| blob | d4051e88e6250ddbb621b18c0dc6f8356411ffd8 |
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 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_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_EXTABLE_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 CPU_NO_EFFICIENT_FFS if !HAVE_MARCH_Z9_109_FEATURES
128 select HAVE_ARCH_SECCOMP_FILTER
129 select HAVE_ARCH_SOFT_DIRTY
130 select HAVE_ARCH_TRACEHOOK
131 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
132 select HAVE_ARCH_VMAP_STACK
133 select HAVE_ASM_MODVERSIONS
134 select HAVE_EBPF_JIT if PACK_STACK && HAVE_MARCH_Z196_FEATURES
135 select HAVE_CMPXCHG_DOUBLE
136 select HAVE_CMPXCHG_LOCAL
137 select HAVE_COPY_THREAD_TLS
138 select HAVE_DEBUG_KMEMLEAK
139 select HAVE_DMA_CONTIGUOUS
140 select HAVE_DYNAMIC_FTRACE
141 select HAVE_DYNAMIC_FTRACE_WITH_REGS
142 select HAVE_FAST_GUP
143 select HAVE_EFFICIENT_UNALIGNED_ACCESS
144 select HAVE_FENTRY
145 select HAVE_FTRACE_MCOUNT_RECORD
146 select HAVE_FUNCTION_GRAPH_TRACER
147 select HAVE_FUNCTION_TRACER
148 select HAVE_FUTEX_CMPXCHG if FUTEX
149 select HAVE_GCC_PLUGINS
150 select HAVE_KERNEL_BZIP2
151 select HAVE_KERNEL_GZIP
152 select HAVE_KERNEL_LZ4
153 select HAVE_KERNEL_LZMA
154 select HAVE_KERNEL_LZO
155 select HAVE_KERNEL_UNCOMPRESSED
156 select HAVE_KERNEL_XZ
157 select HAVE_KPROBES
158 select HAVE_KRETPROBES
159 select HAVE_KVM
160 select HAVE_LIVEPATCH
161 select HAVE_PERF_REGS
162 select HAVE_PERF_USER_STACK_DUMP
163 select HAVE_MEMBLOCK_NODE_MAP
164 select HAVE_MEMBLOCK_PHYS_MAP
165 select HAVE_MMU_GATHER_NO_GATHER
166 select HAVE_MOD_ARCH_SPECIFIC
167 select HAVE_NOP_MCOUNT
168 select HAVE_OPROFILE
169 select HAVE_PCI
170 select HAVE_PERF_EVENTS
171 select HAVE_RCU_TABLE_FREE
172 select HAVE_REGS_AND_STACK_ACCESS_API
173 select HAVE_RELIABLE_STACKTRACE
174 select HAVE_RSEQ
175 select HAVE_SYSCALL_TRACEPOINTS
176 select HAVE_VIRT_CPU_ACCOUNTING
177 select IOMMU_HELPER if PCI
178 select IOMMU_SUPPORT if PCI
179 select MODULES_USE_ELF_RELA
180 select NEED_DMA_MAP_STATE if PCI
181 select NEED_SG_DMA_LENGTH if PCI
182 select OLD_SIGACTION
183 select OLD_SIGSUSPEND3
184 select PCI_DOMAINS if PCI
185 select PCI_MSI if PCI
186 select SPARSE_IRQ
187 select SYSCTL_EXCEPTION_TRACE
188 select THREAD_INFO_IN_TASK
189 select TTY
190 select VIRT_CPU_ACCOUNTING
191 select ARCH_HAS_SCALED_CPUTIME
192 select HAVE_NMI
193 select ARCH_HAS_FORCE_DMA_UNENCRYPTED
194 select SWIOTLB
195 select GENERIC_ALLOCATOR
198 config SCHED_OMIT_FRAME_POINTER
199 def_bool y
201 config PGTABLE_LEVELS
202 int
203 default 5
205 source "kernel/livepatch/Kconfig"
207 menu "Processor type and features"
209 config HAVE_MARCH_Z900_FEATURES
210 def_bool n
212 config HAVE_MARCH_Z990_FEATURES
213 def_bool n
214 select HAVE_MARCH_Z900_FEATURES
216 config HAVE_MARCH_Z9_109_FEATURES
217 def_bool n
218 select HAVE_MARCH_Z990_FEATURES
220 config HAVE_MARCH_Z10_FEATURES
221 def_bool n
222 select HAVE_MARCH_Z9_109_FEATURES
224 config HAVE_MARCH_Z196_FEATURES
225 def_bool n
226 select HAVE_MARCH_Z10_FEATURES
228 config HAVE_MARCH_ZEC12_FEATURES
229 def_bool n
230 select HAVE_MARCH_Z196_FEATURES
232 config HAVE_MARCH_Z13_FEATURES
233 def_bool n
234 select HAVE_MARCH_ZEC12_FEATURES
236 config HAVE_MARCH_Z14_FEATURES
237 def_bool n
238 select HAVE_MARCH_Z13_FEATURES
240 config HAVE_MARCH_Z15_FEATURES
241 def_bool n
242 select HAVE_MARCH_Z14_FEATURES
244 choice
245 prompt "Processor type"
246 default MARCH_Z196
248 config MARCH_Z900
249 bool "IBM zSeries model z800 and z900"
250 select HAVE_MARCH_Z900_FEATURES
251 depends on $(cc-option,-march=z900)
252 help
253 Select this to enable optimizations for model z800/z900 (2064 and
254 2066 series). This will enable some optimizations that are not
255 available on older ESA/390 (31 Bit) only CPUs.
257 config MARCH_Z990
258 bool "IBM zSeries model z890 and z990"
259 select HAVE_MARCH_Z990_FEATURES
260 depends on $(cc-option,-march=z990)
261 help
262 Select this to enable optimizations for model z890/z990 (2084 and
263 2086 series). The kernel will be slightly faster but will not work
264 on older machines.
266 config MARCH_Z9_109
267 bool "IBM System z9"
268 select HAVE_MARCH_Z9_109_FEATURES
269 depends on $(cc-option,-march=z9-109)
270 help
271 Select this to enable optimizations for IBM System z9 (2094 and
272 2096 series). The kernel will be slightly faster but will not work
273 on older machines.
275 config MARCH_Z10
276 bool "IBM System z10"
277 select HAVE_MARCH_Z10_FEATURES
278 depends on $(cc-option,-march=z10)
279 help
280 Select this to enable optimizations for IBM System z10 (2097 and
281 2098 series). The kernel will be slightly faster but will not work
282 on older machines.
284 config MARCH_Z196
285 bool "IBM zEnterprise 114 and 196"
286 select HAVE_MARCH_Z196_FEATURES
287 depends on $(cc-option,-march=z196)
288 help
289 Select this to enable optimizations for IBM zEnterprise 114 and 196
290 (2818 and 2817 series). The kernel will be slightly faster but will
291 not work on older machines.
293 config MARCH_ZEC12
294 bool "IBM zBC12 and zEC12"
295 select HAVE_MARCH_ZEC12_FEATURES
296 depends on $(cc-option,-march=zEC12)
297 help
298 Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
299 2827 series). The kernel will be slightly faster but will not work on
300 older machines.
302 config MARCH_Z13
303 bool "IBM z13s and z13"
304 select HAVE_MARCH_Z13_FEATURES
305 depends on $(cc-option,-march=z13)
306 help
307 Select this to enable optimizations for IBM z13s and z13 (2965 and
308 2964 series). The kernel will be slightly faster but will not work on
309 older machines.
311 config MARCH_Z14
312 bool "IBM z14 ZR1 and z14"
313 select HAVE_MARCH_Z14_FEATURES
314 depends on $(cc-option,-march=z14)
315 help
316 Select this to enable optimizations for IBM z14 ZR1 and z14 (3907
317 and 3906 series). The kernel will be slightly faster but will not
318 work on older machines.
320 config MARCH_Z15
321 bool "IBM z15"
322 select HAVE_MARCH_Z15_FEATURES
323 depends on $(cc-option,-march=z15)
324 help
325 Select this to enable optimizations for IBM z15 (8562
326 and 8561 series). The kernel will be slightly faster but will not
327 work on older machines.
329 endchoice
331 config MARCH_Z900_TUNE
332 def_bool TUNE_Z900 || MARCH_Z900 && TUNE_DEFAULT
334 config MARCH_Z990_TUNE
335 def_bool TUNE_Z990 || MARCH_Z990 && TUNE_DEFAULT
337 config MARCH_Z9_109_TUNE
338 def_bool TUNE_Z9_109 || MARCH_Z9_109 && TUNE_DEFAULT
340 config MARCH_Z10_TUNE
341 def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
343 config MARCH_Z196_TUNE
344 def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
346 config MARCH_ZEC12_TUNE
347 def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
349 config MARCH_Z13_TUNE
350 def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT
352 config MARCH_Z14_TUNE
353 def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT
355 config MARCH_Z15_TUNE
356 def_bool TUNE_Z15 || MARCH_Z15 && TUNE_DEFAULT
358 choice
359 prompt "Tune code generation"
360 default TUNE_DEFAULT
361 help
362 Cause the compiler to tune (-mtune) the generated code for a machine.
363 This will make the code run faster on the selected machine but
364 somewhat slower on other machines.
365 This option only changes how the compiler emits instructions, not the
366 selection of instructions itself, so the resulting kernel will run on
367 all other machines.
369 config TUNE_DEFAULT
370 bool "Default"
371 help
372 Tune the generated code for the target processor for which the kernel
373 will be compiled.
375 config TUNE_Z900
376 bool "IBM zSeries model z800 and z900"
377 depends on $(cc-option,-mtune=z900)
379 config TUNE_Z990
380 bool "IBM zSeries model z890 and z990"
381 depends on $(cc-option,-mtune=z990)
383 config TUNE_Z9_109
384 bool "IBM System z9"
385 depends on $(cc-option,-mtune=z9-109)
387 config TUNE_Z10
388 bool "IBM System z10"
389 depends on $(cc-option,-mtune=z10)
391 config TUNE_Z196
392 bool "IBM zEnterprise 114 and 196"
393 depends on $(cc-option,-mtune=z196)
395 config TUNE_ZEC12
396 bool "IBM zBC12 and zEC12"
397 depends on $(cc-option,-mtune=zEC12)
399 config TUNE_Z13
400 bool "IBM z13s and z13"
401 depends on $(cc-option,-mtune=z13)
403 config TUNE_Z14
404 bool "IBM z14 ZR1 and z14"
405 depends on $(cc-option,-mtune=z14)
407 config TUNE_Z15
408 bool "IBM z15"
409 depends on $(cc-option,-mtune=z15)
411 endchoice
413 config 64BIT
414 def_bool y
416 config COMPAT
417 def_bool y
418 prompt "Kernel support for 31 bit emulation"
419 select COMPAT_BINFMT_ELF if BINFMT_ELF
420 select ARCH_WANT_OLD_COMPAT_IPC
421 select COMPAT_OLD_SIGACTION
422 select HAVE_UID16
423 depends on MULTIUSER
424 help
425 Select this option if you want to enable your system kernel to
426 handle system-calls from ELF binaries for 31 bit ESA. This option
427 (and some other stuff like libraries and such) is needed for
428 executing 31 bit applications. It is safe to say "Y".
430 config SYSVIPC_COMPAT
431 def_bool y if COMPAT && SYSVIPC
433 config SMP
434 def_bool y
436 config NR_CPUS
437 int "Maximum number of CPUs (2-512)"
438 range 2 512
439 default "64"
440 help
441 This allows you to specify the maximum number of CPUs which this
442 kernel will support. The maximum supported value is 512 and the
443 minimum value which makes sense is 2.
445 This is purely to save memory - each supported CPU adds
446 approximately sixteen kilobytes to the kernel image.
448 config HOTPLUG_CPU
449 def_bool y
451 # Some NUMA nodes have memory ranges that span
452 # other nodes. Even though a pfn is valid and
453 # between a node's start and end pfns, it may not
454 # reside on that node. See memmap_init_zone()
455 # for details. <- They meant memory holes!
456 config NODES_SPAN_OTHER_NODES
457 def_bool NUMA
459 config NUMA
460 bool "NUMA support"
461 depends on SCHED_TOPOLOGY
462 default n
463 help
464 Enable NUMA support
466 This option adds NUMA support to the kernel.
468 An operation mode can be selected by appending
469 numa=<method> to the kernel command line.
471 The default behaviour is identical to appending numa=plain to
472 the command line. This will create just one node with all
473 available memory and all CPUs in it.
475 config NODES_SHIFT
476 int "Maximum NUMA nodes (as a power of 2)"
477 range 1 10
478 depends on NUMA
479 default "4"
480 help
481 Specify the maximum number of NUMA nodes available on the target
482 system. Increases memory reserved to accommodate various tables.
484 menu "Select NUMA modes"
485 depends on NUMA
487 config NUMA_EMU
488 bool "NUMA emulation"
489 default y
490 help
491 Numa emulation mode will split the available system memory into
492 equal chunks which then are distributed over the configured number
493 of nodes in a round-robin manner.
495 The number of fake nodes is limited by the number of available memory
496 chunks (i.e. memory size / fake size) and the number of supported
497 nodes in the kernel.
499 The CPUs are assigned to the nodes in a way that partially respects
500 the original machine topology (if supported by the machine).
501 Fair distribution of the CPUs is not guaranteed.
503 config EMU_SIZE
504 hex "NUMA emulation memory chunk size"
505 default 0x10000000
506 range 0x400000 0x100000000
507 depends on NUMA_EMU
508 help
509 Select the default size by which the memory is chopped and then
510 assigned to emulated NUMA nodes.
512 This can be overridden by specifying
514 emu_size=<n>
516 on the kernel command line where also suffixes K, M, G, and T are
517 supported.
519 endmenu
521 config SCHED_SMT
522 def_bool n
524 config SCHED_MC
525 def_bool n
527 config SCHED_BOOK
528 def_bool n
530 config SCHED_DRAWER
531 def_bool n
533 config SCHED_TOPOLOGY
534 def_bool y
535 prompt "Topology scheduler support"
536 select SCHED_SMT
537 select SCHED_MC
538 select SCHED_BOOK
539 select SCHED_DRAWER
540 help
541 Topology scheduler support improves the CPU scheduler's decision
542 making when dealing with machines that have multi-threading,
543 multiple cores or multiple books.
545 source "kernel/Kconfig.hz"
547 config KEXEC
548 def_bool y
549 select KEXEC_CORE
551 config KEXEC_FILE
552 bool "kexec file based system call"
553 select KEXEC_CORE
554 select BUILD_BIN2C
555 depends on CRYPTO
556 depends on CRYPTO_SHA256
557 depends on CRYPTO_SHA256_S390
558 help
559 Enable the kexec file based system call. In contrast to the normal
560 kexec system call this system call takes file descriptors for the
561 kernel and initramfs as arguments.
563 config ARCH_HAS_KEXEC_PURGATORY
564 def_bool y
565 depends on KEXEC_FILE
567 config KEXEC_SIG
568 bool "Verify kernel signature during kexec_file_load() syscall"
569 depends on KEXEC_FILE && MODULE_SIG_FORMAT
570 help
571 This option makes kernel signature verification mandatory for
572 the kexec_file_load() syscall.
574 In addition to that option, you need to enable signature
575 verification for the corresponding kernel image type being
576 loaded in order for this to work.
578 config ARCH_RANDOM
579 def_bool y
580 prompt "s390 architectural random number generation API"
581 help
582 Enable the s390 architectural random number generation API
583 to provide random data for all consumers within the Linux
584 kernel.
586 When enabled the arch_random_* functions declared in linux/random.h
587 are implemented. The implementation is based on the s390 CPACF
588 instruction subfunction TRNG which provides a real true random
589 number generator.
591 If unsure, say Y.
593 config KERNEL_NOBP
594 def_bool n
595 prompt "Enable modified branch prediction for the kernel by default"
596 help
597 If this option is selected the kernel will switch to a modified
598 branch prediction mode if the firmware interface is available.
599 The modified branch prediction mode improves the behaviour in
600 regard to speculative execution.
602 With the option enabled the kernel parameter "nobp=0" or "nospec"
603 can be used to run the kernel in the normal branch prediction mode.
605 With the option disabled the modified branch prediction mode is
606 enabled with the "nobp=1" kernel parameter.
608 If unsure, say N.
610 config EXPOLINE
611 def_bool n
612 prompt "Avoid speculative indirect branches in the kernel"
613 help
614 Compile the kernel with the expoline compiler options to guard
615 against kernel-to-user data leaks by avoiding speculative indirect
616 branches.
617 Requires a compiler with -mindirect-branch=thunk support for full
618 protection. The kernel may run slower.
620 If unsure, say N.
622 choice
623 prompt "Expoline default"
624 depends on EXPOLINE
625 default EXPOLINE_FULL
627 config EXPOLINE_OFF
628 bool "spectre_v2=off"
630 config EXPOLINE_AUTO
631 bool "spectre_v2=auto"
633 config EXPOLINE_FULL
634 bool "spectre_v2=on"
636 endchoice
638 config RELOCATABLE
639 bool "Build a relocatable kernel"
640 select MODULE_REL_CRCS if MODVERSIONS
641 default y
642 help
643 This builds a kernel image that retains relocation information
644 so it can be loaded at an arbitrary address.
645 The kernel is linked as a position-independent executable (PIE)
646 and contains dynamic relocations which are processed early in the
647 bootup process.
648 The relocations make the kernel image about 15% larger (compressed
649 10%), but are discarded at runtime.
651 config RANDOMIZE_BASE
652 bool "Randomize the address of the kernel image (KASLR)"
653 depends on RELOCATABLE
654 default y
655 help
656 In support of Kernel Address Space Layout Randomization (KASLR),
657 this randomizes the address at which the kernel image is loaded,
658 as a security feature that deters exploit attempts relying on
659 knowledge of the location of kernel internals.
661 endmenu
663 menu "Memory setup"
665 config ARCH_SPARSEMEM_ENABLE
666 def_bool y
667 select SPARSEMEM_VMEMMAP_ENABLE
668 select SPARSEMEM_VMEMMAP
670 config ARCH_SPARSEMEM_DEFAULT
671 def_bool y
673 config ARCH_ENABLE_MEMORY_HOTPLUG
674 def_bool y if SPARSEMEM
676 config ARCH_ENABLE_MEMORY_HOTREMOVE
677 def_bool y
679 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
680 def_bool y
682 config FORCE_MAX_ZONEORDER
683 int
684 default "9"
686 config MAX_PHYSMEM_BITS
687 int "Maximum size of supported physical memory in bits (42-53)"
688 range 42 53
689 default "46"
690 help
691 This option specifies the maximum supported size of physical memory
692 in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB).
693 Increasing the number of bits also increases the kernel image size.
694 By default 46 bits (64TB) are supported.
696 config PACK_STACK
697 def_bool y
698 prompt "Pack kernel stack"
699 help
700 This option enables the compiler option -mkernel-backchain if it
701 is available. If the option is available the compiler supports
702 the new stack layout which dramatically reduces the minimum stack
703 frame size. With an old compiler a non-leaf function needs a
704 minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
705 -mkernel-backchain the minimum size drops to 16 byte on 31 bit
706 and 24 byte on 64 bit.
708 Say Y if you are unsure.
710 config CHECK_STACK
711 def_bool y
712 depends on !VMAP_STACK
713 prompt "Detect kernel stack overflow"
714 help
715 This option enables the compiler option -mstack-guard and
716 -mstack-size if they are available. If the compiler supports them
717 it will emit additional code to each function prolog to trigger
718 an illegal operation if the kernel stack is about to overflow.
720 Say N if you are unsure.
722 config STACK_GUARD
723 int "Size of the guard area (128-1024)"
724 range 128 1024
725 depends on CHECK_STACK
726 default "256"
727 help
728 This allows you to specify the size of the guard area at the lower
729 end of the kernel stack. If the kernel stack points into the guard
730 area on function entry an illegal operation is triggered. The size
731 needs to be a power of 2. Please keep in mind that the size of an
732 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
733 The minimum size for the stack guard should be 256 for 31 bit and
734 512 for 64 bit.
736 config WARN_DYNAMIC_STACK
737 def_bool n
738 prompt "Emit compiler warnings for function with dynamic stack usage"
739 help
740 This option enables the compiler option -mwarn-dynamicstack. If the
741 compiler supports this options generates warnings for functions
742 that dynamically allocate stack space using alloca.
744 Say N if you are unsure.
746 endmenu
748 menu "I/O subsystem"
750 config QDIO
751 def_tristate y
752 prompt "QDIO support"
753 ---help---
754 This driver provides the Queued Direct I/O base support for
755 IBM System z.
757 To compile this driver as a module, choose M here: the
758 module will be called qdio.
760 If unsure, say Y.
762 if PCI
764 config PCI_NR_FUNCTIONS
765 int "Maximum number of PCI functions (1-4096)"
766 range 1 4096
767 default "128"
768 help
769 This allows you to specify the maximum number of PCI functions which
770 this kernel will support.
772 endif # PCI
774 config HAS_IOMEM
775 def_bool PCI
777 config CHSC_SCH
778 def_tristate m
779 prompt "Support for CHSC subchannels"
780 help
781 This driver allows usage of CHSC subchannels. A CHSC subchannel
782 is usually present on LPAR only.
783 The driver creates a device /dev/chsc, which may be used to
784 obtain I/O configuration information about the machine and
785 to issue asynchronous chsc commands (DANGEROUS).
786 You will usually only want to use this interface on a special
787 LPAR designated for system management.
789 To compile this driver as a module, choose M here: the
790 module will be called chsc_sch.
792 If unsure, say N.
794 config SCM_BUS
795 def_bool y
796 prompt "SCM bus driver"
797 help
798 Bus driver for Storage Class Memory.
800 config EADM_SCH
801 def_tristate m
802 prompt "Support for EADM subchannels"
803 depends on SCM_BUS
804 help
805 This driver allows usage of EADM subchannels. EADM subchannels act
806 as a communication vehicle for SCM increments.
808 To compile this driver as a module, choose M here: the
809 module will be called eadm_sch.
811 config VFIO_CCW
812 def_tristate n
813 prompt "Support for VFIO-CCW subchannels"
814 depends on S390_CCW_IOMMU && VFIO_MDEV
815 help
816 This driver allows usage of I/O subchannels via VFIO-CCW.
818 To compile this driver as a module, choose M here: the
819 module will be called vfio_ccw.
821 config VFIO_AP
822 def_tristate n
823 prompt "VFIO support for AP devices"
824 depends on S390_AP_IOMMU && VFIO_MDEV_DEVICE && KVM
825 help
826 This driver grants access to Adjunct Processor (AP) devices
827 via the VFIO mediated device interface.
829 To compile this driver as a module, choose M here: the module
830 will be called vfio_ap.
832 endmenu
834 menu "Dump support"
836 config CRASH_DUMP
837 bool "kernel crash dumps"
838 select KEXEC
839 help
840 Generate crash dump after being started by kexec.
841 Crash dump kernels are loaded in the main kernel with kexec-tools
842 into a specially reserved region and then later executed after
843 a crash by kdump/kexec.
844 Refer to <file:Documentation/s390/zfcpdump.rst> for more details on this.
845 This option also enables s390 zfcpdump.
846 See also <file:Documentation/s390/zfcpdump.rst>
848 endmenu
850 config SECCOMP
851 def_bool y
852 prompt "Enable seccomp to safely compute untrusted bytecode"
853 depends on PROC_FS
854 help
855 This kernel feature is useful for number crunching applications
856 that may need to compute untrusted bytecode during their
857 execution. By using pipes or other transports made available to
858 the process as file descriptors supporting the read/write
859 syscalls, it's possible to isolate those applications in
860 their own address space using seccomp. Once seccomp is
861 enabled via /proc/<pid>/seccomp, it cannot be disabled
862 and the task is only allowed to execute a few safe syscalls
863 defined by each seccomp mode.
865 If unsure, say Y.
867 menu "Power Management"
869 config ARCH_HIBERNATION_POSSIBLE
870 def_bool y
872 source "kernel/power/Kconfig"
874 endmenu
876 config CCW
877 def_bool y
879 config HAVE_PNETID
880 tristate
881 default (SMC || CCWGROUP)
883 menu "Virtualization"
885 config PROTECTED_VIRTUALIZATION_GUEST
886 def_bool n
887 prompt "Protected virtualization guest support"
888 help
889 Select this option, if you want to be able to run this
890 kernel as a protected virtualization KVM guest.
891 Protected virtualization capable machines have a mini hypervisor
892 located at machine level (an ultravisor). With help of the
893 Ultravisor, KVM will be able to run "protected" VMs, special
894 VMs whose memory and management data are unavailable to KVM.
896 config PFAULT
897 def_bool y
898 prompt "Pseudo page fault support"
899 help
900 Select this option, if you want to use PFAULT pseudo page fault
901 handling under VM. If running native or in LPAR, this option
902 has no effect. If your VM does not support PFAULT, PAGEEX
903 pseudo page fault handling will be used.
904 Note that VM 4.2 supports PFAULT but has a bug in its
905 implementation that causes some problems.
906 Everybody who wants to run Linux under VM != VM4.2 should select
907 this option.
909 config CMM
910 def_tristate n
911 prompt "Cooperative memory management"
912 help
913 Select this option, if you want to enable the kernel interface
914 to reduce the memory size of the system. This is accomplished
915 by allocating pages of memory and put them "on hold". This only
916 makes sense for a system running under VM where the unused pages
917 will be reused by VM for other guest systems. The interface
918 allows an external monitor to balance memory of many systems.
919 Everybody who wants to run Linux under VM should select this
920 option.
922 config CMM_IUCV
923 def_bool y
924 prompt "IUCV special message interface to cooperative memory management"
925 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
926 help
927 Select this option to enable the special message interface to
928 the cooperative memory management.
930 config APPLDATA_BASE
931 def_bool n
932 prompt "Linux - VM Monitor Stream, base infrastructure"
933 depends on PROC_FS
934 help
935 This provides a kernel interface for creating and updating z/VM APPLDATA
936 monitor records. The monitor records are updated at certain time
937 intervals, once the timer is started.
938 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
939 i.e. enables or disables monitoring on the Linux side.
940 A custom interval value (in seconds) can be written to
941 /proc/appldata/interval.
943 Defaults are 60 seconds interval and timer off.
944 The /proc entries can also be read from, showing the current settings.
946 config APPLDATA_MEM
947 def_tristate m
948 prompt "Monitor memory management statistics"
949 depends on APPLDATA_BASE && VM_EVENT_COUNTERS
950 help
951 This provides memory management related data to the Linux - VM Monitor
952 Stream, like paging/swapping rate, memory utilisation, etc.
953 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
954 APPLDATA monitor record, i.e. enables or disables monitoring this record
955 on the z/VM side.
957 Default is disabled.
958 The /proc entry can also be read from, showing the current settings.
960 This can also be compiled as a module, which will be called
961 appldata_mem.o.
963 config APPLDATA_OS
964 def_tristate m
965 prompt "Monitor OS statistics"
966 depends on APPLDATA_BASE
967 help
968 This provides OS related data to the Linux - VM Monitor Stream, like
969 CPU utilisation, etc.
970 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
971 APPLDATA monitor record, i.e. enables or disables monitoring this record
972 on the z/VM side.
974 Default is disabled.
975 This can also be compiled as a module, which will be called
976 appldata_os.o.
978 config APPLDATA_NET_SUM
979 def_tristate m
980 prompt "Monitor overall network statistics"
981 depends on APPLDATA_BASE && NET
982 help
983 This provides network related data to the Linux - VM Monitor Stream,
984 currently there is only a total sum of network I/O statistics, no
985 per-interface data.
986 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
987 APPLDATA monitor record, i.e. enables or disables monitoring this record
988 on the z/VM side.
990 Default is disabled.
991 This can also be compiled as a module, which will be called
992 appldata_net_sum.o.
994 config S390_HYPFS_FS
995 def_bool y
996 prompt "s390 hypervisor file system support"
997 select SYS_HYPERVISOR
998 help
999 This is a virtual file system intended to provide accounting
1000 information in an s390 hypervisor environment.
1002 source "arch/s390/kvm/Kconfig"
1004 config S390_GUEST
1005 def_bool y
1006 prompt "s390 support for virtio devices"
1007 select TTY
1008 select VIRTUALIZATION
1009 select VIRTIO
1010 select VIRTIO_CONSOLE
1011 help
1012 Enabling this option adds support for virtio based paravirtual device
1013 drivers on s390.
1015 Select this option if you want to run the kernel as a guest under
1016 the KVM hypervisor.
1018 endmenu
1020 menu "Selftests"
1022 config S390_UNWIND_SELFTEST
1023 def_tristate n
1024 prompt "Test unwind functions"
1025 help
1026 This option enables s390 specific stack unwinder testing kernel
1027 module. This option is not useful for distributions or general
1028 kernels, but only for kernel developers working on architecture code.
1030 Say N if you are unsure.
1032 endmenu