xref: /openbmc/linux/arch/s390/Kconfig (revision 55b24334)
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_MEMBARRIER_SYNC_CORE
76	select ARCH_HAS_MEM_ENCRYPT
77	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
78	select ARCH_HAS_PTE_SPECIAL
79	select ARCH_HAS_SCALED_CPUTIME
80	select ARCH_HAS_SET_DIRECT_MAP
81	select ARCH_HAS_SET_MEMORY
82	select ARCH_HAS_STRICT_KERNEL_RWX
83	select ARCH_HAS_STRICT_MODULE_RWX
84	select ARCH_HAS_SYSCALL_WRAPPER
85	select ARCH_HAS_UBSAN_SANITIZE_ALL
86	select ARCH_HAS_VDSO_DATA
87	select ARCH_HAVE_NMI_SAFE_CMPXCHG
88	select ARCH_INLINE_READ_LOCK
89	select ARCH_INLINE_READ_LOCK_BH
90	select ARCH_INLINE_READ_LOCK_IRQ
91	select ARCH_INLINE_READ_LOCK_IRQSAVE
92	select ARCH_INLINE_READ_TRYLOCK
93	select ARCH_INLINE_READ_UNLOCK
94	select ARCH_INLINE_READ_UNLOCK_BH
95	select ARCH_INLINE_READ_UNLOCK_IRQ
96	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
97	select ARCH_INLINE_SPIN_LOCK
98	select ARCH_INLINE_SPIN_LOCK_BH
99	select ARCH_INLINE_SPIN_LOCK_IRQ
100	select ARCH_INLINE_SPIN_LOCK_IRQSAVE
101	select ARCH_INLINE_SPIN_TRYLOCK
102	select ARCH_INLINE_SPIN_TRYLOCK_BH
103	select ARCH_INLINE_SPIN_UNLOCK
104	select ARCH_INLINE_SPIN_UNLOCK_BH
105	select ARCH_INLINE_SPIN_UNLOCK_IRQ
106	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
107	select ARCH_INLINE_WRITE_LOCK
108	select ARCH_INLINE_WRITE_LOCK_BH
109	select ARCH_INLINE_WRITE_LOCK_IRQ
110	select ARCH_INLINE_WRITE_LOCK_IRQSAVE
111	select ARCH_INLINE_WRITE_TRYLOCK
112	select ARCH_INLINE_WRITE_UNLOCK
113	select ARCH_INLINE_WRITE_UNLOCK_BH
114	select ARCH_INLINE_WRITE_UNLOCK_IRQ
115	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
116	select ARCH_STACKWALK
117	select ARCH_SUPPORTS_ATOMIC_RMW
118	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
119	select ARCH_SUPPORTS_HUGETLBFS
120	select ARCH_SUPPORTS_NUMA_BALANCING
121	select ARCH_SUPPORTS_PER_VMA_LOCK
122	select ARCH_USE_BUILTIN_BSWAP
123	select ARCH_USE_CMPXCHG_LOCKREF
124	select ARCH_USE_SYM_ANNOTATIONS
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_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 FUNCTION_ALIGNMENT_8B if CC_IS_GCC
135	select FUNCTION_ALIGNMENT_16B if !CC_IS_GCC
136	select GENERIC_ALLOCATOR
137	select GENERIC_CPU_AUTOPROBE
138	select GENERIC_CPU_VULNERABILITIES
139	select GENERIC_ENTRY
140	select GENERIC_GETTIMEOFDAY
141	select GENERIC_PTDUMP
142	select GENERIC_SMP_IDLE_THREAD
143	select GENERIC_TIME_VSYSCALL
144	select GENERIC_VDSO_TIME_NS
145	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
146	select HAVE_ARCH_AUDITSYSCALL
147	select HAVE_ARCH_JUMP_LABEL
148	select HAVE_ARCH_JUMP_LABEL_RELATIVE
149	select HAVE_ARCH_KASAN
150	select HAVE_ARCH_KASAN_VMALLOC
151	select HAVE_ARCH_KCSAN
152	select HAVE_ARCH_KFENCE
153	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
154	select HAVE_ARCH_SECCOMP_FILTER
155	select HAVE_ARCH_SOFT_DIRTY
156	select HAVE_ARCH_STACKLEAK
157	select HAVE_ARCH_TRACEHOOK
158	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
159	select HAVE_ARCH_VMAP_STACK
160	select HAVE_ASM_MODVERSIONS
161	select HAVE_CMPXCHG_DOUBLE
162	select HAVE_CMPXCHG_LOCAL
163	select HAVE_DEBUG_KMEMLEAK
164	select HAVE_DMA_CONTIGUOUS
165	select HAVE_DYNAMIC_FTRACE
166	select HAVE_DYNAMIC_FTRACE_WITH_ARGS
167	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
168	select HAVE_DYNAMIC_FTRACE_WITH_REGS
169	select HAVE_EBPF_JIT if HAVE_MARCH_Z196_FEATURES
170	select HAVE_EFFICIENT_UNALIGNED_ACCESS
171	select HAVE_FAST_GUP
172	select HAVE_FENTRY
173	select HAVE_FTRACE_MCOUNT_RECORD
174	select HAVE_FUNCTION_ARG_ACCESS_API
175	select HAVE_FUNCTION_ERROR_INJECTION
176	select HAVE_FUNCTION_GRAPH_TRACER
177	select HAVE_FUNCTION_TRACER
178	select HAVE_GCC_PLUGINS
179	select HAVE_GENERIC_VDSO
180	select HAVE_IOREMAP_PROT if PCI
181	select HAVE_KERNEL_BZIP2
182	select HAVE_KERNEL_GZIP
183	select HAVE_KERNEL_LZ4
184	select HAVE_KERNEL_LZMA
185	select HAVE_KERNEL_LZO
186	select HAVE_KERNEL_UNCOMPRESSED
187	select HAVE_KERNEL_XZ
188	select HAVE_KERNEL_ZSTD
189	select HAVE_KPROBES
190	select HAVE_KPROBES_ON_FTRACE
191	select HAVE_KRETPROBES
192	select HAVE_KVM
193	select HAVE_LIVEPATCH
194	select HAVE_MEMBLOCK_PHYS_MAP
195	select HAVE_MOD_ARCH_SPECIFIC
196	select HAVE_NMI
197	select HAVE_NOP_MCOUNT
198	select HAVE_PCI
199	select HAVE_PERF_EVENTS
200	select HAVE_PERF_REGS
201	select HAVE_PERF_USER_STACK_DUMP
202	select HAVE_REGS_AND_STACK_ACCESS_API
203	select HAVE_RELIABLE_STACKTRACE
204	select HAVE_RETHOOK
205	select HAVE_RSEQ
206	select HAVE_SAMPLE_FTRACE_DIRECT
207	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
208	select HAVE_SETUP_PER_CPU_AREA
209	select HAVE_SOFTIRQ_ON_OWN_STACK
210	select HAVE_SYSCALL_TRACEPOINTS
211	select HAVE_VIRT_CPU_ACCOUNTING
212	select HAVE_VIRT_CPU_ACCOUNTING_IDLE
213	select IOMMU_HELPER		if PCI
214	select IOMMU_SUPPORT		if PCI
215	select MMU_GATHER_MERGE_VMAS
216	select MMU_GATHER_NO_GATHER
217	select MMU_GATHER_RCU_TABLE_FREE
218	select MODULES_USE_ELF_RELA
219	select NEED_DMA_MAP_STATE	if PCI
220	select NEED_PER_CPU_EMBED_FIRST_CHUNK
221	select NEED_SG_DMA_LENGTH	if PCI
222	select OLD_SIGACTION
223	select OLD_SIGSUSPEND3
224	select PCI_DOMAINS		if PCI
225	select PCI_MSI			if PCI
226	select PCI_MSI_ARCH_FALLBACKS	if PCI_MSI
227	select SPARSE_IRQ
228	select SWIOTLB
229	select SYSCTL_EXCEPTION_TRACE
230	select THREAD_INFO_IN_TASK
231	select TRACE_IRQFLAGS_SUPPORT
232	select TTY
233	select VIRT_CPU_ACCOUNTING
234	select ZONE_DMA
235	# Note: keep the above list sorted alphabetically
236
237config SCHED_OMIT_FRAME_POINTER
238	def_bool y
239
240config PGTABLE_LEVELS
241	int
242	default 5
243
244source "kernel/livepatch/Kconfig"
245
246menu "Processor type and features"
247
248config HAVE_MARCH_Z10_FEATURES
249	def_bool n
250
251config HAVE_MARCH_Z196_FEATURES
252	def_bool n
253	select HAVE_MARCH_Z10_FEATURES
254
255config HAVE_MARCH_ZEC12_FEATURES
256	def_bool n
257	select HAVE_MARCH_Z196_FEATURES
258
259config HAVE_MARCH_Z13_FEATURES
260	def_bool n
261	select HAVE_MARCH_ZEC12_FEATURES
262
263config HAVE_MARCH_Z14_FEATURES
264	def_bool n
265	select HAVE_MARCH_Z13_FEATURES
266
267config HAVE_MARCH_Z15_FEATURES
268	def_bool n
269	select HAVE_MARCH_Z14_FEATURES
270
271config HAVE_MARCH_Z16_FEATURES
272	def_bool n
273	select HAVE_MARCH_Z15_FEATURES
274
275choice
276	prompt "Processor type"
277	default MARCH_Z196
278
279config MARCH_Z10
280	bool "IBM System z10"
281	select HAVE_MARCH_Z10_FEATURES
282	depends on $(cc-option,-march=z10)
283	help
284	  Select this to enable optimizations for IBM System z10 (2097 and 2098
285	  series). This is the oldest machine generation currently supported.
286
287config MARCH_Z196
288	bool "IBM zEnterprise 114 and 196"
289	select HAVE_MARCH_Z196_FEATURES
290	depends on $(cc-option,-march=z196)
291	help
292	  Select this to enable optimizations for IBM zEnterprise 114 and 196
293	  (2818 and 2817 series). The kernel will be slightly faster but will
294	  not work on older machines.
295
296config MARCH_ZEC12
297	bool "IBM zBC12 and zEC12"
298	select HAVE_MARCH_ZEC12_FEATURES
299	depends on $(cc-option,-march=zEC12)
300	help
301	  Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
302	  2827 series). The kernel will be slightly faster but will not work on
303	  older machines.
304
305config MARCH_Z13
306	bool "IBM z13s and z13"
307	select HAVE_MARCH_Z13_FEATURES
308	depends on $(cc-option,-march=z13)
309	help
310	  Select this to enable optimizations for IBM z13s and z13 (2965 and
311	  2964 series). The kernel will be slightly faster but will not work on
312	  older machines.
313
314config MARCH_Z14
315	bool "IBM z14 ZR1 and z14"
316	select HAVE_MARCH_Z14_FEATURES
317	depends on $(cc-option,-march=z14)
318	help
319	  Select this to enable optimizations for IBM z14 ZR1 and z14 (3907
320	  and 3906 series). The kernel will be slightly faster but will not
321	  work on older machines.
322
323config MARCH_Z15
324	bool "IBM z15"
325	select HAVE_MARCH_Z15_FEATURES
326	depends on $(cc-option,-march=z15)
327	help
328	  Select this to enable optimizations for IBM z15 (8562
329	  and 8561 series). The kernel will be slightly faster but will not
330	  work on older machines.
331
332config MARCH_Z16
333	bool "IBM z16"
334	select HAVE_MARCH_Z16_FEATURES
335	depends on $(cc-option,-march=z16)
336	help
337	  Select this to enable optimizations for IBM z16 (3931 and
338	  3932 series).
339
340endchoice
341
342config MARCH_Z10_TUNE
343	def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
344
345config MARCH_Z196_TUNE
346	def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
347
348config MARCH_ZEC12_TUNE
349	def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
350
351config MARCH_Z13_TUNE
352	def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT
353
354config MARCH_Z14_TUNE
355	def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT
356
357config MARCH_Z15_TUNE
358	def_bool TUNE_Z15 || MARCH_Z15 && TUNE_DEFAULT
359
360config MARCH_Z16_TUNE
361	def_bool TUNE_Z16 || MARCH_Z16 && TUNE_DEFAULT
362
363choice
364	prompt "Tune code generation"
365	default TUNE_DEFAULT
366	help
367	  Cause the compiler to tune (-mtune) the generated code for a machine.
368	  This will make the code run faster on the selected machine but
369	  somewhat slower on other machines.
370	  This option only changes how the compiler emits instructions, not the
371	  selection of instructions itself, so the resulting kernel will run on
372	  all other machines.
373
374config TUNE_DEFAULT
375	bool "Default"
376	help
377	  Tune the generated code for the target processor for which the kernel
378	  will be compiled.
379
380config TUNE_Z10
381	bool "IBM System z10"
382
383config TUNE_Z196
384	bool "IBM zEnterprise 114 and 196"
385	depends on $(cc-option,-mtune=z196)
386
387config TUNE_ZEC12
388	bool "IBM zBC12 and zEC12"
389	depends on $(cc-option,-mtune=zEC12)
390
391config TUNE_Z13
392	bool "IBM z13s and z13"
393	depends on $(cc-option,-mtune=z13)
394
395config TUNE_Z14
396	bool "IBM z14 ZR1 and z14"
397	depends on $(cc-option,-mtune=z14)
398
399config TUNE_Z15
400	bool "IBM z15"
401	depends on $(cc-option,-mtune=z15)
402
403config TUNE_Z16
404	bool "IBM z16"
405	depends on $(cc-option,-mtune=z16)
406
407endchoice
408
409config 64BIT
410	def_bool y
411
412config COMMAND_LINE_SIZE
413	int "Maximum size of kernel command line"
414	default 4096
415	range 896 1048576
416	help
417	  This allows you to specify the maximum length of the kernel command
418	  line.
419
420config COMPAT
421	def_bool y
422	prompt "Kernel support for 31 bit emulation"
423	select ARCH_WANT_OLD_COMPAT_IPC
424	select COMPAT_OLD_SIGACTION
425	select HAVE_UID16
426	depends on MULTIUSER
427	depends on !CC_IS_CLANG
428	help
429	  Select this option if you want to enable your system kernel to
430	  handle system-calls from ELF binaries for 31 bit ESA.  This option
431	  (and some other stuff like libraries and such) is needed for
432	  executing 31 bit applications.  It is safe to say "Y".
433
434config SMP
435	def_bool y
436
437config NR_CPUS
438	int "Maximum number of CPUs (2-512)"
439	range 2 512
440	default "64"
441	help
442	  This allows you to specify the maximum number of CPUs which this
443	  kernel will support. The maximum supported value is 512 and the
444	  minimum value which makes sense is 2.
445
446	  This is purely to save memory - each supported CPU adds
447	  approximately sixteen kilobytes to the kernel image.
448
449config HOTPLUG_CPU
450	def_bool y
451
452config NUMA
453	bool "NUMA support"
454	depends on SCHED_TOPOLOGY
455	default n
456	help
457	  Enable NUMA support
458
459	  This option adds NUMA support to the kernel.
460
461config NODES_SHIFT
462	int
463	depends on NUMA
464	default "1"
465
466config SCHED_SMT
467	def_bool n
468
469config SCHED_MC
470	def_bool n
471
472config SCHED_TOPOLOGY
473	def_bool y
474	prompt "Topology scheduler support"
475	select SCHED_SMT
476	select SCHED_MC
477	help
478	  Topology scheduler support improves the CPU scheduler's decision
479	  making when dealing with machines that have multi-threading,
480	  multiple cores or multiple books.
481
482source "kernel/Kconfig.hz"
483
484config KEXEC
485	def_bool y
486	select KEXEC_CORE
487
488config KEXEC_FILE
489	bool "kexec file based system call"
490	select KEXEC_CORE
491	depends on CRYPTO
492	depends on CRYPTO_SHA256
493	depends on CRYPTO_SHA256_S390
494	help
495	  Enable the kexec file based system call. In contrast to the normal
496	  kexec system call this system call takes file descriptors for the
497	  kernel and initramfs as arguments.
498
499config ARCH_HAS_KEXEC_PURGATORY
500	def_bool y
501	depends on KEXEC_FILE
502
503config KEXEC_SIG
504	bool "Verify kernel signature during kexec_file_load() syscall"
505	depends on KEXEC_FILE && MODULE_SIG_FORMAT
506	help
507	  This option makes kernel signature verification mandatory for
508	  the kexec_file_load() syscall.
509
510	  In addition to that option, you need to enable signature
511	  verification for the corresponding kernel image type being
512	  loaded in order for this to work.
513
514config KERNEL_NOBP
515	def_bool n
516	prompt "Enable modified branch prediction for the kernel by default"
517	help
518	  If this option is selected the kernel will switch to a modified
519	  branch prediction mode if the firmware interface is available.
520	  The modified branch prediction mode improves the behaviour in
521	  regard to speculative execution.
522
523	  With the option enabled the kernel parameter "nobp=0" or "nospec"
524	  can be used to run the kernel in the normal branch prediction mode.
525
526	  With the option disabled the modified branch prediction mode is
527	  enabled with the "nobp=1" kernel parameter.
528
529	  If unsure, say N.
530
531config EXPOLINE
532	def_bool n
533	depends on $(cc-option,-mindirect-branch=thunk)
534	prompt "Avoid speculative indirect branches in the kernel"
535	help
536	  Compile the kernel with the expoline compiler options to guard
537	  against kernel-to-user data leaks by avoiding speculative indirect
538	  branches.
539	  Requires a compiler with -mindirect-branch=thunk support for full
540	  protection. The kernel may run slower.
541
542	  If unsure, say N.
543
544config EXPOLINE_EXTERN
545	def_bool n
546	depends on EXPOLINE
547	depends on CC_IS_GCC && GCC_VERSION >= 110200
548	depends on $(success,$(srctree)/arch/s390/tools/gcc-thunk-extern.sh $(CC))
549	prompt "Generate expolines as extern functions."
550	help
551	  This option is required for some tooling like kpatch. The kernel is
552	  compiled with -mindirect-branch=thunk-extern and requires a newer
553	  compiler.
554
555	  If unsure, say N.
556
557choice
558	prompt "Expoline default"
559	depends on EXPOLINE
560	default EXPOLINE_FULL
561
562config EXPOLINE_OFF
563	bool "spectre_v2=off"
564
565config EXPOLINE_AUTO
566	bool "spectre_v2=auto"
567
568config EXPOLINE_FULL
569	bool "spectre_v2=on"
570
571endchoice
572
573config RELOCATABLE
574	def_bool y
575	help
576	  This builds a kernel image that retains relocation information
577	  so it can be loaded at an arbitrary address.
578	  The kernel is linked as a position-independent executable (PIE)
579	  and contains dynamic relocations which are processed early in the
580	  bootup process.
581	  The relocations make the kernel image about 15% larger (compressed
582	  10%), but are discarded at runtime.
583	  Note: this option exists only for documentation purposes, please do
584	  not remove it.
585
586config RANDOMIZE_BASE
587	bool "Randomize the address of the kernel image (KASLR)"
588	default y
589	help
590	  In support of Kernel Address Space Layout Randomization (KASLR),
591	  this randomizes the address at which the kernel image is loaded,
592	  as a security feature that deters exploit attempts relying on
593	  knowledge of the location of kernel internals.
594
595endmenu
596
597menu "Memory setup"
598
599config ARCH_SPARSEMEM_ENABLE
600	def_bool y
601	select SPARSEMEM_VMEMMAP_ENABLE
602	select SPARSEMEM_VMEMMAP
603
604config ARCH_SPARSEMEM_DEFAULT
605	def_bool y
606
607config MAX_PHYSMEM_BITS
608	int "Maximum size of supported physical memory in bits (42-53)"
609	range 42 53
610	default "46"
611	help
612	  This option specifies the maximum supported size of physical memory
613	  in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB).
614	  Increasing the number of bits also increases the kernel image size.
615	  By default 46 bits (64TB) are supported.
616
617config CHECK_STACK
618	def_bool y
619	depends on !VMAP_STACK
620	prompt "Detect kernel stack overflow"
621	help
622	  This option enables the compiler option -mstack-guard and
623	  -mstack-size if they are available. If the compiler supports them
624	  it will emit additional code to each function prolog to trigger
625	  an illegal operation if the kernel stack is about to overflow.
626
627	  Say N if you are unsure.
628
629config STACK_GUARD
630	int "Size of the guard area (128-1024)"
631	range 128 1024
632	depends on CHECK_STACK
633	default "256"
634	help
635	  This allows you to specify the size of the guard area at the lower
636	  end of the kernel stack. If the kernel stack points into the guard
637	  area on function entry an illegal operation is triggered. The size
638	  needs to be a power of 2. Please keep in mind that the size of an
639	  interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
640	  The minimum size for the stack guard should be 256 for 31 bit and
641	  512 for 64 bit.
642
643endmenu
644
645menu "I/O subsystem"
646
647config QDIO
648	def_tristate y
649	prompt "QDIO support"
650	help
651	  This driver provides the Queued Direct I/O base support for
652	  IBM System z.
653
654	  To compile this driver as a module, choose M here: the
655	  module will be called qdio.
656
657	  If unsure, say Y.
658
659if PCI
660
661config PCI_NR_FUNCTIONS
662	int "Maximum number of PCI functions (1-4096)"
663	range 1 4096
664	default "512"
665	help
666	  This allows you to specify the maximum number of PCI functions which
667	  this kernel will support.
668
669endif # PCI
670
671config HAS_IOMEM
672	def_bool PCI
673
674config CHSC_SCH
675	def_tristate m
676	prompt "Support for CHSC subchannels"
677	help
678	  This driver allows usage of CHSC subchannels. A CHSC subchannel
679	  is usually present on LPAR only.
680	  The driver creates a device /dev/chsc, which may be used to
681	  obtain I/O configuration information about the machine and
682	  to issue asynchronous chsc commands (DANGEROUS).
683	  You will usually only want to use this interface on a special
684	  LPAR designated for system management.
685
686	  To compile this driver as a module, choose M here: the
687	  module will be called chsc_sch.
688
689	  If unsure, say N.
690
691config SCM_BUS
692	def_bool y
693	prompt "SCM bus driver"
694	help
695	  Bus driver for Storage Class Memory.
696
697config EADM_SCH
698	def_tristate m
699	prompt "Support for EADM subchannels"
700	depends on SCM_BUS
701	help
702	  This driver allows usage of EADM subchannels. EADM subchannels act
703	  as a communication vehicle for SCM increments.
704
705	  To compile this driver as a module, choose M here: the
706	  module will be called eadm_sch.
707
708config VFIO_CCW
709	def_tristate n
710	prompt "Support for VFIO-CCW subchannels"
711	depends on VFIO
712	select VFIO_MDEV
713	help
714	  This driver allows usage of I/O subchannels via VFIO-CCW.
715
716	  To compile this driver as a module, choose M here: the
717	  module will be called vfio_ccw.
718
719config VFIO_AP
720	def_tristate n
721	prompt "VFIO support for AP devices"
722	depends on KVM
723	depends on VFIO
724	depends on ZCRYPT
725	select VFIO_MDEV
726	help
727	  This driver grants access to Adjunct Processor (AP) devices
728	  via the VFIO mediated device interface.
729
730	  To compile this driver as a module, choose M here: the module
731	  will be called vfio_ap.
732
733endmenu
734
735menu "Dump support"
736
737config CRASH_DUMP
738	bool "kernel crash dumps"
739	select KEXEC
740	help
741	  Generate crash dump after being started by kexec.
742	  Crash dump kernels are loaded in the main kernel with kexec-tools
743	  into a specially reserved region and then later executed after
744	  a crash by kdump/kexec.
745	  Refer to <file:Documentation/s390/zfcpdump.rst> for more details on this.
746	  This option also enables s390 zfcpdump.
747	  See also <file:Documentation/s390/zfcpdump.rst>
748
749endmenu
750
751config CCW
752	def_bool y
753
754config HAVE_PNETID
755	tristate
756	default (SMC || CCWGROUP)
757
758menu "Virtualization"
759
760config PROTECTED_VIRTUALIZATION_GUEST
761	def_bool n
762	prompt "Protected virtualization guest support"
763	help
764	  Select this option, if you want to be able to run this
765	  kernel as a protected virtualization KVM guest.
766	  Protected virtualization capable machines have a mini hypervisor
767	  located at machine level (an ultravisor). With help of the
768	  Ultravisor, KVM will be able to run "protected" VMs, special
769	  VMs whose memory and management data are unavailable to KVM.
770
771config PFAULT
772	def_bool y
773	prompt "Pseudo page fault support"
774	help
775	  Select this option, if you want to use PFAULT pseudo page fault
776	  handling under VM. If running native or in LPAR, this option
777	  has no effect. If your VM does not support PFAULT, PAGEEX
778	  pseudo page fault handling will be used.
779	  Note that VM 4.2 supports PFAULT but has a bug in its
780	  implementation that causes some problems.
781	  Everybody who wants to run Linux under VM != VM4.2 should select
782	  this option.
783
784config CMM
785	def_tristate n
786	prompt "Cooperative memory management"
787	help
788	  Select this option, if you want to enable the kernel interface
789	  to reduce the memory size of the system. This is accomplished
790	  by allocating pages of memory and put them "on hold". This only
791	  makes sense for a system running under VM where the unused pages
792	  will be reused by VM for other guest systems. The interface
793	  allows an external monitor to balance memory of many systems.
794	  Everybody who wants to run Linux under VM should select this
795	  option.
796
797config CMM_IUCV
798	def_bool y
799	prompt "IUCV special message interface to cooperative memory management"
800	depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
801	help
802	  Select this option to enable the special message interface to
803	  the cooperative memory management.
804
805config APPLDATA_BASE
806	def_bool n
807	prompt "Linux - VM Monitor Stream, base infrastructure"
808	depends on PROC_SYSCTL
809	help
810	  This provides a kernel interface for creating and updating z/VM APPLDATA
811	  monitor records. The monitor records are updated at certain time
812	  intervals, once the timer is started.
813	  Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
814	  i.e. enables or disables monitoring on the Linux side.
815	  A custom interval value (in seconds) can be written to
816	  /proc/appldata/interval.
817
818	  Defaults are 60 seconds interval and timer off.
819	  The /proc entries can also be read from, showing the current settings.
820
821config APPLDATA_MEM
822	def_tristate m
823	prompt "Monitor memory management statistics"
824	depends on APPLDATA_BASE && VM_EVENT_COUNTERS
825	help
826	  This provides memory management related data to the Linux - VM Monitor
827	  Stream, like paging/swapping rate, memory utilisation, etc.
828	  Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
829	  APPLDATA monitor record, i.e. enables or disables monitoring this record
830	  on the z/VM side.
831
832	  Default is disabled.
833	  The /proc entry can also be read from, showing the current settings.
834
835	  This can also be compiled as a module, which will be called
836	  appldata_mem.o.
837
838config APPLDATA_OS
839	def_tristate m
840	prompt "Monitor OS statistics"
841	depends on APPLDATA_BASE
842	help
843	  This provides OS related data to the Linux - VM Monitor Stream, like
844	  CPU utilisation, etc.
845	  Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
846	  APPLDATA monitor record, i.e. enables or disables monitoring this record
847	  on the z/VM side.
848
849	  Default is disabled.
850	  This can also be compiled as a module, which will be called
851	  appldata_os.o.
852
853config APPLDATA_NET_SUM
854	def_tristate m
855	prompt "Monitor overall network statistics"
856	depends on APPLDATA_BASE && NET
857	help
858	  This provides network related data to the Linux - VM Monitor Stream,
859	  currently there is only a total sum of network I/O statistics, no
860	  per-interface data.
861	  Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
862	  APPLDATA monitor record, i.e. enables or disables monitoring this record
863	  on the z/VM side.
864
865	  Default is disabled.
866	  This can also be compiled as a module, which will be called
867	  appldata_net_sum.o.
868
869config S390_HYPFS_FS
870	def_bool y
871	prompt "s390 hypervisor file system support"
872	select SYS_HYPERVISOR
873	help
874	  This is a virtual file system intended to provide accounting
875	  information in an s390 hypervisor environment.
876
877source "arch/s390/kvm/Kconfig"
878
879config S390_GUEST
880	def_bool y
881	prompt "s390 support for virtio devices"
882	select TTY
883	select VIRTUALIZATION
884	select VIRTIO
885	help
886	  Enabling this option adds support for virtio based paravirtual device
887	  drivers on s390.
888
889	  Select this option if you want to run the kernel as a guest under
890	  the KVM hypervisor.
891
892endmenu
893
894config S390_MODULES_SANITY_TEST_HELPERS
895	def_bool n
896
897menu "Selftests"
898
899config S390_UNWIND_SELFTEST
900	def_tristate n
901	depends on KUNIT
902	default KUNIT_ALL_TESTS
903	prompt "Test unwind functions"
904	help
905	  This option enables s390 specific stack unwinder testing kernel
906	  module. This option is not useful for distributions or general
907	  kernels, but only for kernel developers working on architecture code.
908
909	  Say N if you are unsure.
910
911config S390_KPROBES_SANITY_TEST
912	def_tristate n
913	prompt "Enable s390 specific kprobes tests"
914	depends on KPROBES
915	depends on KUNIT
916	help
917	  This option enables an s390 specific kprobes test module. This option
918	  is not useful for distributions or general kernels, but only for kernel
919	  developers working on architecture code.
920
921	  Say N if you are unsure.
922
923config S390_MODULES_SANITY_TEST
924	def_tristate n
925	depends on KUNIT
926	default KUNIT_ALL_TESTS
927	prompt "Enable s390 specific modules tests"
928	select S390_MODULES_SANITY_TEST_HELPERS
929	help
930	  This option enables an s390 specific modules test. This option is
931	  not useful for distributions or general kernels, but only for
932	  kernel developers working on architecture code.
933
934	  Say N if you are unsure.
935endmenu
936