xref: /linux/arch/s390/Kconfig (revision c4101e55974cc7d835fbd2d8e01553a3f61e9e75)
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_NO_INSTR
127	select ARCH_WANT_DEFAULT_BPF_JIT
128	select ARCH_WANT_IPC_PARSE_VERSION
129	select ARCH_WANT_KERNEL_PMD_MKWRITE
130	select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP
131	select BUILDTIME_TABLE_SORT
132	select CLONE_BACKWARDS2
133	select DCACHE_WORD_ACCESS if !KMSAN
134	select DMA_OPS if PCI
135	select DYNAMIC_FTRACE if FUNCTION_TRACER
136	select FUNCTION_ALIGNMENT_8B if CC_IS_GCC
137	select FUNCTION_ALIGNMENT_16B if !CC_IS_GCC
138	select GENERIC_ALLOCATOR
139	select GENERIC_CPU_AUTOPROBE
140	select GENERIC_CPU_VULNERABILITIES
141	select GENERIC_ENTRY
142	select GENERIC_GETTIMEOFDAY
143	select GENERIC_PTDUMP
144	select GENERIC_SMP_IDLE_THREAD
145	select GENERIC_TIME_VSYSCALL
146	select GENERIC_VDSO_TIME_NS
147	select GENERIC_IOREMAP if PCI
148	select HAVE_ALIGNED_STRUCT_PAGE
149	select HAVE_ARCH_AUDITSYSCALL
150	select HAVE_ARCH_JUMP_LABEL
151	select HAVE_ARCH_JUMP_LABEL_RELATIVE
152	select HAVE_ARCH_KASAN
153	select HAVE_ARCH_KASAN_VMALLOC
154	select HAVE_ARCH_KCSAN
155	select HAVE_ARCH_KFENCE
156	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
157	select HAVE_ARCH_SECCOMP_FILTER
158	select HAVE_ARCH_SOFT_DIRTY
159	select HAVE_ARCH_STACKLEAK
160	select HAVE_ARCH_TRACEHOOK
161	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
162	select HAVE_ARCH_VMAP_STACK
163	select HAVE_ASM_MODVERSIONS
164	select HAVE_CMPXCHG_DOUBLE
165	select HAVE_CMPXCHG_LOCAL
166	select HAVE_DEBUG_KMEMLEAK
167	select HAVE_DMA_CONTIGUOUS
168	select HAVE_DYNAMIC_FTRACE
169	select HAVE_DYNAMIC_FTRACE_WITH_ARGS
170	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
171	select HAVE_DYNAMIC_FTRACE_WITH_REGS
172	select HAVE_EBPF_JIT if HAVE_MARCH_Z196_FEATURES
173	select HAVE_EFFICIENT_UNALIGNED_ACCESS
174	select HAVE_FAST_GUP
175	select HAVE_FENTRY
176	select HAVE_FTRACE_MCOUNT_RECORD
177	select HAVE_FUNCTION_ARG_ACCESS_API
178	select HAVE_FUNCTION_ERROR_INJECTION
179	select HAVE_FUNCTION_GRAPH_RETVAL
180	select HAVE_FUNCTION_GRAPH_TRACER
181	select HAVE_FUNCTION_TRACER
182	select HAVE_GCC_PLUGINS
183	select HAVE_GENERIC_VDSO
184	select HAVE_IOREMAP_PROT if PCI
185	select HAVE_KERNEL_BZIP2
186	select HAVE_KERNEL_GZIP
187	select HAVE_KERNEL_LZ4
188	select HAVE_KERNEL_LZMA
189	select HAVE_KERNEL_LZO
190	select HAVE_KERNEL_UNCOMPRESSED
191	select HAVE_KERNEL_XZ
192	select HAVE_KERNEL_ZSTD
193	select HAVE_KPROBES
194	select HAVE_KPROBES_ON_FTRACE
195	select HAVE_KRETPROBES
196	select HAVE_KVM
197	select HAVE_LIVEPATCH
198	select HAVE_MEMBLOCK_PHYS_MAP
199	select HAVE_MOD_ARCH_SPECIFIC
200	select HAVE_NMI
201	select HAVE_NOP_MCOUNT
202	select HAVE_PCI
203	select HAVE_PERF_EVENTS
204	select HAVE_PERF_REGS
205	select HAVE_PERF_USER_STACK_DUMP
206	select HAVE_REGS_AND_STACK_ACCESS_API
207	select HAVE_RELIABLE_STACKTRACE
208	select HAVE_RETHOOK
209	select HAVE_RSEQ
210	select HAVE_SAMPLE_FTRACE_DIRECT
211	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
212	select HAVE_SETUP_PER_CPU_AREA
213	select HAVE_SOFTIRQ_ON_OWN_STACK
214	select HAVE_SYSCALL_TRACEPOINTS
215	select HAVE_VIRT_CPU_ACCOUNTING
216	select HAVE_VIRT_CPU_ACCOUNTING_IDLE
217	select IOMMU_HELPER		if PCI
218	select IOMMU_SUPPORT		if PCI
219	select KEXEC
220	select MMU_GATHER_MERGE_VMAS
221	select MMU_GATHER_NO_GATHER
222	select MMU_GATHER_RCU_TABLE_FREE
223	select MODULES_USE_ELF_RELA
224	select NEED_DMA_MAP_STATE	if PCI
225	select NEED_PER_CPU_EMBED_FIRST_CHUNK
226	select NEED_SG_DMA_LENGTH	if PCI
227	select OLD_SIGACTION
228	select OLD_SIGSUSPEND3
229	select PCI_DOMAINS		if PCI
230	select PCI_MSI			if PCI
231	select PCI_MSI_ARCH_FALLBACKS	if PCI_MSI
232	select SPARSE_IRQ
233	select SWIOTLB
234	select SYSCTL_EXCEPTION_TRACE
235	select THREAD_INFO_IN_TASK
236	select TRACE_IRQFLAGS_SUPPORT
237	select TTY
238	select USER_STACKTRACE_SUPPORT
239	select VIRT_CPU_ACCOUNTING
240	select ZONE_DMA
241	# Note: keep the above list sorted alphabetically
242
243config SCHED_OMIT_FRAME_POINTER
244	def_bool y
245
246config PGTABLE_LEVELS
247	int
248	default 5
249
250source "kernel/livepatch/Kconfig"
251
252config ARCH_SUPPORTS_KEXEC
253	def_bool y
254
255config ARCH_SUPPORTS_KEXEC_FILE
256	def_bool y
257
258config ARCH_SUPPORTS_KEXEC_SIG
259	def_bool MODULE_SIG_FORMAT
260
261config ARCH_SUPPORTS_KEXEC_PURGATORY
262	def_bool y
263
264config ARCH_SUPPORTS_CRASH_DUMP
265	def_bool y
266	help
267	  Refer to <file:Documentation/arch/s390/zfcpdump.rst> for more details on this.
268	  This option also enables s390 zfcpdump.
269	  See also <file:Documentation/arch/s390/zfcpdump.rst>
270
271menu "Processor type and features"
272
273config HAVE_MARCH_Z10_FEATURES
274	def_bool n
275
276config HAVE_MARCH_Z196_FEATURES
277	def_bool n
278	select HAVE_MARCH_Z10_FEATURES
279
280config HAVE_MARCH_ZEC12_FEATURES
281	def_bool n
282	select HAVE_MARCH_Z196_FEATURES
283
284config HAVE_MARCH_Z13_FEATURES
285	def_bool n
286	select HAVE_MARCH_ZEC12_FEATURES
287
288config HAVE_MARCH_Z14_FEATURES
289	def_bool n
290	select HAVE_MARCH_Z13_FEATURES
291
292config HAVE_MARCH_Z15_FEATURES
293	def_bool n
294	select HAVE_MARCH_Z14_FEATURES
295
296config HAVE_MARCH_Z16_FEATURES
297	def_bool n
298	select HAVE_MARCH_Z15_FEATURES
299
300choice
301	prompt "Processor type"
302	default MARCH_Z196
303
304config MARCH_Z10
305	bool "IBM System z10"
306	select HAVE_MARCH_Z10_FEATURES
307	depends on $(cc-option,-march=z10)
308	help
309	  Select this to enable optimizations for IBM System z10 (2097 and 2098
310	  series). This is the oldest machine generation currently supported.
311
312config MARCH_Z196
313	bool "IBM zEnterprise 114 and 196"
314	select HAVE_MARCH_Z196_FEATURES
315	depends on $(cc-option,-march=z196)
316	help
317	  Select this to enable optimizations for IBM zEnterprise 114 and 196
318	  (2818 and 2817 series). The kernel will be slightly faster but will
319	  not work on older machines.
320
321config MARCH_ZEC12
322	bool "IBM zBC12 and zEC12"
323	select HAVE_MARCH_ZEC12_FEATURES
324	depends on $(cc-option,-march=zEC12)
325	help
326	  Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
327	  2827 series). The kernel will be slightly faster but will not work on
328	  older machines.
329
330config MARCH_Z13
331	bool "IBM z13s and z13"
332	select HAVE_MARCH_Z13_FEATURES
333	depends on $(cc-option,-march=z13)
334	help
335	  Select this to enable optimizations for IBM z13s and z13 (2965 and
336	  2964 series). The kernel will be slightly faster but will not work on
337	  older machines.
338
339config MARCH_Z14
340	bool "IBM z14 ZR1 and z14"
341	select HAVE_MARCH_Z14_FEATURES
342	depends on $(cc-option,-march=z14)
343	help
344	  Select this to enable optimizations for IBM z14 ZR1 and z14 (3907
345	  and 3906 series). The kernel will be slightly faster but will not
346	  work on older machines.
347
348config MARCH_Z15
349	bool "IBM z15"
350	select HAVE_MARCH_Z15_FEATURES
351	depends on $(cc-option,-march=z15)
352	help
353	  Select this to enable optimizations for IBM z15 (8562
354	  and 8561 series). The kernel will be slightly faster but will not
355	  work on older machines.
356
357config MARCH_Z16
358	bool "IBM z16"
359	select HAVE_MARCH_Z16_FEATURES
360	depends on $(cc-option,-march=z16)
361	help
362	  Select this to enable optimizations for IBM z16 (3931 and
363	  3932 series).
364
365endchoice
366
367config MARCH_Z10_TUNE
368	def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
369
370config MARCH_Z196_TUNE
371	def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
372
373config MARCH_ZEC12_TUNE
374	def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
375
376config MARCH_Z13_TUNE
377	def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT
378
379config MARCH_Z14_TUNE
380	def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT
381
382config MARCH_Z15_TUNE
383	def_bool TUNE_Z15 || MARCH_Z15 && TUNE_DEFAULT
384
385config MARCH_Z16_TUNE
386	def_bool TUNE_Z16 || MARCH_Z16 && TUNE_DEFAULT
387
388choice
389	prompt "Tune code generation"
390	default TUNE_DEFAULT
391	help
392	  Cause the compiler to tune (-mtune) the generated code for a machine.
393	  This will make the code run faster on the selected machine but
394	  somewhat slower on other machines.
395	  This option only changes how the compiler emits instructions, not the
396	  selection of instructions itself, so the resulting kernel will run on
397	  all other machines.
398
399config TUNE_DEFAULT
400	bool "Default"
401	help
402	  Tune the generated code for the target processor for which the kernel
403	  will be compiled.
404
405config TUNE_Z10
406	bool "IBM System z10"
407
408config TUNE_Z196
409	bool "IBM zEnterprise 114 and 196"
410	depends on $(cc-option,-mtune=z196)
411
412config TUNE_ZEC12
413	bool "IBM zBC12 and zEC12"
414	depends on $(cc-option,-mtune=zEC12)
415
416config TUNE_Z13
417	bool "IBM z13s and z13"
418	depends on $(cc-option,-mtune=z13)
419
420config TUNE_Z14
421	bool "IBM z14 ZR1 and z14"
422	depends on $(cc-option,-mtune=z14)
423
424config TUNE_Z15
425	bool "IBM z15"
426	depends on $(cc-option,-mtune=z15)
427
428config TUNE_Z16
429	bool "IBM z16"
430	depends on $(cc-option,-mtune=z16)
431
432endchoice
433
434config 64BIT
435	def_bool y
436
437config COMMAND_LINE_SIZE
438	int "Maximum size of kernel command line"
439	default 4096
440	range 896 1048576
441	help
442	  This allows you to specify the maximum length of the kernel command
443	  line.
444
445config COMPAT
446	def_bool y
447	prompt "Kernel support for 31 bit emulation"
448	select ARCH_WANT_OLD_COMPAT_IPC
449	select COMPAT_OLD_SIGACTION
450	select HAVE_UID16
451	depends on MULTIUSER
452	depends on !CC_IS_CLANG
453	help
454	  Select this option if you want to enable your system kernel to
455	  handle system-calls from ELF binaries for 31 bit ESA.  This option
456	  (and some other stuff like libraries and such) is needed for
457	  executing 31 bit applications.  It is safe to say "Y".
458
459config SMP
460	def_bool y
461
462config NR_CPUS
463	int "Maximum number of CPUs (2-512)"
464	range 2 512
465	default "64"
466	help
467	  This allows you to specify the maximum number of CPUs which this
468	  kernel will support. The maximum supported value is 512 and the
469	  minimum value which makes sense is 2.
470
471	  This is purely to save memory - each supported CPU adds
472	  approximately sixteen kilobytes to the kernel image.
473
474config HOTPLUG_CPU
475	def_bool y
476
477config NUMA
478	bool "NUMA support"
479	depends on SCHED_TOPOLOGY
480	default n
481	help
482	  Enable NUMA support
483
484	  This option adds NUMA support to the kernel.
485
486config NODES_SHIFT
487	int
488	depends on NUMA
489	default "1"
490
491config SCHED_SMT
492	def_bool n
493
494config SCHED_MC
495	def_bool n
496
497config SCHED_TOPOLOGY
498	def_bool y
499	prompt "Topology scheduler support"
500	select SCHED_SMT
501	select SCHED_MC
502	help
503	  Topology scheduler support improves the CPU scheduler's decision
504	  making when dealing with machines that have multi-threading,
505	  multiple cores or multiple books.
506
507source "kernel/Kconfig.hz"
508
509config CERT_STORE
510	bool "Get user certificates via DIAG320"
511	depends on KEYS
512	select CRYPTO_LIB_SHA256
513	help
514	  Enable this option if you want to access user-provided secure boot
515	  certificates via DIAG 0x320.
516
517	  These certificates will be made available via the keyring named
518	  'cert_store'.
519
520config KERNEL_NOBP
521	def_bool n
522	prompt "Enable modified branch prediction for the kernel by default"
523	help
524	  If this option is selected the kernel will switch to a modified
525	  branch prediction mode if the firmware interface is available.
526	  The modified branch prediction mode improves the behaviour in
527	  regard to speculative execution.
528
529	  With the option enabled the kernel parameter "nobp=0" or "nospec"
530	  can be used to run the kernel in the normal branch prediction mode.
531
532	  With the option disabled the modified branch prediction mode is
533	  enabled with the "nobp=1" kernel parameter.
534
535	  If unsure, say N.
536
537config EXPOLINE
538	def_bool n
539	depends on $(cc-option,-mindirect-branch=thunk)
540	prompt "Avoid speculative indirect branches in the kernel"
541	help
542	  Compile the kernel with the expoline compiler options to guard
543	  against kernel-to-user data leaks by avoiding speculative indirect
544	  branches.
545	  Requires a compiler with -mindirect-branch=thunk support for full
546	  protection. The kernel may run slower.
547
548	  If unsure, say N.
549
550config EXPOLINE_EXTERN
551	def_bool n
552	depends on EXPOLINE
553	depends on CC_IS_GCC && GCC_VERSION >= 110200
554	depends on $(success,$(srctree)/arch/s390/tools/gcc-thunk-extern.sh $(CC))
555	prompt "Generate expolines as extern functions."
556	help
557	  This option is required for some tooling like kpatch. The kernel is
558	  compiled with -mindirect-branch=thunk-extern and requires a newer
559	  compiler.
560
561	  If unsure, say N.
562
563choice
564	prompt "Expoline default"
565	depends on EXPOLINE
566	default EXPOLINE_FULL
567
568config EXPOLINE_OFF
569	bool "spectre_v2=off"
570
571config EXPOLINE_AUTO
572	bool "spectre_v2=auto"
573
574config EXPOLINE_FULL
575	bool "spectre_v2=on"
576
577endchoice
578
579config RELOCATABLE
580	def_bool y
581	help
582	  This builds a kernel image that retains relocation information
583	  so it can be loaded at an arbitrary address.
584	  The kernel is linked as a position-independent executable (PIE)
585	  and contains dynamic relocations which are processed early in the
586	  bootup process.
587	  The relocations make the kernel image about 15% larger (compressed
588	  10%), but are discarded at runtime.
589	  Note: this option exists only for documentation purposes, please do
590	  not remove it.
591
592config RANDOMIZE_BASE
593	bool "Randomize the address of the kernel image (KASLR)"
594	default y
595	help
596	  In support of Kernel Address Space Layout Randomization (KASLR),
597	  this randomizes the address at which the kernel image is loaded,
598	  as a security feature that deters exploit attempts relying on
599	  knowledge of the location of kernel internals.
600
601endmenu
602
603menu "Memory setup"
604
605config ARCH_SPARSEMEM_ENABLE
606	def_bool y
607	select SPARSEMEM_VMEMMAP_ENABLE
608	select SPARSEMEM_VMEMMAP
609
610config ARCH_SPARSEMEM_DEFAULT
611	def_bool y
612
613config MAX_PHYSMEM_BITS
614	int "Maximum size of supported physical memory in bits (42-53)"
615	range 42 53
616	default "46"
617	help
618	  This option specifies the maximum supported size of physical memory
619	  in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB).
620	  Increasing the number of bits also increases the kernel image size.
621	  By default 46 bits (64TB) are supported.
622
623config CHECK_STACK
624	def_bool y
625	depends on !VMAP_STACK
626	prompt "Detect kernel stack overflow"
627	help
628	  This option enables the compiler option -mstack-guard and
629	  -mstack-size if they are available. If the compiler supports them
630	  it will emit additional code to each function prolog to trigger
631	  an illegal operation if the kernel stack is about to overflow.
632
633	  Say N if you are unsure.
634
635config STACK_GUARD
636	int "Size of the guard area (128-1024)"
637	range 128 1024
638	depends on CHECK_STACK
639	default "256"
640	help
641	  This allows you to specify the size of the guard area at the lower
642	  end of the kernel stack. If the kernel stack points into the guard
643	  area on function entry an illegal operation is triggered. The size
644	  needs to be a power of 2. Please keep in mind that the size of an
645	  interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
646	  The minimum size for the stack guard should be 256 for 31 bit and
647	  512 for 64 bit.
648
649endmenu
650
651menu "I/O subsystem"
652
653config QDIO
654	def_tristate y
655	prompt "QDIO support"
656	help
657	  This driver provides the Queued Direct I/O base support for
658	  IBM System z.
659
660	  To compile this driver as a module, choose M here: the
661	  module will be called qdio.
662
663	  If unsure, say Y.
664
665if PCI
666
667config PCI_NR_FUNCTIONS
668	int "Maximum number of PCI functions (1-4096)"
669	range 1 4096
670	default "512"
671	help
672	  This allows you to specify the maximum number of PCI functions which
673	  this kernel will support.
674
675endif # PCI
676
677config HAS_IOMEM
678	def_bool PCI
679
680config CHSC_SCH
681	def_tristate m
682	prompt "Support for CHSC subchannels"
683	help
684	  This driver allows usage of CHSC subchannels. A CHSC subchannel
685	  is usually present on LPAR only.
686	  The driver creates a device /dev/chsc, which may be used to
687	  obtain I/O configuration information about the machine and
688	  to issue asynchronous chsc commands (DANGEROUS).
689	  You will usually only want to use this interface on a special
690	  LPAR designated for system management.
691
692	  To compile this driver as a module, choose M here: the
693	  module will be called chsc_sch.
694
695	  If unsure, say N.
696
697config SCM_BUS
698	def_bool y
699	prompt "SCM bus driver"
700	help
701	  Bus driver for Storage Class Memory.
702
703config EADM_SCH
704	def_tristate m
705	prompt "Support for EADM subchannels"
706	depends on SCM_BUS
707	help
708	  This driver allows usage of EADM subchannels. EADM subchannels act
709	  as a communication vehicle for SCM increments.
710
711	  To compile this driver as a module, choose M here: the
712	  module will be called eadm_sch.
713
714config VFIO_CCW
715	def_tristate n
716	prompt "Support for VFIO-CCW subchannels"
717	depends on VFIO
718	select VFIO_MDEV
719	help
720	  This driver allows usage of I/O subchannels via VFIO-CCW.
721
722	  To compile this driver as a module, choose M here: the
723	  module will be called vfio_ccw.
724
725config VFIO_AP
726	def_tristate n
727	prompt "VFIO support for AP devices"
728	depends on KVM
729	depends on VFIO
730	depends on ZCRYPT
731	select VFIO_MDEV
732	help
733	  This driver grants access to Adjunct Processor (AP) devices
734	  via the VFIO mediated device interface.
735
736	  To compile this driver as a module, choose M here: the module
737	  will be called vfio_ap.
738
739endmenu
740
741config CCW
742	def_bool y
743
744config HAVE_PNETID
745	tristate
746	default (SMC || CCWGROUP)
747
748menu "Virtualization"
749
750config PROTECTED_VIRTUALIZATION_GUEST
751	def_bool n
752	prompt "Protected virtualization guest support"
753	help
754	  Select this option, if you want to be able to run this
755	  kernel as a protected virtualization KVM guest.
756	  Protected virtualization capable machines have a mini hypervisor
757	  located at machine level (an ultravisor). With help of the
758	  Ultravisor, KVM will be able to run "protected" VMs, special
759	  VMs whose memory and management data are unavailable to KVM.
760
761config PFAULT
762	def_bool y
763	prompt "Pseudo page fault support"
764	help
765	  Select this option, if you want to use PFAULT pseudo page fault
766	  handling under VM. If running native or in LPAR, this option
767	  has no effect. If your VM does not support PFAULT, PAGEEX
768	  pseudo page fault handling will be used.
769	  Note that VM 4.2 supports PFAULT but has a bug in its
770	  implementation that causes some problems.
771	  Everybody who wants to run Linux under VM != VM4.2 should select
772	  this option.
773
774config CMM
775	def_tristate n
776	prompt "Cooperative memory management"
777	help
778	  Select this option, if you want to enable the kernel interface
779	  to reduce the memory size of the system. This is accomplished
780	  by allocating pages of memory and put them "on hold". This only
781	  makes sense for a system running under VM where the unused pages
782	  will be reused by VM for other guest systems. The interface
783	  allows an external monitor to balance memory of many systems.
784	  Everybody who wants to run Linux under VM should select this
785	  option.
786
787config CMM_IUCV
788	def_bool y
789	prompt "IUCV special message interface to cooperative memory management"
790	depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
791	help
792	  Select this option to enable the special message interface to
793	  the cooperative memory management.
794
795config APPLDATA_BASE
796	def_bool n
797	prompt "Linux - VM Monitor Stream, base infrastructure"
798	depends on PROC_SYSCTL
799	help
800	  This provides a kernel interface for creating and updating z/VM APPLDATA
801	  monitor records. The monitor records are updated at certain time
802	  intervals, once the timer is started.
803	  Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
804	  i.e. enables or disables monitoring on the Linux side.
805	  A custom interval value (in seconds) can be written to
806	  /proc/appldata/interval.
807
808	  Defaults are 60 seconds interval and timer off.
809	  The /proc entries can also be read from, showing the current settings.
810
811config APPLDATA_MEM
812	def_tristate m
813	prompt "Monitor memory management statistics"
814	depends on APPLDATA_BASE && VM_EVENT_COUNTERS
815	help
816	  This provides memory management related data to the Linux - VM Monitor
817	  Stream, like paging/swapping rate, memory utilisation, etc.
818	  Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
819	  APPLDATA monitor record, i.e. enables or disables monitoring this record
820	  on the z/VM side.
821
822	  Default is disabled.
823	  The /proc entry can also be read from, showing the current settings.
824
825	  This can also be compiled as a module, which will be called
826	  appldata_mem.o.
827
828config APPLDATA_OS
829	def_tristate m
830	prompt "Monitor OS statistics"
831	depends on APPLDATA_BASE
832	help
833	  This provides OS related data to the Linux - VM Monitor Stream, like
834	  CPU utilisation, etc.
835	  Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
836	  APPLDATA monitor record, i.e. enables or disables monitoring this record
837	  on the z/VM side.
838
839	  Default is disabled.
840	  This can also be compiled as a module, which will be called
841	  appldata_os.o.
842
843config APPLDATA_NET_SUM
844	def_tristate m
845	prompt "Monitor overall network statistics"
846	depends on APPLDATA_BASE && NET
847	help
848	  This provides network related data to the Linux - VM Monitor Stream,
849	  currently there is only a total sum of network I/O statistics, no
850	  per-interface data.
851	  Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
852	  APPLDATA monitor record, i.e. enables or disables monitoring this record
853	  on the z/VM side.
854
855	  Default is disabled.
856	  This can also be compiled as a module, which will be called
857	  appldata_net_sum.o.
858
859config S390_HYPFS
860	def_bool y
861	prompt "s390 hypervisor information"
862	help
863	  This provides several binary files at (debugfs)/s390_hypfs/ to
864	  provide accounting information in an s390 hypervisor environment.
865
866config S390_HYPFS_FS
867	def_bool n
868	prompt "s390 hypervisor file system support"
869	select SYS_HYPERVISOR
870	depends on S390_HYPFS
871	help
872	  This is a virtual file system intended to provide accounting
873	  information in an s390 hypervisor environment. This file system
874	  is deprecated and should not be used.
875
876	  Say N if you are unsure.
877
878source "arch/s390/kvm/Kconfig"
879
880config S390_GUEST
881	def_bool y
882	prompt "s390 support for virtio devices"
883	select TTY
884	select VIRTUALIZATION
885	select VIRTIO
886	help
887	  Enabling this option adds support for virtio based paravirtual device
888	  drivers on s390.
889
890	  Select this option if you want to run the kernel as a guest under
891	  the KVM hypervisor.
892
893endmenu
894
895config S390_MODULES_SANITY_TEST_HELPERS
896	def_bool n
897
898menu "Selftests"
899
900config S390_UNWIND_SELFTEST
901	def_tristate n
902	depends on KUNIT
903	default KUNIT_ALL_TESTS
904	prompt "Test unwind functions"
905	help
906	  This option enables s390 specific stack unwinder testing kernel
907	  module. This option is not useful for distributions or general
908	  kernels, but only for kernel developers working on architecture code.
909
910	  Say N if you are unsure.
911
912config S390_KPROBES_SANITY_TEST
913	def_tristate n
914	prompt "Enable s390 specific kprobes tests"
915	depends on KPROBES
916	depends on KUNIT
917	help
918	  This option enables an s390 specific kprobes test module. This option
919	  is not useful for distributions or general kernels, but only for kernel
920	  developers working on architecture code.
921
922	  Say N if you are unsure.
923
924config S390_MODULES_SANITY_TEST
925	def_tristate n
926	depends on KUNIT
927	default KUNIT_ALL_TESTS
928	prompt "Enable s390 specific modules tests"
929	select S390_MODULES_SANITY_TEST_HELPERS
930	help
931	  This option enables an s390 specific modules test. This option is
932	  not useful for distributions or general kernels, but only for
933	  kernel developers working on architecture code.
934
935	  Say N if you are unsure.
936endmenu
937