xref: /linux/arch/s390/Kconfig (revision 07f0148aafe8c95a3a76cd59e9e75b4d78d1d31d)
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 GENERIC_HWEIGHT
21	def_bool y
22
23config GENERIC_BUG
24	def_bool y if BUG
25
26config GENERIC_BUG_RELATIVE_POINTERS
27	def_bool y
28
29config GENERIC_CSUM
30	bool
31	default y if KASAN
32
33config GENERIC_LOCKBREAK
34	def_bool y if PREEMPTION
35
36config PGSTE
37	def_bool y if KVM
38
39config AUDIT_ARCH
40	def_bool y
41
42config NO_IOPORT_MAP
43	def_bool y
44
45config PCI_QUIRKS
46	def_bool n
47
48config ARCH_SUPPORTS_UPROBES
49	def_bool y
50
51config KASAN_SHADOW_OFFSET
52	hex
53	depends on KASAN
54	default 0x1C000000000000
55
56config S390
57	def_bool y
58	#
59	# Note: keep this list sorted alphabetically
60	#
61	imply IMA_SECURE_AND_OR_TRUSTED_BOOT
62	select ALTERNATE_USER_ADDRESS_SPACE
63	select ARCH_32BIT_USTAT_F_TINODE
64	select ARCH_BINFMT_ELF_STATE
65	select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
66	select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM
67	select ARCH_ENABLE_MEMORY_HOTREMOVE
68	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
69	select ARCH_HAS_CURRENT_STACK_POINTER
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_MEM_ENCRYPT
80	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
81	select ARCH_HAS_PTE_SPECIAL
82	select ARCH_HAS_SCALED_CPUTIME
83	select ARCH_HAS_SET_MEMORY
84	select ARCH_HAS_STRICT_KERNEL_RWX
85	select ARCH_HAS_STRICT_MODULE_RWX
86	select ARCH_HAS_SYSCALL_WRAPPER
87	select ARCH_HAS_UBSAN_SANITIZE_ALL
88	select ARCH_HAS_VDSO_DATA
89	select ARCH_HAVE_NMI_SAFE_CMPXCHG
90	select ARCH_INLINE_READ_LOCK
91	select ARCH_INLINE_READ_LOCK_BH
92	select ARCH_INLINE_READ_LOCK_IRQ
93	select ARCH_INLINE_READ_LOCK_IRQSAVE
94	select ARCH_INLINE_READ_TRYLOCK
95	select ARCH_INLINE_READ_UNLOCK
96	select ARCH_INLINE_READ_UNLOCK_BH
97	select ARCH_INLINE_READ_UNLOCK_IRQ
98	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
99	select ARCH_INLINE_SPIN_LOCK
100	select ARCH_INLINE_SPIN_LOCK_BH
101	select ARCH_INLINE_SPIN_LOCK_IRQ
102	select ARCH_INLINE_SPIN_LOCK_IRQSAVE
103	select ARCH_INLINE_SPIN_TRYLOCK
104	select ARCH_INLINE_SPIN_TRYLOCK_BH
105	select ARCH_INLINE_SPIN_UNLOCK
106	select ARCH_INLINE_SPIN_UNLOCK_BH
107	select ARCH_INLINE_SPIN_UNLOCK_IRQ
108	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
109	select ARCH_INLINE_WRITE_LOCK
110	select ARCH_INLINE_WRITE_LOCK_BH
111	select ARCH_INLINE_WRITE_LOCK_IRQ
112	select ARCH_INLINE_WRITE_LOCK_IRQSAVE
113	select ARCH_INLINE_WRITE_TRYLOCK
114	select ARCH_INLINE_WRITE_UNLOCK
115	select ARCH_INLINE_WRITE_UNLOCK_BH
116	select ARCH_INLINE_WRITE_UNLOCK_IRQ
117	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
118	select ARCH_STACKWALK
119	select ARCH_SUPPORTS_ATOMIC_RMW
120	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
121	select ARCH_SUPPORTS_HUGETLBFS
122	select ARCH_SUPPORTS_NUMA_BALANCING
123	select ARCH_USE_BUILTIN_BSWAP
124	select ARCH_USE_CMPXCHG_LOCKREF
125	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
126	select ARCH_WANTS_NO_INSTR
127	select ARCH_WANT_DEFAULT_BPF_JIT
128	select ARCH_WANT_IPC_PARSE_VERSION
129	select ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
130	select BUILDTIME_TABLE_SORT
131	select CLONE_BACKWARDS2
132	select DMA_OPS if PCI
133	select DYNAMIC_FTRACE if FUNCTION_TRACER
134	select GCC12_NO_ARRAY_BOUNDS
135	select GENERIC_ALLOCATOR
136	select GENERIC_CPU_AUTOPROBE
137	select GENERIC_CPU_VULNERABILITIES
138	select GENERIC_ENTRY
139	select GENERIC_GETTIMEOFDAY
140	select GENERIC_PTDUMP
141	select GENERIC_SMP_IDLE_THREAD
142	select GENERIC_TIME_VSYSCALL
143	select GENERIC_VDSO_TIME_NS
144	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
145	select HAVE_ARCH_AUDITSYSCALL
146	select HAVE_ARCH_JUMP_LABEL
147	select HAVE_ARCH_JUMP_LABEL_RELATIVE
148	select HAVE_ARCH_KASAN
149	select HAVE_ARCH_KASAN_VMALLOC
150	select HAVE_ARCH_KCSAN
151	select HAVE_ARCH_KFENCE
152	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
153	select HAVE_ARCH_SECCOMP_FILTER
154	select HAVE_ARCH_SOFT_DIRTY
155	select HAVE_ARCH_TRACEHOOK
156	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
157	select HAVE_ARCH_VMAP_STACK
158	select HAVE_ASM_MODVERSIONS
159	select HAVE_CMPXCHG_DOUBLE
160	select HAVE_CMPXCHG_LOCAL
161	select HAVE_DEBUG_KMEMLEAK
162	select HAVE_DMA_CONTIGUOUS
163	select HAVE_DYNAMIC_FTRACE
164	select HAVE_DYNAMIC_FTRACE_WITH_ARGS
165	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
166	select HAVE_DYNAMIC_FTRACE_WITH_REGS
167	select HAVE_EBPF_JIT if HAVE_MARCH_Z196_FEATURES
168	select HAVE_EFFICIENT_UNALIGNED_ACCESS
169	select HAVE_FAST_GUP
170	select HAVE_FENTRY
171	select HAVE_FTRACE_MCOUNT_RECORD
172	select HAVE_FUNCTION_ARG_ACCESS_API
173	select HAVE_FUNCTION_ERROR_INJECTION
174	select HAVE_FUNCTION_GRAPH_TRACER
175	select HAVE_FUNCTION_TRACER
176	select HAVE_GCC_PLUGINS
177	select HAVE_GENERIC_VDSO
178	select HAVE_IOREMAP_PROT if PCI
179	select HAVE_KERNEL_BZIP2
180	select HAVE_KERNEL_GZIP
181	select HAVE_KERNEL_LZ4
182	select HAVE_KERNEL_LZMA
183	select HAVE_KERNEL_LZO
184	select HAVE_KERNEL_UNCOMPRESSED
185	select HAVE_KERNEL_XZ
186	select HAVE_KERNEL_ZSTD
187	select HAVE_KPROBES
188	select HAVE_KPROBES_ON_FTRACE
189	select HAVE_KRETPROBES
190	select HAVE_KVM
191	select HAVE_LIVEPATCH
192	select HAVE_MEMBLOCK_PHYS_MAP
193	select HAVE_MOD_ARCH_SPECIFIC
194	select HAVE_NMI
195	select HAVE_NOP_MCOUNT
196	select HAVE_PCI
197	select HAVE_PERF_EVENTS
198	select HAVE_PERF_REGS
199	select HAVE_PERF_USER_STACK_DUMP
200	select HAVE_REGS_AND_STACK_ACCESS_API
201	select HAVE_RELIABLE_STACKTRACE
202	select HAVE_RSEQ
203	select HAVE_SAMPLE_FTRACE_DIRECT
204	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
205	select HAVE_SETUP_PER_CPU_AREA
206	select HAVE_SOFTIRQ_ON_OWN_STACK
207	select HAVE_SYSCALL_TRACEPOINTS
208	select HAVE_VIRT_CPU_ACCOUNTING
209	select HAVE_VIRT_CPU_ACCOUNTING_IDLE
210	select IOMMU_HELPER		if PCI
211	select IOMMU_SUPPORT		if PCI
212	select MMU_GATHER_NO_GATHER
213	select MMU_GATHER_RCU_TABLE_FREE
214	select MMU_GATHER_MERGE_VMAS
215	select MODULES_USE_ELF_RELA
216	select NEED_DMA_MAP_STATE	if PCI
217	select NEED_PER_CPU_EMBED_FIRST_CHUNK
218	select NEED_SG_DMA_LENGTH	if PCI
219	select OLD_SIGACTION
220	select OLD_SIGSUSPEND3
221	select PCI_DOMAINS		if PCI
222	select PCI_MSI			if PCI
223	select PCI_MSI_ARCH_FALLBACKS	if PCI_MSI
224	select SPARSE_IRQ
225	select SWIOTLB
226	select SYSCTL_EXCEPTION_TRACE
227	select THREAD_INFO_IN_TASK
228	select TRACE_IRQFLAGS_SUPPORT
229	select TTY
230	select VIRT_CPU_ACCOUNTING
231	select ZONE_DMA
232	# Note: keep the above list sorted alphabetically
233
234config SCHED_OMIT_FRAME_POINTER
235	def_bool y
236
237config PGTABLE_LEVELS
238	int
239	default 5
240
241source "kernel/livepatch/Kconfig"
242
243menu "Processor type and features"
244
245config HAVE_MARCH_Z10_FEATURES
246	def_bool n
247
248config HAVE_MARCH_Z196_FEATURES
249	def_bool n
250	select HAVE_MARCH_Z10_FEATURES
251
252config HAVE_MARCH_ZEC12_FEATURES
253	def_bool n
254	select HAVE_MARCH_Z196_FEATURES
255
256config HAVE_MARCH_Z13_FEATURES
257	def_bool n
258	select HAVE_MARCH_ZEC12_FEATURES
259
260config HAVE_MARCH_Z14_FEATURES
261	def_bool n
262	select HAVE_MARCH_Z13_FEATURES
263
264config HAVE_MARCH_Z15_FEATURES
265	def_bool n
266	select HAVE_MARCH_Z14_FEATURES
267
268config HAVE_MARCH_Z16_FEATURES
269	def_bool n
270	select HAVE_MARCH_Z15_FEATURES
271
272choice
273	prompt "Processor type"
274	default MARCH_Z196
275
276config MARCH_Z10
277	bool "IBM System z10"
278	select HAVE_MARCH_Z10_FEATURES
279	depends on $(cc-option,-march=z10)
280	help
281	  Select this to enable optimizations for IBM System z10 (2097 and 2098
282	  series). This is the oldest machine generation currently supported.
283
284config MARCH_Z196
285	bool "IBM zEnterprise 114 and 196"
286	select HAVE_MARCH_Z196_FEATURES
287	depends on $(cc-option,-march=z196)
288	help
289	  Select this to enable optimizations for IBM zEnterprise 114 and 196
290	  (2818 and 2817 series). The kernel will be slightly faster but will
291	  not work on older machines.
292
293config MARCH_ZEC12
294	bool "IBM zBC12 and zEC12"
295	select HAVE_MARCH_ZEC12_FEATURES
296	depends on $(cc-option,-march=zEC12)
297	help
298	  Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
299	  2827 series). The kernel will be slightly faster but will not work on
300	  older machines.
301
302config MARCH_Z13
303	bool "IBM z13s and z13"
304	select HAVE_MARCH_Z13_FEATURES
305	depends on $(cc-option,-march=z13)
306	help
307	  Select this to enable optimizations for IBM z13s and z13 (2965 and
308	  2964 series). The kernel will be slightly faster but will not work on
309	  older machines.
310
311config MARCH_Z14
312	bool "IBM z14 ZR1 and z14"
313	select HAVE_MARCH_Z14_FEATURES
314	depends on $(cc-option,-march=z14)
315	help
316	  Select this to enable optimizations for IBM z14 ZR1 and z14 (3907
317	  and 3906 series). The kernel will be slightly faster but will not
318	  work on older machines.
319
320config MARCH_Z15
321	bool "IBM z15"
322	select HAVE_MARCH_Z15_FEATURES
323	depends on $(cc-option,-march=z15)
324	help
325	  Select this to enable optimizations for IBM z15 (8562
326	  and 8561 series). The kernel will be slightly faster but will not
327	  work on older machines.
328
329config MARCH_Z16
330	bool "IBM z16"
331	select HAVE_MARCH_Z16_FEATURES
332	depends on $(cc-option,-march=z16)
333	help
334	  Select this to enable optimizations for IBM z16 (3931 and
335	  3932 series).
336
337endchoice
338
339config MARCH_Z10_TUNE
340	def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
341
342config MARCH_Z196_TUNE
343	def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
344
345config MARCH_ZEC12_TUNE
346	def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
347
348config MARCH_Z13_TUNE
349	def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT
350
351config MARCH_Z14_TUNE
352	def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT
353
354config MARCH_Z15_TUNE
355	def_bool TUNE_Z15 || MARCH_Z15 && TUNE_DEFAULT
356
357config MARCH_Z16_TUNE
358	def_bool TUNE_Z16 || MARCH_Z16 && TUNE_DEFAULT
359
360choice
361	prompt "Tune code generation"
362	default TUNE_DEFAULT
363	help
364	  Cause the compiler to tune (-mtune) the generated code for a machine.
365	  This will make the code run faster on the selected machine but
366	  somewhat slower on other machines.
367	  This option only changes how the compiler emits instructions, not the
368	  selection of instructions itself, so the resulting kernel will run on
369	  all other machines.
370
371config TUNE_DEFAULT
372	bool "Default"
373	help
374	  Tune the generated code for the target processor for which the kernel
375	  will be compiled.
376
377config TUNE_Z10
378	bool "IBM System z10"
379
380config TUNE_Z196
381	bool "IBM zEnterprise 114 and 196"
382	depends on $(cc-option,-mtune=z196)
383
384config TUNE_ZEC12
385	bool "IBM zBC12 and zEC12"
386	depends on $(cc-option,-mtune=zEC12)
387
388config TUNE_Z13
389	bool "IBM z13s and z13"
390	depends on $(cc-option,-mtune=z13)
391
392config TUNE_Z14
393	bool "IBM z14 ZR1 and z14"
394	depends on $(cc-option,-mtune=z14)
395
396config TUNE_Z15
397	bool "IBM z15"
398	depends on $(cc-option,-mtune=z15)
399
400config TUNE_Z16
401	bool "IBM z16"
402	depends on $(cc-option,-mtune=z16)
403
404endchoice
405
406config 64BIT
407	def_bool y
408
409config COMMAND_LINE_SIZE
410	int "Maximum size of kernel command line"
411	default 4096
412	range 896 1048576
413	help
414	  This allows you to specify the maximum length of the kernel command
415	  line.
416
417config COMPAT
418	def_bool y
419	prompt "Kernel support for 31 bit emulation"
420	select ARCH_WANT_OLD_COMPAT_IPC
421	select COMPAT_OLD_SIGACTION
422	select HAVE_UID16
423	depends on MULTIUSER
424	depends on !CC_IS_CLANG
425	help
426	  Select this option if you want to enable your system kernel to
427	  handle system-calls from ELF binaries for 31 bit ESA.  This option
428	  (and some other stuff like libraries and such) is needed for
429	  executing 31 bit applications.  It is safe to say "Y".
430
431config SMP
432	def_bool y
433
434config NR_CPUS
435	int "Maximum number of CPUs (2-512)"
436	range 2 512
437	default "64"
438	help
439	  This allows you to specify the maximum number of CPUs which this
440	  kernel will support. The maximum supported value is 512 and the
441	  minimum value which makes sense is 2.
442
443	  This is purely to save memory - each supported CPU adds
444	  approximately sixteen kilobytes to the kernel image.
445
446config HOTPLUG_CPU
447	def_bool y
448
449config NUMA
450	bool "NUMA support"
451	depends on SCHED_TOPOLOGY
452	default n
453	help
454	  Enable NUMA support
455
456	  This option adds NUMA support to the kernel.
457
458config NODES_SHIFT
459	int
460	depends on NUMA
461	default "1"
462
463config SCHED_SMT
464	def_bool n
465
466config SCHED_MC
467	def_bool n
468
469config SCHED_BOOK
470	def_bool n
471
472config SCHED_DRAWER
473	def_bool n
474
475config SCHED_TOPOLOGY
476	def_bool y
477	prompt "Topology scheduler support"
478	select SCHED_SMT
479	select SCHED_MC
480	select SCHED_BOOK
481	select SCHED_DRAWER
482	help
483	  Topology scheduler support improves the CPU scheduler's decision
484	  making when dealing with machines that have multi-threading,
485	  multiple cores or multiple books.
486
487source "kernel/Kconfig.hz"
488
489config KEXEC
490	def_bool y
491	select KEXEC_CORE
492
493config KEXEC_FILE
494	bool "kexec file based system call"
495	select KEXEC_CORE
496	depends on CRYPTO
497	depends on CRYPTO_SHA256
498	depends on CRYPTO_SHA256_S390
499	help
500	  Enable the kexec file based system call. In contrast to the normal
501	  kexec system call this system call takes file descriptors for the
502	  kernel and initramfs as arguments.
503
504config ARCH_HAS_KEXEC_PURGATORY
505	def_bool y
506	depends on KEXEC_FILE
507
508config KEXEC_SIG
509	bool "Verify kernel signature during kexec_file_load() syscall"
510	depends on KEXEC_FILE && MODULE_SIG_FORMAT
511	help
512	  This option makes kernel signature verification mandatory for
513	  the kexec_file_load() syscall.
514
515	  In addition to that option, you need to enable signature
516	  verification for the corresponding kernel image type being
517	  loaded in order for this to work.
518
519config KERNEL_NOBP
520	def_bool n
521	prompt "Enable modified branch prediction for the kernel by default"
522	help
523	  If this option is selected the kernel will switch to a modified
524	  branch prediction mode if the firmware interface is available.
525	  The modified branch prediction mode improves the behaviour in
526	  regard to speculative execution.
527
528	  With the option enabled the kernel parameter "nobp=0" or "nospec"
529	  can be used to run the kernel in the normal branch prediction mode.
530
531	  With the option disabled the modified branch prediction mode is
532	  enabled with the "nobp=1" kernel parameter.
533
534	  If unsure, say N.
535
536config EXPOLINE
537	def_bool n
538	depends on $(cc-option,-mindirect-branch=thunk)
539	prompt "Avoid speculative indirect branches in the kernel"
540	help
541	  Compile the kernel with the expoline compiler options to guard
542	  against kernel-to-user data leaks by avoiding speculative indirect
543	  branches.
544	  Requires a compiler with -mindirect-branch=thunk support for full
545	  protection. The kernel may run slower.
546
547	  If unsure, say N.
548
549config EXPOLINE_EXTERN
550	def_bool n
551	depends on EXPOLINE
552	depends on CC_IS_GCC && GCC_VERSION >= 110200
553	depends on $(success,$(srctree)/arch/s390/tools/gcc-thunk-extern.sh $(CC))
554	prompt "Generate expolines as extern functions."
555	help
556	  This option is required for some tooling like kpatch. The kernel is
557	  compiled with -mindirect-branch=thunk-extern and requires a newer
558	  compiler.
559
560	  If unsure, say N.
561
562choice
563	prompt "Expoline default"
564	depends on EXPOLINE
565	default EXPOLINE_FULL
566
567config EXPOLINE_OFF
568	bool "spectre_v2=off"
569
570config EXPOLINE_AUTO
571	bool "spectre_v2=auto"
572
573config EXPOLINE_FULL
574	bool "spectre_v2=on"
575
576endchoice
577
578config RELOCATABLE
579	def_bool y
580	help
581	  This builds a kernel image that retains relocation information
582	  so it can be loaded at an arbitrary address.
583	  The kernel is linked as a position-independent executable (PIE)
584	  and contains dynamic relocations which are processed early in the
585	  bootup process.
586	  The relocations make the kernel image about 15% larger (compressed
587	  10%), but are discarded at runtime.
588	  Note: this option exists only for documentation purposes, please do
589	  not remove it.
590
591config RANDOMIZE_BASE
592	bool "Randomize the address of the kernel image (KASLR)"
593	default y
594	help
595	  In support of Kernel Address Space Layout Randomization (KASLR),
596	  this randomizes the address at which the kernel image is loaded,
597	  as a security feature that deters exploit attempts relying on
598	  knowledge of the location of kernel internals.
599
600endmenu
601
602menu "Memory setup"
603
604config ARCH_SPARSEMEM_ENABLE
605	def_bool y
606	select SPARSEMEM_VMEMMAP_ENABLE
607	select SPARSEMEM_VMEMMAP
608
609config ARCH_SPARSEMEM_DEFAULT
610	def_bool y
611
612config MAX_PHYSMEM_BITS
613	int "Maximum size of supported physical memory in bits (42-53)"
614	range 42 53
615	default "46"
616	help
617	  This option specifies the maximum supported size of physical memory
618	  in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB).
619	  Increasing the number of bits also increases the kernel image size.
620	  By default 46 bits (64TB) are supported.
621
622config CHECK_STACK
623	def_bool y
624	depends on !VMAP_STACK
625	prompt "Detect kernel stack overflow"
626	help
627	  This option enables the compiler option -mstack-guard and
628	  -mstack-size if they are available. If the compiler supports them
629	  it will emit additional code to each function prolog to trigger
630	  an illegal operation if the kernel stack is about to overflow.
631
632	  Say N if you are unsure.
633
634config STACK_GUARD
635	int "Size of the guard area (128-1024)"
636	range 128 1024
637	depends on CHECK_STACK
638	default "256"
639	help
640	  This allows you to specify the size of the guard area at the lower
641	  end of the kernel stack. If the kernel stack points into the guard
642	  area on function entry an illegal operation is triggered. The size
643	  needs to be a power of 2. Please keep in mind that the size of an
644	  interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
645	  The minimum size for the stack guard should be 256 for 31 bit and
646	  512 for 64 bit.
647
648endmenu
649
650menu "I/O subsystem"
651
652config QDIO
653	def_tristate y
654	prompt "QDIO support"
655	help
656	  This driver provides the Queued Direct I/O base support for
657	  IBM System z.
658
659	  To compile this driver as a module, choose M here: the
660	  module will be called qdio.
661
662	  If unsure, say Y.
663
664if PCI
665
666config PCI_NR_FUNCTIONS
667	int "Maximum number of PCI functions (1-4096)"
668	range 1 4096
669	default "512"
670	help
671	  This allows you to specify the maximum number of PCI functions which
672	  this kernel will support.
673
674endif # PCI
675
676config HAS_IOMEM
677	def_bool PCI
678
679config CHSC_SCH
680	def_tristate m
681	prompt "Support for CHSC subchannels"
682	help
683	  This driver allows usage of CHSC subchannels. A CHSC subchannel
684	  is usually present on LPAR only.
685	  The driver creates a device /dev/chsc, which may be used to
686	  obtain I/O configuration information about the machine and
687	  to issue asynchronous chsc commands (DANGEROUS).
688	  You will usually only want to use this interface on a special
689	  LPAR designated for system management.
690
691	  To compile this driver as a module, choose M here: the
692	  module will be called chsc_sch.
693
694	  If unsure, say N.
695
696config SCM_BUS
697	def_bool y
698	prompt "SCM bus driver"
699	help
700	  Bus driver for Storage Class Memory.
701
702config EADM_SCH
703	def_tristate m
704	prompt "Support for EADM subchannels"
705	depends on SCM_BUS
706	help
707	  This driver allows usage of EADM subchannels. EADM subchannels act
708	  as a communication vehicle for SCM increments.
709
710	  To compile this driver as a module, choose M here: the
711	  module will be called eadm_sch.
712
713config VFIO_CCW
714	def_tristate n
715	prompt "Support for VFIO-CCW subchannels"
716	depends on S390_CCW_IOMMU && VFIO_MDEV
717	help
718	  This driver allows usage of I/O subchannels via VFIO-CCW.
719
720	  To compile this driver as a module, choose M here: the
721	  module will be called vfio_ccw.
722
723config VFIO_AP
724	def_tristate n
725	prompt "VFIO support for AP devices"
726	depends on S390_AP_IOMMU && VFIO_MDEV && KVM
727	depends on ZCRYPT
728	help
729	  This driver grants access to Adjunct Processor (AP) devices
730	  via the VFIO mediated device interface.
731
732	  To compile this driver as a module, choose M here: the module
733	  will be called vfio_ap.
734
735endmenu
736
737menu "Dump support"
738
739config CRASH_DUMP
740	bool "kernel crash dumps"
741	select KEXEC
742	help
743	  Generate crash dump after being started by kexec.
744	  Crash dump kernels are loaded in the main kernel with kexec-tools
745	  into a specially reserved region and then later executed after
746	  a crash by kdump/kexec.
747	  Refer to <file:Documentation/s390/zfcpdump.rst> for more details on this.
748	  This option also enables s390 zfcpdump.
749	  See also <file:Documentation/s390/zfcpdump.rst>
750
751endmenu
752
753config CCW
754	def_bool y
755
756config HAVE_PNETID
757	tristate
758	default (SMC || CCWGROUP)
759
760menu "Virtualization"
761
762config PROTECTED_VIRTUALIZATION_GUEST
763	def_bool n
764	prompt "Protected virtualization guest support"
765	help
766	  Select this option, if you want to be able to run this
767	  kernel as a protected virtualization KVM guest.
768	  Protected virtualization capable machines have a mini hypervisor
769	  located at machine level (an ultravisor). With help of the
770	  Ultravisor, KVM will be able to run "protected" VMs, special
771	  VMs whose memory and management data are unavailable to KVM.
772
773config PFAULT
774	def_bool y
775	prompt "Pseudo page fault support"
776	help
777	  Select this option, if you want to use PFAULT pseudo page fault
778	  handling under VM. If running native or in LPAR, this option
779	  has no effect. If your VM does not support PFAULT, PAGEEX
780	  pseudo page fault handling will be used.
781	  Note that VM 4.2 supports PFAULT but has a bug in its
782	  implementation that causes some problems.
783	  Everybody who wants to run Linux under VM != VM4.2 should select
784	  this option.
785
786config CMM
787	def_tristate n
788	prompt "Cooperative memory management"
789	help
790	  Select this option, if you want to enable the kernel interface
791	  to reduce the memory size of the system. This is accomplished
792	  by allocating pages of memory and put them "on hold". This only
793	  makes sense for a system running under VM where the unused pages
794	  will be reused by VM for other guest systems. The interface
795	  allows an external monitor to balance memory of many systems.
796	  Everybody who wants to run Linux under VM should select this
797	  option.
798
799config CMM_IUCV
800	def_bool y
801	prompt "IUCV special message interface to cooperative memory management"
802	depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
803	help
804	  Select this option to enable the special message interface to
805	  the cooperative memory management.
806
807config APPLDATA_BASE
808	def_bool n
809	prompt "Linux - VM Monitor Stream, base infrastructure"
810	depends on PROC_SYSCTL
811	help
812	  This provides a kernel interface for creating and updating z/VM APPLDATA
813	  monitor records. The monitor records are updated at certain time
814	  intervals, once the timer is started.
815	  Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
816	  i.e. enables or disables monitoring on the Linux side.
817	  A custom interval value (in seconds) can be written to
818	  /proc/appldata/interval.
819
820	  Defaults are 60 seconds interval and timer off.
821	  The /proc entries can also be read from, showing the current settings.
822
823config APPLDATA_MEM
824	def_tristate m
825	prompt "Monitor memory management statistics"
826	depends on APPLDATA_BASE && VM_EVENT_COUNTERS
827	help
828	  This provides memory management related data to the Linux - VM Monitor
829	  Stream, like paging/swapping rate, memory utilisation, etc.
830	  Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
831	  APPLDATA monitor record, i.e. enables or disables monitoring this record
832	  on the z/VM side.
833
834	  Default is disabled.
835	  The /proc entry can also be read from, showing the current settings.
836
837	  This can also be compiled as a module, which will be called
838	  appldata_mem.o.
839
840config APPLDATA_OS
841	def_tristate m
842	prompt "Monitor OS statistics"
843	depends on APPLDATA_BASE
844	help
845	  This provides OS related data to the Linux - VM Monitor Stream, like
846	  CPU utilisation, etc.
847	  Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
848	  APPLDATA monitor record, i.e. enables or disables monitoring this record
849	  on the z/VM side.
850
851	  Default is disabled.
852	  This can also be compiled as a module, which will be called
853	  appldata_os.o.
854
855config APPLDATA_NET_SUM
856	def_tristate m
857	prompt "Monitor overall network statistics"
858	depends on APPLDATA_BASE && NET
859	help
860	  This provides network related data to the Linux - VM Monitor Stream,
861	  currently there is only a total sum of network I/O statistics, no
862	  per-interface data.
863	  Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
864	  APPLDATA monitor record, i.e. enables or disables monitoring this record
865	  on the z/VM side.
866
867	  Default is disabled.
868	  This can also be compiled as a module, which will be called
869	  appldata_net_sum.o.
870
871config S390_HYPFS_FS
872	def_bool y
873	prompt "s390 hypervisor file system support"
874	select SYS_HYPERVISOR
875	help
876	  This is a virtual file system intended to provide accounting
877	  information in an s390 hypervisor environment.
878
879source "arch/s390/kvm/Kconfig"
880
881config S390_GUEST
882	def_bool y
883	prompt "s390 support for virtio devices"
884	select TTY
885	select VIRTUALIZATION
886	select VIRTIO
887	help
888	  Enabling this option adds support for virtio based paravirtual device
889	  drivers on s390.
890
891	  Select this option if you want to run the kernel as a guest under
892	  the KVM hypervisor.
893
894endmenu
895
896config S390_MODULES_SANITY_TEST_HELPERS
897	def_bool n
898
899menu "Selftests"
900
901config S390_UNWIND_SELFTEST
902	def_tristate n
903	depends on KUNIT
904	default KUNIT_ALL_TESTS
905	prompt "Test unwind functions"
906	help
907	  This option enables s390 specific stack unwinder testing kernel
908	  module. This option is not useful for distributions or general
909	  kernels, but only for kernel developers working on architecture code.
910
911	  Say N if you are unsure.
912
913config S390_KPROBES_SANITY_TEST
914	def_tristate n
915	prompt "Enable s390 specific kprobes tests"
916	depends on KPROBES
917	depends on KUNIT
918	help
919	  This option enables an s390 specific kprobes test module. This option
920	  is not useful for distributions or general kernels, but only for kernel
921	  developers working on architecture code.
922
923	  Say N if you are unsure.
924
925config S390_MODULES_SANITY_TEST
926	def_tristate n
927	depends on KUNIT
928	default KUNIT_ALL_TESTS
929	prompt "Enable s390 specific modules tests"
930	select S390_MODULES_SANITY_TEST_HELPERS
931	help
932	  This option enables an s390 specific modules test. This option is
933	  not useful for distributions or general kernels, but only for
934	  kernel developers working on architecture code.
935
936	  Say N if you are unsure.
937endmenu
938