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_VIRTUAL
67	select ARCH_HAS_DEBUG_VM_PGTABLE
68	select ARCH_HAS_DEBUG_WX
69	select ARCH_HAS_DEVMEM_IS_ALLOWED
70	select ARCH_HAS_ELF_RANDOMIZE
71	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
72	select ARCH_HAS_FORTIFY_SOURCE
73	select ARCH_HAS_GCOV_PROFILE_ALL
74	select ARCH_HAS_GIGANTIC_PAGE
75	select ARCH_HAS_KCOV
76	select ARCH_HAS_MEMBARRIER_SYNC_CORE
77	select ARCH_HAS_MEM_ENCRYPT
78	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
79	select ARCH_HAS_PTE_SPECIAL
80	select ARCH_HAS_SCALED_CPUTIME
81	select ARCH_HAS_SET_DIRECT_MAP
82	select ARCH_HAS_SET_MEMORY
83	select ARCH_HAS_STRICT_KERNEL_RWX
84	select ARCH_HAS_STRICT_MODULE_RWX
85	select ARCH_HAS_SYSCALL_WRAPPER
86	select ARCH_HAS_UBSAN
87	select ARCH_HAS_VDSO_DATA
88	select ARCH_HAVE_NMI_SAFE_CMPXCHG
89	select ARCH_INLINE_READ_LOCK
90	select ARCH_INLINE_READ_LOCK_BH
91	select ARCH_INLINE_READ_LOCK_IRQ
92	select ARCH_INLINE_READ_LOCK_IRQSAVE
93	select ARCH_INLINE_READ_TRYLOCK
94	select ARCH_INLINE_READ_UNLOCK
95	select ARCH_INLINE_READ_UNLOCK_BH
96	select ARCH_INLINE_READ_UNLOCK_IRQ
97	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
98	select ARCH_INLINE_SPIN_LOCK
99	select ARCH_INLINE_SPIN_LOCK_BH
100	select ARCH_INLINE_SPIN_LOCK_IRQ
101	select ARCH_INLINE_SPIN_LOCK_IRQSAVE
102	select ARCH_INLINE_SPIN_TRYLOCK
103	select ARCH_INLINE_SPIN_TRYLOCK_BH
104	select ARCH_INLINE_SPIN_UNLOCK
105	select ARCH_INLINE_SPIN_UNLOCK_BH
106	select ARCH_INLINE_SPIN_UNLOCK_IRQ
107	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
108	select ARCH_INLINE_WRITE_LOCK
109	select ARCH_INLINE_WRITE_LOCK_BH
110	select ARCH_INLINE_WRITE_LOCK_IRQ
111	select ARCH_INLINE_WRITE_LOCK_IRQSAVE
112	select ARCH_INLINE_WRITE_TRYLOCK
113	select ARCH_INLINE_WRITE_UNLOCK
114	select ARCH_INLINE_WRITE_UNLOCK_BH
115	select ARCH_INLINE_WRITE_UNLOCK_IRQ
116	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
117	select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
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_INT128 if CC_HAS_INT128 && CC_IS_CLANG
123	select ARCH_SUPPORTS_NUMA_BALANCING
124	select ARCH_SUPPORTS_PER_VMA_LOCK
125	select ARCH_USE_BUILTIN_BSWAP
126	select ARCH_USE_CMPXCHG_LOCKREF
127	select ARCH_USE_SYM_ANNOTATIONS
128	select ARCH_WANTS_NO_INSTR
129	select ARCH_WANT_DEFAULT_BPF_JIT
130	select ARCH_WANT_IPC_PARSE_VERSION
131	select ARCH_WANT_KERNEL_PMD_MKWRITE
132	select ARCH_WANT_LD_ORPHAN_WARN
133	select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP
134	select BUILDTIME_TABLE_SORT
135	select CLONE_BACKWARDS2
136	select DCACHE_WORD_ACCESS if !KMSAN
137	select DMA_OPS if PCI
138	select DYNAMIC_FTRACE if FUNCTION_TRACER
139	select FUNCTION_ALIGNMENT_8B if CC_IS_GCC
140	select FUNCTION_ALIGNMENT_16B if !CC_IS_GCC
141	select GENERIC_ALLOCATOR
142	select GENERIC_CPU_AUTOPROBE
143	select GENERIC_CPU_VULNERABILITIES
144	select GENERIC_ENTRY
145	select GENERIC_GETTIMEOFDAY
146	select GENERIC_PTDUMP
147	select GENERIC_SMP_IDLE_THREAD
148	select GENERIC_TIME_VSYSCALL
149	select GENERIC_VDSO_TIME_NS
150	select GENERIC_IOREMAP if PCI
151	select HAVE_ALIGNED_STRUCT_PAGE
152	select HAVE_ARCH_AUDITSYSCALL
153	select HAVE_ARCH_JUMP_LABEL
154	select HAVE_ARCH_JUMP_LABEL_RELATIVE
155	select HAVE_ARCH_KASAN
156	select HAVE_ARCH_KASAN_VMALLOC
157	select HAVE_ARCH_KCSAN
158	select HAVE_ARCH_KFENCE
159	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
160	select HAVE_ARCH_SECCOMP_FILTER
161	select HAVE_ARCH_SOFT_DIRTY
162	select HAVE_ARCH_STACKLEAK
163	select HAVE_ARCH_TRACEHOOK
164	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
165	select HAVE_ARCH_VMAP_STACK
166	select HAVE_ASM_MODVERSIONS
167	select HAVE_CMPXCHG_DOUBLE
168	select HAVE_CMPXCHG_LOCAL
169	select HAVE_DEBUG_KMEMLEAK
170	select HAVE_DMA_CONTIGUOUS
171	select HAVE_DYNAMIC_FTRACE
172	select HAVE_DYNAMIC_FTRACE_WITH_ARGS
173	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
174	select HAVE_DYNAMIC_FTRACE_WITH_REGS
175	select HAVE_EBPF_JIT if HAVE_MARCH_Z196_FEATURES
176	select HAVE_EFFICIENT_UNALIGNED_ACCESS
177	select HAVE_FAST_GUP
178	select HAVE_FENTRY
179	select HAVE_FTRACE_MCOUNT_RECORD
180	select HAVE_FUNCTION_ARG_ACCESS_API
181	select HAVE_FUNCTION_ERROR_INJECTION
182	select HAVE_FUNCTION_GRAPH_RETVAL
183	select HAVE_FUNCTION_GRAPH_TRACER
184	select HAVE_FUNCTION_TRACER
185	select HAVE_GCC_PLUGINS
186	select HAVE_GENERIC_VDSO
187	select HAVE_IOREMAP_PROT if PCI
188	select HAVE_KERNEL_BZIP2
189	select HAVE_KERNEL_GZIP
190	select HAVE_KERNEL_LZ4
191	select HAVE_KERNEL_LZMA
192	select HAVE_KERNEL_LZO
193	select HAVE_KERNEL_UNCOMPRESSED
194	select HAVE_KERNEL_XZ
195	select HAVE_KERNEL_ZSTD
196	select HAVE_KPROBES
197	select HAVE_KPROBES_ON_FTRACE
198	select HAVE_KRETPROBES
199	select HAVE_LIVEPATCH
200	select HAVE_MEMBLOCK_PHYS_MAP
201	select HAVE_MOD_ARCH_SPECIFIC
202	select HAVE_NMI
203	select HAVE_NOP_MCOUNT
204	select HAVE_PAGE_SIZE_4KB
205	select HAVE_PCI
206	select HAVE_PERF_EVENTS
207	select HAVE_PERF_REGS
208	select HAVE_PERF_USER_STACK_DUMP
209	select HAVE_REGS_AND_STACK_ACCESS_API
210	select HAVE_RELIABLE_STACKTRACE
211	select HAVE_RETHOOK
212	select HAVE_RSEQ
213	select HAVE_SAMPLE_FTRACE_DIRECT
214	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
215	select HAVE_SETUP_PER_CPU_AREA
216	select HAVE_SOFTIRQ_ON_OWN_STACK
217	select HAVE_SYSCALL_TRACEPOINTS
218	select HAVE_VIRT_CPU_ACCOUNTING
219	select HAVE_VIRT_CPU_ACCOUNTING_IDLE
220	select IOMMU_HELPER		if PCI
221	select IOMMU_SUPPORT		if PCI
222	select MMU_GATHER_MERGE_VMAS
223	select MMU_GATHER_NO_GATHER
224	select MMU_GATHER_RCU_TABLE_FREE
225	select MODULES_USE_ELF_RELA
226	select NEED_DMA_MAP_STATE	if PCI
227	select NEED_PER_CPU_EMBED_FIRST_CHUNK
228	select NEED_SG_DMA_LENGTH	if PCI
229	select OLD_SIGACTION
230	select OLD_SIGSUSPEND3
231	select PCI_DOMAINS		if PCI
232	select PCI_MSI			if PCI
233	select PCI_MSI_ARCH_FALLBACKS	if PCI_MSI
234	select SPARSE_IRQ
235	select SWIOTLB
236	select SYSCTL_EXCEPTION_TRACE
237	select THREAD_INFO_IN_TASK
238	select TRACE_IRQFLAGS_SUPPORT
239	select TTY
240	select USER_STACKTRACE_SUPPORT
241	select VIRT_CPU_ACCOUNTING
242	select ZONE_DMA
243	# Note: keep the above list sorted alphabetically
244
245config SCHED_OMIT_FRAME_POINTER
246	def_bool y
247
248config PGTABLE_LEVELS
249	int
250	default 5
251
252source "kernel/livepatch/Kconfig"
253
254config ARCH_SUPPORTS_KEXEC
255	def_bool y
256
257config ARCH_SUPPORTS_KEXEC_FILE
258	def_bool y
259
260config ARCH_SUPPORTS_KEXEC_SIG
261	def_bool MODULE_SIG_FORMAT
262
263config ARCH_SUPPORTS_KEXEC_PURGATORY
264	def_bool y
265
266config ARCH_SUPPORTS_CRASH_DUMP
267	def_bool y
268	help
269	  Refer to <file:Documentation/arch/s390/zfcpdump.rst> for more details on this.
270	  This option also enables s390 zfcpdump.
271	  See also <file:Documentation/arch/s390/zfcpdump.rst>
272
273menu "Processor type and features"
274
275config HAVE_MARCH_Z10_FEATURES
276	def_bool n
277
278config HAVE_MARCH_Z196_FEATURES
279	def_bool n
280	select HAVE_MARCH_Z10_FEATURES
281
282config HAVE_MARCH_ZEC12_FEATURES
283	def_bool n
284	select HAVE_MARCH_Z196_FEATURES
285
286config HAVE_MARCH_Z13_FEATURES
287	def_bool n
288	select HAVE_MARCH_ZEC12_FEATURES
289
290config HAVE_MARCH_Z14_FEATURES
291	def_bool n
292	select HAVE_MARCH_Z13_FEATURES
293
294config HAVE_MARCH_Z15_FEATURES
295	def_bool n
296	select HAVE_MARCH_Z14_FEATURES
297
298config HAVE_MARCH_Z16_FEATURES
299	def_bool n
300	select HAVE_MARCH_Z15_FEATURES
301
302choice
303	prompt "Processor type"
304	default MARCH_Z196
305
306config MARCH_Z10
307	bool "IBM System z10"
308	select HAVE_MARCH_Z10_FEATURES
309	depends on $(cc-option,-march=z10)
310	help
311	  Select this to enable optimizations for IBM System z10 (2097 and 2098
312	  series). This is the oldest machine generation currently supported.
313
314config MARCH_Z196
315	bool "IBM zEnterprise 114 and 196"
316	select HAVE_MARCH_Z196_FEATURES
317	depends on $(cc-option,-march=z196)
318	help
319	  Select this to enable optimizations for IBM zEnterprise 114 and 196
320	  (2818 and 2817 series). The kernel will be slightly faster but will
321	  not work on older machines.
322
323config MARCH_ZEC12
324	bool "IBM zBC12 and zEC12"
325	select HAVE_MARCH_ZEC12_FEATURES
326	depends on $(cc-option,-march=zEC12)
327	help
328	  Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
329	  2827 series). The kernel will be slightly faster but will not work on
330	  older machines.
331
332config MARCH_Z13
333	bool "IBM z13s and z13"
334	select HAVE_MARCH_Z13_FEATURES
335	depends on $(cc-option,-march=z13)
336	help
337	  Select this to enable optimizations for IBM z13s and z13 (2965 and
338	  2964 series). The kernel will be slightly faster but will not work on
339	  older machines.
340
341config MARCH_Z14
342	bool "IBM z14 ZR1 and z14"
343	select HAVE_MARCH_Z14_FEATURES
344	depends on $(cc-option,-march=z14)
345	help
346	  Select this to enable optimizations for IBM z14 ZR1 and z14 (3907
347	  and 3906 series). The kernel will be slightly faster but will not
348	  work on older machines.
349
350config MARCH_Z15
351	bool "IBM z15"
352	select HAVE_MARCH_Z15_FEATURES
353	depends on $(cc-option,-march=z15)
354	help
355	  Select this to enable optimizations for IBM z15 (8562
356	  and 8561 series). The kernel will be slightly faster but will not
357	  work on older machines.
358
359config MARCH_Z16
360	bool "IBM z16"
361	select HAVE_MARCH_Z16_FEATURES
362	depends on $(cc-option,-march=z16)
363	help
364	  Select this to enable optimizations for IBM z16 (3931 and
365	  3932 series).
366
367endchoice
368
369config MARCH_Z10_TUNE
370	def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
371
372config MARCH_Z196_TUNE
373	def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
374
375config MARCH_ZEC12_TUNE
376	def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
377
378config MARCH_Z13_TUNE
379	def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT
380
381config MARCH_Z14_TUNE
382	def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT
383
384config MARCH_Z15_TUNE
385	def_bool TUNE_Z15 || MARCH_Z15 && TUNE_DEFAULT
386
387config MARCH_Z16_TUNE
388	def_bool TUNE_Z16 || MARCH_Z16 && TUNE_DEFAULT
389
390choice
391	prompt "Tune code generation"
392	default TUNE_DEFAULT
393	help
394	  Cause the compiler to tune (-mtune) the generated code for a machine.
395	  This will make the code run faster on the selected machine but
396	  somewhat slower on other machines.
397	  This option only changes how the compiler emits instructions, not the
398	  selection of instructions itself, so the resulting kernel will run on
399	  all other machines.
400
401config TUNE_DEFAULT
402	bool "Default"
403	help
404	  Tune the generated code for the target processor for which the kernel
405	  will be compiled.
406
407config TUNE_Z10
408	bool "IBM System z10"
409
410config TUNE_Z196
411	bool "IBM zEnterprise 114 and 196"
412	depends on $(cc-option,-mtune=z196)
413
414config TUNE_ZEC12
415	bool "IBM zBC12 and zEC12"
416	depends on $(cc-option,-mtune=zEC12)
417
418config TUNE_Z13
419	bool "IBM z13s and z13"
420	depends on $(cc-option,-mtune=z13)
421
422config TUNE_Z14
423	bool "IBM z14 ZR1 and z14"
424	depends on $(cc-option,-mtune=z14)
425
426config TUNE_Z15
427	bool "IBM z15"
428	depends on $(cc-option,-mtune=z15)
429
430config TUNE_Z16
431	bool "IBM z16"
432	depends on $(cc-option,-mtune=z16)
433
434endchoice
435
436config 64BIT
437	def_bool y
438
439config COMMAND_LINE_SIZE
440	int "Maximum size of kernel command line"
441	default 4096
442	range 896 1048576
443	help
444	  This allows you to specify the maximum length of the kernel command
445	  line.
446
447config COMPAT
448	def_bool n
449	prompt "Kernel support for 31 bit emulation"
450	select ARCH_WANT_OLD_COMPAT_IPC
451	select COMPAT_OLD_SIGACTION
452	select HAVE_UID16
453	depends on MULTIUSER
454	depends on !CC_IS_CLANG && !LD_IS_LLD
455	help
456	  Select this option if you want to enable your system kernel to
457	  handle system-calls from ELF binaries for 31 bit ESA.  This option
458	  (and some other stuff like libraries and such) is needed for
459	  executing 31 bit applications.
460
461	  If unsure say N.
462
463config SMP
464	def_bool y
465
466config NR_CPUS
467	int "Maximum number of CPUs (2-512)"
468	range 2 512
469	default "64"
470	help
471	  This allows you to specify the maximum number of CPUs which this
472	  kernel will support. The maximum supported value is 512 and the
473	  minimum value which makes sense is 2.
474
475	  This is purely to save memory - each supported CPU adds
476	  approximately sixteen kilobytes to the kernel image.
477
478config HOTPLUG_CPU
479	def_bool y
480
481config NUMA
482	bool "NUMA support"
483	depends on SCHED_TOPOLOGY
484	default n
485	help
486	  Enable NUMA support
487
488	  This option adds NUMA support to the kernel.
489
490config NODES_SHIFT
491	int
492	depends on NUMA
493	default "1"
494
495config SCHED_SMT
496	def_bool n
497
498config SCHED_MC
499	def_bool n
500
501config SCHED_TOPOLOGY
502	def_bool y
503	prompt "Topology scheduler support"
504	select SCHED_SMT
505	select SCHED_MC
506	help
507	  Topology scheduler support improves the CPU scheduler's decision
508	  making when dealing with machines that have multi-threading,
509	  multiple cores or multiple books.
510
511source "kernel/Kconfig.hz"
512
513config CERT_STORE
514	bool "Get user certificates via DIAG320"
515	depends on KEYS
516	select CRYPTO_LIB_SHA256
517	help
518	  Enable this option if you want to access user-provided secure boot
519	  certificates via DIAG 0x320.
520
521	  These certificates will be made available via the keyring named
522	  'cert_store'.
523
524config KERNEL_NOBP
525	def_bool n
526	prompt "Enable modified branch prediction for the kernel by default"
527	help
528	  If this option is selected the kernel will switch to a modified
529	  branch prediction mode if the firmware interface is available.
530	  The modified branch prediction mode improves the behaviour in
531	  regard to speculative execution.
532
533	  With the option enabled the kernel parameter "nobp=0" or "nospec"
534	  can be used to run the kernel in the normal branch prediction mode.
535
536	  With the option disabled the modified branch prediction mode is
537	  enabled with the "nobp=1" kernel parameter.
538
539	  If unsure, say N.
540
541config EXPOLINE
542	def_bool n
543	depends on $(cc-option,-mindirect-branch=thunk)
544	prompt "Avoid speculative indirect branches in the kernel"
545	help
546	  Compile the kernel with the expoline compiler options to guard
547	  against kernel-to-user data leaks by avoiding speculative indirect
548	  branches.
549	  Requires a compiler with -mindirect-branch=thunk support for full
550	  protection. The kernel may run slower.
551
552	  If unsure, say N.
553
554config EXPOLINE_EXTERN
555	def_bool n
556	depends on EXPOLINE
557	depends on CC_IS_GCC && GCC_VERSION >= 110200
558	depends on $(success,$(srctree)/arch/s390/tools/gcc-thunk-extern.sh $(CC))
559	prompt "Generate expolines as extern functions."
560	help
561	  This option is required for some tooling like kpatch. The kernel is
562	  compiled with -mindirect-branch=thunk-extern and requires a newer
563	  compiler.
564
565	  If unsure, say N.
566
567choice
568	prompt "Expoline default"
569	depends on EXPOLINE
570	default EXPOLINE_FULL
571
572config EXPOLINE_OFF
573	bool "spectre_v2=off"
574
575config EXPOLINE_AUTO
576	bool "spectre_v2=auto"
577
578config EXPOLINE_FULL
579	bool "spectre_v2=on"
580
581endchoice
582
583config RELOCATABLE
584	def_bool y
585	help
586	  This builds a kernel image that retains relocation information
587	  so it can be loaded at an arbitrary address.
588	  The relocations make the kernel image about 15% larger (compressed
589	  10%), but are discarded at runtime.
590	  Note: this option exists only for documentation purposes, please do
591	  not remove it.
592
593config PIE_BUILD
594	def_bool CC_IS_CLANG && !$(cc-option,-munaligned-symbols)
595	help
596	  If the compiler is unable to generate code that can manage unaligned
597	  symbols, the kernel is linked as a position-independent executable
598	  (PIE) and includes dynamic relocations that are processed early
599	  during bootup.
600
601	  For kpatch functionality, it is recommended to build the kernel
602	  without the PIE_BUILD option. PIE_BUILD is only enabled when the
603	  compiler lacks proper support for handling unaligned symbols.
604
605config RANDOMIZE_BASE
606	bool "Randomize the address of the kernel image (KASLR)"
607	default y
608	help
609	  In support of Kernel Address Space Layout Randomization (KASLR),
610	  this randomizes the address at which the kernel image is loaded,
611	  as a security feature that deters exploit attempts relying on
612	  knowledge of the location of kernel internals.
613
614endmenu
615
616menu "Memory setup"
617
618config ARCH_SPARSEMEM_ENABLE
619	def_bool y
620	select SPARSEMEM_VMEMMAP_ENABLE
621	select SPARSEMEM_VMEMMAP
622
623config ARCH_SPARSEMEM_DEFAULT
624	def_bool y
625
626config MAX_PHYSMEM_BITS
627	int "Maximum size of supported physical memory in bits (42-53)"
628	range 42 53
629	default "46"
630	help
631	  This option specifies the maximum supported size of physical memory
632	  in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB).
633	  Increasing the number of bits also increases the kernel image size.
634	  By default 46 bits (64TB) are supported.
635
636config CHECK_STACK
637	def_bool y
638	depends on !VMAP_STACK
639	prompt "Detect kernel stack overflow"
640	help
641	  This option enables the compiler option -mstack-guard and
642	  -mstack-size if they are available. If the compiler supports them
643	  it will emit additional code to each function prolog to trigger
644	  an illegal operation if the kernel stack is about to overflow.
645
646	  Say N if you are unsure.
647
648config STACK_GUARD
649	int "Size of the guard area (128-1024)"
650	range 128 1024
651	depends on CHECK_STACK
652	default "256"
653	help
654	  This allows you to specify the size of the guard area at the lower
655	  end of the kernel stack. If the kernel stack points into the guard
656	  area on function entry an illegal operation is triggered. The size
657	  needs to be a power of 2. Please keep in mind that the size of an
658	  interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
659	  The minimum size for the stack guard should be 256 for 31 bit and
660	  512 for 64 bit.
661
662endmenu
663
664menu "I/O subsystem"
665
666config QDIO
667	def_tristate y
668	prompt "QDIO support"
669	help
670	  This driver provides the Queued Direct I/O base support for
671	  IBM System z.
672
673	  To compile this driver as a module, choose M here: the
674	  module will be called qdio.
675
676	  If unsure, say Y.
677
678if PCI
679
680config PCI_NR_FUNCTIONS
681	int "Maximum number of PCI functions (1-4096)"
682	range 1 4096
683	default "512"
684	help
685	  This allows you to specify the maximum number of PCI functions which
686	  this kernel will support.
687
688endif # PCI
689
690config HAS_IOMEM
691	def_bool PCI
692
693config CHSC_SCH
694	def_tristate m
695	prompt "Support for CHSC subchannels"
696	help
697	  This driver allows usage of CHSC subchannels. A CHSC subchannel
698	  is usually present on LPAR only.
699	  The driver creates a device /dev/chsc, which may be used to
700	  obtain I/O configuration information about the machine and
701	  to issue asynchronous chsc commands (DANGEROUS).
702	  You will usually only want to use this interface on a special
703	  LPAR designated for system management.
704
705	  To compile this driver as a module, choose M here: the
706	  module will be called chsc_sch.
707
708	  If unsure, say N.
709
710config SCM_BUS
711	def_bool y
712	prompt "SCM bus driver"
713	help
714	  Bus driver for Storage Class Memory.
715
716config EADM_SCH
717	def_tristate m
718	prompt "Support for EADM subchannels"
719	depends on SCM_BUS
720	help
721	  This driver allows usage of EADM subchannels. EADM subchannels act
722	  as a communication vehicle for SCM increments.
723
724	  To compile this driver as a module, choose M here: the
725	  module will be called eadm_sch.
726
727config VFIO_CCW
728	def_tristate n
729	prompt "Support for VFIO-CCW subchannels"
730	depends on VFIO
731	select VFIO_MDEV
732	help
733	  This driver allows usage of I/O subchannels via VFIO-CCW.
734
735	  To compile this driver as a module, choose M here: the
736	  module will be called vfio_ccw.
737
738config VFIO_AP
739	def_tristate n
740	prompt "VFIO support for AP devices"
741	depends on KVM
742	depends on VFIO
743	depends on ZCRYPT
744	select VFIO_MDEV
745	help
746	  This driver grants access to Adjunct Processor (AP) devices
747	  via the VFIO mediated device interface.
748
749	  To compile this driver as a module, choose M here: the module
750	  will be called vfio_ap.
751
752endmenu
753
754config CCW
755	def_bool y
756
757config HAVE_PNETID
758	tristate
759	default (SMC || CCWGROUP)
760
761menu "Virtualization"
762
763config PROTECTED_VIRTUALIZATION_GUEST
764	def_bool n
765	prompt "Protected virtualization guest support"
766	help
767	  Select this option, if you want to be able to run this
768	  kernel as a protected virtualization KVM guest.
769	  Protected virtualization capable machines have a mini hypervisor
770	  located at machine level (an ultravisor). With help of the
771	  Ultravisor, KVM will be able to run "protected" VMs, special
772	  VMs whose memory and management data are unavailable to KVM.
773
774config PFAULT
775	def_bool y
776	prompt "Pseudo page fault support"
777	help
778	  Select this option, if you want to use PFAULT pseudo page fault
779	  handling under VM. If running native or in LPAR, this option
780	  has no effect. If your VM does not support PFAULT, PAGEEX
781	  pseudo page fault handling will be used.
782	  Note that VM 4.2 supports PFAULT but has a bug in its
783	  implementation that causes some problems.
784	  Everybody who wants to run Linux under VM != VM4.2 should select
785	  this option.
786
787config CMM
788	def_tristate n
789	prompt "Cooperative memory management"
790	help
791	  Select this option, if you want to enable the kernel interface
792	  to reduce the memory size of the system. This is accomplished
793	  by allocating pages of memory and put them "on hold". This only
794	  makes sense for a system running under VM where the unused pages
795	  will be reused by VM for other guest systems. The interface
796	  allows an external monitor to balance memory of many systems.
797	  Everybody who wants to run Linux under VM should select this
798	  option.
799
800config CMM_IUCV
801	def_bool y
802	prompt "IUCV special message interface to cooperative memory management"
803	depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
804	help
805	  Select this option to enable the special message interface to
806	  the cooperative memory management.
807
808config APPLDATA_BASE
809	def_bool n
810	prompt "Linux - VM Monitor Stream, base infrastructure"
811	depends on PROC_SYSCTL
812	help
813	  This provides a kernel interface for creating and updating z/VM APPLDATA
814	  monitor records. The monitor records are updated at certain time
815	  intervals, once the timer is started.
816	  Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
817	  i.e. enables or disables monitoring on the Linux side.
818	  A custom interval value (in seconds) can be written to
819	  /proc/appldata/interval.
820
821	  Defaults are 60 seconds interval and timer off.
822	  The /proc entries can also be read from, showing the current settings.
823
824config APPLDATA_MEM
825	def_tristate m
826	prompt "Monitor memory management statistics"
827	depends on APPLDATA_BASE && VM_EVENT_COUNTERS
828	help
829	  This provides memory management related data to the Linux - VM Monitor
830	  Stream, like paging/swapping rate, memory utilisation, etc.
831	  Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
832	  APPLDATA monitor record, i.e. enables or disables monitoring this record
833	  on the z/VM side.
834
835	  Default is disabled.
836	  The /proc entry can also be read from, showing the current settings.
837
838	  This can also be compiled as a module, which will be called
839	  appldata_mem.o.
840
841config APPLDATA_OS
842	def_tristate m
843	prompt "Monitor OS statistics"
844	depends on APPLDATA_BASE
845	help
846	  This provides OS related data to the Linux - VM Monitor Stream, like
847	  CPU utilisation, etc.
848	  Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
849	  APPLDATA monitor record, i.e. enables or disables monitoring this record
850	  on the z/VM side.
851
852	  Default is disabled.
853	  This can also be compiled as a module, which will be called
854	  appldata_os.o.
855
856config APPLDATA_NET_SUM
857	def_tristate m
858	prompt "Monitor overall network statistics"
859	depends on APPLDATA_BASE && NET
860	help
861	  This provides network related data to the Linux - VM Monitor Stream,
862	  currently there is only a total sum of network I/O statistics, no
863	  per-interface data.
864	  Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
865	  APPLDATA monitor record, i.e. enables or disables monitoring this record
866	  on the z/VM side.
867
868	  Default is disabled.
869	  This can also be compiled as a module, which will be called
870	  appldata_net_sum.o.
871
872config S390_HYPFS
873	def_bool y
874	prompt "s390 hypervisor information"
875	help
876	  This provides several binary files at (debugfs)/s390_hypfs/ to
877	  provide accounting information in an s390 hypervisor environment.
878
879config S390_HYPFS_FS
880	def_bool n
881	prompt "s390 hypervisor file system support"
882	select SYS_HYPERVISOR
883	depends on S390_HYPFS
884	help
885	  This is a virtual file system intended to provide accounting
886	  information in an s390 hypervisor environment. This file system
887	  is deprecated and should not be used.
888
889	  Say N if you are unsure.
890
891source "arch/s390/kvm/Kconfig"
892
893config S390_GUEST
894	def_bool y
895	prompt "s390 support for virtio devices"
896	select TTY
897	select VIRTUALIZATION
898	select VIRTIO
899	help
900	  Enabling this option adds support for virtio based paravirtual device
901	  drivers on s390.
902
903	  Select this option if you want to run the kernel as a guest under
904	  the KVM hypervisor.
905
906endmenu
907
908config S390_MODULES_SANITY_TEST_HELPERS
909	def_bool n
910
911menu "Selftests"
912
913config S390_UNWIND_SELFTEST
914	def_tristate n
915	depends on KUNIT
916	default KUNIT_ALL_TESTS
917	prompt "Test unwind functions"
918	help
919	  This option enables s390 specific stack unwinder testing kernel
920	  module. This option is not useful for distributions or general
921	  kernels, but only for kernel developers working on architecture code.
922
923	  Say N if you are unsure.
924
925config S390_KPROBES_SANITY_TEST
926	def_tristate n
927	prompt "Enable s390 specific kprobes tests"
928	depends on KPROBES
929	depends on KUNIT
930	help
931	  This option enables an s390 specific kprobes test module. This option
932	  is not useful for distributions or general kernels, but only for kernel
933	  developers working on architecture code.
934
935	  Say N if you are unsure.
936
937config S390_MODULES_SANITY_TEST
938	def_tristate n
939	depends on KUNIT
940	default KUNIT_ALL_TESTS
941	prompt "Enable s390 specific modules tests"
942	select S390_MODULES_SANITY_TEST_HELPERS
943	help
944	  This option enables an s390 specific modules test. This option is
945	  not useful for distributions or general kernels, but only for
946	  kernel developers working on architecture code.
947
948	  Say N if you are unsure.
949endmenu
950