xref: /linux/arch/s390/Kconfig (revision c434e25b62f8efcfbb6bf1f7ce55960206c1137e)
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 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_DEVICES
146	select GENERIC_CPU_AUTOPROBE
147	select GENERIC_CPU_VULNERABILITIES
148	select GENERIC_ENTRY
149	select GENERIC_GETTIMEOFDAY
150	select GENERIC_PTDUMP
151	select GENERIC_SMP_IDLE_THREAD
152	select GENERIC_TIME_VSYSCALL
153	select GENERIC_VDSO_TIME_NS
154	select GENERIC_IOREMAP if PCI
155	select HAVE_ALIGNED_STRUCT_PAGE
156	select HAVE_ARCH_AUDITSYSCALL
157	select HAVE_ARCH_JUMP_LABEL
158	select HAVE_ARCH_JUMP_LABEL_RELATIVE
159	select HAVE_ARCH_KASAN
160	select HAVE_ARCH_KASAN_VMALLOC
161	select HAVE_ARCH_KCSAN
162	select HAVE_ARCH_KFENCE
163	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
164	select HAVE_ARCH_SECCOMP_FILTER
165	select HAVE_ARCH_SOFT_DIRTY
166	select HAVE_ARCH_STACKLEAK
167	select HAVE_ARCH_TRACEHOOK
168	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
169	select HAVE_ARCH_VMAP_STACK
170	select HAVE_ASM_MODVERSIONS
171	select HAVE_CMPXCHG_DOUBLE
172	select HAVE_CMPXCHG_LOCAL
173	select HAVE_DEBUG_KMEMLEAK
174	select HAVE_DMA_CONTIGUOUS
175	select HAVE_DYNAMIC_FTRACE
176	select HAVE_DYNAMIC_FTRACE_WITH_ARGS
177	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
178	select HAVE_DYNAMIC_FTRACE_WITH_REGS
179	select HAVE_EBPF_JIT if HAVE_MARCH_Z196_FEATURES
180	select HAVE_EFFICIENT_UNALIGNED_ACCESS
181	select HAVE_GUP_FAST
182	select HAVE_FENTRY
183	select HAVE_FTRACE_MCOUNT_RECORD
184	select HAVE_FUNCTION_ARG_ACCESS_API
185	select HAVE_FUNCTION_ERROR_INJECTION
186	select HAVE_FUNCTION_GRAPH_RETVAL
187	select HAVE_FUNCTION_GRAPH_TRACER
188	select HAVE_FUNCTION_TRACER
189	select HAVE_GCC_PLUGINS
190	select HAVE_GENERIC_VDSO
191	select HAVE_IOREMAP_PROT if PCI
192	select HAVE_KERNEL_BZIP2
193	select HAVE_KERNEL_GZIP
194	select HAVE_KERNEL_LZ4
195	select HAVE_KERNEL_LZMA
196	select HAVE_KERNEL_LZO
197	select HAVE_KERNEL_UNCOMPRESSED
198	select HAVE_KERNEL_XZ
199	select HAVE_KERNEL_ZSTD
200	select HAVE_KPROBES
201	select HAVE_KPROBES_ON_FTRACE
202	select HAVE_KRETPROBES
203	select HAVE_LIVEPATCH
204	select HAVE_MEMBLOCK_PHYS_MAP
205	select HAVE_MOD_ARCH_SPECIFIC
206	select HAVE_NMI
207	select HAVE_NOP_MCOUNT
208	select HAVE_PAGE_SIZE_4KB
209	select HAVE_PCI
210	select HAVE_PERF_EVENTS
211	select HAVE_PERF_REGS
212	select HAVE_PERF_USER_STACK_DUMP
213	select HAVE_REGS_AND_STACK_ACCESS_API
214	select HAVE_RELIABLE_STACKTRACE
215	select HAVE_RETHOOK
216	select HAVE_RSEQ
217	select HAVE_SAMPLE_FTRACE_DIRECT
218	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
219	select HAVE_SETUP_PER_CPU_AREA
220	select HAVE_SOFTIRQ_ON_OWN_STACK
221	select HAVE_SYSCALL_TRACEPOINTS
222	select HAVE_VIRT_CPU_ACCOUNTING
223	select HAVE_VIRT_CPU_ACCOUNTING_IDLE
224	select IOMMU_HELPER		if PCI
225	select IOMMU_SUPPORT		if PCI
226	select MMU_GATHER_MERGE_VMAS
227	select MMU_GATHER_NO_GATHER
228	select MMU_GATHER_RCU_TABLE_FREE
229	select MODULES_USE_ELF_RELA
230	select NEED_DMA_MAP_STATE	if PCI
231	select NEED_PER_CPU_EMBED_FIRST_CHUNK
232	select NEED_SG_DMA_LENGTH	if PCI
233	select OLD_SIGACTION
234	select OLD_SIGSUSPEND3
235	select PCI_DOMAINS		if PCI
236	select PCI_MSI			if PCI
237	select PCI_MSI_ARCH_FALLBACKS	if PCI_MSI
238	select SPARSE_IRQ
239	select SWIOTLB
240	select SYSCTL_EXCEPTION_TRACE
241	select THREAD_INFO_IN_TASK
242	select TRACE_IRQFLAGS_SUPPORT
243	select TTY
244	select USER_STACKTRACE_SUPPORT
245	select VIRT_CPU_ACCOUNTING
246	select ZONE_DMA
247	# Note: keep the above list sorted alphabetically
248
249config SCHED_OMIT_FRAME_POINTER
250	def_bool y
251
252config PGTABLE_LEVELS
253	int
254	default 5
255
256source "kernel/livepatch/Kconfig"
257
258config ARCH_SUPPORTS_KEXEC
259	def_bool y
260
261config ARCH_SUPPORTS_KEXEC_FILE
262	def_bool y
263
264config ARCH_SUPPORTS_KEXEC_SIG
265	def_bool MODULE_SIG_FORMAT
266
267config ARCH_SUPPORTS_KEXEC_PURGATORY
268	def_bool y
269
270config ARCH_SUPPORTS_CRASH_DUMP
271	def_bool y
272	help
273	  Refer to <file:Documentation/arch/s390/zfcpdump.rst> for more details on this.
274	  This option also enables s390 zfcpdump.
275	  See also <file:Documentation/arch/s390/zfcpdump.rst>
276
277menu "Processor type and features"
278
279config HAVE_MARCH_Z10_FEATURES
280	def_bool n
281
282config HAVE_MARCH_Z196_FEATURES
283	def_bool n
284	select HAVE_MARCH_Z10_FEATURES
285
286config HAVE_MARCH_ZEC12_FEATURES
287	def_bool n
288	select HAVE_MARCH_Z196_FEATURES
289
290config HAVE_MARCH_Z13_FEATURES
291	def_bool n
292	select HAVE_MARCH_ZEC12_FEATURES
293
294config HAVE_MARCH_Z14_FEATURES
295	def_bool n
296	select HAVE_MARCH_Z13_FEATURES
297
298config HAVE_MARCH_Z15_FEATURES
299	def_bool n
300	select HAVE_MARCH_Z14_FEATURES
301
302config HAVE_MARCH_Z16_FEATURES
303	def_bool n
304	select HAVE_MARCH_Z15_FEATURES
305
306choice
307	prompt "Processor type"
308	default MARCH_Z196
309
310config MARCH_Z10
311	bool "IBM System z10"
312	select HAVE_MARCH_Z10_FEATURES
313	depends on $(cc-option,-march=z10)
314	help
315	  Select this to enable optimizations for IBM System z10 (2097 and 2098
316	  series). This is the oldest machine generation currently supported.
317
318config MARCH_Z196
319	bool "IBM zEnterprise 114 and 196"
320	select HAVE_MARCH_Z196_FEATURES
321	depends on $(cc-option,-march=z196)
322	help
323	  Select this to enable optimizations for IBM zEnterprise 114 and 196
324	  (2818 and 2817 series). The kernel will be slightly faster but will
325	  not work on older machines.
326
327config MARCH_ZEC12
328	bool "IBM zBC12 and zEC12"
329	select HAVE_MARCH_ZEC12_FEATURES
330	depends on $(cc-option,-march=zEC12)
331	help
332	  Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
333	  2827 series). The kernel will be slightly faster but will not work on
334	  older machines.
335
336config MARCH_Z13
337	bool "IBM z13s and z13"
338	select HAVE_MARCH_Z13_FEATURES
339	depends on $(cc-option,-march=z13)
340	help
341	  Select this to enable optimizations for IBM z13s and z13 (2965 and
342	  2964 series). The kernel will be slightly faster but will not work on
343	  older machines.
344
345config MARCH_Z14
346	bool "IBM z14 ZR1 and z14"
347	select HAVE_MARCH_Z14_FEATURES
348	depends on $(cc-option,-march=z14)
349	help
350	  Select this to enable optimizations for IBM z14 ZR1 and z14 (3907
351	  and 3906 series). The kernel will be slightly faster but will not
352	  work on older machines.
353
354config MARCH_Z15
355	bool "IBM z15"
356	select HAVE_MARCH_Z15_FEATURES
357	depends on $(cc-option,-march=z15)
358	help
359	  Select this to enable optimizations for IBM z15 (8562
360	  and 8561 series). The kernel will be slightly faster but will not
361	  work on older machines.
362
363config MARCH_Z16
364	bool "IBM z16"
365	select HAVE_MARCH_Z16_FEATURES
366	depends on $(cc-option,-march=z16)
367	help
368	  Select this to enable optimizations for IBM z16 (3931 and
369	  3932 series).
370
371endchoice
372
373config MARCH_Z10_TUNE
374	def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
375
376config MARCH_Z196_TUNE
377	def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
378
379config MARCH_ZEC12_TUNE
380	def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
381
382config MARCH_Z13_TUNE
383	def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT
384
385config MARCH_Z14_TUNE
386	def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT
387
388config MARCH_Z15_TUNE
389	def_bool TUNE_Z15 || MARCH_Z15 && TUNE_DEFAULT
390
391config MARCH_Z16_TUNE
392	def_bool TUNE_Z16 || MARCH_Z16 && TUNE_DEFAULT
393
394choice
395	prompt "Tune code generation"
396	default TUNE_DEFAULT
397	help
398	  Cause the compiler to tune (-mtune) the generated code for a machine.
399	  This will make the code run faster on the selected machine but
400	  somewhat slower on other machines.
401	  This option only changes how the compiler emits instructions, not the
402	  selection of instructions itself, so the resulting kernel will run on
403	  all other machines.
404
405config TUNE_DEFAULT
406	bool "Default"
407	help
408	  Tune the generated code for the target processor for which the kernel
409	  will be compiled.
410
411config TUNE_Z10
412	bool "IBM System z10"
413
414config TUNE_Z196
415	bool "IBM zEnterprise 114 and 196"
416	depends on $(cc-option,-mtune=z196)
417
418config TUNE_ZEC12
419	bool "IBM zBC12 and zEC12"
420	depends on $(cc-option,-mtune=zEC12)
421
422config TUNE_Z13
423	bool "IBM z13s and z13"
424	depends on $(cc-option,-mtune=z13)
425
426config TUNE_Z14
427	bool "IBM z14 ZR1 and z14"
428	depends on $(cc-option,-mtune=z14)
429
430config TUNE_Z15
431	bool "IBM z15"
432	depends on $(cc-option,-mtune=z15)
433
434config TUNE_Z16
435	bool "IBM z16"
436	depends on $(cc-option,-mtune=z16)
437
438endchoice
439
440config 64BIT
441	def_bool y
442
443config COMMAND_LINE_SIZE
444	int "Maximum size of kernel command line"
445	default 4096
446	range 896 1048576
447	help
448	  This allows you to specify the maximum length of the kernel command
449	  line.
450
451config COMPAT
452	def_bool n
453	prompt "Kernel support for 31 bit emulation"
454	select ARCH_WANT_OLD_COMPAT_IPC
455	select COMPAT_OLD_SIGACTION
456	select HAVE_UID16
457	depends on MULTIUSER
458	depends on !CC_IS_CLANG && !LD_IS_LLD
459	help
460	  Select this option if you want to enable your system kernel to
461	  handle system-calls from ELF binaries for 31 bit ESA.  This option
462	  (and some other stuff like libraries and such) is needed for
463	  executing 31 bit applications.
464
465	  If unsure say N.
466
467config SMP
468	def_bool y
469
470config NR_CPUS
471	int "Maximum number of CPUs (2-512)"
472	range 2 512
473	default "64"
474	help
475	  This allows you to specify the maximum number of CPUs which this
476	  kernel will support. The maximum supported value is 512 and the
477	  minimum value which makes sense is 2.
478
479	  This is purely to save memory - each supported CPU adds
480	  approximately sixteen kilobytes to the kernel image.
481
482config HOTPLUG_CPU
483	def_bool y
484
485config NUMA
486	bool "NUMA support"
487	depends on SCHED_TOPOLOGY
488	default n
489	help
490	  Enable NUMA support
491
492	  This option adds NUMA support to the kernel.
493
494config NODES_SHIFT
495	int
496	depends on NUMA
497	default "1"
498
499config SCHED_SMT
500	def_bool n
501
502config SCHED_MC
503	def_bool n
504
505config SCHED_TOPOLOGY
506	def_bool y
507	prompt "Topology scheduler support"
508	select SCHED_SMT
509	select SCHED_MC
510	help
511	  Topology scheduler support improves the CPU scheduler's decision
512	  making when dealing with machines that have multi-threading,
513	  multiple cores or multiple books.
514
515source "kernel/Kconfig.hz"
516
517config CERT_STORE
518	bool "Get user certificates via DIAG320"
519	depends on KEYS
520	select CRYPTO_LIB_SHA256
521	help
522	  Enable this option if you want to access user-provided secure boot
523	  certificates via DIAG 0x320.
524
525	  These certificates will be made available via the keyring named
526	  'cert_store'.
527
528config KERNEL_NOBP
529	def_bool n
530	prompt "Enable modified branch prediction for the kernel by default"
531	help
532	  If this option is selected the kernel will switch to a modified
533	  branch prediction mode if the firmware interface is available.
534	  The modified branch prediction mode improves the behaviour in
535	  regard to speculative execution.
536
537	  With the option enabled the kernel parameter "nobp=0" or "nospec"
538	  can be used to run the kernel in the normal branch prediction mode.
539
540	  With the option disabled the modified branch prediction mode is
541	  enabled with the "nobp=1" kernel parameter.
542
543	  If unsure, say N.
544
545config EXPOLINE
546	def_bool n
547	depends on $(cc-option,-mindirect-branch=thunk)
548	prompt "Avoid speculative indirect branches in the kernel"
549	help
550	  Compile the kernel with the expoline compiler options to guard
551	  against kernel-to-user data leaks by avoiding speculative indirect
552	  branches.
553	  Requires a compiler with -mindirect-branch=thunk support for full
554	  protection. The kernel may run slower.
555
556	  If unsure, say N.
557
558config EXPOLINE_EXTERN
559	def_bool y if EXPOLINE
560	depends on EXPOLINE
561	depends on CC_IS_GCC && GCC_VERSION >= 110200
562	depends on $(success,$(srctree)/arch/s390/tools/gcc-thunk-extern.sh $(CC))
563	prompt "Generate expolines as extern functions."
564	help
565	  This option is required for some tooling like kpatch. The kernel is
566	  compiled with -mindirect-branch=thunk-extern and requires a newer
567	  compiler.
568
569	  If unsure, say N.
570
571choice
572	prompt "Expoline default"
573	depends on EXPOLINE
574	default EXPOLINE_FULL
575
576config EXPOLINE_OFF
577	bool "spectre_v2=off"
578
579config EXPOLINE_AUTO
580	bool "spectre_v2=auto"
581
582config EXPOLINE_FULL
583	bool "spectre_v2=on"
584
585endchoice
586
587config RELOCATABLE
588	def_bool y
589	help
590	  This builds a kernel image that retains relocation information
591	  so it can be loaded at an arbitrary address.
592	  The relocations make the kernel image about 15% larger (compressed
593	  10%), but are discarded at runtime.
594	  Note: this option exists only for documentation purposes, please do
595	  not remove it.
596
597config RANDOMIZE_BASE
598	bool "Randomize the address of the kernel image (KASLR)"
599	default y
600	help
601	  In support of Kernel Address Space Layout Randomization (KASLR),
602	  this randomizes the address at which the kernel image is loaded,
603	  as a security feature that deters exploit attempts relying on
604	  knowledge of the location of kernel internals.
605
606config KERNEL_IMAGE_BASE
607	hex "Kernel image base address"
608	range 0x100000 0x1FFFFFE0000000 if !KASAN
609	range 0x100000 0x1BFFFFE0000000 if KASAN
610	default 0x3FFE0000000 if !KASAN
611	default 0x7FFFE0000000 if KASAN
612	help
613	  This is the address at which the kernel image is loaded in case
614	  Kernel Address Space Layout Randomization (KASLR) is disabled.
615
616	  In case the Protected virtualization guest support is enabled the
617	  Ultravisor imposes a virtual address limit. If the value of this
618	  option leads to the kernel image exceeding the Ultravisor limit,
619	  this option is ignored and the image is loaded below the limit.
620
621	  If the value of this option leads to the kernel image overlapping
622	  the virtual memory where other data structures are located, this
623	  option is ignored and the image is loaded above the structures.
624
625endmenu
626
627menu "Memory setup"
628
629config ARCH_SPARSEMEM_ENABLE
630	def_bool y
631	select SPARSEMEM_VMEMMAP_ENABLE
632	select SPARSEMEM_VMEMMAP
633
634config ARCH_SPARSEMEM_DEFAULT
635	def_bool y
636
637config MAX_PHYSMEM_BITS
638	int "Maximum size of supported physical memory in bits (42-53)"
639	range 42 53
640	default "46"
641	help
642	  This option specifies the maximum supported size of physical memory
643	  in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB).
644	  Increasing the number of bits also increases the kernel image size.
645	  By default 46 bits (64TB) are supported.
646
647config CHECK_STACK
648	def_bool y
649	depends on !VMAP_STACK
650	prompt "Detect kernel stack overflow"
651	help
652	  This option enables the compiler option -mstack-guard and
653	  -mstack-size if they are available. If the compiler supports them
654	  it will emit additional code to each function prolog to trigger
655	  an illegal operation if the kernel stack is about to overflow.
656
657	  Say N if you are unsure.
658
659config STACK_GUARD
660	int "Size of the guard area (128-1024)"
661	range 128 1024
662	depends on CHECK_STACK
663	default "256"
664	help
665	  This allows you to specify the size of the guard area at the lower
666	  end of the kernel stack. If the kernel stack points into the guard
667	  area on function entry an illegal operation is triggered. The size
668	  needs to be a power of 2. Please keep in mind that the size of an
669	  interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
670	  The minimum size for the stack guard should be 256 for 31 bit and
671	  512 for 64 bit.
672
673endmenu
674
675menu "I/O subsystem"
676
677config QDIO
678	def_tristate y
679	prompt "QDIO support"
680	help
681	  This driver provides the Queued Direct I/O base support for
682	  IBM System z.
683
684	  To compile this driver as a module, choose M here: the
685	  module will be called qdio.
686
687	  If unsure, say Y.
688
689if PCI
690
691config PCI_NR_FUNCTIONS
692	int "Maximum number of PCI functions (1-4096)"
693	range 1 4096
694	default "512"
695	help
696	  This allows you to specify the maximum number of PCI functions which
697	  this kernel will support.
698
699endif # PCI
700
701config HAS_IOMEM
702	def_bool PCI
703
704config CHSC_SCH
705	def_tristate m
706	prompt "Support for CHSC subchannels"
707	help
708	  This driver allows usage of CHSC subchannels. A CHSC subchannel
709	  is usually present on LPAR only.
710	  The driver creates a device /dev/chsc, which may be used to
711	  obtain I/O configuration information about the machine and
712	  to issue asynchronous chsc commands (DANGEROUS).
713	  You will usually only want to use this interface on a special
714	  LPAR designated for system management.
715
716	  To compile this driver as a module, choose M here: the
717	  module will be called chsc_sch.
718
719	  If unsure, say N.
720
721config SCM_BUS
722	def_bool y
723	prompt "SCM bus driver"
724	help
725	  Bus driver for Storage Class Memory.
726
727config EADM_SCH
728	def_tristate m
729	prompt "Support for EADM subchannels"
730	depends on SCM_BUS
731	help
732	  This driver allows usage of EADM subchannels. EADM subchannels act
733	  as a communication vehicle for SCM increments.
734
735	  To compile this driver as a module, choose M here: the
736	  module will be called eadm_sch.
737
738config AP
739	def_tristate y
740	prompt "Support for Adjunct Processors (ap)"
741	help
742	  This driver allows usage to Adjunct Processor (AP) devices via
743	  the ap bus, cards and queues. Supported Adjunct Processors are
744	  the CryptoExpress Cards (CEX).
745
746	  To compile this driver as a module, choose M here: the
747	  module will be called ap.
748
749	  If unsure, say Y (default).
750
751config AP_DEBUG
752	def_bool n
753	prompt "Enable debug features for Adjunct Processor (ap) devices"
754	depends on AP
755	help
756	  Say 'Y' here to enable some additional debug features for Adjunct
757	  Processor (ap) devices.
758
759	  There will be some more sysfs attributes displayed for ap queues.
760
761	  Do not enable on production level kernel build.
762
763	  If unsure, say N.
764
765config VFIO_CCW
766	def_tristate n
767	prompt "Support for VFIO-CCW subchannels"
768	depends on VFIO
769	select VFIO_MDEV
770	help
771	  This driver allows usage of I/O subchannels via VFIO-CCW.
772
773	  To compile this driver as a module, choose M here: the
774	  module will be called vfio_ccw.
775
776config VFIO_AP
777	def_tristate n
778	prompt "VFIO support for AP devices"
779	depends on KVM
780	depends on VFIO
781	depends on AP
782	select VFIO_MDEV
783	help
784	  This driver grants access to Adjunct Processor (AP) devices
785	  via the VFIO mediated device interface.
786
787	  To compile this driver as a module, choose M here: the module
788	  will be called vfio_ap.
789
790endmenu
791
792config CCW
793	def_bool y
794
795config HAVE_PNETID
796	tristate
797	default (SMC || CCWGROUP)
798
799menu "Virtualization"
800
801config PROTECTED_VIRTUALIZATION_GUEST
802	def_bool n
803	prompt "Protected virtualization guest support"
804	help
805	  Select this option, if you want to be able to run this
806	  kernel as a protected virtualization KVM guest.
807	  Protected virtualization capable machines have a mini hypervisor
808	  located at machine level (an ultravisor). With help of the
809	  Ultravisor, KVM will be able to run "protected" VMs, special
810	  VMs whose memory and management data are unavailable to KVM.
811
812config PFAULT
813	def_bool y
814	prompt "Pseudo page fault support"
815	help
816	  Select this option, if you want to use PFAULT pseudo page fault
817	  handling under VM. If running native or in LPAR, this option
818	  has no effect. If your VM does not support PFAULT, PAGEEX
819	  pseudo page fault handling will be used.
820	  Note that VM 4.2 supports PFAULT but has a bug in its
821	  implementation that causes some problems.
822	  Everybody who wants to run Linux under VM != VM4.2 should select
823	  this option.
824
825config CMM
826	def_tristate n
827	prompt "Cooperative memory management"
828	help
829	  Select this option, if you want to enable the kernel interface
830	  to reduce the memory size of the system. This is accomplished
831	  by allocating pages of memory and put them "on hold". This only
832	  makes sense for a system running under VM where the unused pages
833	  will be reused by VM for other guest systems. The interface
834	  allows an external monitor to balance memory of many systems.
835	  Everybody who wants to run Linux under VM should select this
836	  option.
837
838config CMM_IUCV
839	def_bool y
840	prompt "IUCV special message interface to cooperative memory management"
841	depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
842	help
843	  Select this option to enable the special message interface to
844	  the cooperative memory management.
845
846config APPLDATA_BASE
847	def_bool n
848	prompt "Linux - VM Monitor Stream, base infrastructure"
849	depends on PROC_SYSCTL
850	help
851	  This provides a kernel interface for creating and updating z/VM APPLDATA
852	  monitor records. The monitor records are updated at certain time
853	  intervals, once the timer is started.
854	  Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
855	  i.e. enables or disables monitoring on the Linux side.
856	  A custom interval value (in seconds) can be written to
857	  /proc/appldata/interval.
858
859	  Defaults are 60 seconds interval and timer off.
860	  The /proc entries can also be read from, showing the current settings.
861
862config APPLDATA_MEM
863	def_tristate m
864	prompt "Monitor memory management statistics"
865	depends on APPLDATA_BASE && VM_EVENT_COUNTERS
866	help
867	  This provides memory management related data to the Linux - VM Monitor
868	  Stream, like paging/swapping rate, memory utilisation, etc.
869	  Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
870	  APPLDATA monitor record, i.e. enables or disables monitoring this record
871	  on the z/VM side.
872
873	  Default is disabled.
874	  The /proc entry can also be read from, showing the current settings.
875
876	  This can also be compiled as a module, which will be called
877	  appldata_mem.o.
878
879config APPLDATA_OS
880	def_tristate m
881	prompt "Monitor OS statistics"
882	depends on APPLDATA_BASE
883	help
884	  This provides OS related data to the Linux - VM Monitor Stream, like
885	  CPU utilisation, etc.
886	  Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
887	  APPLDATA monitor record, i.e. enables or disables monitoring this record
888	  on the z/VM side.
889
890	  Default is disabled.
891	  This can also be compiled as a module, which will be called
892	  appldata_os.o.
893
894config APPLDATA_NET_SUM
895	def_tristate m
896	prompt "Monitor overall network statistics"
897	depends on APPLDATA_BASE && NET
898	help
899	  This provides network related data to the Linux - VM Monitor Stream,
900	  currently there is only a total sum of network I/O statistics, no
901	  per-interface data.
902	  Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
903	  APPLDATA monitor record, i.e. enables or disables monitoring this record
904	  on the z/VM side.
905
906	  Default is disabled.
907	  This can also be compiled as a module, which will be called
908	  appldata_net_sum.o.
909
910config S390_HYPFS
911	def_bool y
912	prompt "s390 hypervisor information"
913	help
914	  This provides several binary files at (debugfs)/s390_hypfs/ to
915	  provide accounting information in an s390 hypervisor environment.
916
917config S390_HYPFS_FS
918	def_bool n
919	prompt "s390 hypervisor file system support"
920	select SYS_HYPERVISOR
921	depends on S390_HYPFS
922	help
923	  This is a virtual file system intended to provide accounting
924	  information in an s390 hypervisor environment. This file system
925	  is deprecated and should not be used.
926
927	  Say N if you are unsure.
928
929source "arch/s390/kvm/Kconfig"
930
931config S390_GUEST
932	def_bool y
933	prompt "s390 support for virtio devices"
934	select TTY
935	select VIRTUALIZATION
936	select VIRTIO
937	help
938	  Enabling this option adds support for virtio based paravirtual device
939	  drivers on s390.
940
941	  Select this option if you want to run the kernel as a guest under
942	  the KVM hypervisor.
943
944endmenu
945
946config S390_MODULES_SANITY_TEST_HELPERS
947	def_bool n
948
949menu "Selftests"
950
951config S390_UNWIND_SELFTEST
952	def_tristate n
953	depends on KUNIT
954	default KUNIT_ALL_TESTS
955	prompt "Test unwind functions"
956	help
957	  This option enables s390 specific stack unwinder testing kernel
958	  module. This option is not useful for distributions or general
959	  kernels, but only for kernel developers working on architecture code.
960
961	  Say N if you are unsure.
962
963config S390_KPROBES_SANITY_TEST
964	def_tristate n
965	prompt "Enable s390 specific kprobes tests"
966	depends on KPROBES
967	depends on KUNIT
968	help
969	  This option enables an s390 specific kprobes test module. This option
970	  is not useful for distributions or general kernels, but only for kernel
971	  developers working on architecture code.
972
973	  Say N if you are unsure.
974
975config S390_MODULES_SANITY_TEST
976	def_tristate n
977	depends on KUNIT
978	default KUNIT_ALL_TESTS
979	prompt "Enable s390 specific modules tests"
980	select S390_MODULES_SANITY_TEST_HELPERS
981	help
982	  This option enables an s390 specific modules test. This option is
983	  not useful for distributions or general kernels, but only for
984	  kernel developers working on architecture code.
985
986	  Say N if you are unsure.
987endmenu
988