xref: /linux/arch/s390/Kconfig (revision ef815d2cba782e96b9aad9483523d474ed41c62a)
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_INT128 if CC_HAS_INT128 && CC_IS_CLANG
121	select ARCH_SUPPORTS_NUMA_BALANCING
122	select ARCH_SUPPORTS_PER_VMA_LOCK
123	select ARCH_USE_BUILTIN_BSWAP
124	select ARCH_USE_CMPXCHG_LOCKREF
125	select ARCH_USE_SYM_ANNOTATIONS
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 FUNCTION_ALIGNMENT_8B if CC_IS_GCC
136	select FUNCTION_ALIGNMENT_16B if !CC_IS_GCC
137	select GENERIC_ALLOCATOR
138	select GENERIC_CPU_AUTOPROBE
139	select GENERIC_CPU_VULNERABILITIES
140	select GENERIC_ENTRY
141	select GENERIC_GETTIMEOFDAY
142	select GENERIC_PTDUMP
143	select GENERIC_SMP_IDLE_THREAD
144	select GENERIC_TIME_VSYSCALL
145	select GENERIC_VDSO_TIME_NS
146	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
147	select HAVE_ARCH_AUDITSYSCALL
148	select HAVE_ARCH_JUMP_LABEL
149	select HAVE_ARCH_JUMP_LABEL_RELATIVE
150	select HAVE_ARCH_KASAN
151	select HAVE_ARCH_KASAN_VMALLOC
152	select HAVE_ARCH_KCSAN
153	select HAVE_ARCH_KFENCE
154	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
155	select HAVE_ARCH_SECCOMP_FILTER
156	select HAVE_ARCH_SOFT_DIRTY
157	select HAVE_ARCH_STACKLEAK
158	select HAVE_ARCH_TRACEHOOK
159	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
160	select HAVE_ARCH_VMAP_STACK
161	select HAVE_ASM_MODVERSIONS
162	select HAVE_CMPXCHG_DOUBLE
163	select HAVE_CMPXCHG_LOCAL
164	select HAVE_DEBUG_KMEMLEAK
165	select HAVE_DMA_CONTIGUOUS
166	select HAVE_DYNAMIC_FTRACE
167	select HAVE_DYNAMIC_FTRACE_WITH_ARGS
168	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
169	select HAVE_DYNAMIC_FTRACE_WITH_REGS
170	select HAVE_EBPF_JIT if HAVE_MARCH_Z196_FEATURES
171	select HAVE_EFFICIENT_UNALIGNED_ACCESS
172	select HAVE_FAST_GUP
173	select HAVE_FENTRY
174	select HAVE_FTRACE_MCOUNT_RECORD
175	select HAVE_FUNCTION_ARG_ACCESS_API
176	select HAVE_FUNCTION_ERROR_INJECTION
177	select HAVE_FUNCTION_GRAPH_TRACER
178	select HAVE_FUNCTION_TRACER
179	select HAVE_GCC_PLUGINS
180	select HAVE_GENERIC_VDSO
181	select HAVE_IOREMAP_PROT if PCI
182	select HAVE_KERNEL_BZIP2
183	select HAVE_KERNEL_GZIP
184	select HAVE_KERNEL_LZ4
185	select HAVE_KERNEL_LZMA
186	select HAVE_KERNEL_LZO
187	select HAVE_KERNEL_UNCOMPRESSED
188	select HAVE_KERNEL_XZ
189	select HAVE_KERNEL_ZSTD
190	select HAVE_KPROBES
191	select HAVE_KPROBES_ON_FTRACE
192	select HAVE_KRETPROBES
193	select HAVE_KVM
194	select HAVE_LIVEPATCH
195	select HAVE_MEMBLOCK_PHYS_MAP
196	select HAVE_MOD_ARCH_SPECIFIC
197	select HAVE_NMI
198	select HAVE_NOP_MCOUNT
199	select HAVE_PCI
200	select HAVE_PERF_EVENTS
201	select HAVE_PERF_REGS
202	select HAVE_PERF_USER_STACK_DUMP
203	select HAVE_REGS_AND_STACK_ACCESS_API
204	select HAVE_RELIABLE_STACKTRACE
205	select HAVE_RETHOOK
206	select HAVE_RSEQ
207	select HAVE_SAMPLE_FTRACE_DIRECT
208	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
209	select HAVE_SETUP_PER_CPU_AREA
210	select HAVE_SOFTIRQ_ON_OWN_STACK
211	select HAVE_SYSCALL_TRACEPOINTS
212	select HAVE_VIRT_CPU_ACCOUNTING
213	select HAVE_VIRT_CPU_ACCOUNTING_IDLE
214	select IOMMU_HELPER		if PCI
215	select IOMMU_SUPPORT		if PCI
216	select KEXEC
217	select MMU_GATHER_MERGE_VMAS
218	select MMU_GATHER_NO_GATHER
219	select MMU_GATHER_RCU_TABLE_FREE
220	select MODULES_USE_ELF_RELA
221	select NEED_DMA_MAP_STATE	if PCI
222	select NEED_PER_CPU_EMBED_FIRST_CHUNK
223	select NEED_SG_DMA_LENGTH	if PCI
224	select OLD_SIGACTION
225	select OLD_SIGSUSPEND3
226	select PCI_DOMAINS		if PCI
227	select PCI_MSI			if PCI
228	select PCI_MSI_ARCH_FALLBACKS	if PCI_MSI
229	select SPARSE_IRQ
230	select SWIOTLB
231	select SYSCTL_EXCEPTION_TRACE
232	select THREAD_INFO_IN_TASK
233	select TRACE_IRQFLAGS_SUPPORT
234	select TTY
235	select VIRT_CPU_ACCOUNTING
236	select ZONE_DMA
237	# Note: keep the above list sorted alphabetically
238
239config SCHED_OMIT_FRAME_POINTER
240	def_bool y
241
242config PGTABLE_LEVELS
243	int
244	default 5
245
246source "kernel/livepatch/Kconfig"
247
248config ARCH_SUPPORTS_KEXEC
249	def_bool y
250
251config ARCH_SUPPORTS_KEXEC_FILE
252	def_bool CRYPTO && CRYPTO_SHA256 && CRYPTO_SHA256_S390
253
254config ARCH_SUPPORTS_KEXEC_SIG
255	def_bool MODULE_SIG_FORMAT
256
257config ARCH_SUPPORTS_KEXEC_PURGATORY
258	def_bool KEXEC_FILE
259
260config ARCH_SUPPORTS_CRASH_DUMP
261	def_bool y
262	help
263	  Refer to <file:Documentation/s390/zfcpdump.rst> for more details on this.
264	  This option also enables s390 zfcpdump.
265	  See also <file:Documentation/s390/zfcpdump.rst>
266
267menu "Processor type and features"
268
269config HAVE_MARCH_Z10_FEATURES
270	def_bool n
271
272config HAVE_MARCH_Z196_FEATURES
273	def_bool n
274	select HAVE_MARCH_Z10_FEATURES
275
276config HAVE_MARCH_ZEC12_FEATURES
277	def_bool n
278	select HAVE_MARCH_Z196_FEATURES
279
280config HAVE_MARCH_Z13_FEATURES
281	def_bool n
282	select HAVE_MARCH_ZEC12_FEATURES
283
284config HAVE_MARCH_Z14_FEATURES
285	def_bool n
286	select HAVE_MARCH_Z13_FEATURES
287
288config HAVE_MARCH_Z15_FEATURES
289	def_bool n
290	select HAVE_MARCH_Z14_FEATURES
291
292config HAVE_MARCH_Z16_FEATURES
293	def_bool n
294	select HAVE_MARCH_Z15_FEATURES
295
296choice
297	prompt "Processor type"
298	default MARCH_Z196
299
300config MARCH_Z10
301	bool "IBM System z10"
302	select HAVE_MARCH_Z10_FEATURES
303	depends on $(cc-option,-march=z10)
304	help
305	  Select this to enable optimizations for IBM System z10 (2097 and 2098
306	  series). This is the oldest machine generation currently supported.
307
308config MARCH_Z196
309	bool "IBM zEnterprise 114 and 196"
310	select HAVE_MARCH_Z196_FEATURES
311	depends on $(cc-option,-march=z196)
312	help
313	  Select this to enable optimizations for IBM zEnterprise 114 and 196
314	  (2818 and 2817 series). The kernel will be slightly faster but will
315	  not work on older machines.
316
317config MARCH_ZEC12
318	bool "IBM zBC12 and zEC12"
319	select HAVE_MARCH_ZEC12_FEATURES
320	depends on $(cc-option,-march=zEC12)
321	help
322	  Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
323	  2827 series). The kernel will be slightly faster but will not work on
324	  older machines.
325
326config MARCH_Z13
327	bool "IBM z13s and z13"
328	select HAVE_MARCH_Z13_FEATURES
329	depends on $(cc-option,-march=z13)
330	help
331	  Select this to enable optimizations for IBM z13s and z13 (2965 and
332	  2964 series). The kernel will be slightly faster but will not work on
333	  older machines.
334
335config MARCH_Z14
336	bool "IBM z14 ZR1 and z14"
337	select HAVE_MARCH_Z14_FEATURES
338	depends on $(cc-option,-march=z14)
339	help
340	  Select this to enable optimizations for IBM z14 ZR1 and z14 (3907
341	  and 3906 series). The kernel will be slightly faster but will not
342	  work on older machines.
343
344config MARCH_Z15
345	bool "IBM z15"
346	select HAVE_MARCH_Z15_FEATURES
347	depends on $(cc-option,-march=z15)
348	help
349	  Select this to enable optimizations for IBM z15 (8562
350	  and 8561 series). The kernel will be slightly faster but will not
351	  work on older machines.
352
353config MARCH_Z16
354	bool "IBM z16"
355	select HAVE_MARCH_Z16_FEATURES
356	depends on $(cc-option,-march=z16)
357	help
358	  Select this to enable optimizations for IBM z16 (3931 and
359	  3932 series).
360
361endchoice
362
363config MARCH_Z10_TUNE
364	def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
365
366config MARCH_Z196_TUNE
367	def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
368
369config MARCH_ZEC12_TUNE
370	def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
371
372config MARCH_Z13_TUNE
373	def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT
374
375config MARCH_Z14_TUNE
376	def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT
377
378config MARCH_Z15_TUNE
379	def_bool TUNE_Z15 || MARCH_Z15 && TUNE_DEFAULT
380
381config MARCH_Z16_TUNE
382	def_bool TUNE_Z16 || MARCH_Z16 && TUNE_DEFAULT
383
384choice
385	prompt "Tune code generation"
386	default TUNE_DEFAULT
387	help
388	  Cause the compiler to tune (-mtune) the generated code for a machine.
389	  This will make the code run faster on the selected machine but
390	  somewhat slower on other machines.
391	  This option only changes how the compiler emits instructions, not the
392	  selection of instructions itself, so the resulting kernel will run on
393	  all other machines.
394
395config TUNE_DEFAULT
396	bool "Default"
397	help
398	  Tune the generated code for the target processor for which the kernel
399	  will be compiled.
400
401config TUNE_Z10
402	bool "IBM System z10"
403
404config TUNE_Z196
405	bool "IBM zEnterprise 114 and 196"
406	depends on $(cc-option,-mtune=z196)
407
408config TUNE_ZEC12
409	bool "IBM zBC12 and zEC12"
410	depends on $(cc-option,-mtune=zEC12)
411
412config TUNE_Z13
413	bool "IBM z13s and z13"
414	depends on $(cc-option,-mtune=z13)
415
416config TUNE_Z14
417	bool "IBM z14 ZR1 and z14"
418	depends on $(cc-option,-mtune=z14)
419
420config TUNE_Z15
421	bool "IBM z15"
422	depends on $(cc-option,-mtune=z15)
423
424config TUNE_Z16
425	bool "IBM z16"
426	depends on $(cc-option,-mtune=z16)
427
428endchoice
429
430config 64BIT
431	def_bool y
432
433config COMMAND_LINE_SIZE
434	int "Maximum size of kernel command line"
435	default 4096
436	range 896 1048576
437	help
438	  This allows you to specify the maximum length of the kernel command
439	  line.
440
441config COMPAT
442	def_bool y
443	prompt "Kernel support for 31 bit emulation"
444	select ARCH_WANT_OLD_COMPAT_IPC
445	select COMPAT_OLD_SIGACTION
446	select HAVE_UID16
447	depends on MULTIUSER
448	depends on !CC_IS_CLANG
449	help
450	  Select this option if you want to enable your system kernel to
451	  handle system-calls from ELF binaries for 31 bit ESA.  This option
452	  (and some other stuff like libraries and such) is needed for
453	  executing 31 bit applications.  It is safe to say "Y".
454
455config SMP
456	def_bool y
457
458config NR_CPUS
459	int "Maximum number of CPUs (2-512)"
460	range 2 512
461	default "64"
462	help
463	  This allows you to specify the maximum number of CPUs which this
464	  kernel will support. The maximum supported value is 512 and the
465	  minimum value which makes sense is 2.
466
467	  This is purely to save memory - each supported CPU adds
468	  approximately sixteen kilobytes to the kernel image.
469
470config HOTPLUG_CPU
471	def_bool y
472
473config NUMA
474	bool "NUMA support"
475	depends on SCHED_TOPOLOGY
476	default n
477	help
478	  Enable NUMA support
479
480	  This option adds NUMA support to the kernel.
481
482config NODES_SHIFT
483	int
484	depends on NUMA
485	default "1"
486
487config SCHED_SMT
488	def_bool n
489
490config SCHED_MC
491	def_bool n
492
493config SCHED_TOPOLOGY
494	def_bool y
495	prompt "Topology scheduler support"
496	select SCHED_SMT
497	select SCHED_MC
498	help
499	  Topology scheduler support improves the CPU scheduler's decision
500	  making when dealing with machines that have multi-threading,
501	  multiple cores or multiple books.
502
503source "kernel/Kconfig.hz"
504
505config KERNEL_NOBP
506	def_bool n
507	prompt "Enable modified branch prediction for the kernel by default"
508	help
509	  If this option is selected the kernel will switch to a modified
510	  branch prediction mode if the firmware interface is available.
511	  The modified branch prediction mode improves the behaviour in
512	  regard to speculative execution.
513
514	  With the option enabled the kernel parameter "nobp=0" or "nospec"
515	  can be used to run the kernel in the normal branch prediction mode.
516
517	  With the option disabled the modified branch prediction mode is
518	  enabled with the "nobp=1" kernel parameter.
519
520	  If unsure, say N.
521
522config EXPOLINE
523	def_bool n
524	depends on $(cc-option,-mindirect-branch=thunk)
525	prompt "Avoid speculative indirect branches in the kernel"
526	help
527	  Compile the kernel with the expoline compiler options to guard
528	  against kernel-to-user data leaks by avoiding speculative indirect
529	  branches.
530	  Requires a compiler with -mindirect-branch=thunk support for full
531	  protection. The kernel may run slower.
532
533	  If unsure, say N.
534
535config EXPOLINE_EXTERN
536	def_bool n
537	depends on EXPOLINE
538	depends on CC_IS_GCC && GCC_VERSION >= 110200
539	depends on $(success,$(srctree)/arch/s390/tools/gcc-thunk-extern.sh $(CC))
540	prompt "Generate expolines as extern functions."
541	help
542	  This option is required for some tooling like kpatch. The kernel is
543	  compiled with -mindirect-branch=thunk-extern and requires a newer
544	  compiler.
545
546	  If unsure, say N.
547
548choice
549	prompt "Expoline default"
550	depends on EXPOLINE
551	default EXPOLINE_FULL
552
553config EXPOLINE_OFF
554	bool "spectre_v2=off"
555
556config EXPOLINE_AUTO
557	bool "spectre_v2=auto"
558
559config EXPOLINE_FULL
560	bool "spectre_v2=on"
561
562endchoice
563
564config RELOCATABLE
565	def_bool y
566	help
567	  This builds a kernel image that retains relocation information
568	  so it can be loaded at an arbitrary address.
569	  The kernel is linked as a position-independent executable (PIE)
570	  and contains dynamic relocations which are processed early in the
571	  bootup process.
572	  The relocations make the kernel image about 15% larger (compressed
573	  10%), but are discarded at runtime.
574	  Note: this option exists only for documentation purposes, please do
575	  not remove it.
576
577config RANDOMIZE_BASE
578	bool "Randomize the address of the kernel image (KASLR)"
579	default y
580	help
581	  In support of Kernel Address Space Layout Randomization (KASLR),
582	  this randomizes the address at which the kernel image is loaded,
583	  as a security feature that deters exploit attempts relying on
584	  knowledge of the location of kernel internals.
585
586endmenu
587
588menu "Memory setup"
589
590config ARCH_SPARSEMEM_ENABLE
591	def_bool y
592	select SPARSEMEM_VMEMMAP_ENABLE
593	select SPARSEMEM_VMEMMAP
594
595config ARCH_SPARSEMEM_DEFAULT
596	def_bool y
597
598config MAX_PHYSMEM_BITS
599	int "Maximum size of supported physical memory in bits (42-53)"
600	range 42 53
601	default "46"
602	help
603	  This option specifies the maximum supported size of physical memory
604	  in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB).
605	  Increasing the number of bits also increases the kernel image size.
606	  By default 46 bits (64TB) are supported.
607
608config CHECK_STACK
609	def_bool y
610	depends on !VMAP_STACK
611	prompt "Detect kernel stack overflow"
612	help
613	  This option enables the compiler option -mstack-guard and
614	  -mstack-size if they are available. If the compiler supports them
615	  it will emit additional code to each function prolog to trigger
616	  an illegal operation if the kernel stack is about to overflow.
617
618	  Say N if you are unsure.
619
620config STACK_GUARD
621	int "Size of the guard area (128-1024)"
622	range 128 1024
623	depends on CHECK_STACK
624	default "256"
625	help
626	  This allows you to specify the size of the guard area at the lower
627	  end of the kernel stack. If the kernel stack points into the guard
628	  area on function entry an illegal operation is triggered. The size
629	  needs to be a power of 2. Please keep in mind that the size of an
630	  interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
631	  The minimum size for the stack guard should be 256 for 31 bit and
632	  512 for 64 bit.
633
634endmenu
635
636menu "I/O subsystem"
637
638config QDIO
639	def_tristate y
640	prompt "QDIO support"
641	help
642	  This driver provides the Queued Direct I/O base support for
643	  IBM System z.
644
645	  To compile this driver as a module, choose M here: the
646	  module will be called qdio.
647
648	  If unsure, say Y.
649
650if PCI
651
652config PCI_NR_FUNCTIONS
653	int "Maximum number of PCI functions (1-4096)"
654	range 1 4096
655	default "512"
656	help
657	  This allows you to specify the maximum number of PCI functions which
658	  this kernel will support.
659
660endif # PCI
661
662config HAS_IOMEM
663	def_bool PCI
664
665config CHSC_SCH
666	def_tristate m
667	prompt "Support for CHSC subchannels"
668	help
669	  This driver allows usage of CHSC subchannels. A CHSC subchannel
670	  is usually present on LPAR only.
671	  The driver creates a device /dev/chsc, which may be used to
672	  obtain I/O configuration information about the machine and
673	  to issue asynchronous chsc commands (DANGEROUS).
674	  You will usually only want to use this interface on a special
675	  LPAR designated for system management.
676
677	  To compile this driver as a module, choose M here: the
678	  module will be called chsc_sch.
679
680	  If unsure, say N.
681
682config SCM_BUS
683	def_bool y
684	prompt "SCM bus driver"
685	help
686	  Bus driver for Storage Class Memory.
687
688config EADM_SCH
689	def_tristate m
690	prompt "Support for EADM subchannels"
691	depends on SCM_BUS
692	help
693	  This driver allows usage of EADM subchannels. EADM subchannels act
694	  as a communication vehicle for SCM increments.
695
696	  To compile this driver as a module, choose M here: the
697	  module will be called eadm_sch.
698
699config VFIO_CCW
700	def_tristate n
701	prompt "Support for VFIO-CCW subchannels"
702	depends on VFIO
703	select VFIO_MDEV
704	help
705	  This driver allows usage of I/O subchannels via VFIO-CCW.
706
707	  To compile this driver as a module, choose M here: the
708	  module will be called vfio_ccw.
709
710config VFIO_AP
711	def_tristate n
712	prompt "VFIO support for AP devices"
713	depends on KVM
714	depends on VFIO
715	depends on ZCRYPT
716	select VFIO_MDEV
717	help
718	  This driver grants access to Adjunct Processor (AP) devices
719	  via the VFIO mediated device interface.
720
721	  To compile this driver as a module, choose M here: the module
722	  will be called vfio_ap.
723
724endmenu
725
726config CCW
727	def_bool y
728
729config HAVE_PNETID
730	tristate
731	default (SMC || CCWGROUP)
732
733menu "Virtualization"
734
735config PROTECTED_VIRTUALIZATION_GUEST
736	def_bool n
737	prompt "Protected virtualization guest support"
738	help
739	  Select this option, if you want to be able to run this
740	  kernel as a protected virtualization KVM guest.
741	  Protected virtualization capable machines have a mini hypervisor
742	  located at machine level (an ultravisor). With help of the
743	  Ultravisor, KVM will be able to run "protected" VMs, special
744	  VMs whose memory and management data are unavailable to KVM.
745
746config PFAULT
747	def_bool y
748	prompt "Pseudo page fault support"
749	help
750	  Select this option, if you want to use PFAULT pseudo page fault
751	  handling under VM. If running native or in LPAR, this option
752	  has no effect. If your VM does not support PFAULT, PAGEEX
753	  pseudo page fault handling will be used.
754	  Note that VM 4.2 supports PFAULT but has a bug in its
755	  implementation that causes some problems.
756	  Everybody who wants to run Linux under VM != VM4.2 should select
757	  this option.
758
759config CMM
760	def_tristate n
761	prompt "Cooperative memory management"
762	help
763	  Select this option, if you want to enable the kernel interface
764	  to reduce the memory size of the system. This is accomplished
765	  by allocating pages of memory and put them "on hold". This only
766	  makes sense for a system running under VM where the unused pages
767	  will be reused by VM for other guest systems. The interface
768	  allows an external monitor to balance memory of many systems.
769	  Everybody who wants to run Linux under VM should select this
770	  option.
771
772config CMM_IUCV
773	def_bool y
774	prompt "IUCV special message interface to cooperative memory management"
775	depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
776	help
777	  Select this option to enable the special message interface to
778	  the cooperative memory management.
779
780config APPLDATA_BASE
781	def_bool n
782	prompt "Linux - VM Monitor Stream, base infrastructure"
783	depends on PROC_SYSCTL
784	help
785	  This provides a kernel interface for creating and updating z/VM APPLDATA
786	  monitor records. The monitor records are updated at certain time
787	  intervals, once the timer is started.
788	  Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
789	  i.e. enables or disables monitoring on the Linux side.
790	  A custom interval value (in seconds) can be written to
791	  /proc/appldata/interval.
792
793	  Defaults are 60 seconds interval and timer off.
794	  The /proc entries can also be read from, showing the current settings.
795
796config APPLDATA_MEM
797	def_tristate m
798	prompt "Monitor memory management statistics"
799	depends on APPLDATA_BASE && VM_EVENT_COUNTERS
800	help
801	  This provides memory management related data to the Linux - VM Monitor
802	  Stream, like paging/swapping rate, memory utilisation, etc.
803	  Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
804	  APPLDATA monitor record, i.e. enables or disables monitoring this record
805	  on the z/VM side.
806
807	  Default is disabled.
808	  The /proc entry can also be read from, showing the current settings.
809
810	  This can also be compiled as a module, which will be called
811	  appldata_mem.o.
812
813config APPLDATA_OS
814	def_tristate m
815	prompt "Monitor OS statistics"
816	depends on APPLDATA_BASE
817	help
818	  This provides OS related data to the Linux - VM Monitor Stream, like
819	  CPU utilisation, etc.
820	  Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
821	  APPLDATA monitor record, i.e. enables or disables monitoring this record
822	  on the z/VM side.
823
824	  Default is disabled.
825	  This can also be compiled as a module, which will be called
826	  appldata_os.o.
827
828config APPLDATA_NET_SUM
829	def_tristate m
830	prompt "Monitor overall network statistics"
831	depends on APPLDATA_BASE && NET
832	help
833	  This provides network related data to the Linux - VM Monitor Stream,
834	  currently there is only a total sum of network I/O statistics, no
835	  per-interface data.
836	  Writing 1 or 0 to /proc/appldata/net_sum 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	  This can also be compiled as a module, which will be called
842	  appldata_net_sum.o.
843
844config S390_HYPFS_FS
845	def_bool y
846	prompt "s390 hypervisor file system support"
847	select SYS_HYPERVISOR
848	help
849	  This is a virtual file system intended to provide accounting
850	  information in an s390 hypervisor environment.
851
852source "arch/s390/kvm/Kconfig"
853
854config S390_GUEST
855	def_bool y
856	prompt "s390 support for virtio devices"
857	select TTY
858	select VIRTUALIZATION
859	select VIRTIO
860	help
861	  Enabling this option adds support for virtio based paravirtual device
862	  drivers on s390.
863
864	  Select this option if you want to run the kernel as a guest under
865	  the KVM hypervisor.
866
867endmenu
868
869config S390_MODULES_SANITY_TEST_HELPERS
870	def_bool n
871
872menu "Selftests"
873
874config S390_UNWIND_SELFTEST
875	def_tristate n
876	depends on KUNIT
877	default KUNIT_ALL_TESTS
878	prompt "Test unwind functions"
879	help
880	  This option enables s390 specific stack unwinder testing kernel
881	  module. This option is not useful for distributions or general
882	  kernels, but only for kernel developers working on architecture code.
883
884	  Say N if you are unsure.
885
886config S390_KPROBES_SANITY_TEST
887	def_tristate n
888	prompt "Enable s390 specific kprobes tests"
889	depends on KPROBES
890	depends on KUNIT
891	help
892	  This option enables an s390 specific kprobes test module. This option
893	  is not useful for distributions or general kernels, but only for kernel
894	  developers working on architecture code.
895
896	  Say N if you are unsure.
897
898config S390_MODULES_SANITY_TEST
899	def_tristate n
900	depends on KUNIT
901	default KUNIT_ALL_TESTS
902	prompt "Enable s390 specific modules tests"
903	select S390_MODULES_SANITY_TEST_HELPERS
904	help
905	  This option enables an s390 specific modules test. This option is
906	  not useful for distributions or general kernels, but only for
907	  kernel developers working on architecture code.
908
909	  Say N if you are unsure.
910endmenu
911