xref: /linux/arch/s390/Kconfig (revision ba05b39d54eef78043b5c8ee90545cb06a98ae6f)
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 y
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 PCI_QUIRKS
45	def_bool n
46
47config ARCH_SUPPORTS_UPROBES
48	def_bool y
49
50config KASAN_SHADOW_OFFSET
51	hex
52	depends on KASAN
53	default 0x1C000000000000
54
55config S390
56	def_bool y
57	#
58	# Note: keep this list sorted alphabetically
59	#
60	imply IMA_SECURE_AND_OR_TRUSTED_BOOT
61	select ALTERNATE_USER_ADDRESS_SPACE
62	select ARCH_32BIT_USTAT_F_TINODE
63	select ARCH_BINFMT_ELF_STATE
64	select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
65	select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM
66	select ARCH_ENABLE_MEMORY_HOTREMOVE
67	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
68	select ARCH_HAS_CURRENT_STACK_POINTER
69	select ARCH_HAS_DEBUG_VIRTUAL
70	select ARCH_HAS_DEBUG_VM_PGTABLE
71	select ARCH_HAS_DEBUG_WX
72	select ARCH_HAS_DEVMEM_IS_ALLOWED
73	select ARCH_HAS_ELF_RANDOMIZE
74	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
75	select ARCH_HAS_FORTIFY_SOURCE
76	select ARCH_HAS_GCOV_PROFILE_ALL
77	select ARCH_HAS_GIGANTIC_PAGE
78	select ARCH_HAS_KCOV
79	select ARCH_HAS_MEMBARRIER_SYNC_CORE
80	select ARCH_HAS_MEM_ENCRYPT
81	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
82	select ARCH_HAS_PTE_SPECIAL
83	select ARCH_HAS_SCALED_CPUTIME
84	select ARCH_HAS_SET_DIRECT_MAP
85	select ARCH_HAS_SET_MEMORY
86	select ARCH_HAS_STRICT_KERNEL_RWX
87	select ARCH_HAS_STRICT_MODULE_RWX
88	select ARCH_HAS_SYSCALL_WRAPPER
89	select ARCH_HAS_UBSAN
90	select ARCH_HAS_VDSO_DATA
91	select ARCH_HAVE_NMI_SAFE_CMPXCHG
92	select ARCH_INLINE_READ_LOCK
93	select ARCH_INLINE_READ_LOCK_BH
94	select ARCH_INLINE_READ_LOCK_IRQ
95	select ARCH_INLINE_READ_LOCK_IRQSAVE
96	select ARCH_INLINE_READ_TRYLOCK
97	select ARCH_INLINE_READ_UNLOCK
98	select ARCH_INLINE_READ_UNLOCK_BH
99	select ARCH_INLINE_READ_UNLOCK_IRQ
100	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
101	select ARCH_INLINE_SPIN_LOCK
102	select ARCH_INLINE_SPIN_LOCK_BH
103	select ARCH_INLINE_SPIN_LOCK_IRQ
104	select ARCH_INLINE_SPIN_LOCK_IRQSAVE
105	select ARCH_INLINE_SPIN_TRYLOCK
106	select ARCH_INLINE_SPIN_TRYLOCK_BH
107	select ARCH_INLINE_SPIN_UNLOCK
108	select ARCH_INLINE_SPIN_UNLOCK_BH
109	select ARCH_INLINE_SPIN_UNLOCK_IRQ
110	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
111	select ARCH_INLINE_WRITE_LOCK
112	select ARCH_INLINE_WRITE_LOCK_BH
113	select ARCH_INLINE_WRITE_LOCK_IRQ
114	select ARCH_INLINE_WRITE_LOCK_IRQSAVE
115	select ARCH_INLINE_WRITE_TRYLOCK
116	select ARCH_INLINE_WRITE_UNLOCK
117	select ARCH_INLINE_WRITE_UNLOCK_BH
118	select ARCH_INLINE_WRITE_UNLOCK_IRQ
119	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
120	select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
121	select ARCH_STACKWALK
122	select ARCH_SUPPORTS_ATOMIC_RMW
123	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
124	select ARCH_SUPPORTS_HUGETLBFS
125	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && CC_IS_CLANG
126	select ARCH_SUPPORTS_NUMA_BALANCING
127	select ARCH_SUPPORTS_PER_VMA_LOCK
128	select ARCH_USE_BUILTIN_BSWAP
129	select ARCH_USE_CMPXCHG_LOCKREF
130	select ARCH_USE_SYM_ANNOTATIONS
131	select ARCH_WANTS_NO_INSTR
132	select ARCH_WANT_DEFAULT_BPF_JIT
133	select ARCH_WANT_IPC_PARSE_VERSION
134	select ARCH_WANT_KERNEL_PMD_MKWRITE
135	select ARCH_WANT_LD_ORPHAN_WARN
136	select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP
137	select BUILDTIME_TABLE_SORT
138	select CLONE_BACKWARDS2
139	select DCACHE_WORD_ACCESS if !KMSAN
140	select DMA_OPS if PCI
141	select DYNAMIC_FTRACE if FUNCTION_TRACER
142	select FUNCTION_ALIGNMENT_8B if CC_IS_GCC
143	select FUNCTION_ALIGNMENT_16B if !CC_IS_GCC
144	select GENERIC_ALLOCATOR
145	select GENERIC_CPU_AUTOPROBE
146	select GENERIC_CPU_VULNERABILITIES
147	select GENERIC_ENTRY
148	select GENERIC_GETTIMEOFDAY
149	select GENERIC_PTDUMP
150	select GENERIC_SMP_IDLE_THREAD
151	select GENERIC_TIME_VSYSCALL
152	select GENERIC_VDSO_TIME_NS
153	select GENERIC_IOREMAP if PCI
154	select HAVE_ALIGNED_STRUCT_PAGE
155	select HAVE_ARCH_AUDITSYSCALL
156	select HAVE_ARCH_JUMP_LABEL
157	select HAVE_ARCH_JUMP_LABEL_RELATIVE
158	select HAVE_ARCH_KASAN
159	select HAVE_ARCH_KASAN_VMALLOC
160	select HAVE_ARCH_KCSAN
161	select HAVE_ARCH_KFENCE
162	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
163	select HAVE_ARCH_SECCOMP_FILTER
164	select HAVE_ARCH_SOFT_DIRTY
165	select HAVE_ARCH_STACKLEAK
166	select HAVE_ARCH_TRACEHOOK
167	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
168	select HAVE_ARCH_VMAP_STACK
169	select HAVE_ASM_MODVERSIONS
170	select HAVE_CMPXCHG_DOUBLE
171	select HAVE_CMPXCHG_LOCAL
172	select HAVE_DEBUG_KMEMLEAK
173	select HAVE_DMA_CONTIGUOUS
174	select HAVE_DYNAMIC_FTRACE
175	select HAVE_DYNAMIC_FTRACE_WITH_ARGS
176	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
177	select HAVE_DYNAMIC_FTRACE_WITH_REGS
178	select HAVE_EBPF_JIT if HAVE_MARCH_Z196_FEATURES
179	select HAVE_EFFICIENT_UNALIGNED_ACCESS
180	select HAVE_FAST_GUP
181	select HAVE_FENTRY
182	select HAVE_FTRACE_MCOUNT_RECORD
183	select HAVE_FUNCTION_ARG_ACCESS_API
184	select HAVE_FUNCTION_ERROR_INJECTION
185	select HAVE_FUNCTION_GRAPH_RETVAL
186	select HAVE_FUNCTION_GRAPH_TRACER
187	select HAVE_FUNCTION_TRACER
188	select HAVE_GCC_PLUGINS
189	select HAVE_GENERIC_VDSO
190	select HAVE_IOREMAP_PROT if PCI
191	select HAVE_KERNEL_BZIP2
192	select HAVE_KERNEL_GZIP
193	select HAVE_KERNEL_LZ4
194	select HAVE_KERNEL_LZMA
195	select HAVE_KERNEL_LZO
196	select HAVE_KERNEL_UNCOMPRESSED
197	select HAVE_KERNEL_XZ
198	select HAVE_KERNEL_ZSTD
199	select HAVE_KPROBES
200	select HAVE_KPROBES_ON_FTRACE
201	select HAVE_KRETPROBES
202	select HAVE_LIVEPATCH
203	select HAVE_MEMBLOCK_PHYS_MAP
204	select HAVE_MOD_ARCH_SPECIFIC
205	select HAVE_NMI
206	select HAVE_NOP_MCOUNT
207	select HAVE_PAGE_SIZE_4KB
208	select HAVE_PCI
209	select HAVE_PERF_EVENTS
210	select HAVE_PERF_REGS
211	select HAVE_PERF_USER_STACK_DUMP
212	select HAVE_REGS_AND_STACK_ACCESS_API
213	select HAVE_RELIABLE_STACKTRACE
214	select HAVE_RETHOOK
215	select HAVE_RSEQ
216	select HAVE_SAMPLE_FTRACE_DIRECT
217	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
218	select HAVE_SETUP_PER_CPU_AREA
219	select HAVE_SOFTIRQ_ON_OWN_STACK
220	select HAVE_SYSCALL_TRACEPOINTS
221	select HAVE_VIRT_CPU_ACCOUNTING
222	select HAVE_VIRT_CPU_ACCOUNTING_IDLE
223	select IOMMU_HELPER		if PCI
224	select IOMMU_SUPPORT		if PCI
225	select MMU_GATHER_MERGE_VMAS
226	select MMU_GATHER_NO_GATHER
227	select MMU_GATHER_RCU_TABLE_FREE
228	select MODULES_USE_ELF_RELA
229	select NEED_DMA_MAP_STATE	if PCI
230	select NEED_PER_CPU_EMBED_FIRST_CHUNK
231	select NEED_SG_DMA_LENGTH	if PCI
232	select OLD_SIGACTION
233	select OLD_SIGSUSPEND3
234	select PCI_DOMAINS		if PCI
235	select PCI_MSI			if PCI
236	select PCI_MSI_ARCH_FALLBACKS	if PCI_MSI
237	select SPARSE_IRQ
238	select SWIOTLB
239	select SYSCTL_EXCEPTION_TRACE
240	select THREAD_INFO_IN_TASK
241	select TRACE_IRQFLAGS_SUPPORT
242	select TTY
243	select USER_STACKTRACE_SUPPORT
244	select VIRT_CPU_ACCOUNTING
245	select ZONE_DMA
246	# Note: keep the above list sorted alphabetically
247
248config SCHED_OMIT_FRAME_POINTER
249	def_bool y
250
251config PGTABLE_LEVELS
252	int
253	default 5
254
255source "kernel/livepatch/Kconfig"
256
257config ARCH_SUPPORTS_KEXEC
258	def_bool y
259
260config ARCH_SUPPORTS_KEXEC_FILE
261	def_bool y
262
263config ARCH_SUPPORTS_KEXEC_SIG
264	def_bool MODULE_SIG_FORMAT
265
266config ARCH_SUPPORTS_KEXEC_PURGATORY
267	def_bool y
268
269config ARCH_SUPPORTS_CRASH_DUMP
270	def_bool y
271	help
272	  Refer to <file:Documentation/arch/s390/zfcpdump.rst> for more details on this.
273	  This option also enables s390 zfcpdump.
274	  See also <file:Documentation/arch/s390/zfcpdump.rst>
275
276menu "Processor type and features"
277
278config HAVE_MARCH_Z10_FEATURES
279	def_bool n
280
281config HAVE_MARCH_Z196_FEATURES
282	def_bool n
283	select HAVE_MARCH_Z10_FEATURES
284
285config HAVE_MARCH_ZEC12_FEATURES
286	def_bool n
287	select HAVE_MARCH_Z196_FEATURES
288
289config HAVE_MARCH_Z13_FEATURES
290	def_bool n
291	select HAVE_MARCH_ZEC12_FEATURES
292
293config HAVE_MARCH_Z14_FEATURES
294	def_bool n
295	select HAVE_MARCH_Z13_FEATURES
296
297config HAVE_MARCH_Z15_FEATURES
298	def_bool n
299	select HAVE_MARCH_Z14_FEATURES
300
301config HAVE_MARCH_Z16_FEATURES
302	def_bool n
303	select HAVE_MARCH_Z15_FEATURES
304
305choice
306	prompt "Processor type"
307	default MARCH_Z196
308
309config MARCH_Z10
310	bool "IBM System z10"
311	select HAVE_MARCH_Z10_FEATURES
312	depends on $(cc-option,-march=z10)
313	help
314	  Select this to enable optimizations for IBM System z10 (2097 and 2098
315	  series). This is the oldest machine generation currently supported.
316
317config MARCH_Z196
318	bool "IBM zEnterprise 114 and 196"
319	select HAVE_MARCH_Z196_FEATURES
320	depends on $(cc-option,-march=z196)
321	help
322	  Select this to enable optimizations for IBM zEnterprise 114 and 196
323	  (2818 and 2817 series). The kernel will be slightly faster but will
324	  not work on older machines.
325
326config MARCH_ZEC12
327	bool "IBM zBC12 and zEC12"
328	select HAVE_MARCH_ZEC12_FEATURES
329	depends on $(cc-option,-march=zEC12)
330	help
331	  Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
332	  2827 series). The kernel will be slightly faster but will not work on
333	  older machines.
334
335config MARCH_Z13
336	bool "IBM z13s and z13"
337	select HAVE_MARCH_Z13_FEATURES
338	depends on $(cc-option,-march=z13)
339	help
340	  Select this to enable optimizations for IBM z13s and z13 (2965 and
341	  2964 series). The kernel will be slightly faster but will not work on
342	  older machines.
343
344config MARCH_Z14
345	bool "IBM z14 ZR1 and z14"
346	select HAVE_MARCH_Z14_FEATURES
347	depends on $(cc-option,-march=z14)
348	help
349	  Select this to enable optimizations for IBM z14 ZR1 and z14 (3907
350	  and 3906 series). The kernel will be slightly faster but will not
351	  work on older machines.
352
353config MARCH_Z15
354	bool "IBM z15"
355	select HAVE_MARCH_Z15_FEATURES
356	depends on $(cc-option,-march=z15)
357	help
358	  Select this to enable optimizations for IBM z15 (8562
359	  and 8561 series). The kernel will be slightly faster but will not
360	  work on older machines.
361
362config MARCH_Z16
363	bool "IBM z16"
364	select HAVE_MARCH_Z16_FEATURES
365	depends on $(cc-option,-march=z16)
366	help
367	  Select this to enable optimizations for IBM z16 (3931 and
368	  3932 series).
369
370endchoice
371
372config MARCH_Z10_TUNE
373	def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
374
375config MARCH_Z196_TUNE
376	def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
377
378config MARCH_ZEC12_TUNE
379	def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
380
381config MARCH_Z13_TUNE
382	def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT
383
384config MARCH_Z14_TUNE
385	def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT
386
387config MARCH_Z15_TUNE
388	def_bool TUNE_Z15 || MARCH_Z15 && TUNE_DEFAULT
389
390config MARCH_Z16_TUNE
391	def_bool TUNE_Z16 || MARCH_Z16 && TUNE_DEFAULT
392
393choice
394	prompt "Tune code generation"
395	default TUNE_DEFAULT
396	help
397	  Cause the compiler to tune (-mtune) the generated code for a machine.
398	  This will make the code run faster on the selected machine but
399	  somewhat slower on other machines.
400	  This option only changes how the compiler emits instructions, not the
401	  selection of instructions itself, so the resulting kernel will run on
402	  all other machines.
403
404config TUNE_DEFAULT
405	bool "Default"
406	help
407	  Tune the generated code for the target processor for which the kernel
408	  will be compiled.
409
410config TUNE_Z10
411	bool "IBM System z10"
412
413config TUNE_Z196
414	bool "IBM zEnterprise 114 and 196"
415	depends on $(cc-option,-mtune=z196)
416
417config TUNE_ZEC12
418	bool "IBM zBC12 and zEC12"
419	depends on $(cc-option,-mtune=zEC12)
420
421config TUNE_Z13
422	bool "IBM z13s and z13"
423	depends on $(cc-option,-mtune=z13)
424
425config TUNE_Z14
426	bool "IBM z14 ZR1 and z14"
427	depends on $(cc-option,-mtune=z14)
428
429config TUNE_Z15
430	bool "IBM z15"
431	depends on $(cc-option,-mtune=z15)
432
433config TUNE_Z16
434	bool "IBM z16"
435	depends on $(cc-option,-mtune=z16)
436
437endchoice
438
439config 64BIT
440	def_bool y
441
442config COMMAND_LINE_SIZE
443	int "Maximum size of kernel command line"
444	default 4096
445	range 896 1048576
446	help
447	  This allows you to specify the maximum length of the kernel command
448	  line.
449
450config COMPAT
451	def_bool n
452	prompt "Kernel support for 31 bit emulation"
453	select ARCH_WANT_OLD_COMPAT_IPC
454	select COMPAT_OLD_SIGACTION
455	select HAVE_UID16
456	depends on MULTIUSER
457	depends on !CC_IS_CLANG && !LD_IS_LLD
458	help
459	  Select this option if you want to enable your system kernel to
460	  handle system-calls from ELF binaries for 31 bit ESA.  This option
461	  (and some other stuff like libraries and such) is needed for
462	  executing 31 bit applications.
463
464	  If unsure say N.
465
466config SMP
467	def_bool y
468
469config NR_CPUS
470	int "Maximum number of CPUs (2-512)"
471	range 2 512
472	default "64"
473	help
474	  This allows you to specify the maximum number of CPUs which this
475	  kernel will support. The maximum supported value is 512 and the
476	  minimum value which makes sense is 2.
477
478	  This is purely to save memory - each supported CPU adds
479	  approximately sixteen kilobytes to the kernel image.
480
481config HOTPLUG_CPU
482	def_bool y
483
484config NUMA
485	bool "NUMA support"
486	depends on SCHED_TOPOLOGY
487	default n
488	help
489	  Enable NUMA support
490
491	  This option adds NUMA support to the kernel.
492
493config NODES_SHIFT
494	int
495	depends on NUMA
496	default "1"
497
498config SCHED_SMT
499	def_bool n
500
501config SCHED_MC
502	def_bool n
503
504config SCHED_TOPOLOGY
505	def_bool y
506	prompt "Topology scheduler support"
507	select SCHED_SMT
508	select SCHED_MC
509	help
510	  Topology scheduler support improves the CPU scheduler's decision
511	  making when dealing with machines that have multi-threading,
512	  multiple cores or multiple books.
513
514source "kernel/Kconfig.hz"
515
516config CERT_STORE
517	bool "Get user certificates via DIAG320"
518	depends on KEYS
519	select CRYPTO_LIB_SHA256
520	help
521	  Enable this option if you want to access user-provided secure boot
522	  certificates via DIAG 0x320.
523
524	  These certificates will be made available via the keyring named
525	  'cert_store'.
526
527config KERNEL_NOBP
528	def_bool n
529	prompt "Enable modified branch prediction for the kernel by default"
530	help
531	  If this option is selected the kernel will switch to a modified
532	  branch prediction mode if the firmware interface is available.
533	  The modified branch prediction mode improves the behaviour in
534	  regard to speculative execution.
535
536	  With the option enabled the kernel parameter "nobp=0" or "nospec"
537	  can be used to run the kernel in the normal branch prediction mode.
538
539	  With the option disabled the modified branch prediction mode is
540	  enabled with the "nobp=1" kernel parameter.
541
542	  If unsure, say N.
543
544config EXPOLINE
545	def_bool n
546	depends on $(cc-option,-mindirect-branch=thunk)
547	prompt "Avoid speculative indirect branches in the kernel"
548	help
549	  Compile the kernel with the expoline compiler options to guard
550	  against kernel-to-user data leaks by avoiding speculative indirect
551	  branches.
552	  Requires a compiler with -mindirect-branch=thunk support for full
553	  protection. The kernel may run slower.
554
555	  If unsure, say N.
556
557config EXPOLINE_EXTERN
558	def_bool y if EXPOLINE
559	depends on EXPOLINE
560	depends on CC_IS_GCC && GCC_VERSION >= 110200
561	depends on $(success,$(srctree)/arch/s390/tools/gcc-thunk-extern.sh $(CC))
562	prompt "Generate expolines as extern functions."
563	help
564	  This option is required for some tooling like kpatch. The kernel is
565	  compiled with -mindirect-branch=thunk-extern and requires a newer
566	  compiler.
567
568	  If unsure, say N.
569
570choice
571	prompt "Expoline default"
572	depends on EXPOLINE
573	default EXPOLINE_FULL
574
575config EXPOLINE_OFF
576	bool "spectre_v2=off"
577
578config EXPOLINE_AUTO
579	bool "spectre_v2=auto"
580
581config EXPOLINE_FULL
582	bool "spectre_v2=on"
583
584endchoice
585
586config RELOCATABLE
587	def_bool y
588	help
589	  This builds a kernel image that retains relocation information
590	  so it can be loaded at an arbitrary address.
591	  The relocations make the kernel image about 15% larger (compressed
592	  10%), but are discarded at runtime.
593	  Note: this option exists only for documentation purposes, please do
594	  not remove it.
595
596config PIE_BUILD
597	def_bool CC_IS_CLANG && !$(cc-option,-munaligned-symbols)
598	help
599	  If the compiler is unable to generate code that can manage unaligned
600	  symbols, the kernel is linked as a position-independent executable
601	  (PIE) and includes dynamic relocations that are processed early
602	  during bootup.
603
604	  For kpatch functionality, it is recommended to build the kernel
605	  without the PIE_BUILD option. PIE_BUILD is only enabled when the
606	  compiler lacks proper support for handling unaligned symbols.
607
608config RANDOMIZE_BASE
609	bool "Randomize the address of the kernel image (KASLR)"
610	default y
611	help
612	  In support of Kernel Address Space Layout Randomization (KASLR),
613	  this randomizes the address at which the kernel image is loaded,
614	  as a security feature that deters exploit attempts relying on
615	  knowledge of the location of kernel internals.
616
617config KERNEL_IMAGE_BASE
618	hex "Kernel image base address"
619	range 0x100000 0x1FFFFFE0000000 if !KASAN
620	range 0x100000 0x1BFFFFE0000000 if KASAN
621	default 0x3FFE0000000 if !KASAN
622	default 0x7FFFE0000000 if KASAN
623	help
624	  This is the address at which the kernel image is loaded in case
625	  Kernel Address Space Layout Randomization (KASLR) is disabled.
626
627	  In case the Protected virtualization guest support is enabled the
628	  Ultravisor imposes a virtual address limit. If the value of this
629	  option leads to the kernel image exceeding the Ultravisor limit,
630	  this option is ignored and the image is loaded below the limit.
631
632	  If the value of this option leads to the kernel image overlapping
633	  the virtual memory where other data structures are located, this
634	  option is ignored and the image is loaded above the structures.
635
636endmenu
637
638menu "Memory setup"
639
640config ARCH_SPARSEMEM_ENABLE
641	def_bool y
642	select SPARSEMEM_VMEMMAP_ENABLE
643	select SPARSEMEM_VMEMMAP
644
645config ARCH_SPARSEMEM_DEFAULT
646	def_bool y
647
648config MAX_PHYSMEM_BITS
649	int "Maximum size of supported physical memory in bits (42-53)"
650	range 42 53
651	default "46"
652	help
653	  This option specifies the maximum supported size of physical memory
654	  in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB).
655	  Increasing the number of bits also increases the kernel image size.
656	  By default 46 bits (64TB) are supported.
657
658config CHECK_STACK
659	def_bool y
660	depends on !VMAP_STACK
661	prompt "Detect kernel stack overflow"
662	help
663	  This option enables the compiler option -mstack-guard and
664	  -mstack-size if they are available. If the compiler supports them
665	  it will emit additional code to each function prolog to trigger
666	  an illegal operation if the kernel stack is about to overflow.
667
668	  Say N if you are unsure.
669
670config STACK_GUARD
671	int "Size of the guard area (128-1024)"
672	range 128 1024
673	depends on CHECK_STACK
674	default "256"
675	help
676	  This allows you to specify the size of the guard area at the lower
677	  end of the kernel stack. If the kernel stack points into the guard
678	  area on function entry an illegal operation is triggered. The size
679	  needs to be a power of 2. Please keep in mind that the size of an
680	  interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
681	  The minimum size for the stack guard should be 256 for 31 bit and
682	  512 for 64 bit.
683
684endmenu
685
686menu "I/O subsystem"
687
688config QDIO
689	def_tristate y
690	prompt "QDIO support"
691	help
692	  This driver provides the Queued Direct I/O base support for
693	  IBM System z.
694
695	  To compile this driver as a module, choose M here: the
696	  module will be called qdio.
697
698	  If unsure, say Y.
699
700if PCI
701
702config PCI_NR_FUNCTIONS
703	int "Maximum number of PCI functions (1-4096)"
704	range 1 4096
705	default "512"
706	help
707	  This allows you to specify the maximum number of PCI functions which
708	  this kernel will support.
709
710endif # PCI
711
712config HAS_IOMEM
713	def_bool PCI
714
715config CHSC_SCH
716	def_tristate m
717	prompt "Support for CHSC subchannels"
718	help
719	  This driver allows usage of CHSC subchannels. A CHSC subchannel
720	  is usually present on LPAR only.
721	  The driver creates a device /dev/chsc, which may be used to
722	  obtain I/O configuration information about the machine and
723	  to issue asynchronous chsc commands (DANGEROUS).
724	  You will usually only want to use this interface on a special
725	  LPAR designated for system management.
726
727	  To compile this driver as a module, choose M here: the
728	  module will be called chsc_sch.
729
730	  If unsure, say N.
731
732config SCM_BUS
733	def_bool y
734	prompt "SCM bus driver"
735	help
736	  Bus driver for Storage Class Memory.
737
738config EADM_SCH
739	def_tristate m
740	prompt "Support for EADM subchannels"
741	depends on SCM_BUS
742	help
743	  This driver allows usage of EADM subchannels. EADM subchannels act
744	  as a communication vehicle for SCM increments.
745
746	  To compile this driver as a module, choose M here: the
747	  module will be called eadm_sch.
748
749config AP
750	def_tristate y
751	prompt "Support for Adjunct Processors (ap)"
752	help
753	  This driver allows usage to Adjunct Processor (AP) devices via
754	  the ap bus, cards and queues. Supported Adjunct Processors are
755	  the CryptoExpress Cards (CEX).
756
757	  To compile this driver as a module, choose M here: the
758	  module will be called ap.
759
760	  If unsure, say Y (default).
761
762config AP_DEBUG
763	def_bool n
764	prompt "Enable debug features for Adjunct Processor (ap) devices"
765	depends on AP
766	help
767	  Say 'Y' here to enable some additional debug features for Adjunct
768	  Processor (ap) devices.
769
770	  There will be some more sysfs attributes displayed for ap queues.
771
772	  Do not enable on production level kernel build.
773
774	  If unsure, say N.
775
776config VFIO_CCW
777	def_tristate n
778	prompt "Support for VFIO-CCW subchannels"
779	depends on VFIO
780	select VFIO_MDEV
781	help
782	  This driver allows usage of I/O subchannels via VFIO-CCW.
783
784	  To compile this driver as a module, choose M here: the
785	  module will be called vfio_ccw.
786
787config VFIO_AP
788	def_tristate n
789	prompt "VFIO support for AP devices"
790	depends on KVM
791	depends on VFIO
792	depends on AP
793	select VFIO_MDEV
794	help
795	  This driver grants access to Adjunct Processor (AP) devices
796	  via the VFIO mediated device interface.
797
798	  To compile this driver as a module, choose M here: the module
799	  will be called vfio_ap.
800
801endmenu
802
803config CCW
804	def_bool y
805
806config HAVE_PNETID
807	tristate
808	default (SMC || CCWGROUP)
809
810menu "Virtualization"
811
812config PROTECTED_VIRTUALIZATION_GUEST
813	def_bool n
814	prompt "Protected virtualization guest support"
815	help
816	  Select this option, if you want to be able to run this
817	  kernel as a protected virtualization KVM guest.
818	  Protected virtualization capable machines have a mini hypervisor
819	  located at machine level (an ultravisor). With help of the
820	  Ultravisor, KVM will be able to run "protected" VMs, special
821	  VMs whose memory and management data are unavailable to KVM.
822
823config PFAULT
824	def_bool y
825	prompt "Pseudo page fault support"
826	help
827	  Select this option, if you want to use PFAULT pseudo page fault
828	  handling under VM. If running native or in LPAR, this option
829	  has no effect. If your VM does not support PFAULT, PAGEEX
830	  pseudo page fault handling will be used.
831	  Note that VM 4.2 supports PFAULT but has a bug in its
832	  implementation that causes some problems.
833	  Everybody who wants to run Linux under VM != VM4.2 should select
834	  this option.
835
836config CMM
837	def_tristate n
838	prompt "Cooperative memory management"
839	help
840	  Select this option, if you want to enable the kernel interface
841	  to reduce the memory size of the system. This is accomplished
842	  by allocating pages of memory and put them "on hold". This only
843	  makes sense for a system running under VM where the unused pages
844	  will be reused by VM for other guest systems. The interface
845	  allows an external monitor to balance memory of many systems.
846	  Everybody who wants to run Linux under VM should select this
847	  option.
848
849config CMM_IUCV
850	def_bool y
851	prompt "IUCV special message interface to cooperative memory management"
852	depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
853	help
854	  Select this option to enable the special message interface to
855	  the cooperative memory management.
856
857config APPLDATA_BASE
858	def_bool n
859	prompt "Linux - VM Monitor Stream, base infrastructure"
860	depends on PROC_SYSCTL
861	help
862	  This provides a kernel interface for creating and updating z/VM APPLDATA
863	  monitor records. The monitor records are updated at certain time
864	  intervals, once the timer is started.
865	  Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
866	  i.e. enables or disables monitoring on the Linux side.
867	  A custom interval value (in seconds) can be written to
868	  /proc/appldata/interval.
869
870	  Defaults are 60 seconds interval and timer off.
871	  The /proc entries can also be read from, showing the current settings.
872
873config APPLDATA_MEM
874	def_tristate m
875	prompt "Monitor memory management statistics"
876	depends on APPLDATA_BASE && VM_EVENT_COUNTERS
877	help
878	  This provides memory management related data to the Linux - VM Monitor
879	  Stream, like paging/swapping rate, memory utilisation, etc.
880	  Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
881	  APPLDATA monitor record, i.e. enables or disables monitoring this record
882	  on the z/VM side.
883
884	  Default is disabled.
885	  The /proc entry can also be read from, showing the current settings.
886
887	  This can also be compiled as a module, which will be called
888	  appldata_mem.o.
889
890config APPLDATA_OS
891	def_tristate m
892	prompt "Monitor OS statistics"
893	depends on APPLDATA_BASE
894	help
895	  This provides OS related data to the Linux - VM Monitor Stream, like
896	  CPU utilisation, etc.
897	  Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
898	  APPLDATA monitor record, i.e. enables or disables monitoring this record
899	  on the z/VM side.
900
901	  Default is disabled.
902	  This can also be compiled as a module, which will be called
903	  appldata_os.o.
904
905config APPLDATA_NET_SUM
906	def_tristate m
907	prompt "Monitor overall network statistics"
908	depends on APPLDATA_BASE && NET
909	help
910	  This provides network related data to the Linux - VM Monitor Stream,
911	  currently there is only a total sum of network I/O statistics, no
912	  per-interface data.
913	  Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
914	  APPLDATA monitor record, i.e. enables or disables monitoring this record
915	  on the z/VM side.
916
917	  Default is disabled.
918	  This can also be compiled as a module, which will be called
919	  appldata_net_sum.o.
920
921config S390_HYPFS
922	def_bool y
923	prompt "s390 hypervisor information"
924	help
925	  This provides several binary files at (debugfs)/s390_hypfs/ to
926	  provide accounting information in an s390 hypervisor environment.
927
928config S390_HYPFS_FS
929	def_bool n
930	prompt "s390 hypervisor file system support"
931	select SYS_HYPERVISOR
932	depends on S390_HYPFS
933	help
934	  This is a virtual file system intended to provide accounting
935	  information in an s390 hypervisor environment. This file system
936	  is deprecated and should not be used.
937
938	  Say N if you are unsure.
939
940source "arch/s390/kvm/Kconfig"
941
942config S390_GUEST
943	def_bool y
944	prompt "s390 support for virtio devices"
945	select TTY
946	select VIRTUALIZATION
947	select VIRTIO
948	help
949	  Enabling this option adds support for virtio based paravirtual device
950	  drivers on s390.
951
952	  Select this option if you want to run the kernel as a guest under
953	  the KVM hypervisor.
954
955endmenu
956
957config S390_MODULES_SANITY_TEST_HELPERS
958	def_bool n
959
960menu "Selftests"
961
962config S390_UNWIND_SELFTEST
963	def_tristate n
964	depends on KUNIT
965	default KUNIT_ALL_TESTS
966	prompt "Test unwind functions"
967	help
968	  This option enables s390 specific stack unwinder testing kernel
969	  module. This option is not useful for distributions or general
970	  kernels, but only for kernel developers working on architecture code.
971
972	  Say N if you are unsure.
973
974config S390_KPROBES_SANITY_TEST
975	def_tristate n
976	prompt "Enable s390 specific kprobes tests"
977	depends on KPROBES
978	depends on KUNIT
979	help
980	  This option enables an s390 specific kprobes test module. This option
981	  is not useful for distributions or general kernels, but only for kernel
982	  developers working on architecture code.
983
984	  Say N if you are unsure.
985
986config S390_MODULES_SANITY_TEST
987	def_tristate n
988	depends on KUNIT
989	default KUNIT_ALL_TESTS
990	prompt "Enable s390 specific modules tests"
991	select S390_MODULES_SANITY_TEST_HELPERS
992	help
993	  This option enables an s390 specific modules test. This option is
994	  not useful for distributions or general kernels, but only for
995	  kernel developers working on architecture code.
996
997	  Say N if you are unsure.
998endmenu
999