xref: /openbmc/linux/arch/s390/Kconfig (revision 5085e036)
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_MEM_ENCRYPT
76	select ARCH_HAS_PTE_SPECIAL
77	select ARCH_HAS_SCALED_CPUTIME
78	select ARCH_HAS_SET_MEMORY
79	select ARCH_HAS_STRICT_KERNEL_RWX
80	select ARCH_HAS_STRICT_MODULE_RWX
81	select ARCH_HAS_SYSCALL_WRAPPER
82	select ARCH_HAS_UBSAN_SANITIZE_ALL
83	select ARCH_HAS_VDSO_DATA
84	select ARCH_HAVE_NMI_SAFE_CMPXCHG
85	select ARCH_INLINE_READ_LOCK
86	select ARCH_INLINE_READ_LOCK_BH
87	select ARCH_INLINE_READ_LOCK_IRQ
88	select ARCH_INLINE_READ_LOCK_IRQSAVE
89	select ARCH_INLINE_READ_TRYLOCK
90	select ARCH_INLINE_READ_UNLOCK
91	select ARCH_INLINE_READ_UNLOCK_BH
92	select ARCH_INLINE_READ_UNLOCK_IRQ
93	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
94	select ARCH_INLINE_SPIN_LOCK
95	select ARCH_INLINE_SPIN_LOCK_BH
96	select ARCH_INLINE_SPIN_LOCK_IRQ
97	select ARCH_INLINE_SPIN_LOCK_IRQSAVE
98	select ARCH_INLINE_SPIN_TRYLOCK
99	select ARCH_INLINE_SPIN_TRYLOCK_BH
100	select ARCH_INLINE_SPIN_UNLOCK
101	select ARCH_INLINE_SPIN_UNLOCK_BH
102	select ARCH_INLINE_SPIN_UNLOCK_IRQ
103	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
104	select ARCH_INLINE_WRITE_LOCK
105	select ARCH_INLINE_WRITE_LOCK_BH
106	select ARCH_INLINE_WRITE_LOCK_IRQ
107	select ARCH_INLINE_WRITE_LOCK_IRQSAVE
108	select ARCH_INLINE_WRITE_TRYLOCK
109	select ARCH_INLINE_WRITE_UNLOCK
110	select ARCH_INLINE_WRITE_UNLOCK_BH
111	select ARCH_INLINE_WRITE_UNLOCK_IRQ
112	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
113	select ARCH_STACKWALK
114	select ARCH_SUPPORTS_ATOMIC_RMW
115	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
116	select ARCH_SUPPORTS_HUGETLBFS
117	select ARCH_SUPPORTS_NUMA_BALANCING
118	select ARCH_USE_BUILTIN_BSWAP
119	select ARCH_USE_CMPXCHG_LOCKREF
120	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
121	select ARCH_WANTS_NO_INSTR
122	select ARCH_WANT_DEFAULT_BPF_JIT
123	select ARCH_WANT_IPC_PARSE_VERSION
124	select BUILDTIME_TABLE_SORT
125	select CLONE_BACKWARDS2
126	select DMA_OPS if PCI
127	select DYNAMIC_FTRACE if FUNCTION_TRACER
128	select GCC12_NO_ARRAY_BOUNDS
129	select GENERIC_ALLOCATOR
130	select GENERIC_CPU_AUTOPROBE
131	select GENERIC_CPU_VULNERABILITIES
132	select GENERIC_ENTRY
133	select GENERIC_GETTIMEOFDAY
134	select GENERIC_PTDUMP
135	select GENERIC_SMP_IDLE_THREAD
136	select GENERIC_TIME_VSYSCALL
137	select GENERIC_VDSO_TIME_NS
138	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
139	select HAVE_ARCH_AUDITSYSCALL
140	select HAVE_ARCH_JUMP_LABEL
141	select HAVE_ARCH_JUMP_LABEL_RELATIVE
142	select HAVE_ARCH_KASAN
143	select HAVE_ARCH_KASAN_VMALLOC
144	select HAVE_ARCH_KCSAN
145	select HAVE_ARCH_KFENCE
146	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
147	select HAVE_ARCH_SECCOMP_FILTER
148	select HAVE_ARCH_SOFT_DIRTY
149	select HAVE_ARCH_TRACEHOOK
150	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
151	select HAVE_ARCH_VMAP_STACK
152	select HAVE_ASM_MODVERSIONS
153	select HAVE_CMPXCHG_DOUBLE
154	select HAVE_CMPXCHG_LOCAL
155	select HAVE_DEBUG_KMEMLEAK
156	select HAVE_DMA_CONTIGUOUS
157	select HAVE_DYNAMIC_FTRACE
158	select HAVE_DYNAMIC_FTRACE_WITH_ARGS
159	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
160	select HAVE_DYNAMIC_FTRACE_WITH_REGS
161	select HAVE_EBPF_JIT if HAVE_MARCH_Z196_FEATURES
162	select HAVE_EFFICIENT_UNALIGNED_ACCESS
163	select HAVE_FAST_GUP
164	select HAVE_FENTRY
165	select HAVE_FTRACE_MCOUNT_RECORD
166	select HAVE_FUNCTION_ARG_ACCESS_API
167	select HAVE_FUNCTION_ERROR_INJECTION
168	select HAVE_FUNCTION_GRAPH_TRACER
169	select HAVE_FUNCTION_TRACER
170	select HAVE_GCC_PLUGINS
171	select HAVE_GENERIC_VDSO
172	select HAVE_IOREMAP_PROT if PCI
173	select HAVE_KERNEL_BZIP2
174	select HAVE_KERNEL_GZIP
175	select HAVE_KERNEL_LZ4
176	select HAVE_KERNEL_LZMA
177	select HAVE_KERNEL_LZO
178	select HAVE_KERNEL_UNCOMPRESSED
179	select HAVE_KERNEL_XZ
180	select HAVE_KERNEL_ZSTD
181	select HAVE_KPROBES
182	select HAVE_KPROBES_ON_FTRACE
183	select HAVE_KRETPROBES
184	select HAVE_KVM
185	select HAVE_LIVEPATCH
186	select HAVE_MEMBLOCK_PHYS_MAP
187	select HAVE_MOD_ARCH_SPECIFIC
188	select HAVE_NMI
189	select HAVE_NOP_MCOUNT
190	select HAVE_PCI
191	select HAVE_PERF_EVENTS
192	select HAVE_PERF_REGS
193	select HAVE_PERF_USER_STACK_DUMP
194	select HAVE_REGS_AND_STACK_ACCESS_API
195	select HAVE_RELIABLE_STACKTRACE
196	select HAVE_RSEQ
197	select HAVE_SAMPLE_FTRACE_DIRECT
198	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
199	select HAVE_SOFTIRQ_ON_OWN_STACK
200	select HAVE_SYSCALL_TRACEPOINTS
201	select HAVE_VIRT_CPU_ACCOUNTING
202	select HAVE_VIRT_CPU_ACCOUNTING_IDLE
203	select IOMMU_HELPER		if PCI
204	select IOMMU_SUPPORT		if PCI
205	select MMU_GATHER_NO_GATHER
206	select MMU_GATHER_RCU_TABLE_FREE
207	select MODULES_USE_ELF_RELA
208	select NEED_DMA_MAP_STATE	if PCI
209	select NEED_SG_DMA_LENGTH	if PCI
210	select OLD_SIGACTION
211	select OLD_SIGSUSPEND3
212	select PCI_DOMAINS		if PCI
213	select PCI_MSI			if PCI
214	select PCI_MSI_ARCH_FALLBACKS	if PCI_MSI
215	select SPARSE_IRQ
216	select SWIOTLB
217	select SYSCTL_EXCEPTION_TRACE
218	select THREAD_INFO_IN_TASK
219	select TRACE_IRQFLAGS_SUPPORT
220	select TTY
221	select VIRT_CPU_ACCOUNTING
222	select ZONE_DMA
223	# Note: keep the above list sorted alphabetically
224
225config SCHED_OMIT_FRAME_POINTER
226	def_bool y
227
228config PGTABLE_LEVELS
229	int
230	default 5
231
232source "kernel/livepatch/Kconfig"
233
234menu "Processor type and features"
235
236config HAVE_MARCH_Z10_FEATURES
237	def_bool n
238
239config HAVE_MARCH_Z196_FEATURES
240	def_bool n
241	select HAVE_MARCH_Z10_FEATURES
242
243config HAVE_MARCH_ZEC12_FEATURES
244	def_bool n
245	select HAVE_MARCH_Z196_FEATURES
246
247config HAVE_MARCH_Z13_FEATURES
248	def_bool n
249	select HAVE_MARCH_ZEC12_FEATURES
250
251config HAVE_MARCH_Z14_FEATURES
252	def_bool n
253	select HAVE_MARCH_Z13_FEATURES
254
255config HAVE_MARCH_Z15_FEATURES
256	def_bool n
257	select HAVE_MARCH_Z14_FEATURES
258
259config HAVE_MARCH_Z16_FEATURES
260	def_bool n
261	select HAVE_MARCH_Z15_FEATURES
262
263choice
264	prompt "Processor type"
265	default MARCH_Z196
266
267config MARCH_Z10
268	bool "IBM System z10"
269	select HAVE_MARCH_Z10_FEATURES
270	depends on $(cc-option,-march=z10)
271	help
272	  Select this to enable optimizations for IBM System z10 (2097 and 2098
273	  series). This is the oldest machine generation currently supported.
274
275config MARCH_Z196
276	bool "IBM zEnterprise 114 and 196"
277	select HAVE_MARCH_Z196_FEATURES
278	depends on $(cc-option,-march=z196)
279	help
280	  Select this to enable optimizations for IBM zEnterprise 114 and 196
281	  (2818 and 2817 series). The kernel will be slightly faster but will
282	  not work on older machines.
283
284config MARCH_ZEC12
285	bool "IBM zBC12 and zEC12"
286	select HAVE_MARCH_ZEC12_FEATURES
287	depends on $(cc-option,-march=zEC12)
288	help
289	  Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
290	  2827 series). The kernel will be slightly faster but will not work on
291	  older machines.
292
293config MARCH_Z13
294	bool "IBM z13s and z13"
295	select HAVE_MARCH_Z13_FEATURES
296	depends on $(cc-option,-march=z13)
297	help
298	  Select this to enable optimizations for IBM z13s and z13 (2965 and
299	  2964 series). The kernel will be slightly faster but will not work on
300	  older machines.
301
302config MARCH_Z14
303	bool "IBM z14 ZR1 and z14"
304	select HAVE_MARCH_Z14_FEATURES
305	depends on $(cc-option,-march=z14)
306	help
307	  Select this to enable optimizations for IBM z14 ZR1 and z14 (3907
308	  and 3906 series). The kernel will be slightly faster but will not
309	  work on older machines.
310
311config MARCH_Z15
312	bool "IBM z15"
313	select HAVE_MARCH_Z15_FEATURES
314	depends on $(cc-option,-march=z15)
315	help
316	  Select this to enable optimizations for IBM z15 (8562
317	  and 8561 series). The kernel will be slightly faster but will not
318	  work on older machines.
319
320config MARCH_Z16
321	bool "IBM z16"
322	select HAVE_MARCH_Z16_FEATURES
323	depends on $(cc-option,-march=z16)
324	help
325	  Select this to enable optimizations for IBM z16 (3931 and
326	  3932 series).
327
328endchoice
329
330config MARCH_Z10_TUNE
331	def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
332
333config MARCH_Z196_TUNE
334	def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
335
336config MARCH_ZEC12_TUNE
337	def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
338
339config MARCH_Z13_TUNE
340	def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT
341
342config MARCH_Z14_TUNE
343	def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT
344
345config MARCH_Z15_TUNE
346	def_bool TUNE_Z15 || MARCH_Z15 && TUNE_DEFAULT
347
348config MARCH_Z16_TUNE
349	def_bool TUNE_Z16 || MARCH_Z16 && TUNE_DEFAULT
350
351choice
352	prompt "Tune code generation"
353	default TUNE_DEFAULT
354	help
355	  Cause the compiler to tune (-mtune) the generated code for a machine.
356	  This will make the code run faster on the selected machine but
357	  somewhat slower on other machines.
358	  This option only changes how the compiler emits instructions, not the
359	  selection of instructions itself, so the resulting kernel will run on
360	  all other machines.
361
362config TUNE_DEFAULT
363	bool "Default"
364	help
365	  Tune the generated code for the target processor for which the kernel
366	  will be compiled.
367
368config TUNE_Z10
369	bool "IBM System z10"
370
371config TUNE_Z196
372	bool "IBM zEnterprise 114 and 196"
373	depends on $(cc-option,-mtune=z196)
374
375config TUNE_ZEC12
376	bool "IBM zBC12 and zEC12"
377	depends on $(cc-option,-mtune=zEC12)
378
379config TUNE_Z13
380	bool "IBM z13s and z13"
381	depends on $(cc-option,-mtune=z13)
382
383config TUNE_Z14
384	bool "IBM z14 ZR1 and z14"
385	depends on $(cc-option,-mtune=z14)
386
387config TUNE_Z15
388	bool "IBM z15"
389	depends on $(cc-option,-mtune=z15)
390
391config TUNE_Z16
392	bool "IBM z16"
393	depends on $(cc-option,-mtune=z16)
394
395endchoice
396
397config 64BIT
398	def_bool y
399
400config COMMAND_LINE_SIZE
401	int "Maximum size of kernel command line"
402	default 4096
403	range 896 1048576
404	help
405	  This allows you to specify the maximum length of the kernel command
406	  line.
407
408config COMPAT
409	def_bool y
410	prompt "Kernel support for 31 bit emulation"
411	select ARCH_WANT_OLD_COMPAT_IPC
412	select COMPAT_OLD_SIGACTION
413	select HAVE_UID16
414	depends on MULTIUSER
415	depends on !CC_IS_CLANG
416	help
417	  Select this option if you want to enable your system kernel to
418	  handle system-calls from ELF binaries for 31 bit ESA.  This option
419	  (and some other stuff like libraries and such) is needed for
420	  executing 31 bit applications.  It is safe to say "Y".
421
422config SMP
423	def_bool y
424
425config NR_CPUS
426	int "Maximum number of CPUs (2-512)"
427	range 2 512
428	default "64"
429	help
430	  This allows you to specify the maximum number of CPUs which this
431	  kernel will support. The maximum supported value is 512 and the
432	  minimum value which makes sense is 2.
433
434	  This is purely to save memory - each supported CPU adds
435	  approximately sixteen kilobytes to the kernel image.
436
437config HOTPLUG_CPU
438	def_bool y
439
440config NUMA
441	bool "NUMA support"
442	depends on SCHED_TOPOLOGY
443	default n
444	help
445	  Enable NUMA support
446
447	  This option adds NUMA support to the kernel.
448
449config NODES_SHIFT
450	int
451	depends on NUMA
452	default "1"
453
454config SCHED_SMT
455	def_bool n
456
457config SCHED_MC
458	def_bool n
459
460config SCHED_BOOK
461	def_bool n
462
463config SCHED_DRAWER
464	def_bool n
465
466config SCHED_TOPOLOGY
467	def_bool y
468	prompt "Topology scheduler support"
469	select SCHED_SMT
470	select SCHED_MC
471	select SCHED_BOOK
472	select SCHED_DRAWER
473	help
474	  Topology scheduler support improves the CPU scheduler's decision
475	  making when dealing with machines that have multi-threading,
476	  multiple cores or multiple books.
477
478source "kernel/Kconfig.hz"
479
480config KEXEC
481	def_bool y
482	select KEXEC_CORE
483
484config KEXEC_FILE
485	bool "kexec file based system call"
486	select KEXEC_CORE
487	depends on CRYPTO
488	depends on CRYPTO_SHA256
489	depends on CRYPTO_SHA256_S390
490	help
491	  Enable the kexec file based system call. In contrast to the normal
492	  kexec system call this system call takes file descriptors for the
493	  kernel and initramfs as arguments.
494
495config ARCH_HAS_KEXEC_PURGATORY
496	def_bool y
497	depends on KEXEC_FILE
498
499config KEXEC_SIG
500	bool "Verify kernel signature during kexec_file_load() syscall"
501	depends on KEXEC_FILE && MODULE_SIG_FORMAT
502	help
503	  This option makes kernel signature verification mandatory for
504	  the kexec_file_load() syscall.
505
506	  In addition to that option, you need to enable signature
507	  verification for the corresponding kernel image type being
508	  loaded in order for this to work.
509
510config ARCH_RANDOM
511	def_bool y
512	prompt "s390 architectural random number generation API"
513	help
514	  Enable the s390 architectural random number generation API
515	  to provide random data for all consumers within the Linux
516	  kernel.
517
518	  When enabled the arch_random_* functions declared in linux/random.h
519	  are implemented. The implementation is based on the s390 CPACF
520	  instruction subfunction TRNG which provides a real true random
521	  number generator.
522
523	  If unsure, say Y.
524
525config KERNEL_NOBP
526	def_bool n
527	prompt "Enable modified branch prediction for the kernel by default"
528	help
529	  If this option is selected the kernel will switch to a modified
530	  branch prediction mode if the firmware interface is available.
531	  The modified branch prediction mode improves the behaviour in
532	  regard to speculative execution.
533
534	  With the option enabled the kernel parameter "nobp=0" or "nospec"
535	  can be used to run the kernel in the normal branch prediction mode.
536
537	  With the option disabled the modified branch prediction mode is
538	  enabled with the "nobp=1" kernel parameter.
539
540	  If unsure, say N.
541
542config EXPOLINE
543	def_bool n
544	depends on $(cc-option,-mindirect-branch=thunk)
545	prompt "Avoid speculative indirect branches in the kernel"
546	help
547	  Compile the kernel with the expoline compiler options to guard
548	  against kernel-to-user data leaks by avoiding speculative indirect
549	  branches.
550	  Requires a compiler with -mindirect-branch=thunk support for full
551	  protection. The kernel may run slower.
552
553	  If unsure, say N.
554
555config EXPOLINE_EXTERN
556	def_bool n
557	depends on EXPOLINE
558	depends on CC_IS_GCC && GCC_VERSION >= 110200
559	depends on $(success,$(srctree)/arch/s390/tools/gcc-thunk-extern.sh $(CC))
560	prompt "Generate expolines as extern functions."
561	help
562	  This option is required for some tooling like kpatch. The kernel is
563	  compiled with -mindirect-branch=thunk-extern and requires a newer
564	  compiler.
565
566	  If unsure, say N.
567
568choice
569	prompt "Expoline default"
570	depends on EXPOLINE
571	default EXPOLINE_FULL
572
573config EXPOLINE_OFF
574	bool "spectre_v2=off"
575
576config EXPOLINE_AUTO
577	bool "spectre_v2=auto"
578
579config EXPOLINE_FULL
580	bool "spectre_v2=on"
581
582endchoice
583
584config RELOCATABLE
585	bool "Build a relocatable kernel"
586	default y
587	help
588	  This builds a kernel image that retains relocation information
589	  so it can be loaded at an arbitrary address.
590	  The kernel is linked as a position-independent executable (PIE)
591	  and contains dynamic relocations which are processed early in the
592	  bootup process.
593	  The relocations make the kernel image about 15% larger (compressed
594	  10%), but are discarded at runtime.
595
596config RANDOMIZE_BASE
597	bool "Randomize the address of the kernel image (KASLR)"
598	depends on RELOCATABLE
599	default y
600	help
601	  In support of Kernel Address Space Layout Randomization (KASLR),
602	  this randomizes the address at which the kernel image is loaded,
603	  as a security feature that deters exploit attempts relying on
604	  knowledge of the location of kernel internals.
605
606endmenu
607
608menu "Memory setup"
609
610config ARCH_SPARSEMEM_ENABLE
611	def_bool y
612	select SPARSEMEM_VMEMMAP_ENABLE
613	select SPARSEMEM_VMEMMAP
614
615config ARCH_SPARSEMEM_DEFAULT
616	def_bool y
617
618config MAX_PHYSMEM_BITS
619	int "Maximum size of supported physical memory in bits (42-53)"
620	range 42 53
621	default "46"
622	help
623	  This option specifies the maximum supported size of physical memory
624	  in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB).
625	  Increasing the number of bits also increases the kernel image size.
626	  By default 46 bits (64TB) are supported.
627
628config CHECK_STACK
629	def_bool y
630	depends on !VMAP_STACK
631	prompt "Detect kernel stack overflow"
632	help
633	  This option enables the compiler option -mstack-guard and
634	  -mstack-size if they are available. If the compiler supports them
635	  it will emit additional code to each function prolog to trigger
636	  an illegal operation if the kernel stack is about to overflow.
637
638	  Say N if you are unsure.
639
640config STACK_GUARD
641	int "Size of the guard area (128-1024)"
642	range 128 1024
643	depends on CHECK_STACK
644	default "256"
645	help
646	  This allows you to specify the size of the guard area at the lower
647	  end of the kernel stack. If the kernel stack points into the guard
648	  area on function entry an illegal operation is triggered. The size
649	  needs to be a power of 2. Please keep in mind that the size of an
650	  interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
651	  The minimum size for the stack guard should be 256 for 31 bit and
652	  512 for 64 bit.
653
654endmenu
655
656menu "I/O subsystem"
657
658config QDIO
659	def_tristate y
660	prompt "QDIO support"
661	help
662	  This driver provides the Queued Direct I/O base support for
663	  IBM System z.
664
665	  To compile this driver as a module, choose M here: the
666	  module will be called qdio.
667
668	  If unsure, say Y.
669
670if PCI
671
672config PCI_NR_FUNCTIONS
673	int "Maximum number of PCI functions (1-4096)"
674	range 1 4096
675	default "512"
676	help
677	  This allows you to specify the maximum number of PCI functions which
678	  this kernel will support.
679
680endif # PCI
681
682config HAS_IOMEM
683	def_bool PCI
684
685config CHSC_SCH
686	def_tristate m
687	prompt "Support for CHSC subchannels"
688	help
689	  This driver allows usage of CHSC subchannels. A CHSC subchannel
690	  is usually present on LPAR only.
691	  The driver creates a device /dev/chsc, which may be used to
692	  obtain I/O configuration information about the machine and
693	  to issue asynchronous chsc commands (DANGEROUS).
694	  You will usually only want to use this interface on a special
695	  LPAR designated for system management.
696
697	  To compile this driver as a module, choose M here: the
698	  module will be called chsc_sch.
699
700	  If unsure, say N.
701
702config SCM_BUS
703	def_bool y
704	prompt "SCM bus driver"
705	help
706	  Bus driver for Storage Class Memory.
707
708config EADM_SCH
709	def_tristate m
710	prompt "Support for EADM subchannels"
711	depends on SCM_BUS
712	help
713	  This driver allows usage of EADM subchannels. EADM subchannels act
714	  as a communication vehicle for SCM increments.
715
716	  To compile this driver as a module, choose M here: the
717	  module will be called eadm_sch.
718
719config VFIO_CCW
720	def_tristate n
721	prompt "Support for VFIO-CCW subchannels"
722	depends on S390_CCW_IOMMU && VFIO_MDEV
723	help
724	  This driver allows usage of I/O subchannels via VFIO-CCW.
725
726	  To compile this driver as a module, choose M here: the
727	  module will be called vfio_ccw.
728
729config VFIO_AP
730	def_tristate n
731	prompt "VFIO support for AP devices"
732	depends on S390_AP_IOMMU && VFIO_MDEV && KVM
733	depends on ZCRYPT
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