| blob | 734996784d03419b782524c15b1da63b70edc315 |
1 # SPDX-License-Identifier: GPL-2.0
2 config MMU
3 def_bool y
5 config ZONE_DMA
6 def_bool y
8 config CPU_BIG_ENDIAN
9 def_bool y
11 config LOCKDEP_SUPPORT
12 def_bool y
14 config STACKTRACE_SUPPORT
15 def_bool y
17 config ARCH_HAS_ILOG2_U32
18 def_bool n
20 config ARCH_HAS_ILOG2_U64
21 def_bool n
23 config GENERIC_HWEIGHT
24 def_bool y
26 config GENERIC_BUG
27 def_bool y if BUG
29 config GENERIC_BUG_RELATIVE_POINTERS
30 def_bool y
32 config GENERIC_LOCKBREAK
33 def_bool y if PREEMPTTION
35 config PGSTE
36 def_bool y if KVM
38 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
39 def_bool y
41 config AUDIT_ARCH
42 def_bool y
44 config NO_IOPORT_MAP
45 def_bool y
47 config PCI_QUIRKS
48 def_bool n
50 config ARCH_SUPPORTS_UPROBES
51 def_bool y
53 config KASAN_SHADOW_OFFSET
54 hex
55 depends on KASAN
56 default 0x18000000000000 if KASAN_S390_4_LEVEL_PAGING
57 default 0x30000000000
59 config S390
60 def_bool y
61 select ARCH_BINFMT_ELF_STATE
62 select ARCH_HAS_DEVMEM_IS_ALLOWED
63 select ARCH_HAS_ELF_RANDOMIZE
64 select ARCH_HAS_FORTIFY_SOURCE
65 select ARCH_HAS_GCOV_PROFILE_ALL
66 select ARCH_HAS_GIGANTIC_PAGE
67 select ARCH_HAS_KCOV
68 select ARCH_HAS_MEM_ENCRYPT
69 select ARCH_HAS_PTE_SPECIAL
70 select ARCH_HAS_SET_MEMORY
71 select ARCH_HAS_STRICT_KERNEL_RWX
72 select ARCH_HAS_STRICT_MODULE_RWX
73 select ARCH_HAS_SYSCALL_WRAPPER
74 select ARCH_HAS_UBSAN_SANITIZE_ALL
75 select ARCH_HAVE_NMI_SAFE_CMPXCHG
76 select ARCH_INLINE_READ_LOCK
77 select ARCH_INLINE_READ_LOCK_BH
78 select ARCH_INLINE_READ_LOCK_IRQ
79 select ARCH_INLINE_READ_LOCK_IRQSAVE
80 select ARCH_INLINE_READ_TRYLOCK
81 select ARCH_INLINE_READ_UNLOCK
82 select ARCH_INLINE_READ_UNLOCK_BH
83 select ARCH_INLINE_READ_UNLOCK_IRQ
84 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
85 select ARCH_INLINE_SPIN_LOCK
86 select ARCH_INLINE_SPIN_LOCK_BH
87 select ARCH_INLINE_SPIN_LOCK_IRQ
88 select ARCH_INLINE_SPIN_LOCK_IRQSAVE
89 select ARCH_INLINE_SPIN_TRYLOCK
90 select ARCH_INLINE_SPIN_TRYLOCK_BH
91 select ARCH_INLINE_SPIN_UNLOCK
92 select ARCH_INLINE_SPIN_UNLOCK_BH
93 select ARCH_INLINE_SPIN_UNLOCK_IRQ
94 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
95 select ARCH_INLINE_WRITE_LOCK
96 select ARCH_INLINE_WRITE_LOCK_BH
97 select ARCH_INLINE_WRITE_LOCK_IRQ
98 select ARCH_INLINE_WRITE_LOCK_IRQSAVE
99 select ARCH_INLINE_WRITE_TRYLOCK
100 select ARCH_INLINE_WRITE_UNLOCK
101 select ARCH_INLINE_WRITE_UNLOCK_BH
102 select ARCH_INLINE_WRITE_UNLOCK_IRQ
103 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
104 select ARCH_KEEP_MEMBLOCK
105 select ARCH_SAVE_PAGE_KEYS if HIBERNATION
106 select ARCH_STACKWALK
107 select ARCH_SUPPORTS_ATOMIC_RMW
108 select ARCH_SUPPORTS_NUMA_BALANCING
109 select ARCH_USE_BUILTIN_BSWAP
110 select ARCH_USE_CMPXCHG_LOCKREF
111 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
112 select ARCH_WANT_IPC_PARSE_VERSION
113 select BUILDTIME_TABLE_SORT
114 select CLONE_BACKWARDS2
115 select DYNAMIC_FTRACE if FUNCTION_TRACER
116 select GENERIC_CLOCKEVENTS
117 select GENERIC_CPU_AUTOPROBE
118 select GENERIC_CPU_VULNERABILITIES
119 select GENERIC_FIND_FIRST_BIT
120 select GENERIC_SMP_IDLE_THREAD
121 select GENERIC_TIME_VSYSCALL
122 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
123 select HAVE_ARCH_AUDITSYSCALL
124 select HAVE_ARCH_JUMP_LABEL
125 select HAVE_ARCH_JUMP_LABEL_RELATIVE
126 select HAVE_ARCH_KASAN
127 select HAVE_ARCH_KASAN_VMALLOC
128 select CPU_NO_EFFICIENT_FFS if !HAVE_MARCH_Z9_109_FEATURES
129 select HAVE_ARCH_SECCOMP_FILTER
130 select HAVE_ARCH_SOFT_DIRTY
131 select HAVE_ARCH_TRACEHOOK
132 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
133 select HAVE_ARCH_VMAP_STACK
134 select HAVE_ASM_MODVERSIONS
135 select HAVE_EBPF_JIT if PACK_STACK && HAVE_MARCH_Z196_FEATURES
136 select HAVE_CMPXCHG_DOUBLE
137 select HAVE_CMPXCHG_LOCAL
138 select HAVE_COPY_THREAD_TLS
139 select HAVE_DEBUG_KMEMLEAK
140 select HAVE_DMA_CONTIGUOUS
141 select HAVE_DYNAMIC_FTRACE
142 select HAVE_DYNAMIC_FTRACE_WITH_REGS
143 select HAVE_FAST_GUP
144 select HAVE_EFFICIENT_UNALIGNED_ACCESS
145 select HAVE_FENTRY
146 select HAVE_FTRACE_MCOUNT_RECORD
147 select HAVE_FUNCTION_GRAPH_TRACER
148 select HAVE_FUNCTION_TRACER
149 select HAVE_FUTEX_CMPXCHG if FUTEX
150 select HAVE_GCC_PLUGINS
151 select HAVE_KERNEL_BZIP2
152 select HAVE_KERNEL_GZIP
153 select HAVE_KERNEL_LZ4
154 select HAVE_KERNEL_LZMA
155 select HAVE_KERNEL_LZO
156 select HAVE_KERNEL_UNCOMPRESSED
157 select HAVE_KERNEL_XZ
158 select HAVE_KPROBES
159 select HAVE_KRETPROBES
160 select HAVE_KVM
161 select HAVE_LIVEPATCH
162 select HAVE_PERF_REGS
163 select HAVE_PERF_USER_STACK_DUMP
164 select HAVE_MEMBLOCK_NODE_MAP
165 select HAVE_MEMBLOCK_PHYS_MAP
166 select MMU_GATHER_NO_GATHER
167 select HAVE_MOD_ARCH_SPECIFIC
168 select HAVE_NOP_MCOUNT
169 select HAVE_OPROFILE
170 select HAVE_PCI
171 select HAVE_PERF_EVENTS
172 select MMU_GATHER_RCU_TABLE_FREE
173 select HAVE_REGS_AND_STACK_ACCESS_API
174 select HAVE_RELIABLE_STACKTRACE
175 select HAVE_RSEQ
176 select HAVE_SYSCALL_TRACEPOINTS
177 select HAVE_VIRT_CPU_ACCOUNTING
178 select IOMMU_HELPER if PCI
179 select IOMMU_SUPPORT if PCI
180 select MODULES_USE_ELF_RELA
181 select NEED_DMA_MAP_STATE if PCI
182 select NEED_SG_DMA_LENGTH if PCI
183 select OLD_SIGACTION
184 select OLD_SIGSUSPEND3
185 select PCI_DOMAINS if PCI
186 select PCI_MSI if PCI
187 select SPARSE_IRQ
188 select SYSCTL_EXCEPTION_TRACE
189 select THREAD_INFO_IN_TASK
190 select TTY
191 select VIRT_CPU_ACCOUNTING
192 select ARCH_HAS_SCALED_CPUTIME
193 select HAVE_NMI
194 select ARCH_HAS_FORCE_DMA_UNENCRYPTED
195 select SWIOTLB
196 select GENERIC_ALLOCATOR
199 config SCHED_OMIT_FRAME_POINTER
200 def_bool y
202 config PGTABLE_LEVELS
203 int
204 default 5
206 source "kernel/livepatch/Kconfig"
208 menu "Processor type and features"
210 config HAVE_MARCH_Z900_FEATURES
211 def_bool n
213 config HAVE_MARCH_Z990_FEATURES
214 def_bool n
215 select HAVE_MARCH_Z900_FEATURES
217 config HAVE_MARCH_Z9_109_FEATURES
218 def_bool n
219 select HAVE_MARCH_Z990_FEATURES
221 config HAVE_MARCH_Z10_FEATURES
222 def_bool n
223 select HAVE_MARCH_Z9_109_FEATURES
225 config HAVE_MARCH_Z196_FEATURES
226 def_bool n
227 select HAVE_MARCH_Z10_FEATURES
229 config HAVE_MARCH_ZEC12_FEATURES
230 def_bool n
231 select HAVE_MARCH_Z196_FEATURES
233 config HAVE_MARCH_Z13_FEATURES
234 def_bool n
235 select HAVE_MARCH_ZEC12_FEATURES
237 config HAVE_MARCH_Z14_FEATURES
238 def_bool n
239 select HAVE_MARCH_Z13_FEATURES
241 config HAVE_MARCH_Z15_FEATURES
242 def_bool n
243 select HAVE_MARCH_Z14_FEATURES
245 choice
246 prompt "Processor type"
247 default MARCH_Z196
249 config MARCH_Z900
250 bool "IBM zSeries model z800 and z900"
251 select HAVE_MARCH_Z900_FEATURES
252 depends on $(cc-option,-march=z900)
253 help
254 Select this to enable optimizations for model z800/z900 (2064 and
255 2066 series). This will enable some optimizations that are not
256 available on older ESA/390 (31 Bit) only CPUs.
258 config MARCH_Z990
259 bool "IBM zSeries model z890 and z990"
260 select HAVE_MARCH_Z990_FEATURES
261 depends on $(cc-option,-march=z990)
262 help
263 Select this to enable optimizations for model z890/z990 (2084 and
264 2086 series). The kernel will be slightly faster but will not work
265 on older machines.
267 config MARCH_Z9_109
268 bool "IBM System z9"
269 select HAVE_MARCH_Z9_109_FEATURES
270 depends on $(cc-option,-march=z9-109)
271 help
272 Select this to enable optimizations for IBM System z9 (2094 and
273 2096 series). The kernel will be slightly faster but will not work
274 on older machines.
276 config MARCH_Z10
277 bool "IBM System z10"
278 select HAVE_MARCH_Z10_FEATURES
279 depends on $(cc-option,-march=z10)
280 help
281 Select this to enable optimizations for IBM System z10 (2097 and
282 2098 series). The kernel will be slightly faster but will not work
283 on older machines.
285 config MARCH_Z196
286 bool "IBM zEnterprise 114 and 196"
287 select HAVE_MARCH_Z196_FEATURES
288 depends on $(cc-option,-march=z196)
289 help
290 Select this to enable optimizations for IBM zEnterprise 114 and 196
291 (2818 and 2817 series). The kernel will be slightly faster but will
292 not work on older machines.
294 config MARCH_ZEC12
295 bool "IBM zBC12 and zEC12"
296 select HAVE_MARCH_ZEC12_FEATURES
297 depends on $(cc-option,-march=zEC12)
298 help
299 Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
300 2827 series). The kernel will be slightly faster but will not work on
301 older machines.
303 config MARCH_Z13
304 bool "IBM z13s and z13"
305 select HAVE_MARCH_Z13_FEATURES
306 depends on $(cc-option,-march=z13)
307 help
308 Select this to enable optimizations for IBM z13s and z13 (2965 and
309 2964 series). The kernel will be slightly faster but will not work on
310 older machines.
312 config MARCH_Z14
313 bool "IBM z14 ZR1 and z14"
314 select HAVE_MARCH_Z14_FEATURES
315 depends on $(cc-option,-march=z14)
316 help
317 Select this to enable optimizations for IBM z14 ZR1 and z14 (3907
318 and 3906 series). The kernel will be slightly faster but will not
319 work on older machines.
321 config MARCH_Z15
322 bool "IBM z15"
323 select HAVE_MARCH_Z15_FEATURES
324 depends on $(cc-option,-march=z15)
325 help
326 Select this to enable optimizations for IBM z15 (8562
327 and 8561 series). The kernel will be slightly faster but will not
328 work on older machines.
330 endchoice
332 config MARCH_Z900_TUNE
333 def_bool TUNE_Z900 || MARCH_Z900 && TUNE_DEFAULT
335 config MARCH_Z990_TUNE
336 def_bool TUNE_Z990 || MARCH_Z990 && TUNE_DEFAULT
338 config MARCH_Z9_109_TUNE
339 def_bool TUNE_Z9_109 || MARCH_Z9_109 && TUNE_DEFAULT
341 config MARCH_Z10_TUNE
342 def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
344 config MARCH_Z196_TUNE
345 def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
347 config MARCH_ZEC12_TUNE
348 def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
350 config MARCH_Z13_TUNE
351 def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT
353 config MARCH_Z14_TUNE
354 def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT
356 config MARCH_Z15_TUNE
357 def_bool TUNE_Z15 || MARCH_Z15 && TUNE_DEFAULT
359 choice
360 prompt "Tune code generation"
361 default TUNE_DEFAULT
362 help
363 Cause the compiler to tune (-mtune) the generated code for a machine.
364 This will make the code run faster on the selected machine but
365 somewhat slower on other machines.
366 This option only changes how the compiler emits instructions, not the
367 selection of instructions itself, so the resulting kernel will run on
368 all other machines.
370 config TUNE_DEFAULT
371 bool "Default"
372 help
373 Tune the generated code for the target processor for which the kernel
374 will be compiled.
376 config TUNE_Z900
377 bool "IBM zSeries model z800 and z900"
378 depends on $(cc-option,-mtune=z900)
380 config TUNE_Z990
381 bool "IBM zSeries model z890 and z990"
382 depends on $(cc-option,-mtune=z990)
384 config TUNE_Z9_109
385 bool "IBM System z9"
386 depends on $(cc-option,-mtune=z9-109)
388 config TUNE_Z10
389 bool "IBM System z10"
390 depends on $(cc-option,-mtune=z10)
392 config TUNE_Z196
393 bool "IBM zEnterprise 114 and 196"
394 depends on $(cc-option,-mtune=z196)
396 config TUNE_ZEC12
397 bool "IBM zBC12 and zEC12"
398 depends on $(cc-option,-mtune=zEC12)
400 config TUNE_Z13
401 bool "IBM z13s and z13"
402 depends on $(cc-option,-mtune=z13)
404 config TUNE_Z14
405 bool "IBM z14 ZR1 and z14"
406 depends on $(cc-option,-mtune=z14)
408 config TUNE_Z15
409 bool "IBM z15"
410 depends on $(cc-option,-mtune=z15)
412 endchoice
414 config 64BIT
415 def_bool y
417 config COMPAT
418 def_bool y
419 prompt "Kernel support for 31 bit emulation"
420 select COMPAT_BINFMT_ELF if BINFMT_ELF
421 select ARCH_WANT_OLD_COMPAT_IPC
422 select COMPAT_OLD_SIGACTION
423 select HAVE_UID16
424 depends on MULTIUSER
425 help
426 Select this option if you want to enable your system kernel to
427 handle system-calls from ELF binaries for 31 bit ESA. This option
428 (and some other stuff like libraries and such) is needed for
429 executing 31 bit applications. It is safe to say "Y".
431 config SYSVIPC_COMPAT
432 def_bool y if COMPAT && SYSVIPC
434 config SMP
435 def_bool y
437 config NR_CPUS
438 int "Maximum number of CPUs (2-512)"
439 range 2 512
440 default "64"
441 help
442 This allows you to specify the maximum number of CPUs which this
443 kernel will support. The maximum supported value is 512 and the
444 minimum value which makes sense is 2.
446 This is purely to save memory - each supported CPU adds
447 approximately sixteen kilobytes to the kernel image.
449 config HOTPLUG_CPU
450 def_bool y
452 # Some NUMA nodes have memory ranges that span
453 # other nodes. Even though a pfn is valid and
454 # between a node's start and end pfns, it may not
455 # reside on that node. See memmap_init_zone()
456 # for details. <- They meant memory holes!
457 config NODES_SPAN_OTHER_NODES
458 def_bool NUMA
460 config NUMA
461 bool "NUMA support"
462 depends on SCHED_TOPOLOGY
463 default n
464 help
465 Enable NUMA support
467 This option adds NUMA support to the kernel.
469 An operation mode can be selected by appending
470 numa=<method> to the kernel command line.
472 The default behaviour is identical to appending numa=plain to
473 the command line. This will create just one node with all
474 available memory and all CPUs in it.
476 config NODES_SHIFT
477 int "Maximum NUMA nodes (as a power of 2)"
478 range 1 10
479 depends on NUMA
480 default "4"
481 help
482 Specify the maximum number of NUMA nodes available on the target
483 system. Increases memory reserved to accommodate various tables.
485 menu "Select NUMA modes"
486 depends on NUMA
488 config NUMA_EMU
489 bool "NUMA emulation"
490 default y
491 help
492 Numa emulation mode will split the available system memory into
493 equal chunks which then are distributed over the configured number
494 of nodes in a round-robin manner.
496 The number of fake nodes is limited by the number of available memory
497 chunks (i.e. memory size / fake size) and the number of supported
498 nodes in the kernel.
500 The CPUs are assigned to the nodes in a way that partially respects
501 the original machine topology (if supported by the machine).
502 Fair distribution of the CPUs is not guaranteed.
504 config EMU_SIZE
505 hex "NUMA emulation memory chunk size"
506 default 0x10000000
507 range 0x400000 0x100000000
508 depends on NUMA_EMU
509 help
510 Select the default size by which the memory is chopped and then
511 assigned to emulated NUMA nodes.
513 This can be overridden by specifying
515 emu_size=<n>
517 on the kernel command line where also suffixes K, M, G, and T are
518 supported.
520 endmenu
522 config SCHED_SMT
523 def_bool n
525 config SCHED_MC
526 def_bool n
528 config SCHED_BOOK
529 def_bool n
531 config SCHED_DRAWER
532 def_bool n
534 config SCHED_TOPOLOGY
535 def_bool y
536 prompt "Topology scheduler support"
537 select SCHED_SMT
538 select SCHED_MC
539 select SCHED_BOOK
540 select SCHED_DRAWER
541 help
542 Topology scheduler support improves the CPU scheduler's decision
543 making when dealing with machines that have multi-threading,
544 multiple cores or multiple books.
546 source "kernel/Kconfig.hz"
548 config KEXEC
549 def_bool y
550 select KEXEC_CORE
552 config KEXEC_FILE
553 bool "kexec file based system call"
554 select KEXEC_CORE
555 select BUILD_BIN2C
556 depends on CRYPTO
557 depends on CRYPTO_SHA256
558 depends on CRYPTO_SHA256_S390
559 help
560 Enable the kexec file based system call. In contrast to the normal
561 kexec system call this system call takes file descriptors for the
562 kernel and initramfs as arguments.
564 config ARCH_HAS_KEXEC_PURGATORY
565 def_bool y
566 depends on KEXEC_FILE
568 config KEXEC_SIG
569 bool "Verify kernel signature during kexec_file_load() syscall"
570 depends on KEXEC_FILE && MODULE_SIG_FORMAT
571 help
572 This option makes kernel signature verification mandatory for
573 the kexec_file_load() syscall.
575 In addition to that option, you need to enable signature
576 verification for the corresponding kernel image type being
577 loaded in order for this to work.
579 config ARCH_RANDOM
580 def_bool y
581 prompt "s390 architectural random number generation API"
582 help
583 Enable the s390 architectural random number generation API
584 to provide random data for all consumers within the Linux
585 kernel.
587 When enabled the arch_random_* functions declared in linux/random.h
588 are implemented. The implementation is based on the s390 CPACF
589 instruction subfunction TRNG which provides a real true random
590 number generator.
592 If unsure, say Y.
594 config KERNEL_NOBP
595 def_bool n
596 prompt "Enable modified branch prediction for the kernel by default"
597 help
598 If this option is selected the kernel will switch to a modified
599 branch prediction mode if the firmware interface is available.
600 The modified branch prediction mode improves the behaviour in
601 regard to speculative execution.
603 With the option enabled the kernel parameter "nobp=0" or "nospec"
604 can be used to run the kernel in the normal branch prediction mode.
606 With the option disabled the modified branch prediction mode is
607 enabled with the "nobp=1" kernel parameter.
609 If unsure, say N.
611 config EXPOLINE
612 def_bool n
613 prompt "Avoid speculative indirect branches in the kernel"
614 help
615 Compile the kernel with the expoline compiler options to guard
616 against kernel-to-user data leaks by avoiding speculative indirect
617 branches.
618 Requires a compiler with -mindirect-branch=thunk support for full
619 protection. The kernel may run slower.
621 If unsure, say N.
623 choice
624 prompt "Expoline default"
625 depends on EXPOLINE
626 default EXPOLINE_FULL
628 config EXPOLINE_OFF
629 bool "spectre_v2=off"
631 config EXPOLINE_AUTO
632 bool "spectre_v2=auto"
634 config EXPOLINE_FULL
635 bool "spectre_v2=on"
637 endchoice
639 config RELOCATABLE
640 bool "Build a relocatable kernel"
641 select MODULE_REL_CRCS if MODVERSIONS
642 default y
643 help
644 This builds a kernel image that retains relocation information
645 so it can be loaded at an arbitrary address.
646 The kernel is linked as a position-independent executable (PIE)
647 and contains dynamic relocations which are processed early in the
648 bootup process.
649 The relocations make the kernel image about 15% larger (compressed
650 10%), but are discarded at runtime.
652 config RANDOMIZE_BASE
653 bool "Randomize the address of the kernel image (KASLR)"
654 depends on RELOCATABLE
655 default y
656 help
657 In support of Kernel Address Space Layout Randomization (KASLR),
658 this randomizes the address at which the kernel image is loaded,
659 as a security feature that deters exploit attempts relying on
660 knowledge of the location of kernel internals.
662 endmenu
664 menu "Memory setup"
666 config ARCH_SPARSEMEM_ENABLE
667 def_bool y
668 select SPARSEMEM_VMEMMAP_ENABLE
669 select SPARSEMEM_VMEMMAP
671 config ARCH_SPARSEMEM_DEFAULT
672 def_bool y
674 config ARCH_ENABLE_MEMORY_HOTPLUG
675 def_bool y if SPARSEMEM
677 config ARCH_ENABLE_MEMORY_HOTREMOVE
678 def_bool y
680 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
681 def_bool y
683 config FORCE_MAX_ZONEORDER
684 int
685 default "9"
687 config MAX_PHYSMEM_BITS
688 int "Maximum size of supported physical memory in bits (42-53)"
689 range 42 53
690 default "46"
691 help
692 This option specifies the maximum supported size of physical memory
693 in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB).
694 Increasing the number of bits also increases the kernel image size.
695 By default 46 bits (64TB) are supported.
697 config PACK_STACK
698 def_bool y
699 prompt "Pack kernel stack"
700 help
701 This option enables the compiler option -mkernel-backchain if it
702 is available. If the option is available the compiler supports
703 the new stack layout which dramatically reduces the minimum stack
704 frame size. With an old compiler a non-leaf function needs a
705 minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
706 -mkernel-backchain the minimum size drops to 16 byte on 31 bit
707 and 24 byte on 64 bit.
709 Say Y if you are unsure.
711 config CHECK_STACK
712 def_bool y
713 depends on !VMAP_STACK
714 prompt "Detect kernel stack overflow"
715 help
716 This option enables the compiler option -mstack-guard and
717 -mstack-size if they are available. If the compiler supports them
718 it will emit additional code to each function prolog to trigger
719 an illegal operation if the kernel stack is about to overflow.
721 Say N if you are unsure.
723 config STACK_GUARD
724 int "Size of the guard area (128-1024)"
725 range 128 1024
726 depends on CHECK_STACK
727 default "256"
728 help
729 This allows you to specify the size of the guard area at the lower
730 end of the kernel stack. If the kernel stack points into the guard
731 area on function entry an illegal operation is triggered. The size
732 needs to be a power of 2. Please keep in mind that the size of an
733 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
734 The minimum size for the stack guard should be 256 for 31 bit and
735 512 for 64 bit.
737 config WARN_DYNAMIC_STACK
738 def_bool n
739 prompt "Emit compiler warnings for function with dynamic stack usage"
740 help
741 This option enables the compiler option -mwarn-dynamicstack. If the
742 compiler supports this options generates warnings for functions
743 that dynamically allocate stack space using alloca.
745 Say N if you are unsure.
747 endmenu
749 menu "I/O subsystem"
751 config QDIO
752 def_tristate y
753 prompt "QDIO support"
754 ---help---
755 This driver provides the Queued Direct I/O base support for
756 IBM System z.
758 To compile this driver as a module, choose M here: the
759 module will be called qdio.
761 If unsure, say Y.
763 if PCI
765 config PCI_NR_FUNCTIONS
766 int "Maximum number of PCI functions (1-4096)"
767 range 1 4096
768 default "128"
769 help
770 This allows you to specify the maximum number of PCI functions which
771 this kernel will support.
773 endif # PCI
775 config HAS_IOMEM
776 def_bool PCI
778 config CHSC_SCH
779 def_tristate m
780 prompt "Support for CHSC subchannels"
781 help
782 This driver allows usage of CHSC subchannels. A CHSC subchannel
783 is usually present on LPAR only.
784 The driver creates a device /dev/chsc, which may be used to
785 obtain I/O configuration information about the machine and
786 to issue asynchronous chsc commands (DANGEROUS).
787 You will usually only want to use this interface on a special
788 LPAR designated for system management.
790 To compile this driver as a module, choose M here: the
791 module will be called chsc_sch.
793 If unsure, say N.
795 config SCM_BUS
796 def_bool y
797 prompt "SCM bus driver"
798 help
799 Bus driver for Storage Class Memory.
801 config EADM_SCH
802 def_tristate m
803 prompt "Support for EADM subchannels"
804 depends on SCM_BUS
805 help
806 This driver allows usage of EADM subchannels. EADM subchannels act
807 as a communication vehicle for SCM increments.
809 To compile this driver as a module, choose M here: the
810 module will be called eadm_sch.
812 config VFIO_CCW
813 def_tristate n
814 prompt "Support for VFIO-CCW subchannels"
815 depends on S390_CCW_IOMMU && VFIO_MDEV
816 help
817 This driver allows usage of I/O subchannels via VFIO-CCW.
819 To compile this driver as a module, choose M here: the
820 module will be called vfio_ccw.
822 config VFIO_AP
823 def_tristate n
824 prompt "VFIO support for AP devices"
825 depends on S390_AP_IOMMU && VFIO_MDEV_DEVICE && KVM
826 help
827 This driver grants access to Adjunct Processor (AP) devices
828 via the VFIO mediated device interface.
830 To compile this driver as a module, choose M here: the module
831 will be called vfio_ap.
833 endmenu
835 menu "Dump support"
837 config CRASH_DUMP
838 bool "kernel crash dumps"
839 select KEXEC
840 help
841 Generate crash dump after being started by kexec.
842 Crash dump kernels are loaded in the main kernel with kexec-tools
843 into a specially reserved region and then later executed after
844 a crash by kdump/kexec.
845 Refer to <file:Documentation/s390/zfcpdump.rst> for more details on this.
846 This option also enables s390 zfcpdump.
847 See also <file:Documentation/s390/zfcpdump.rst>
849 endmenu
851 config SECCOMP
852 def_bool y
853 prompt "Enable seccomp to safely compute untrusted bytecode"
854 depends on PROC_FS
855 help
856 This kernel feature is useful for number crunching applications
857 that may need to compute untrusted bytecode during their
858 execution. By using pipes or other transports made available to
859 the process as file descriptors supporting the read/write
860 syscalls, it's possible to isolate those applications in
861 their own address space using seccomp. Once seccomp is
862 enabled via /proc/<pid>/seccomp, it cannot be disabled
863 and the task is only allowed to execute a few safe syscalls
864 defined by each seccomp mode.
866 If unsure, say Y.
868 menu "Power Management"
870 config ARCH_HIBERNATION_POSSIBLE
871 def_bool y
873 source "kernel/power/Kconfig"
875 endmenu
877 config CCW
878 def_bool y
880 config HAVE_PNETID
881 tristate
882 default (SMC || CCWGROUP)
884 menu "Virtualization"
886 config PROTECTED_VIRTUALIZATION_GUEST
887 def_bool n
888 prompt "Protected virtualization guest support"
889 help
890 Select this option, if you want to be able to run this
891 kernel as a protected virtualization KVM guest.
892 Protected virtualization capable machines have a mini hypervisor
893 located at machine level (an ultravisor). With help of the
894 Ultravisor, KVM will be able to run "protected" VMs, special
895 VMs whose memory and management data are unavailable to KVM.
897 config PFAULT
898 def_bool y
899 prompt "Pseudo page fault support"
900 help
901 Select this option, if you want to use PFAULT pseudo page fault
902 handling under VM. If running native or in LPAR, this option
903 has no effect. If your VM does not support PFAULT, PAGEEX
904 pseudo page fault handling will be used.
905 Note that VM 4.2 supports PFAULT but has a bug in its
906 implementation that causes some problems.
907 Everybody who wants to run Linux under VM != VM4.2 should select
908 this option.
910 config CMM
911 def_tristate n
912 prompt "Cooperative memory management"
913 help
914 Select this option, if you want to enable the kernel interface
915 to reduce the memory size of the system. This is accomplished
916 by allocating pages of memory and put them "on hold". This only
917 makes sense for a system running under VM where the unused pages
918 will be reused by VM for other guest systems. The interface
919 allows an external monitor to balance memory of many systems.
920 Everybody who wants to run Linux under VM should select this
921 option.
923 config CMM_IUCV
924 def_bool y
925 prompt "IUCV special message interface to cooperative memory management"
926 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
927 help
928 Select this option to enable the special message interface to
929 the cooperative memory management.
931 config APPLDATA_BASE
932 def_bool n
933 prompt "Linux - VM Monitor Stream, base infrastructure"
934 depends on PROC_FS
935 help
936 This provides a kernel interface for creating and updating z/VM APPLDATA
937 monitor records. The monitor records are updated at certain time
938 intervals, once the timer is started.
939 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
940 i.e. enables or disables monitoring on the Linux side.
941 A custom interval value (in seconds) can be written to
942 /proc/appldata/interval.
944 Defaults are 60 seconds interval and timer off.
945 The /proc entries can also be read from, showing the current settings.
947 config APPLDATA_MEM
948 def_tristate m
949 prompt "Monitor memory management statistics"
950 depends on APPLDATA_BASE && VM_EVENT_COUNTERS
951 help
952 This provides memory management related data to the Linux - VM Monitor
953 Stream, like paging/swapping rate, memory utilisation, etc.
954 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
955 APPLDATA monitor record, i.e. enables or disables monitoring this record
956 on the z/VM side.
958 Default is disabled.
959 The /proc entry can also be read from, showing the current settings.
961 This can also be compiled as a module, which will be called
962 appldata_mem.o.
964 config APPLDATA_OS
965 def_tristate m
966 prompt "Monitor OS statistics"
967 depends on APPLDATA_BASE
968 help
969 This provides OS related data to the Linux - VM Monitor Stream, like
970 CPU utilisation, etc.
971 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
972 APPLDATA monitor record, i.e. enables or disables monitoring this record
973 on the z/VM side.
975 Default is disabled.
976 This can also be compiled as a module, which will be called
977 appldata_os.o.
979 config APPLDATA_NET_SUM
980 def_tristate m
981 prompt "Monitor overall network statistics"
982 depends on APPLDATA_BASE && NET
983 help
984 This provides network related data to the Linux - VM Monitor Stream,
985 currently there is only a total sum of network I/O statistics, no
986 per-interface data.
987 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
988 APPLDATA monitor record, i.e. enables or disables monitoring this record
989 on the z/VM side.
991 Default is disabled.
992 This can also be compiled as a module, which will be called
993 appldata_net_sum.o.
995 config S390_HYPFS_FS
996 def_bool y
997 prompt "s390 hypervisor file system support"
998 select SYS_HYPERVISOR
999 help
1000 This is a virtual file system intended to provide accounting
1001 information in an s390 hypervisor environment.
1003 source "arch/s390/kvm/Kconfig"
1005 config S390_GUEST
1006 def_bool y
1007 prompt "s390 support for virtio devices"
1008 select TTY
1009 select VIRTUALIZATION
1010 select VIRTIO
1011 select VIRTIO_CONSOLE
1012 help
1013 Enabling this option adds support for virtio based paravirtual device
1014 drivers on s390.
1016 Select this option if you want to run the kernel as a guest under
1017 the KVM hypervisor.
1019 endmenu
1021 menu "Selftests"
1023 config S390_UNWIND_SELFTEST
1024 def_tristate n
1025 prompt "Test unwind functions"
1026 help
1027 This option enables s390 specific stack unwinder testing kernel
1028 module. This option is not useful for distributions or general
1029 kernels, but only for kernel developers working on architecture code.
1031 Say N if you are unsure.
1033 endmenu