961	  the KVM hypervisor.
962
963endmenu
964
965config S390_MODULES_SANITY_TEST_HELPERS
966	def_bool n
967
968menu "Selftests"
969
970config S390_UNWIND_SELFTEST
971	def_tristate n
972	depends on KUNIT
973	default KUNIT_ALL_TESTS
974	prompt "Test unwind functions"
975	help
976	  This option enables s390 specific stack unwinder testing kernel
977	  module. This option is not useful for distributions or general
978	  kernels, but only for kernel developers working on architecture code.
979
980	  Say N if you are unsure.
981
982config S390_KPROBES_SANITY_TEST
983	def_tristate n
984	prompt "Enable s390 specific kprobes tests"
985	depends on KPROBES
986	depends on KUNIT
987	help
988	  This option enables an s390 specific kprobes test module. This option
989	  is not useful for distributions or general kernels, but only for kernel
990	  developers working on architecture code.
991
992	  Say N if you are unsure.
993
994config S390_MODULES_SANITY_TEST
995	def_tristate n
996	depends on KUNIT
997	default KUNIT_ALL_TESTS
998	prompt "Enable s390 specific modules tests"
999	select S390_MODULES_SANITY_TEST_HELPERS
1000	help
1001	  This option enables an s390 specific modules test. This option is
1002	  not useful for distributions or general kernels, but only for
1003	  kernel developers working on architecture code.
1004
1005	  Say N if you are unsure.
1006endmenu
1007