xref: /openbmc/linux/arch/s390/Kconfig (revision da1d9caf)
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_LOCKBREAK
30	def_bool y if PREEMPTION
31
32config PGSTE
33	def_bool y if KVM
34
35config AUDIT_ARCH
36	def_bool y
37
38config NO_IOPORT_MAP
39	def_bool y
40
41config PCI_QUIRKS
42	def_bool n
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 S390
53	def_bool y
54	#
55	# Note: keep this list sorted alphabetically
56	#
57	imply IMA_SECURE_AND_OR_TRUSTED_BOOT
58	select ALTERNATE_USER_ADDRESS_SPACE
59	select ARCH_32BIT_USTAT_F_TINODE
60	select ARCH_BINFMT_ELF_STATE
61	select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
62	select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM
63	select ARCH_ENABLE_MEMORY_HOTREMOVE
64	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
65	select ARCH_HAS_CURRENT_STACK_POINTER
66	select ARCH_HAS_DEBUG_VM_PGTABLE
67	select ARCH_HAS_DEBUG_WX
68	select ARCH_HAS_DEVMEM_IS_ALLOWED
69	select ARCH_HAS_ELF_RANDOMIZE
70	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
71	select ARCH_HAS_FORTIFY_SOURCE
72	select ARCH_HAS_GCOV_PROFILE_ALL
73	select ARCH_HAS_GIGANTIC_PAGE
74	select ARCH_HAS_KCOV
75	select ARCH_HAS_MEM_ENCRYPT
76	select ARCH_HAS_PTE_SPECIAL
77	select ARCH_HAS_SCALED_CPUTIME
78	select ARCH_HAS_SET_MEMORY
79	select ARCH_HAS_STRICT_KERNEL_RWX
80	select ARCH_HAS_STRICT_MODULE_RWX
81	select ARCH_HAS_SYSCALL_WRAPPER
82	select ARCH_HAS_UBSAN_SANITIZE_ALL
83	select ARCH_HAS_VDSO_DATA
84	select ARCH_HAVE_NMI_SAFE_CMPXCHG
85	select ARCH_INLINE_READ_LOCK
86	select ARCH_INLINE_READ_LOCK_BH
87	select ARCH_INLINE_READ_LOCK_IRQ
88	select ARCH_INLINE_READ_LOCK_IRQSAVE
89	select ARCH_INLINE_READ_TRYLOCK
90	select ARCH_INLINE_READ_UNLOCK
91	select ARCH_INLINE_READ_UNLOCK_BH
92	select ARCH_INLINE_READ_UNLOCK_IRQ
93	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
94	select ARCH_INLINE_SPIN_LOCK
95	select ARCH_INLINE_SPIN_LOCK_BH
96	select ARCH_INLINE_SPIN_LOCK_IRQ
97	select ARCH_INLINE_SPIN_LOCK_IRQSAVE
98	select ARCH_INLINE_SPIN_TRYLOCK
99	select ARCH_INLINE_SPIN_TRYLOCK_BH
100	select ARCH_INLINE_SPIN_UNLOCK
101	select ARCH_INLINE_SPIN_UNLOCK_BH
102	select ARCH_INLINE_SPIN_UNLOCK_IRQ
103	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
104	select ARCH_INLINE_WRITE_LOCK
105	select ARCH_INLINE_WRITE_LOCK_BH
106	select ARCH_INLINE_WRITE_LOCK_IRQ
107	select ARCH_INLINE_WRITE_LOCK_IRQSAVE
108	select ARCH_INLINE_WRITE_TRYLOCK
109	select ARCH_INLINE_WRITE_UNLOCK
110	select ARCH_INLINE_WRITE_UNLOCK_BH
111	select ARCH_INLINE_WRITE_UNLOCK_IRQ
112	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
113	select ARCH_STACKWALK
114	select ARCH_SUPPORTS_ATOMIC_RMW
115	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
116	select ARCH_SUPPORTS_HUGETLBFS
117	select ARCH_SUPPORTS_NUMA_BALANCING
118	select ARCH_USE_BUILTIN_BSWAP
119	select ARCH_USE_CMPXCHG_LOCKREF
120	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
121	select ARCH_WANTS_NO_INSTR
122	select ARCH_WANT_DEFAULT_BPF_JIT
123	select ARCH_WANT_IPC_PARSE_VERSION
124	select BUILDTIME_TABLE_SORT
125	select CLONE_BACKWARDS2
126	select DMA_OPS if PCI
127	select DYNAMIC_FTRACE if FUNCTION_TRACER
128	select GCC12_NO_ARRAY_BOUNDS
129	select GENERIC_ALLOCATOR
130	select GENERIC_CPU_AUTOPROBE
131	select GENERIC_CPU_VULNERABILITIES
132	select GENERIC_ENTRY
133	select GENERIC_GETTIMEOFDAY
134	select GENERIC_PTDUMP
135	select GENERIC_SMP_IDLE_THREAD
136	select GENERIC_TIME_VSYSCALL
137	select GENERIC_VDSO_TIME_NS
138	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
139	select HAVE_ARCH_AUDITSYSCALL
140	select HAVE_ARCH_JUMP_LABEL
141	select HAVE_ARCH_JUMP_LABEL_RELATIVE
142	select HAVE_ARCH_KASAN
143	select HAVE_ARCH_KASAN_VMALLOC
144	select HAVE_ARCH_KCSAN
145	select HAVE_ARCH_KFENCE
146	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
147	select HAVE_ARCH_SECCOMP_FILTER
148	select HAVE_ARCH_SOFT_DIRTY
149	select HAVE_ARCH_TRACEHOOK
150	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
151	select HAVE_ARCH_VMAP_STACK
152	select HAVE_ASM_MODVERSIONS
153	select HAVE_CMPXCHG_DOUBLE
154	select HAVE_CMPXCHG_LOCAL
155	select HAVE_DEBUG_KMEMLEAK
156	select HAVE_DMA_CONTIGUOUS
157	select HAVE_DYNAMIC_FTRACE
158	select HAVE_DYNAMIC_FTRACE_WITH_ARGS
159	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
160	select HAVE_DYNAMIC_FTRACE_WITH_REGS
161	select HAVE_EBPF_JIT if HAVE_MARCH_Z196_FEATURES
162	select HAVE_EFFICIENT_UNALIGNED_ACCESS
163	select HAVE_FAST_GUP
164	select HAVE_FENTRY
165	select HAVE_FTRACE_MCOUNT_RECORD
166	select HAVE_FUNCTION_ARG_ACCESS_API
167	select HAVE_FUNCTION_ERROR_INJECTION
168	select HAVE_FUNCTION_GRAPH_TRACER
169	select HAVE_FUNCTION_TRACER
170	select HAVE_GCC_PLUGINS
171	select HAVE_GENERIC_VDSO
172	select HAVE_IOREMAP_PROT if PCI
173	select HAVE_KERNEL_BZIP2
174	select HAVE_KERNEL_GZIP
175	select HAVE_KERNEL_LZ4
176	select HAVE_KERNEL_LZMA
177	select HAVE_KERNEL_LZO
178	select HAVE_KERNEL_UNCOMPRESSED
179	select HAVE_KERNEL_XZ
180	select HAVE_KERNEL_ZSTD
181	select HAVE_KPROBES
182	select HAVE_KPROBES_ON_FTRACE
183	select HAVE_KRETPROBES
184	select HAVE_KVM
185	select HAVE_LIVEPATCH
186	select HAVE_MEMBLOCK_PHYS_MAP
187	select HAVE_MOD_ARCH_SPECIFIC
188	select HAVE_NMI
189	select HAVE_NOP_MCOUNT
190	select HAVE_PCI
191	select HAVE_PERF_EVENTS
192	select HAVE_PERF_REGS
193	select HAVE_PERF_USER_STACK_DUMP
194	select HAVE_REGS_AND_STACK_ACCESS_API
195	select HAVE_RELIABLE_STACKTRACE
196	select HAVE_RSEQ
197	select HAVE_SAMPLE_FTRACE_DIRECT
198	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
199	select HAVE_SOFTIRQ_ON_OWN_STACK
200	select HAVE_SYSCALL_TRACEPOINTS
201	select HAVE_VIRT_CPU_ACCOUNTING
202	select HAVE_VIRT_CPU_ACCOUNTING_IDLE
203	select IOMMU_HELPER		if PCI
204	select IOMMU_SUPPORT		if PCI
205	select MMU_GATHER_NO_GATHER
206	select MMU_GATHER_RCU_TABLE_FREE
207	select MODULES_USE_ELF_RELA
208	select NEED_DMA_MAP_STATE	if PCI
209	select NEED_SG_DMA_LENGTH	if PCI
210	select OLD_SIGACTION
211	select OLD_SIGSUSPEND3
212	select PCI_DOMAINS		if PCI
213	select PCI_MSI			if PCI
214	select PCI_MSI_ARCH_FALLBACKS	if PCI_MSI
215	select SPARSE_IRQ
216	select SWIOTLB
217	select SYSCTL_EXCEPTION_TRACE
218	select THREAD_INFO_IN_TASK
219	select TRACE_IRQFLAGS_SUPPORT
220	select TTY
221	select VIRT_CPU_ACCOUNTING
222	select ZONE_DMA
223	# Note: keep the above list sorted alphabetically
224
225config SCHED_OMIT_FRAME_POINTER
226	def_bool y
227
228config PGTABLE_LEVELS
229	int
230	default 5
231
232source "kernel/livepatch/Kconfig"
233
234menu "Processor type and features"
235
236config HAVE_MARCH_Z10_FEATURES
237	def_bool n
238
239config HAVE_MARCH_Z196_FEATURES
240	def_bool n
241	select HAVE_MARCH_Z10_FEATURES
242
243config HAVE_MARCH_ZEC12_FEATURES
244	def_bool n
245	select HAVE_MARCH_Z196_FEATURES
246
247config HAVE_MARCH_Z13_FEATURES
248	def_bool n
249	select HAVE_MARCH_ZEC12_FEATURES
250
251config HAVE_MARCH_Z14_FEATURES
252	def_bool n
253	select HAVE_MARCH_Z13_FEATURES
254
255config HAVE_MARCH_Z15_FEATURES
256	def_bool n
257	select HAVE_MARCH_Z14_FEATURES
258
259config HAVE_MARCH_Z16_FEATURES
260	def_bool n
261	select HAVE_MARCH_Z15_FEATURES
262
263choice
264	prompt "Processor type"
265	default MARCH_Z196
266
267config MARCH_Z10
268	bool "IBM System z10"
269	select HAVE_MARCH_Z10_FEATURES
270	depends on $(cc-option,-march=z10)
271	help
272	  Select this to enable optimizations for IBM System z10 (2097 and 2098
273	  series). This is the oldest machine generation currently supported.
274
275config MARCH_Z196
276	bool "IBM zEnterprise 114 and 196"
277	select HAVE_MARCH_Z196_FEATURES
278	depends on $(cc-option,-march=z196)
279	help
280	  Select this to enable optimizations for IBM zEnterprise 114 and 196
281	  (2818 and 2817 series). The kernel will be slightly faster but will
282	  not work on older machines.
283
284config MARCH_ZEC12
285	bool "IBM zBC12 and zEC12"
286	select HAVE_MARCH_ZEC12_FEATURES
287	depends on $(cc-option,-march=zEC12)
288	help
289	  Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
290	  2827 series). The kernel will be slightly faster but will not work on
291	  older machines.
292
293config MARCH_Z13
294	bool "IBM z13s and z13"
295	select HAVE_MARCH_Z13_FEATURES
296	depends on $(cc-option,-march=z13)
297	help
298	  Select this to enable optimizations for IBM z13s and z13 (2965 and
299	  2964 series). The kernel will be slightly faster but will not work on
300	  older machines.
301
302config MARCH_Z14
303	bool "IBM z14 ZR1 and z14"
304	select HAVE_MARCH_Z14_FEATURES
305	depends on $(cc-option,-march=z14)
306	help
307	  Select this to enable optimizations for IBM z14 ZR1 and z14 (3907
308	  and 3906 series). The kernel will be slightly faster but will not
309	  work on older machines.
310
311config MARCH_Z15
312	bool "IBM z15"
313	select HAVE_MARCH_Z15_FEATURES
314	depends on $(cc-option,-march=z15)
315	help
316	  Select this to enable optimizations for IBM z15 (8562
317	  and 8561 series). The kernel will be slightly faster but will not
318	  work on older machines.
319
320config MARCH_Z16
321	bool "IBM z16"
322	select HAVE_MARCH_Z16_FEATURES
323	depends on $(cc-option,-march=z16)
324	help
325	  Select this to enable optimizations for IBM z16 (3931 and
326	  3932 series).
327
328endchoice
329
330config MARCH_Z10_TUNE
331	def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
332
333config MARCH_Z196_TUNE
334	def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
335
336config MARCH_ZEC12_TUNE
337	def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
338
339config MARCH_Z13_TUNE
340	def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT
341
342config MARCH_Z14_TUNE
343	def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT
344
345config MARCH_Z15_TUNE
346	def_bool TUNE_Z15 || MARCH_Z15 && TUNE_DEFAULT
347
348config MARCH_Z16_TUNE
349	def_bool TUNE_Z16 || MARCH_Z16 && TUNE_DEFAULT
350
351choice
352	prompt "Tune code generation"
353	default TUNE_DEFAULT
354	help
355	  Cause the compiler to tune (-mtune) the generated code for a machine.
356	  This will make the code run faster on the selected machine but
357	  somewhat slower on other machines.
358	  This option only changes how the compiler emits instructions, not the
359	  selection of instructions itself, so the resulting kernel will run on
360	  all other machines.
361
362config TUNE_DEFAULT
363	bool "Default"
364	help
365	  Tune the generated code for the target processor for which the kernel
366	  will be compiled.
367
368config TUNE_Z10
369	bool "IBM System z10"
370
371config TUNE_Z196
372	bool "IBM zEnterprise 114 and 196"
373	depends on $(cc-option,-mtune=z196)
374
375config TUNE_ZEC12
376	bool "IBM zBC12 and zEC12"
377	depends on $(cc-option,-mtune=zEC12)
378
379config TUNE_Z13
380	bool "IBM z13s and z13"
381	depends on $(cc-option,-mtune=z13)
382
383config TUNE_Z14
384	bool "IBM z14 ZR1 and z14"
385	depends on $(cc-option,-mtune=z14)
386
387config TUNE_Z15
388	bool "IBM z15"
389	depends on $(cc-option,-mtune=z15)
390
391config TUNE_Z16
392	bool "IBM z16"
393	depends on $(cc-option,-mtune=z16)
394
395endchoice
396
397config 64BIT
398	def_bool y
399
400config COMMAND_LINE_SIZE
401	int "Maximum size of kernel command line"
402	default 4096
403	range 896 1048576
404	help
405	  This allows you to specify the maximum length of the kernel command
406	  line.
407
408config COMPAT
409	def_bool y
410	prompt "Kernel support for 31 bit emulation"
411	select ARCH_WANT_OLD_COMPAT_IPC
412	select COMPAT_OLD_SIGACTION
413	select HAVE_UID16
414	depends on MULTIUSER
415	depends on !CC_IS_CLANG
416	help
417	  Select this option if you want to enable your system kernel to
418	  handle system-calls from ELF binaries for 31 bit ESA.  This option
419	  (and some other stuff like libraries and such) is needed for
420	  executing 31 bit applications.  It is safe to say "Y".
421
422config SMP
423	def_bool y
424
425config NR_CPUS
426	int "Maximum number of CPUs (2-512)"
427	range 2 512
428	default "64"
429	help
430	  This allows you to specify the maximum number of CPUs which this
431	  kernel will support. The maximum supported value is 512 and the
432	  minimum value which makes sense is 2.
433
434	  This is purely to save memory - each supported CPU adds
435	  approximately sixteen kilobytes to the kernel image.
436
437config HOTPLUG_CPU
438	def_bool y
439
440config NUMA
441	bool "NUMA support"
442	depends on SCHED_TOPOLOGY
443	default n
444	help
445	  Enable NUMA support
446
447	  This option adds NUMA support to the kernel.
448
449config NODES_SHIFT
450	int
451	depends on NUMA
452	default "1"
453
454config SCHED_SMT
455	def_bool n
456
457config SCHED_MC
458	def_bool n
459
460config SCHED_BOOK
461	def_bool n
462
463config SCHED_DRAWER
464	def_bool n
465
466config SCHED_TOPOLOGY
467	def_bool y
468	prompt "Topology scheduler support"
469	select SCHED_SMT
470	select SCHED_MC
471	select SCHED_BOOK
472	select SCHED_DRAWER
473	help
474	  Topology scheduler support improves the CPU scheduler's decision
475	  making when dealing with machines that have multi-threading,
476	  multiple cores or multiple books.
477
478source "kernel/Kconfig.hz"
479
480config KEXEC
481	def_bool y
482	select KEXEC_CORE
483
484config KEXEC_FILE
485	bool "kexec file based system call"
486	select KEXEC_CORE
487	select BUILD_BIN2C
488	depends on CRYPTO
489	depends on CRYPTO_SHA256
490	depends on CRYPTO_SHA256_S390
491	help
492	  Enable the kexec file based system call. In contrast to the normal
493	  kexec system call this system call takes file descriptors for the
494	  kernel and initramfs as arguments.
495
496config ARCH_HAS_KEXEC_PURGATORY
497	def_bool y
498	depends on KEXEC_FILE
499
500config KEXEC_SIG
501	bool "Verify kernel signature during kexec_file_load() syscall"
502	depends on KEXEC_FILE && MODULE_SIG_FORMAT
503	help
504	  This option makes kernel signature verification mandatory for
505	  the kexec_file_load() syscall.
506
507	  In addition to that option, you need to enable signature
508	  verification for the corresponding kernel image type being
509	  loaded in order for this to work.
510
511config ARCH_RANDOM
512	def_bool y
513	prompt "s390 architectural random number generation API"
514	help
515	  Enable the s390 architectural random number generation API
516	  to provide random data for all consumers within the Linux
517	  kernel.
518
519	  When enabled the arch_random_* functions declared in linux/random.h
520	  are implemented. The implementation is based on the s390 CPACF
521	  instruction subfunction TRNG which provides a real true random
522	  number generator.
523
524	  If unsure, say Y.
525
526config KERNEL_NOBP
527	def_bool n
528	prompt "Enable modified branch prediction for the kernel by default"
529	help
530	  If this option is selected the kernel will switch to a modified
531	  branch prediction mode if the firmware interface is available.
532	  The modified branch prediction mode improves the behaviour in
533	  regard to speculative execution.
534
535	  With the option enabled the kernel parameter "nobp=0" or "nospec"
536	  can be used to run the kernel in the normal branch prediction mode.
537
538	  With the option disabled the modified branch prediction mode is
539	  enabled with the "nobp=1" kernel parameter.
540
541	  If unsure, say N.
542
543config EXPOLINE
544	def_bool n
545	depends on $(cc-option,-mindirect-branch=thunk)
546	prompt "Avoid speculative indirect branches in the kernel"
547	help
548	  Compile the kernel with the expoline compiler options to guard
549	  against kernel-to-user data leaks by avoiding speculative indirect
550	  branches.
551	  Requires a compiler with -mindirect-branch=thunk support for full
552	  protection. The kernel may run slower.
553
554	  If unsure, say N.
555
556config EXPOLINE_EXTERN
557	def_bool n
558	depends on EXPOLINE
559	depends on CC_IS_GCC && GCC_VERSION >= 110200
560	depends on $(success,$(srctree)/arch/s390/tools/gcc-thunk-extern.sh $(CC))
561	prompt "Generate expolines as extern functions."
562	help
563	  This option is required for some tooling like kpatch. The kernel is
564	  compiled with -mindirect-branch=thunk-extern and requires a newer
565	  compiler.
566
567	  If unsure, say N.
568
569choice
570	prompt "Expoline default"
571	depends on EXPOLINE
572	default EXPOLINE_FULL
573
574config EXPOLINE_OFF
575	bool "spectre_v2=off"
576
577config EXPOLINE_AUTO
578	bool "spectre_v2=auto"
579
580config EXPOLINE_FULL
581	bool "spectre_v2=on"
582
583endchoice
584
585config RELOCATABLE
586	bool "Build a relocatable kernel"
587	default 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 kernel is linked as a position-independent executable (PIE)
592	  and contains dynamic relocations which are processed early in the
593	  bootup process.
594	  The relocations make the kernel image about 15% larger (compressed
595	  10%), but are discarded at runtime.
596
597config RANDOMIZE_BASE
598	bool "Randomize the address of the kernel image (KASLR)"
599	depends on RELOCATABLE
600	default y
601	help
602	  In support of Kernel Address Space Layout Randomization (KASLR),
603	  this randomizes the address at which the kernel image is loaded,
604	  as a security feature that deters exploit attempts relying on
605	  knowledge of the location of kernel internals.
606
607endmenu
608
609menu "Memory setup"
610
611config ARCH_SPARSEMEM_ENABLE
612	def_bool y
613	select SPARSEMEM_VMEMMAP_ENABLE
614	select SPARSEMEM_VMEMMAP
615
616config ARCH_SPARSEMEM_DEFAULT
617	def_bool y
618
619config MAX_PHYSMEM_BITS
620	int "Maximum size of supported physical memory in bits (42-53)"
621	range 42 53
622	default "46"
623	help
624	  This option specifies the maximum supported size of physical memory
625	  in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB).
626	  Increasing the number of bits also increases the kernel image size.
627	  By default 46 bits (64TB) are supported.
628
629config CHECK_STACK
630	def_bool y
631	depends on !VMAP_STACK
632	prompt "Detect kernel stack overflow"
633	help
634	  This option enables the compiler option -mstack-guard and
635	  -mstack-size if they are available. If the compiler supports them
636	  it will emit additional code to each function prolog to trigger
637	  an illegal operation if the kernel stack is about to overflow.
638
639	  Say N if you are unsure.
640
641config STACK_GUARD
642	int "Size of the guard area (128-1024)"
643	range 128 1024
644	depends on CHECK_STACK
645	default "256"
646	help
647	  This allows you to specify the size of the guard area at the lower
648	  end of the kernel stack. If the kernel stack points into the guard
649	  area on function entry an illegal operation is triggered. The size
650	  needs to be a power of 2. Please keep in mind that the size of an
651	  interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
652	  The minimum size for the stack guard should be 256 for 31 bit and
653	  512 for 64 bit.
654
655endmenu
656
657menu "I/O subsystem"
658
659config QDIO
660	def_tristate y
661	prompt "QDIO support"
662	help
663	  This driver provides the Queued Direct I/O base support for
664	  IBM System z.
665
666	  To compile this driver as a module, choose M here: the
667	  module will be called qdio.
668
669	  If unsure, say Y.
670
671if PCI
672
673config PCI_NR_FUNCTIONS
674	int "Maximum number of PCI functions (1-4096)"
675	range 1 4096
676	default "512"
677	help
678	  This allows you to specify the maximum number of PCI functions which
679	  this kernel will support.
680
681endif # PCI
682
683config HAS_IOMEM
684	def_bool PCI
685
686config CHSC_SCH
687	def_tristate m
688	prompt "Support for CHSC subchannels"
689	help
690	  This driver allows usage of CHSC subchannels. A CHSC subchannel
691	  is usually present on LPAR only.
692	  The driver creates a device /dev/chsc, which may be used to
693	  obtain I/O configuration information about the machine and
694	  to issue asynchronous chsc commands (DANGEROUS).
695	  You will usually only want to use this interface on a special
696	  LPAR designated for system management.
697
698	  To compile this driver as a module, choose M here: the
699	  module will be called chsc_sch.
700
701	  If unsure, say N.
702
703config SCM_BUS
704	def_bool y
705	prompt "SCM bus driver"
706	help
707	  Bus driver for Storage Class Memory.
708
709config EADM_SCH
710	def_tristate m
711	prompt "Support for EADM subchannels"
712	depends on SCM_BUS
713	help
714	  This driver allows usage of EADM subchannels. EADM subchannels act
715	  as a communication vehicle for SCM increments.
716
717	  To compile this driver as a module, choose M here: the
718	  module will be called eadm_sch.
719
720config VFIO_CCW
721	def_tristate n
722	prompt "Support for VFIO-CCW subchannels"
723	depends on S390_CCW_IOMMU && VFIO_MDEV
724	help
725	  This driver allows usage of I/O subchannels via VFIO-CCW.
726
727	  To compile this driver as a module, choose M here: the
728	  module will be called vfio_ccw.
729
730config VFIO_AP
731	def_tristate n
732	prompt "VFIO support for AP devices"
733	depends on S390_AP_IOMMU && VFIO_MDEV && KVM
734	depends on ZCRYPT
735	help
736	  This driver grants access to Adjunct Processor (AP) devices
737	  via the VFIO mediated device interface.
738
739	  To compile this driver as a module, choose M here: the module
740	  will be called vfio_ap.
741
742endmenu
743
744menu "Dump support"
745
746config CRASH_DUMP
747	bool "kernel crash dumps"
748	select KEXEC
749	help
750	  Generate crash dump after being started by kexec.
751	  Crash dump kernels are loaded in the main kernel with kexec-tools
752	  into a specially reserved region and then later executed after
753	  a crash by kdump/kexec.
754	  Refer to <file:Documentation/s390/zfcpdump.rst> for more details on this.
755	  This option also enables s390 zfcpdump.
756	  See also <file:Documentation/s390/zfcpdump.rst>
757
758endmenu
759
760config CCW
761	def_bool y
762
763config HAVE_PNETID
764	tristate
765	default (SMC || CCWGROUP)
766
767menu "Virtualization"
768
769config PROTECTED_VIRTUALIZATION_GUEST
770	def_bool n
771	prompt "Protected virtualization guest support"
772	help
773	  Select this option, if you want to be able to run this
774	  kernel as a protected virtualization KVM guest.
775	  Protected virtualization capable machines have a mini hypervisor
776	  located at machine level (an ultravisor). With help of the
777	  Ultravisor, KVM will be able to run "protected" VMs, special
778	  VMs whose memory and management data are unavailable to KVM.
779
780config PFAULT
781	def_bool y
782	prompt "Pseudo page fault support"
783	help
784	  Select this option, if you want to use PFAULT pseudo page fault
785	  handling under VM. If running native or in LPAR, this option
786	  has no effect. If your VM does not support PFAULT, PAGEEX
787	  pseudo page fault handling will be used.
788	  Note that VM 4.2 supports PFAULT but has a bug in its
789	  implementation that causes some problems.
790	  Everybody who wants to run Linux under VM != VM4.2 should select
791	  this option.
792
793config CMM
794	def_tristate n
795	prompt "Cooperative memory management"
796	help
797	  Select this option, if you want to enable the kernel interface
798	  to reduce the memory size of the system. This is accomplished
799	  by allocating pages of memory and put them "on hold". This only
800	  makes sense for a system running under VM where the unused pages
801	  will be reused by VM for other guest systems. The interface
802	  allows an external monitor to balance memory of many systems.
803	  Everybody who wants to run Linux under VM should select this
804	  option.
805
806config CMM_IUCV
807	def_bool y
808	prompt "IUCV special message interface to cooperative memory management"
809	depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
810	help
811	  Select this option to enable the special message interface to
812	  the cooperative memory management.
813
814config APPLDATA_BASE
815	def_bool n
816	prompt "Linux - VM Monitor Stream, base infrastructure"
817	depends on PROC_SYSCTL
818	help
819	  This provides a kernel interface for creating and updating z/VM APPLDATA
820	  monitor records. The monitor records are updated at certain time
821	  intervals, once the timer is started.
822	  Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
823	  i.e. enables or disables monitoring on the Linux side.
824	  A custom interval value (in seconds) can be written to
825	  /proc/appldata/interval.
826
827	  Defaults are 60 seconds interval and timer off.
828	  The /proc entries can also be read from, showing the current settings.
829
830config APPLDATA_MEM
831	def_tristate m
832	prompt "Monitor memory management statistics"
833	depends on APPLDATA_BASE && VM_EVENT_COUNTERS
834	help
835	  This provides memory management related data to the Linux - VM Monitor
836	  Stream, like paging/swapping rate, memory utilisation, etc.
837	  Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
838	  APPLDATA monitor record, i.e. enables or disables monitoring this record
839	  on the z/VM side.
840
841	  Default is disabled.
842	  The /proc entry can also be read from, showing the current settings.
843
844	  This can also be compiled as a module, which will be called
845	  appldata_mem.o.
846
847config APPLDATA_OS
848	def_tristate m
849	prompt "Monitor OS statistics"
850	depends on APPLDATA_BASE
851	help
852	  This provides OS related data to the Linux - VM Monitor Stream, like
853	  CPU utilisation, etc.
854	  Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
855	  APPLDATA monitor record, i.e. enables or disables monitoring this record
856	  on the z/VM side.
857
858	  Default is disabled.
859	  This can also be compiled as a module, which will be called
860	  appldata_os.o.
861
862config APPLDATA_NET_SUM
863	def_tristate m
864	prompt "Monitor overall network statistics"
865	depends on APPLDATA_BASE && NET
866	help
867	  This provides network related data to the Linux - VM Monitor Stream,
868	  currently there is only a total sum of network I/O statistics, no
869	  per-interface data.
870	  Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
871	  APPLDATA monitor record, i.e. enables or disables monitoring this record
872	  on the z/VM side.
873
874	  Default is disabled.
875	  This can also be compiled as a module, which will be called
876	  appldata_net_sum.o.
877
878config S390_HYPFS_FS
879	def_bool y
880	prompt "s390 hypervisor file system support"
881	select SYS_HYPERVISOR
882	help
883	  This is a virtual file system intended to provide accounting
884	  information in an s390 hypervisor environment.
885
886source "arch/s390/kvm/Kconfig"
887
888config S390_GUEST
889	def_bool y
890	prompt "s390 support for virtio devices"
891	select TTY
892	select VIRTUALIZATION
893	select VIRTIO
894	help
895	  Enabling this option adds support for virtio based paravirtual device
896	  drivers on s390.
897
898	  Select this option if you want to run the kernel as a guest under
899	  the KVM hypervisor.
900
901endmenu
902
903config S390_MODULES_SANITY_TEST_HELPERS
904	def_bool n
905
906menu "Selftests"
907
908config S390_UNWIND_SELFTEST
909	def_tristate n
910	depends on KUNIT
911	default KUNIT_ALL_TESTS
912	prompt "Test unwind functions"
913	help
914	  This option enables s390 specific stack unwinder testing kernel
915	  module. This option is not useful for distributions or general
916	  kernels, but only for kernel developers working on architecture code.
917
918	  Say N if you are unsure.
919
920config S390_KPROBES_SANITY_TEST
921	def_tristate n
922	prompt "Enable s390 specific kprobes tests"
923	depends on KPROBES
924	depends on KUNIT
925	help
926	  This option enables an s390 specific kprobes test module. This option
927	  is not useful for distributions or general kernels, but only for kernel
928	  developers working on architecture code.
929
930	  Say N if you are unsure.
931
932config S390_MODULES_SANITY_TEST
933	def_tristate n
934	depends on KUNIT
935	default KUNIT_ALL_TESTS
936	prompt "Enable s390 specific modules tests"
937	select S390_MODULES_SANITY_TEST_HELPERS
938	help
939	  This option enables an s390 specific modules test. This option is
940	  not useful for distributions or general kernels, but only for
941	  kernel developers working on architecture code.
942
943	  Say N if you are unsure.
944endmenu
945