| blob | 109243fdb6ec96d04349072329db3367e233e724 |
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 SMP && PREEMPT
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_PTE_SPECIAL
69 select ARCH_HAS_SET_MEMORY
70 select ARCH_HAS_STRICT_KERNEL_RWX
71 select ARCH_HAS_STRICT_MODULE_RWX
72 select ARCH_HAS_SYSCALL_WRAPPER
73 select ARCH_HAS_UBSAN_SANITIZE_ALL
74 select ARCH_HAVE_NMI_SAFE_CMPXCHG
75 select ARCH_INLINE_READ_LOCK
76 select ARCH_INLINE_READ_LOCK_BH
77 select ARCH_INLINE_READ_LOCK_IRQ
78 select ARCH_INLINE_READ_LOCK_IRQSAVE
79 select ARCH_INLINE_READ_TRYLOCK
80 select ARCH_INLINE_READ_UNLOCK
81 select ARCH_INLINE_READ_UNLOCK_BH
82 select ARCH_INLINE_READ_UNLOCK_IRQ
83 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
84 select ARCH_INLINE_SPIN_LOCK
85 select ARCH_INLINE_SPIN_LOCK_BH
86 select ARCH_INLINE_SPIN_LOCK_IRQ
87 select ARCH_INLINE_SPIN_LOCK_IRQSAVE
88 select ARCH_INLINE_SPIN_TRYLOCK
89 select ARCH_INLINE_SPIN_TRYLOCK_BH
90 select ARCH_INLINE_SPIN_UNLOCK
91 select ARCH_INLINE_SPIN_UNLOCK_BH
92 select ARCH_INLINE_SPIN_UNLOCK_IRQ
93 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
94 select ARCH_INLINE_WRITE_LOCK
95 select ARCH_INLINE_WRITE_LOCK_BH
96 select ARCH_INLINE_WRITE_LOCK_IRQ
97 select ARCH_INLINE_WRITE_LOCK_IRQSAVE
98 select ARCH_INLINE_WRITE_TRYLOCK
99 select ARCH_INLINE_WRITE_UNLOCK
100 select ARCH_INLINE_WRITE_UNLOCK_BH
101 select ARCH_INLINE_WRITE_UNLOCK_IRQ
102 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
103 select ARCH_KEEP_MEMBLOCK
104 select ARCH_SAVE_PAGE_KEYS if HIBERNATION
105 select ARCH_SUPPORTS_ATOMIC_RMW
106 select ARCH_SUPPORTS_NUMA_BALANCING
107 select ARCH_USE_BUILTIN_BSWAP
108 select ARCH_USE_CMPXCHG_LOCKREF
109 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
110 select ARCH_WANT_IPC_PARSE_VERSION
111 select BUILDTIME_EXTABLE_SORT
112 select CLONE_BACKWARDS2
113 select DYNAMIC_FTRACE if FUNCTION_TRACER
114 select GENERIC_CLOCKEVENTS
115 select GENERIC_CPU_AUTOPROBE
116 select GENERIC_CPU_DEVICES if !SMP
117 select GENERIC_CPU_VULNERABILITIES
118 select GENERIC_FIND_FIRST_BIT
119 select GENERIC_SMP_IDLE_THREAD
120 select GENERIC_TIME_VSYSCALL
121 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
122 select HAVE_ARCH_AUDITSYSCALL
123 select HAVE_ARCH_JUMP_LABEL
124 select HAVE_ARCH_JUMP_LABEL_RELATIVE
125 select HAVE_ARCH_KASAN
126 select CPU_NO_EFFICIENT_FFS if !HAVE_MARCH_Z9_109_FEATURES
127 select HAVE_ARCH_SECCOMP_FILTER
128 select HAVE_ARCH_SOFT_DIRTY
129 select HAVE_ARCH_TRACEHOOK
130 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
131 select HAVE_ARCH_VMAP_STACK
132 select HAVE_EBPF_JIT if PACK_STACK && HAVE_MARCH_Z196_FEATURES
133 select HAVE_CMPXCHG_DOUBLE
134 select HAVE_CMPXCHG_LOCAL
135 select HAVE_COPY_THREAD_TLS
136 select HAVE_DEBUG_KMEMLEAK
137 select HAVE_DMA_CONTIGUOUS
138 select HAVE_DYNAMIC_FTRACE
139 select HAVE_DYNAMIC_FTRACE_WITH_REGS
140 select HAVE_EFFICIENT_UNALIGNED_ACCESS
141 select HAVE_FENTRY
142 select HAVE_FTRACE_MCOUNT_RECORD
143 select HAVE_FUNCTION_GRAPH_TRACER
144 select HAVE_FUNCTION_TRACER
145 select HAVE_FUTEX_CMPXCHG if FUTEX
146 select HAVE_GCC_PLUGINS
147 select HAVE_GENERIC_GUP
148 select HAVE_KERNEL_BZIP2
149 select HAVE_KERNEL_GZIP
150 select HAVE_KERNEL_LZ4
151 select HAVE_KERNEL_LZMA
152 select HAVE_KERNEL_LZO
153 select HAVE_KERNEL_UNCOMPRESSED
154 select HAVE_KERNEL_XZ
155 select HAVE_KPROBES
156 select HAVE_KRETPROBES
157 select HAVE_KVM
158 select HAVE_LIVEPATCH
159 select HAVE_PERF_REGS
160 select HAVE_PERF_USER_STACK_DUMP
161 select HAVE_MEMBLOCK_NODE_MAP
162 select HAVE_MEMBLOCK_PHYS_MAP
163 select HAVE_MMU_GATHER_NO_GATHER
164 select HAVE_MOD_ARCH_SPECIFIC
165 select HAVE_NOP_MCOUNT
166 select HAVE_OPROFILE
167 select HAVE_PCI
168 select HAVE_PERF_EVENTS
169 select HAVE_RCU_TABLE_FREE
170 select HAVE_REGS_AND_STACK_ACCESS_API
171 select HAVE_RSEQ
172 select HAVE_SYSCALL_TRACEPOINTS
173 select HAVE_VIRT_CPU_ACCOUNTING
174 select IOMMU_HELPER if PCI
175 select IOMMU_SUPPORT if PCI
176 select MODULES_USE_ELF_RELA
177 select NEED_DMA_MAP_STATE if PCI
178 select NEED_SG_DMA_LENGTH if PCI
179 select OLD_SIGACTION
180 select OLD_SIGSUSPEND3
181 select PCI_DOMAINS if PCI
182 select PCI_MSI if PCI
183 select SPARSE_IRQ
184 select SYSCTL_EXCEPTION_TRACE
185 select THREAD_INFO_IN_TASK
186 select TTY
187 select VIRT_CPU_ACCOUNTING
188 select ARCH_HAS_SCALED_CPUTIME
189 select HAVE_NMI
192 config SCHED_OMIT_FRAME_POINTER
193 def_bool y
195 config PGTABLE_LEVELS
196 int
197 default 5
199 source "kernel/livepatch/Kconfig"
201 menu "Processor type and features"
203 config HAVE_MARCH_Z900_FEATURES
204 def_bool n
206 config HAVE_MARCH_Z990_FEATURES
207 def_bool n
208 select HAVE_MARCH_Z900_FEATURES
210 config HAVE_MARCH_Z9_109_FEATURES
211 def_bool n
212 select HAVE_MARCH_Z990_FEATURES
214 config HAVE_MARCH_Z10_FEATURES
215 def_bool n
216 select HAVE_MARCH_Z9_109_FEATURES
218 config HAVE_MARCH_Z196_FEATURES
219 def_bool n
220 select HAVE_MARCH_Z10_FEATURES
222 config HAVE_MARCH_ZEC12_FEATURES
223 def_bool n
224 select HAVE_MARCH_Z196_FEATURES
226 config HAVE_MARCH_Z13_FEATURES
227 def_bool n
228 select HAVE_MARCH_ZEC12_FEATURES
230 config HAVE_MARCH_Z14_FEATURES
231 def_bool n
232 select HAVE_MARCH_Z13_FEATURES
234 choice
235 prompt "Processor type"
236 default MARCH_Z196
238 config MARCH_Z900
239 bool "IBM zSeries model z800 and z900"
240 depends on !CC_IS_CLANG
241 select HAVE_MARCH_Z900_FEATURES
242 help
243 Select this to enable optimizations for model z800/z900 (2064 and
244 2066 series). This will enable some optimizations that are not
245 available on older ESA/390 (31 Bit) only CPUs.
247 config MARCH_Z990
248 bool "IBM zSeries model z890 and z990"
249 depends on !CC_IS_CLANG
250 select HAVE_MARCH_Z990_FEATURES
251 help
252 Select this to enable optimizations for model z890/z990 (2084 and
253 2086 series). The kernel will be slightly faster but will not work
254 on older machines.
256 config MARCH_Z9_109
257 bool "IBM System z9"
258 depends on !CC_IS_CLANG
259 select HAVE_MARCH_Z9_109_FEATURES
260 help
261 Select this to enable optimizations for IBM System z9 (2094 and
262 2096 series). The kernel will be slightly faster but will not work
263 on older machines.
265 config MARCH_Z10
266 bool "IBM System z10"
267 select HAVE_MARCH_Z10_FEATURES
268 help
269 Select this to enable optimizations for IBM System z10 (2097 and
270 2098 series). The kernel will be slightly faster but will not work
271 on older machines.
273 config MARCH_Z196
274 bool "IBM zEnterprise 114 and 196"
275 select HAVE_MARCH_Z196_FEATURES
276 help
277 Select this to enable optimizations for IBM zEnterprise 114 and 196
278 (2818 and 2817 series). The kernel will be slightly faster but will
279 not work on older machines.
281 config MARCH_ZEC12
282 bool "IBM zBC12 and zEC12"
283 select HAVE_MARCH_ZEC12_FEATURES
284 help
285 Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
286 2827 series). The kernel will be slightly faster but will not work on
287 older machines.
289 config MARCH_Z13
290 bool "IBM z13s and z13"
291 select HAVE_MARCH_Z13_FEATURES
292 help
293 Select this to enable optimizations for IBM z13s and z13 (2965 and
294 2964 series). The kernel will be slightly faster but will not work on
295 older machines.
297 config MARCH_Z14
298 bool "IBM z14 ZR1 and z14"
299 select HAVE_MARCH_Z14_FEATURES
300 help
301 Select this to enable optimizations for IBM z14 ZR1 and z14 (3907
302 and 3906 series). The kernel will be slightly faster but will not
303 work on older machines.
305 endchoice
307 config MARCH_Z900_TUNE
308 def_bool TUNE_Z900 || MARCH_Z900 && TUNE_DEFAULT
310 config MARCH_Z990_TUNE
311 def_bool TUNE_Z990 || MARCH_Z990 && TUNE_DEFAULT
313 config MARCH_Z9_109_TUNE
314 def_bool TUNE_Z9_109 || MARCH_Z9_109 && TUNE_DEFAULT
316 config MARCH_Z10_TUNE
317 def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
319 config MARCH_Z196_TUNE
320 def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
322 config MARCH_ZEC12_TUNE
323 def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
325 config MARCH_Z13_TUNE
326 def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT
328 config MARCH_Z14_TUNE
329 def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT
331 choice
332 prompt "Tune code generation"
333 default TUNE_DEFAULT
334 help
335 Cause the compiler to tune (-mtune) the generated code for a machine.
336 This will make the code run faster on the selected machine but
337 somewhat slower on other machines.
338 This option only changes how the compiler emits instructions, not the
339 selection of instructions itself, so the resulting kernel will run on
340 all other machines.
342 config TUNE_DEFAULT
343 bool "Default"
344 help
345 Tune the generated code for the target processor for which the kernel
346 will be compiled.
348 config TUNE_Z900
349 bool "IBM zSeries model z800 and z900"
350 depends on !CC_IS_CLANG
352 config TUNE_Z990
353 bool "IBM zSeries model z890 and z990"
354 depends on !CC_IS_CLANG
356 config TUNE_Z9_109
357 bool "IBM System z9"
358 depends on !CC_IS_CLANG
360 config TUNE_Z10
361 bool "IBM System z10"
363 config TUNE_Z196
364 bool "IBM zEnterprise 114 and 196"
366 config TUNE_ZEC12
367 bool "IBM zBC12 and zEC12"
369 config TUNE_Z13
370 bool "IBM z13"
372 config TUNE_Z14
373 bool "IBM z14"
375 endchoice
377 config 64BIT
378 def_bool y
380 config COMPAT
381 def_bool y
382 prompt "Kernel support for 31 bit emulation"
383 select COMPAT_BINFMT_ELF if BINFMT_ELF
384 select ARCH_WANT_OLD_COMPAT_IPC
385 select COMPAT_OLD_SIGACTION
386 select HAVE_UID16
387 depends on MULTIUSER
388 help
389 Select this option if you want to enable your system kernel to
390 handle system-calls from ELF binaries for 31 bit ESA. This option
391 (and some other stuff like libraries and such) is needed for
392 executing 31 bit applications. It is safe to say "Y".
394 config COMPAT_VDSO
395 def_bool COMPAT && !CC_IS_CLANG
397 config SYSVIPC_COMPAT
398 def_bool y if COMPAT && SYSVIPC
400 config SMP
401 def_bool y
402 prompt "Symmetric multi-processing support"
403 ---help---
404 This enables support for systems with more than one CPU. If you have
405 a system with only one CPU, like most personal computers, say N. If
406 you have a system with more than one CPU, say Y.
408 If you say N here, the kernel will run on uni- and multiprocessor
409 machines, but will use only one CPU of a multiprocessor machine. If
410 you say Y here, the kernel will run on many, but not all,
411 uniprocessor machines. On a uniprocessor machine, the kernel
412 will run faster if you say N here.
414 See also the SMP-HOWTO available at
415 <http://www.tldp.org/docs.html#howto>.
417 Even if you don't know what to do here, say Y.
419 config NR_CPUS
420 int "Maximum number of CPUs (2-512)"
421 range 2 512
422 depends on SMP
423 default "64"
424 help
425 This allows you to specify the maximum number of CPUs which this
426 kernel will support. The maximum supported value is 512 and the
427 minimum value which makes sense is 2.
429 This is purely to save memory - each supported CPU adds
430 approximately sixteen kilobytes to the kernel image.
432 config HOTPLUG_CPU
433 def_bool y
434 prompt "Support for hot-pluggable CPUs"
435 depends on SMP
436 help
437 Say Y here to be able to turn CPUs off and on. CPUs
438 can be controlled through /sys/devices/system/cpu/cpu#.
439 Say N if you want to disable CPU hotplug.
441 # Some NUMA nodes have memory ranges that span
442 # other nodes. Even though a pfn is valid and
443 # between a node's start and end pfns, it may not
444 # reside on that node. See memmap_init_zone()
445 # for details. <- They meant memory holes!
446 config NODES_SPAN_OTHER_NODES
447 def_bool NUMA
449 config NUMA
450 bool "NUMA support"
451 depends on SMP && SCHED_TOPOLOGY
452 default n
453 help
454 Enable NUMA support
456 This option adds NUMA support to the kernel.
458 An operation mode can be selected by appending
459 numa=<method> to the kernel command line.
461 The default behaviour is identical to appending numa=plain to
462 the command line. This will create just one node with all
463 available memory and all CPUs in it.
465 config NODES_SHIFT
466 int "Maximum NUMA nodes (as a power of 2)"
467 range 1 10
468 depends on NUMA
469 default "4"
470 help
471 Specify the maximum number of NUMA nodes available on the target
472 system. Increases memory reserved to accommodate various tables.
474 menu "Select NUMA modes"
475 depends on NUMA
477 config NUMA_EMU
478 bool "NUMA emulation"
479 default y
480 help
481 Numa emulation mode will split the available system memory into
482 equal chunks which then are distributed over the configured number
483 of nodes in a round-robin manner.
485 The number of fake nodes is limited by the number of available memory
486 chunks (i.e. memory size / fake size) and the number of supported
487 nodes in the kernel.
489 The CPUs are assigned to the nodes in a way that partially respects
490 the original machine topology (if supported by the machine).
491 Fair distribution of the CPUs is not guaranteed.
493 config EMU_SIZE
494 hex "NUMA emulation memory chunk size"
495 default 0x10000000
496 range 0x400000 0x100000000
497 depends on NUMA_EMU
498 help
499 Select the default size by which the memory is chopped and then
500 assigned to emulated NUMA nodes.
502 This can be overridden by specifying
504 emu_size=<n>
506 on the kernel command line where also suffixes K, M, G, and T are
507 supported.
509 endmenu
511 config SCHED_SMT
512 def_bool n
514 config SCHED_MC
515 def_bool n
517 config SCHED_BOOK
518 def_bool n
520 config SCHED_DRAWER
521 def_bool n
523 config SCHED_TOPOLOGY
524 def_bool y
525 prompt "Topology scheduler support"
526 depends on SMP
527 select SCHED_SMT
528 select SCHED_MC
529 select SCHED_BOOK
530 select SCHED_DRAWER
531 help
532 Topology scheduler support improves the CPU scheduler's decision
533 making when dealing with machines that have multi-threading,
534 multiple cores or multiple books.
536 source "kernel/Kconfig.hz"
538 config KEXEC
539 def_bool y
540 select KEXEC_CORE
542 config KEXEC_FILE
543 bool "kexec file based system call"
544 select KEXEC_CORE
545 select BUILD_BIN2C
546 depends on CRYPTO
547 depends on CRYPTO_SHA256
548 depends on CRYPTO_SHA256_S390
549 help
550 Enable the kexec file based system call. In contrast to the normal
551 kexec system call this system call takes file descriptors for the
552 kernel and initramfs as arguments.
554 config ARCH_HAS_KEXEC_PURGATORY
555 def_bool y
556 depends on KEXEC_FILE
558 config KEXEC_VERIFY_SIG
559 bool "Verify kernel signature during kexec_file_load() syscall"
560 depends on KEXEC_FILE && SYSTEM_DATA_VERIFICATION
561 help
562 This option makes kernel signature verification mandatory for
563 the kexec_file_load() syscall.
565 In addition to that option, you need to enable signature
566 verification for the corresponding kernel image type being
567 loaded in order for this to work.
569 config ARCH_RANDOM
570 def_bool y
571 prompt "s390 architectural random number generation API"
572 help
573 Enable the s390 architectural random number generation API
574 to provide random data for all consumers within the Linux
575 kernel.
577 When enabled the arch_random_* functions declared in linux/random.h
578 are implemented. The implementation is based on the s390 CPACF
579 instruction subfunction TRNG which provides a real true random
580 number generator.
582 If unsure, say Y.
584 config KERNEL_NOBP
585 def_bool n
586 prompt "Enable modified branch prediction for the kernel by default"
587 help
588 If this option is selected the kernel will switch to a modified
589 branch prediction mode if the firmware interface is available.
590 The modified branch prediction mode improves the behaviour in
591 regard to speculative execution.
593 With the option enabled the kernel parameter "nobp=0" or "nospec"
594 can be used to run the kernel in the normal branch prediction mode.
596 With the option disabled the modified branch prediction mode is
597 enabled with the "nobp=1" kernel parameter.
599 If unsure, say N.
601 config EXPOLINE
602 def_bool n
603 prompt "Avoid speculative indirect branches in the kernel"
604 help
605 Compile the kernel with the expoline compiler options to guard
606 against kernel-to-user data leaks by avoiding speculative indirect
607 branches.
608 Requires a compiler with -mindirect-branch=thunk support for full
609 protection. The kernel may run slower.
611 If unsure, say N.
613 choice
614 prompt "Expoline default"
615 depends on EXPOLINE
616 default EXPOLINE_FULL
618 config EXPOLINE_OFF
619 bool "spectre_v2=off"
621 config EXPOLINE_AUTO
622 bool "spectre_v2=auto"
624 config EXPOLINE_FULL
625 bool "spectre_v2=on"
627 endchoice
629 config RELOCATABLE
630 bool "Build a relocatable kernel"
631 select MODULE_REL_CRCS if MODVERSIONS
632 default y
633 help
634 This builds a kernel image that retains relocation information
635 so it can be loaded at an arbitrary address.
636 The kernel is linked as a position-independent executable (PIE)
637 and contains dynamic relocations which are processed early in the
638 bootup process.
639 The relocations make the kernel image about 15% larger (compressed
640 10%), but are discarded at runtime.
642 config RANDOMIZE_BASE
643 bool "Randomize the address of the kernel image (KASLR)"
644 depends on RELOCATABLE
645 default y
646 help
647 In support of Kernel Address Space Layout Randomization (KASLR),
648 this randomizes the address at which the kernel image is loaded,
649 as a security feature that deters exploit attempts relying on
650 knowledge of the location of kernel internals.
652 endmenu
654 menu "Memory setup"
656 config ARCH_SPARSEMEM_ENABLE
657 def_bool y
658 select SPARSEMEM_VMEMMAP_ENABLE
659 select SPARSEMEM_VMEMMAP
661 config ARCH_SPARSEMEM_DEFAULT
662 def_bool y
664 config ARCH_SELECT_MEMORY_MODEL
665 def_bool y
667 config ARCH_ENABLE_MEMORY_HOTPLUG
668 def_bool y if SPARSEMEM
670 config ARCH_ENABLE_MEMORY_HOTREMOVE
671 def_bool y
673 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
674 def_bool y
676 config FORCE_MAX_ZONEORDER
677 int
678 default "9"
680 config MAX_PHYSMEM_BITS
681 int "Maximum size of supported physical memory in bits (42-53)"
682 range 42 53
683 default "46"
684 help
685 This option specifies the maximum supported size of physical memory
686 in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB).
687 Increasing the number of bits also increases the kernel image size.
688 By default 46 bits (64TB) are supported.
690 config PACK_STACK
691 def_bool y
692 prompt "Pack kernel stack"
693 help
694 This option enables the compiler option -mkernel-backchain if it
695 is available. If the option is available the compiler supports
696 the new stack layout which dramatically reduces the minimum stack
697 frame size. With an old compiler a non-leaf function needs a
698 minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
699 -mkernel-backchain the minimum size drops to 16 byte on 31 bit
700 and 24 byte on 64 bit.
702 Say Y if you are unsure.
704 config CHECK_STACK
705 def_bool y
706 depends on !VMAP_STACK
707 prompt "Detect kernel stack overflow"
708 help
709 This option enables the compiler option -mstack-guard and
710 -mstack-size if they are available. If the compiler supports them
711 it will emit additional code to each function prolog to trigger
712 an illegal operation if the kernel stack is about to overflow.
714 Say N if you are unsure.
716 config STACK_GUARD
717 int "Size of the guard area (128-1024)"
718 range 128 1024
719 depends on CHECK_STACK
720 default "256"
721 help
722 This allows you to specify the size of the guard area at the lower
723 end of the kernel stack. If the kernel stack points into the guard
724 area on function entry an illegal operation is triggered. The size
725 needs to be a power of 2. Please keep in mind that the size of an
726 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
727 The minimum size for the stack guard should be 256 for 31 bit and
728 512 for 64 bit.
730 config WARN_DYNAMIC_STACK
731 def_bool n
732 prompt "Emit compiler warnings for function with dynamic stack usage"
733 help
734 This option enables the compiler option -mwarn-dynamicstack. If the
735 compiler supports this options generates warnings for functions
736 that dynamically allocate stack space using alloca.
738 Say N if you are unsure.
740 endmenu
742 menu "I/O subsystem"
744 config QDIO
745 def_tristate y
746 prompt "QDIO support"
747 ---help---
748 This driver provides the Queued Direct I/O base support for
749 IBM System z.
751 To compile this driver as a module, choose M here: the
752 module will be called qdio.
754 If unsure, say Y.
756 if PCI
758 config PCI_NR_FUNCTIONS
759 int "Maximum number of PCI functions (1-4096)"
760 range 1 4096
761 default "128"
762 help
763 This allows you to specify the maximum number of PCI functions which
764 this kernel will support.
766 endif # PCI
768 config HAS_IOMEM
769 def_bool PCI
771 config CHSC_SCH
772 def_tristate m
773 prompt "Support for CHSC subchannels"
774 help
775 This driver allows usage of CHSC subchannels. A CHSC subchannel
776 is usually present on LPAR only.
777 The driver creates a device /dev/chsc, which may be used to
778 obtain I/O configuration information about the machine and
779 to issue asynchronous chsc commands (DANGEROUS).
780 You will usually only want to use this interface on a special
781 LPAR designated for system management.
783 To compile this driver as a module, choose M here: the
784 module will be called chsc_sch.
786 If unsure, say N.
788 config SCM_BUS
789 def_bool y
790 prompt "SCM bus driver"
791 help
792 Bus driver for Storage Class Memory.
794 config EADM_SCH
795 def_tristate m
796 prompt "Support for EADM subchannels"
797 depends on SCM_BUS
798 help
799 This driver allows usage of EADM subchannels. EADM subchannels act
800 as a communication vehicle for SCM increments.
802 To compile this driver as a module, choose M here: the
803 module will be called eadm_sch.
805 config VFIO_CCW
806 def_tristate n
807 prompt "Support for VFIO-CCW subchannels"
808 depends on S390_CCW_IOMMU && VFIO_MDEV
809 help
810 This driver allows usage of I/O subchannels via VFIO-CCW.
812 To compile this driver as a module, choose M here: the
813 module will be called vfio_ccw.
815 config VFIO_AP
816 def_tristate n
817 prompt "VFIO support for AP devices"
818 depends on S390_AP_IOMMU && VFIO_MDEV_DEVICE && KVM
819 help
820 This driver grants access to Adjunct Processor (AP) devices
821 via the VFIO mediated device interface.
823 To compile this driver as a module, choose M here: the module
824 will be called vfio_ap.
826 endmenu
828 menu "Dump support"
830 config CRASH_DUMP
831 bool "kernel crash dumps"
832 depends on SMP
833 select KEXEC
834 help
835 Generate crash dump after being started by kexec.
836 Crash dump kernels are loaded in the main kernel with kexec-tools
837 into a specially reserved region and then later executed after
838 a crash by kdump/kexec.
839 Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
840 This option also enables s390 zfcpdump.
841 See also <file:Documentation/s390/zfcpdump.txt>
843 endmenu
845 config SECCOMP
846 def_bool y
847 prompt "Enable seccomp to safely compute untrusted bytecode"
848 depends on PROC_FS
849 help
850 This kernel feature is useful for number crunching applications
851 that may need to compute untrusted bytecode during their
852 execution. By using pipes or other transports made available to
853 the process as file descriptors supporting the read/write
854 syscalls, it's possible to isolate those applications in
855 their own address space using seccomp. Once seccomp is
856 enabled via /proc/<pid>/seccomp, it cannot be disabled
857 and the task is only allowed to execute a few safe syscalls
858 defined by each seccomp mode.
860 If unsure, say Y.
862 menu "Power Management"
864 config ARCH_HIBERNATION_POSSIBLE
865 def_bool y
867 source "kernel/power/Kconfig"
869 endmenu
871 config CCW
872 def_bool y
874 config HAVE_PNETID
875 tristate
876 default (SMC || CCWGROUP)
878 menu "Virtualization"
880 config PROTECTED_VIRTUALIZATION_GUEST
881 def_bool n
882 prompt "Protected virtualization guest support"
883 help
884 Select this option, if you want to be able to run this
885 kernel as a protected virtualization KVM guest.
886 Protected virtualization capable machines have a mini hypervisor
887 located at machine level (an ultravisor). With help of the
888 Ultravisor, KVM will be able to run "protected" VMs, special
889 VMs whose memory and management data are unavailable to KVM.
891 config PFAULT
892 def_bool y
893 prompt "Pseudo page fault support"
894 help
895 Select this option, if you want to use PFAULT pseudo page fault
896 handling under VM. If running native or in LPAR, this option
897 has no effect. If your VM does not support PFAULT, PAGEEX
898 pseudo page fault handling will be used.
899 Note that VM 4.2 supports PFAULT but has a bug in its
900 implementation that causes some problems.
901 Everybody who wants to run Linux under VM != VM4.2 should select
902 this option.
904 config CMM
905 def_tristate n
906 prompt "Cooperative memory management"
907 help
908 Select this option, if you want to enable the kernel interface
909 to reduce the memory size of the system. This is accomplished
910 by allocating pages of memory and put them "on hold". This only
911 makes sense for a system running under VM where the unused pages
912 will be reused by VM for other guest systems. The interface
913 allows an external monitor to balance memory of many systems.
914 Everybody who wants to run Linux under VM should select this
915 option.
917 config CMM_IUCV
918 def_bool y
919 prompt "IUCV special message interface to cooperative memory management"
920 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
921 help
922 Select this option to enable the special message interface to
923 the cooperative memory management.
925 config APPLDATA_BASE
926 def_bool n
927 prompt "Linux - VM Monitor Stream, base infrastructure"
928 depends on PROC_FS
929 help
930 This provides a kernel interface for creating and updating z/VM APPLDATA
931 monitor records. The monitor records are updated at certain time
932 intervals, once the timer is started.
933 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
934 i.e. enables or disables monitoring on the Linux side.
935 A custom interval value (in seconds) can be written to
936 /proc/appldata/interval.
938 Defaults are 60 seconds interval and timer off.
939 The /proc entries can also be read from, showing the current settings.
941 config APPLDATA_MEM
942 def_tristate m
943 prompt "Monitor memory management statistics"
944 depends on APPLDATA_BASE && VM_EVENT_COUNTERS
945 help
946 This provides memory management related data to the Linux - VM Monitor
947 Stream, like paging/swapping rate, memory utilisation, etc.
948 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
949 APPLDATA monitor record, i.e. enables or disables monitoring this record
950 on the z/VM side.
952 Default is disabled.
953 The /proc entry can also be read from, showing the current settings.
955 This can also be compiled as a module, which will be called
956 appldata_mem.o.
958 config APPLDATA_OS
959 def_tristate m
960 prompt "Monitor OS statistics"
961 depends on APPLDATA_BASE
962 help
963 This provides OS related data to the Linux - VM Monitor Stream, like
964 CPU utilisation, etc.
965 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
966 APPLDATA monitor record, i.e. enables or disables monitoring this record
967 on the z/VM side.
969 Default is disabled.
970 This can also be compiled as a module, which will be called
971 appldata_os.o.
973 config APPLDATA_NET_SUM
974 def_tristate m
975 prompt "Monitor overall network statistics"
976 depends on APPLDATA_BASE && NET
977 help
978 This provides network related data to the Linux - VM Monitor Stream,
979 currently there is only a total sum of network I/O statistics, no
980 per-interface data.
981 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
982 APPLDATA monitor record, i.e. enables or disables monitoring this record
983 on the z/VM side.
985 Default is disabled.
986 This can also be compiled as a module, which will be called
987 appldata_net_sum.o.
989 config S390_HYPFS_FS
990 def_bool y
991 prompt "s390 hypervisor file system support"
992 select SYS_HYPERVISOR
993 help
994 This is a virtual file system intended to provide accounting
995 information in an s390 hypervisor environment.
997 source "arch/s390/kvm/Kconfig"
999 config S390_GUEST
1000 def_bool y
1001 prompt "s390 support for virtio devices"
1002 select TTY
1003 select VIRTUALIZATION
1004 select VIRTIO
1005 select VIRTIO_CONSOLE
1006 help
1007 Enabling this option adds support for virtio based paravirtual device
1008 drivers on s390.
1010 Select this option if you want to run the kernel as a guest under
1011 the KVM hypervisor.
1013 endmenu