xref: /openbmc/linux/arch/s390/Kconfig (revision d21077fb)
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_SUPPORTS_PER_VMA_LOCK
124	select ARCH_USE_BUILTIN_BSWAP
125	select ARCH_USE_CMPXCHG_LOCKREF
126	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
127	select ARCH_WANTS_NO_INSTR
128	select ARCH_WANT_DEFAULT_BPF_JIT
129	select ARCH_WANT_IPC_PARSE_VERSION
130	select ARCH_WANT_OPTIMIZE_VMEMMAP
131	select BUILDTIME_TABLE_SORT
132	select CLONE_BACKWARDS2
133	select DMA_OPS if PCI
134	select DYNAMIC_FTRACE if FUNCTION_TRACER
135	select GCC12_NO_ARRAY_BOUNDS
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_TRACEHOOK
157	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
158	select HAVE_ARCH_VMAP_STACK
159	select HAVE_ASM_MODVERSIONS
160	select HAVE_CMPXCHG_DOUBLE
161	select HAVE_CMPXCHG_LOCAL
162	select HAVE_DEBUG_KMEMLEAK
163	select HAVE_DMA_CONTIGUOUS
164	select HAVE_DYNAMIC_FTRACE
165	select HAVE_DYNAMIC_FTRACE_WITH_ARGS
166	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
167	select HAVE_DYNAMIC_FTRACE_WITH_REGS
168	select HAVE_EBPF_JIT if HAVE_MARCH_Z196_FEATURES
169	select HAVE_EFFICIENT_UNALIGNED_ACCESS
170	select HAVE_FAST_GUP
171	select HAVE_FENTRY
172	select HAVE_FTRACE_MCOUNT_RECORD
173	select HAVE_FUNCTION_ARG_ACCESS_API
174	select HAVE_FUNCTION_ERROR_INJECTION
175	select HAVE_FUNCTION_GRAPH_TRACER
176	select HAVE_FUNCTION_TRACER
177	select HAVE_GCC_PLUGINS
178	select HAVE_GENERIC_VDSO
179	select HAVE_IOREMAP_PROT if PCI
180	select HAVE_KERNEL_BZIP2
181	select HAVE_KERNEL_GZIP
182	select HAVE_KERNEL_LZ4
183	select HAVE_KERNEL_LZMA
184	select HAVE_KERNEL_LZO
185	select HAVE_KERNEL_UNCOMPRESSED
186	select HAVE_KERNEL_XZ
187	select HAVE_KERNEL_ZSTD
188	select HAVE_KPROBES
189	select HAVE_KPROBES_ON_FTRACE
190	select HAVE_KRETPROBES
191	select HAVE_KVM
192	select HAVE_LIVEPATCH
193	select HAVE_MEMBLOCK_PHYS_MAP
194	select HAVE_MOD_ARCH_SPECIFIC
195	select HAVE_NMI
196	select HAVE_NOP_MCOUNT
197	select HAVE_PCI
198	select HAVE_PERF_EVENTS
199	select HAVE_PERF_REGS
200	select HAVE_PERF_USER_STACK_DUMP
201	select HAVE_REGS_AND_STACK_ACCESS_API
202	select HAVE_RELIABLE_STACKTRACE
203	select HAVE_RETHOOK
204	select HAVE_RSEQ
205	select HAVE_SAMPLE_FTRACE_DIRECT
206	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
207	select HAVE_SETUP_PER_CPU_AREA
208	select HAVE_SOFTIRQ_ON_OWN_STACK
209	select HAVE_SYSCALL_TRACEPOINTS
210	select HAVE_VIRT_CPU_ACCOUNTING
211	select HAVE_VIRT_CPU_ACCOUNTING_IDLE
212	select IOMMU_HELPER		if PCI
213	select IOMMU_SUPPORT		if PCI
214	select MMU_GATHER_MERGE_VMAS
215	select MMU_GATHER_NO_GATHER
216	select MMU_GATHER_RCU_TABLE_FREE
217	select MODULES_USE_ELF_RELA
218	select NEED_DMA_MAP_STATE	if PCI
219	select NEED_PER_CPU_EMBED_FIRST_CHUNK
220	select NEED_SG_DMA_LENGTH	if PCI
221	select OLD_SIGACTION
222	select OLD_SIGSUSPEND3
223	select PCI_DOMAINS		if PCI
224	select PCI_MSI			if PCI
225	select PCI_MSI_ARCH_FALLBACKS	if PCI_MSI
226	select SPARSE_IRQ
227	select SWIOTLB
228	select SYSCTL_EXCEPTION_TRACE
229	select THREAD_INFO_IN_TASK
230	select TRACE_IRQFLAGS_SUPPORT
231	select TTY
232	select VIRT_CPU_ACCOUNTING
233	select ZONE_DMA
234	# Note: keep the above list sorted alphabetically
235
236config SCHED_OMIT_FRAME_POINTER
237	def_bool y
238
239config PGTABLE_LEVELS
240	int
241	default 5
242
243source "kernel/livepatch/Kconfig"
244
245menu "Processor type and features"
246
247config HAVE_MARCH_Z10_FEATURES
248	def_bool n
249
250config HAVE_MARCH_Z196_FEATURES
251	def_bool n
252	select HAVE_MARCH_Z10_FEATURES
253
254config HAVE_MARCH_ZEC12_FEATURES
255	def_bool n
256	select HAVE_MARCH_Z196_FEATURES
257
258config HAVE_MARCH_Z13_FEATURES
259	def_bool n
260	select HAVE_MARCH_ZEC12_FEATURES
261
262config HAVE_MARCH_Z14_FEATURES
263	def_bool n
264	select HAVE_MARCH_Z13_FEATURES
265
266config HAVE_MARCH_Z15_FEATURES
267	def_bool n
268	select HAVE_MARCH_Z14_FEATURES
269
270config HAVE_MARCH_Z16_FEATURES
271	def_bool n
272	select HAVE_MARCH_Z15_FEATURES
273
274choice
275	prompt "Processor type"
276	default MARCH_Z196
277
278config MARCH_Z10
279	bool "IBM System z10"
280	select HAVE_MARCH_Z10_FEATURES
281	depends on $(cc-option,-march=z10)
282	help
283	  Select this to enable optimizations for IBM System z10 (2097 and 2098
284	  series). This is the oldest machine generation currently supported.
285
286config MARCH_Z196
287	bool "IBM zEnterprise 114 and 196"
288	select HAVE_MARCH_Z196_FEATURES
289	depends on $(cc-option,-march=z196)
290	help
291	  Select this to enable optimizations for IBM zEnterprise 114 and 196
292	  (2818 and 2817 series). The kernel will be slightly faster but will
293	  not work on older machines.
294
295config MARCH_ZEC12
296	bool "IBM zBC12 and zEC12"
297	select HAVE_MARCH_ZEC12_FEATURES
298	depends on $(cc-option,-march=zEC12)
299	help
300	  Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
301	  2827 series). The kernel will be slightly faster but will not work on
302	  older machines.
303
304config MARCH_Z13
305	bool "IBM z13s and z13"
306	select HAVE_MARCH_Z13_FEATURES
307	depends on $(cc-option,-march=z13)
308	help
309	  Select this to enable optimizations for IBM z13s and z13 (2965 and
310	  2964 series). The kernel will be slightly faster but will not work on
311	  older machines.
312
313config MARCH_Z14
314	bool "IBM z14 ZR1 and z14"
315	select HAVE_MARCH_Z14_FEATURES
316	depends on $(cc-option,-march=z14)
317	help
318	  Select this to enable optimizations for IBM z14 ZR1 and z14 (3907
319	  and 3906 series). The kernel will be slightly faster but will not
320	  work on older machines.
321
322config MARCH_Z15
323	bool "IBM z15"
324	select HAVE_MARCH_Z15_FEATURES
325	depends on $(cc-option,-march=z15)
326	help
327	  Select this to enable optimizations for IBM z15 (8562
328	  and 8561 series). The kernel will be slightly faster but will not
329	  work on older machines.
330
331config MARCH_Z16
332	bool "IBM z16"
333	select HAVE_MARCH_Z16_FEATURES
334	depends on $(cc-option,-march=z16)
335	help
336	  Select this to enable optimizations for IBM z16 (3931 and
337	  3932 series).
338
339endchoice
340
341config MARCH_Z10_TUNE
342	def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
343
344config MARCH_Z196_TUNE
345	def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
346
347config MARCH_ZEC12_TUNE
348	def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
349
350config MARCH_Z13_TUNE
351	def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT
352
353config MARCH_Z14_TUNE
354	def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT
355
356config MARCH_Z15_TUNE
357	def_bool TUNE_Z15 || MARCH_Z15 && TUNE_DEFAULT
358
359config MARCH_Z16_TUNE
360	def_bool TUNE_Z16 || MARCH_Z16 && TUNE_DEFAULT
361
362choice
363	prompt "Tune code generation"
364	default TUNE_DEFAULT
365	help
366	  Cause the compiler to tune (-mtune) the generated code for a machine.
367	  This will make the code run faster on the selected machine but
368	  somewhat slower on other machines.
369	  This option only changes how the compiler emits instructions, not the
370	  selection of instructions itself, so the resulting kernel will run on
371	  all other machines.
372
373config TUNE_DEFAULT
374	bool "Default"
375	help
376	  Tune the generated code for the target processor for which the kernel
377	  will be compiled.
378
379config TUNE_Z10
380	bool "IBM System z10"
381
382config TUNE_Z196
383	bool "IBM zEnterprise 114 and 196"
384	depends on $(cc-option,-mtune=z196)
385
386config TUNE_ZEC12
387	bool "IBM zBC12 and zEC12"
388	depends on $(cc-option,-mtune=zEC12)
389
390config TUNE_Z13
391	bool "IBM z13s and z13"
392	depends on $(cc-option,-mtune=z13)
393
394config TUNE_Z14
395	bool "IBM z14 ZR1 and z14"
396	depends on $(cc-option,-mtune=z14)
397
398config TUNE_Z15
399	bool "IBM z15"
400	depends on $(cc-option,-mtune=z15)
401
402config TUNE_Z16
403	bool "IBM z16"
404	depends on $(cc-option,-mtune=z16)
405
406endchoice
407
408config 64BIT
409	def_bool y
410
411config COMMAND_LINE_SIZE
412	int "Maximum size of kernel command line"
413	default 4096
414	range 896 1048576
415	help
416	  This allows you to specify the maximum length of the kernel command
417	  line.
418
419config COMPAT
420	def_bool y
421	prompt "Kernel support for 31 bit emulation"
422	select ARCH_WANT_OLD_COMPAT_IPC
423	select COMPAT_OLD_SIGACTION
424	select HAVE_UID16
425	depends on MULTIUSER
426	depends on !CC_IS_CLANG
427	help
428	  Select this option if you want to enable your system kernel to
429	  handle system-calls from ELF binaries for 31 bit ESA.  This option
430	  (and some other stuff like libraries and such) is needed for
431	  executing 31 bit applications.  It is safe to say "Y".
432
433config SMP
434	def_bool y
435
436config NR_CPUS
437	int "Maximum number of CPUs (2-512)"
438	range 2 512
439	default "64"
440	help
441	  This allows you to specify the maximum number of CPUs which this
442	  kernel will support. The maximum supported value is 512 and the
443	  minimum value which makes sense is 2.
444
445	  This is purely to save memory - each supported CPU adds
446	  approximately sixteen kilobytes to the kernel image.
447
448config HOTPLUG_CPU
449	def_bool y
450
451config NUMA
452	bool "NUMA support"
453	depends on SCHED_TOPOLOGY
454	default n
455	help
456	  Enable NUMA support
457
458	  This option adds NUMA support to the kernel.
459
460config NODES_SHIFT
461	int
462	depends on NUMA
463	default "1"
464
465config SCHED_SMT
466	def_bool n
467
468config SCHED_MC
469	def_bool n
470
471config SCHED_BOOK
472	def_bool n
473
474config SCHED_DRAWER
475	def_bool n
476
477config SCHED_TOPOLOGY
478	def_bool y
479	prompt "Topology scheduler support"
480	select SCHED_SMT
481	select SCHED_MC
482	select SCHED_BOOK
483	select SCHED_DRAWER
484	help
485	  Topology scheduler support improves the CPU scheduler's decision
486	  making when dealing with machines that have multi-threading,
487	  multiple cores or multiple books.
488
489source "kernel/Kconfig.hz"
490
491config KEXEC
492	def_bool y
493	select KEXEC_CORE
494
495config KEXEC_FILE
496	bool "kexec file based system call"
497	select KEXEC_CORE
498	depends on CRYPTO
499	depends on CRYPTO_SHA256
500	depends on CRYPTO_SHA256_S390
501	help
502	  Enable the kexec file based system call. In contrast to the normal
503	  kexec system call this system call takes file descriptors for the
504	  kernel and initramfs as arguments.
505
506config ARCH_HAS_KEXEC_PURGATORY
507	def_bool y
508	depends on KEXEC_FILE
509
510config KEXEC_SIG
511	bool "Verify kernel signature during kexec_file_load() syscall"
512	depends on KEXEC_FILE && MODULE_SIG_FORMAT
513	help
514	  This option makes kernel signature verification mandatory for
515	  the kexec_file_load() syscall.
516
517	  In addition to that option, you need to enable signature
518	  verification for the corresponding kernel image type being
519	  loaded in order for this to work.
520
521config KERNEL_NOBP
522	def_bool n
523	prompt "Enable modified branch prediction for the kernel by default"
524	help
525	  If this option is selected the kernel will switch to a modified
526	  branch prediction mode if the firmware interface is available.
527	  The modified branch prediction mode improves the behaviour in
528	  regard to speculative execution.
529
530	  With the option enabled the kernel parameter "nobp=0" or "nospec"
531	  can be used to run the kernel in the normal branch prediction mode.
532
533	  With the option disabled the modified branch prediction mode is
534	  enabled with the "nobp=1" kernel parameter.
535
536	  If unsure, say N.
537
538config EXPOLINE
539	def_bool n
540	depends on $(cc-option,-mindirect-branch=thunk)
541	prompt "Avoid speculative indirect branches in the kernel"
542	help
543	  Compile the kernel with the expoline compiler options to guard
544	  against kernel-to-user data leaks by avoiding speculative indirect
545	  branches.
546	  Requires a compiler with -mindirect-branch=thunk support for full
547	  protection. The kernel may run slower.
548
549	  If unsure, say N.
550
551config EXPOLINE_EXTERN
552	def_bool n
553	depends on EXPOLINE
554	depends on CC_IS_GCC && GCC_VERSION >= 110200
555	depends on $(success,$(srctree)/arch/s390/tools/gcc-thunk-extern.sh $(CC))
556	prompt "Generate expolines as extern functions."
557	help
558	  This option is required for some tooling like kpatch. The kernel is
559	  compiled with -mindirect-branch=thunk-extern and requires a newer
560	  compiler.
561
562	  If unsure, say N.
563
564choice
565	prompt "Expoline default"
566	depends on EXPOLINE
567	default EXPOLINE_FULL
568
569config EXPOLINE_OFF
570	bool "spectre_v2=off"
571
572config EXPOLINE_AUTO
573	bool "spectre_v2=auto"
574
575config EXPOLINE_FULL
576	bool "spectre_v2=on"
577
578endchoice
579
580config RELOCATABLE
581	def_bool y
582	help
583	  This builds a kernel image that retains relocation information
584	  so it can be loaded at an arbitrary address.
585	  The kernel is linked as a position-independent executable (PIE)
586	  and contains dynamic relocations which are processed early in the
587	  bootup process.
588	  The relocations make the kernel image about 15% larger (compressed
589	  10%), but are discarded at runtime.
590	  Note: this option exists only for documentation purposes, please do
591	  not remove it.
592
593config RANDOMIZE_BASE
594	bool "Randomize the address of the kernel image (KASLR)"
595	default y
596	help
597	  In support of Kernel Address Space Layout Randomization (KASLR),
598	  this randomizes the address at which the kernel image is loaded,
599	  as a security feature that deters exploit attempts relying on
600	  knowledge of the location of kernel internals.
601
602endmenu
603
604menu "Memory setup"
605
606config ARCH_SPARSEMEM_ENABLE
607	def_bool y
608	select SPARSEMEM_VMEMMAP_ENABLE
609	select SPARSEMEM_VMEMMAP
610
611config ARCH_SPARSEMEM_DEFAULT
612	def_bool y
613
614config MAX_PHYSMEM_BITS
615	int "Maximum size of supported physical memory in bits (42-53)"
616	range 42 53
617	default "46"
618	help
619	  This option specifies the maximum supported size of physical memory
620	  in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB).
621	  Increasing the number of bits also increases the kernel image size.
622	  By default 46 bits (64TB) are supported.
623
624config CHECK_STACK
625	def_bool y
626	depends on !VMAP_STACK
627	prompt "Detect kernel stack overflow"
628	help
629	  This option enables the compiler option -mstack-guard and
630	  -mstack-size if they are available. If the compiler supports them
631	  it will emit additional code to each function prolog to trigger
632	  an illegal operation if the kernel stack is about to overflow.
633
634	  Say N if you are unsure.
635
636config STACK_GUARD
637	int "Size of the guard area (128-1024)"
638	range 128 1024
639	depends on CHECK_STACK
640	default "256"
641	help
642	  This allows you to specify the size of the guard area at the lower
643	  end of the kernel stack. If the kernel stack points into the guard
644	  area on function entry an illegal operation is triggered. The size
645	  needs to be a power of 2. Please keep in mind that the size of an
646	  interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
647	  The minimum size for the stack guard should be 256 for 31 bit and
648	  512 for 64 bit.
649
650endmenu
651
652menu "I/O subsystem"
653
654config QDIO
655	def_tristate y
656	prompt "QDIO support"
657	help
658	  This driver provides the Queued Direct I/O base support for
659	  IBM System z.
660
661	  To compile this driver as a module, choose M here: the
662	  module will be called qdio.
663
664	  If unsure, say Y.
665
666if PCI
667
668config PCI_NR_FUNCTIONS
669	int "Maximum number of PCI functions (1-4096)"
670	range 1 4096
671	default "512"
672	help
673	  This allows you to specify the maximum number of PCI functions which
674	  this kernel will support.
675
676endif # PCI
677
678config HAS_IOMEM
679	def_bool PCI
680
681config CHSC_SCH
682	def_tristate m
683	prompt "Support for CHSC subchannels"
684	help
685	  This driver allows usage of CHSC subchannels. A CHSC subchannel
686	  is usually present on LPAR only.
687	  The driver creates a device /dev/chsc, which may be used to
688	  obtain I/O configuration information about the machine and
689	  to issue asynchronous chsc commands (DANGEROUS).
690	  You will usually only want to use this interface on a special
691	  LPAR designated for system management.
692
693	  To compile this driver as a module, choose M here: the
694	  module will be called chsc_sch.
695
696	  If unsure, say N.
697
698config SCM_BUS
699	def_bool y
700	prompt "SCM bus driver"
701	help
702	  Bus driver for Storage Class Memory.
703
704config EADM_SCH
705	def_tristate m
706	prompt "Support for EADM subchannels"
707	depends on SCM_BUS
708	help
709	  This driver allows usage of EADM subchannels. EADM subchannels act
710	  as a communication vehicle for SCM increments.
711
712	  To compile this driver as a module, choose M here: the
713	  module will be called eadm_sch.
714
715config VFIO_CCW
716	def_tristate n
717	prompt "Support for VFIO-CCW subchannels"
718	depends on S390_CCW_IOMMU
719	depends on VFIO
720	select VFIO_MDEV
721	help
722	  This driver allows usage of I/O subchannels via VFIO-CCW.
723
724	  To compile this driver as a module, choose M here: the
725	  module will be called vfio_ccw.
726
727config VFIO_AP
728	def_tristate n
729	prompt "VFIO support for AP devices"
730	depends on S390_AP_IOMMU && KVM
731	depends on VFIO
732	depends on ZCRYPT
733	select VFIO_MDEV
734	help
735	  This driver grants access to Adjunct Processor (AP) devices
736	  via the VFIO mediated device interface.
737
738	  To compile this driver as a module, choose M here: the module
739	  will be called vfio_ap.
740
741endmenu
742
743menu "Dump support"
744
745config CRASH_DUMP
746	bool "kernel crash dumps"
747	select KEXEC
748	help
749	  Generate crash dump after being started by kexec.
750	  Crash dump kernels are loaded in the main kernel with kexec-tools
751	  into a specially reserved region and then later executed after
752	  a crash by kdump/kexec.
753	  Refer to <file:Documentation/s390/zfcpdump.rst> for more details on this.
754	  This option also enables s390 zfcpdump.
755	  See also <file:Documentation/s390/zfcpdump.rst>
756
757endmenu
758
759config CCW
760	def_bool y
761
762config HAVE_PNETID
763	tristate
764	default (SMC || CCWGROUP)
765
766menu "Virtualization"
767
768config PROTECTED_VIRTUALIZATION_GUEST
769	def_bool n
770	prompt "Protected virtualization guest support"
771	help
772	  Select this option, if you want to be able to run this
773	  kernel as a protected virtualization KVM guest.
774	  Protected virtualization capable machines have a mini hypervisor
775	  located at machine level (an ultravisor). With help of the
776	  Ultravisor, KVM will be able to run "protected" VMs, special
777	  VMs whose memory and management data are unavailable to KVM.
778
779config PFAULT
780	def_bool y
781	prompt "Pseudo page fault support"
782	help
783	  Select this option, if you want to use PFAULT pseudo page fault
784	  handling under VM. If running native or in LPAR, this option
785	  has no effect. If your VM does not support PFAULT, PAGEEX
786	  pseudo page fault handling will be used.
787	  Note that VM 4.2 supports PFAULT but has a bug in its
788	  implementation that causes some problems.
789	  Everybody who wants to run Linux under VM != VM4.2 should select
790	  this option.
791
792config CMM
793	def_tristate n
794	prompt "Cooperative memory management"
795	help
796	  Select this option, if you want to enable the kernel interface
797	  to reduce the memory size of the system. This is accomplished
798	  by allocating pages of memory and put them "on hold". This only
799	  makes sense for a system running under VM where the unused pages
800	  will be reused by VM for other guest systems. The interface
801	  allows an external monitor to balance memory of many systems.
802	  Everybody who wants to run Linux under VM should select this
803	  option.
804
805config CMM_IUCV
806	def_bool y
807	prompt "IUCV special message interface to cooperative memory management"
808	depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
809	help
810	  Select this option to enable the special message interface to
811	  the cooperative memory management.
812
813config APPLDATA_BASE
814	def_bool n
815	prompt "Linux - VM Monitor Stream, base infrastructure"
816	depends on PROC_SYSCTL
817	help
818	  This provides a kernel interface for creating and updating z/VM APPLDATA
819	  monitor records. The monitor records are updated at certain time
820	  intervals, once the timer is started.
821	  Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
822	  i.e. enables or disables monitoring on the Linux side.
823	  A custom interval value (in seconds) can be written to
824	  /proc/appldata/interval.
825
826	  Defaults are 60 seconds interval and timer off.
827	  The /proc entries can also be read from, showing the current settings.
828
829config APPLDATA_MEM
830	def_tristate m
831	prompt "Monitor memory management statistics"
832	depends on APPLDATA_BASE && VM_EVENT_COUNTERS
833	help
834	  This provides memory management related data to the Linux - VM Monitor
835	  Stream, like paging/swapping rate, memory utilisation, etc.
836	  Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
837	  APPLDATA monitor record, i.e. enables or disables monitoring this record
838	  on the z/VM side.
839
840	  Default is disabled.
841	  The /proc entry can also be read from, showing the current settings.
842
843	  This can also be compiled as a module, which will be called
844	  appldata_mem.o.
845
846config APPLDATA_OS
847	def_tristate m
848	prompt "Monitor OS statistics"
849	depends on APPLDATA_BASE
850	help
851	  This provides OS related data to the Linux - VM Monitor Stream, like
852	  CPU utilisation, etc.
853	  Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
854	  APPLDATA monitor record, i.e. enables or disables monitoring this record
855	  on the z/VM side.
856
857	  Default is disabled.
858	  This can also be compiled as a module, which will be called
859	  appldata_os.o.
860
861config APPLDATA_NET_SUM
862	def_tristate m
863	prompt "Monitor overall network statistics"
864	depends on APPLDATA_BASE && NET
865	help
866	  This provides network related data to the Linux - VM Monitor Stream,
867	  currently there is only a total sum of network I/O statistics, no
868	  per-interface data.
869	  Writing 1 or 0 to /proc/appldata/net_sum 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	  This can also be compiled as a module, which will be called
875	  appldata_net_sum.o.
876
877config S390_HYPFS_FS
878	def_bool y
879	prompt "s390 hypervisor file system support"
880	select SYS_HYPERVISOR
881	help
882	  This is a virtual file system intended to provide accounting
883	  information in an s390 hypervisor environment.
884
885source "arch/s390/kvm/Kconfig"
886
887config S390_GUEST
888	def_bool y
889	prompt "s390 support for virtio devices"
890	select TTY
891	select VIRTUALIZATION
892	select VIRTIO
893	help
894	  Enabling this option adds support for virtio based paravirtual device
895	  drivers on s390.
896
897	  Select this option if you want to run the kernel as a guest under
898	  the KVM hypervisor.
899
900endmenu
901
902config S390_MODULES_SANITY_TEST_HELPERS
903	def_bool n
904
905menu "Selftests"
906
907config S390_UNWIND_SELFTEST
908	def_tristate n
909	depends on KUNIT
910	default KUNIT_ALL_TESTS
911	prompt "Test unwind functions"
912	help
913	  This option enables s390 specific stack unwinder testing kernel
914	  module. This option is not useful for distributions or general
915	  kernels, but only for kernel developers working on architecture code.
916
917	  Say N if you are unsure.
918
919config S390_KPROBES_SANITY_TEST
920	def_tristate n
921	prompt "Enable s390 specific kprobes tests"
922	depends on KPROBES
923	depends on KUNIT
924	help
925	  This option enables an s390 specific kprobes test module. This option
926	  is not useful for distributions or general kernels, but only for kernel
927	  developers working on architecture code.
928
929	  Say N if you are unsure.
930
931config S390_MODULES_SANITY_TEST
932	def_tristate n
933	depends on KUNIT
934	default KUNIT_ALL_TESTS
935	prompt "Enable s390 specific modules tests"
936	select S390_MODULES_SANITY_TEST_HELPERS
937	help
938	  This option enables an s390 specific modules test. This option is
939	  not useful for distributions or general kernels, but only for
940	  kernel developers working on architecture code.
941
942	  Say N if you are unsure.
943endmenu
944