1 # SPDX-License-Identifier: GPL-2.0
11 config STACKTRACE_SUPPORT
14 config ARCH_HAS_ILOG2_U32
17 config ARCH_HAS_ILOG2_U64
20 config ARCH_PROC_KCORE_TEXT
23 config GENERIC_HWEIGHT
29 config GENERIC_BUG_RELATIVE_POINTERS
32 config GENERIC_LOCKBREAK
33 def_bool y if PREEMPTION
47 config ARCH_SUPPORTS_UPROBES
50 config KASAN_SHADOW_OFFSET
53 default 0x1C000000000000
58 # Note: keep this list sorted alphabetically
60 imply IMA_SECURE_AND_OR_TRUSTED_BOOT
61 select ALTERNATE_USER_ADDRESS_SPACE
62 select ARCH_32BIT_USTAT_F_TINODE
63 select ARCH_BINFMT_ELF_STATE
64 select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
65 select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM
66 select ARCH_ENABLE_MEMORY_HOTREMOVE
67 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
68 select ARCH_HAS_CURRENT_STACK_POINTER
69 select ARCH_HAS_DEBUG_VIRTUAL
70 select ARCH_HAS_DEBUG_VM_PGTABLE
71 select ARCH_HAS_DEBUG_WX
72 select ARCH_HAS_DEVMEM_IS_ALLOWED
73 select ARCH_HAS_ELF_RANDOMIZE
74 select ARCH_HAS_FORCE_DMA_UNENCRYPTED
75 select ARCH_HAS_FORTIFY_SOURCE
76 select ARCH_HAS_GCOV_PROFILE_ALL
77 select ARCH_HAS_GIGANTIC_PAGE
79 select ARCH_HAS_MEMBARRIER_SYNC_CORE
80 select ARCH_HAS_MEM_ENCRYPT
81 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
82 select ARCH_HAS_PTE_SPECIAL
83 select ARCH_HAS_SCALED_CPUTIME
84 select ARCH_HAS_SET_DIRECT_MAP
85 select ARCH_HAS_SET_MEMORY
86 select ARCH_HAS_STRICT_KERNEL_RWX
87 select ARCH_HAS_STRICT_MODULE_RWX
88 select ARCH_HAS_SYSCALL_WRAPPER
90 select ARCH_HAS_VDSO_DATA
91 select ARCH_HAVE_NMI_SAFE_CMPXCHG
92 select ARCH_INLINE_READ_LOCK
93 select ARCH_INLINE_READ_LOCK_BH
94 select ARCH_INLINE_READ_LOCK_IRQ
95 select ARCH_INLINE_READ_LOCK_IRQSAVE
96 select ARCH_INLINE_READ_TRYLOCK
97 select ARCH_INLINE_READ_UNLOCK
98 select ARCH_INLINE_READ_UNLOCK_BH
99 select ARCH_INLINE_READ_UNLOCK_IRQ
100 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
101 select ARCH_INLINE_SPIN_LOCK
102 select ARCH_INLINE_SPIN_LOCK_BH
103 select ARCH_INLINE_SPIN_LOCK_IRQ
104 select ARCH_INLINE_SPIN_LOCK_IRQSAVE
105 select ARCH_INLINE_SPIN_TRYLOCK
106 select ARCH_INLINE_SPIN_TRYLOCK_BH
107 select ARCH_INLINE_SPIN_UNLOCK
108 select ARCH_INLINE_SPIN_UNLOCK_BH
109 select ARCH_INLINE_SPIN_UNLOCK_IRQ
110 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
111 select ARCH_INLINE_WRITE_LOCK
112 select ARCH_INLINE_WRITE_LOCK_BH
113 select ARCH_INLINE_WRITE_LOCK_IRQ
114 select ARCH_INLINE_WRITE_LOCK_IRQSAVE
115 select ARCH_INLINE_WRITE_TRYLOCK
116 select ARCH_INLINE_WRITE_UNLOCK
117 select ARCH_INLINE_WRITE_UNLOCK_BH
118 select ARCH_INLINE_WRITE_UNLOCK_IRQ
119 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
120 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
121 select ARCH_STACKWALK
122 select ARCH_SUPPORTS_ATOMIC_RMW
123 select ARCH_SUPPORTS_DEBUG_PAGEALLOC
124 select ARCH_SUPPORTS_HUGETLBFS
125 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && CC_IS_CLANG
126 select ARCH_SUPPORTS_NUMA_BALANCING
127 select ARCH_SUPPORTS_PER_VMA_LOCK
128 select ARCH_USE_BUILTIN_BSWAP
129 select ARCH_USE_CMPXCHG_LOCKREF
130 select ARCH_USE_SYM_ANNOTATIONS
131 select ARCH_WANTS_NO_INSTR
132 select ARCH_WANT_DEFAULT_BPF_JIT
133 select ARCH_WANT_IPC_PARSE_VERSION
134 select ARCH_WANT_KERNEL_PMD_MKWRITE
135 select ARCH_WANT_LD_ORPHAN_WARN
136 select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP
137 select BUILDTIME_TABLE_SORT
138 select CLONE_BACKWARDS2
139 select DCACHE_WORD_ACCESS if !KMSAN
140 select DMA_OPS if PCI
141 select DYNAMIC_FTRACE if FUNCTION_TRACER
142 select FUNCTION_ALIGNMENT_8B if CC_IS_GCC
143 select FUNCTION_ALIGNMENT_16B if !CC_IS_GCC
144 select GENERIC_ALLOCATOR
145 select GENERIC_CPU_AUTOPROBE
146 select GENERIC_CPU_VULNERABILITIES
148 select GENERIC_GETTIMEOFDAY
149 select GENERIC_PTDUMP
150 select GENERIC_SMP_IDLE_THREAD
151 select GENERIC_TIME_VSYSCALL
152 select GENERIC_VDSO_TIME_NS
153 select GENERIC_IOREMAP if PCI
154 select HAVE_ALIGNED_STRUCT_PAGE
155 select HAVE_ARCH_AUDITSYSCALL
156 select HAVE_ARCH_JUMP_LABEL
157 select HAVE_ARCH_JUMP_LABEL_RELATIVE
158 select HAVE_ARCH_KASAN
159 select HAVE_ARCH_KASAN_VMALLOC
160 select HAVE_ARCH_KCSAN
161 select HAVE_ARCH_KFENCE
162 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
163 select HAVE_ARCH_SECCOMP_FILTER
164 select HAVE_ARCH_SOFT_DIRTY
165 select HAVE_ARCH_STACKLEAK
166 select HAVE_ARCH_TRACEHOOK
167 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
168 select HAVE_ARCH_VMAP_STACK
169 select HAVE_ASM_MODVERSIONS
170 select HAVE_CMPXCHG_DOUBLE
171 select HAVE_CMPXCHG_LOCAL
172 select HAVE_DEBUG_KMEMLEAK
173 select HAVE_DMA_CONTIGUOUS
174 select HAVE_DYNAMIC_FTRACE
175 select HAVE_DYNAMIC_FTRACE_WITH_ARGS
176 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
177 select HAVE_DYNAMIC_FTRACE_WITH_REGS
178 select HAVE_EBPF_JIT if HAVE_MARCH_Z196_FEATURES
179 select HAVE_EFFICIENT_UNALIGNED_ACCESS
182 select HAVE_FTRACE_MCOUNT_RECORD
183 select HAVE_FUNCTION_ARG_ACCESS_API
184 select HAVE_FUNCTION_ERROR_INJECTION
185 select HAVE_FUNCTION_GRAPH_RETVAL
186 select HAVE_FUNCTION_GRAPH_TRACER
187 select HAVE_FUNCTION_TRACER
188 select HAVE_GCC_PLUGINS
189 select HAVE_GENERIC_VDSO
190 select HAVE_IOREMAP_PROT if PCI
191 select HAVE_KERNEL_BZIP2
192 select HAVE_KERNEL_GZIP
193 select HAVE_KERNEL_LZ4
194 select HAVE_KERNEL_LZMA
195 select HAVE_KERNEL_LZO
196 select HAVE_KERNEL_UNCOMPRESSED
197 select HAVE_KERNEL_XZ
198 select HAVE_KERNEL_ZSTD
200 select HAVE_KPROBES_ON_FTRACE
201 select HAVE_KRETPROBES
202 select HAVE_LIVEPATCH
203 select HAVE_MEMBLOCK_PHYS_MAP
204 select HAVE_MOD_ARCH_SPECIFIC
206 select HAVE_NOP_MCOUNT
207 select HAVE_PAGE_SIZE_4KB
209 select HAVE_PERF_EVENTS
210 select HAVE_PERF_REGS
211 select HAVE_PERF_USER_STACK_DUMP
212 select HAVE_REGS_AND_STACK_ACCESS_API
213 select HAVE_RELIABLE_STACKTRACE
216 select HAVE_SAMPLE_FTRACE_DIRECT
217 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
218 select HAVE_SETUP_PER_CPU_AREA
219 select HAVE_SOFTIRQ_ON_OWN_STACK
220 select HAVE_SYSCALL_TRACEPOINTS
221 select HAVE_VIRT_CPU_ACCOUNTING
222 select HAVE_VIRT_CPU_ACCOUNTING_IDLE
223 select IOMMU_HELPER if PCI
224 select IOMMU_SUPPORT if PCI
225 select MMU_GATHER_MERGE_VMAS
226 select MMU_GATHER_NO_GATHER
227 select MMU_GATHER_RCU_TABLE_FREE
228 select MODULES_USE_ELF_RELA
229 select NEED_DMA_MAP_STATE if PCI
230 select NEED_PER_CPU_EMBED_FIRST_CHUNK
231 select NEED_SG_DMA_LENGTH if PCI
233 select OLD_SIGSUSPEND3
234 select PCI_DOMAINS if PCI
235 select PCI_MSI if PCI
236 select PCI_MSI_ARCH_FALLBACKS if PCI_MSI
239 select SYSCTL_EXCEPTION_TRACE
240 select THREAD_INFO_IN_TASK
241 select TRACE_IRQFLAGS_SUPPORT
243 select USER_STACKTRACE_SUPPORT
244 select VIRT_CPU_ACCOUNTING
246 # Note: keep the above list sorted alphabetically
248 config SCHED_OMIT_FRAME_POINTER
251 config PGTABLE_LEVELS
255 source "kernel/livepatch/Kconfig"
257 config ARCH_SUPPORTS_KEXEC
260 config ARCH_SUPPORTS_KEXEC_FILE
263 config ARCH_SUPPORTS_KEXEC_SIG
264 def_bool MODULE_SIG_FORMAT
266 config ARCH_SUPPORTS_KEXEC_PURGATORY
269 config ARCH_SUPPORTS_CRASH_DUMP
272 Refer to <file:Documentation/arch/s390/zfcpdump.rst> for more details on this.
273 This option also enables s390 zfcpdump.
274 See also <file:Documentation/arch/s390/zfcpdump.rst>
276 menu "Processor type and features"
278 config HAVE_MARCH_Z10_FEATURES
281 config HAVE_MARCH_Z196_FEATURES
283 select HAVE_MARCH_Z10_FEATURES
285 config HAVE_MARCH_ZEC12_FEATURES
287 select HAVE_MARCH_Z196_FEATURES
289 config HAVE_MARCH_Z13_FEATURES
291 select HAVE_MARCH_ZEC12_FEATURES
293 config HAVE_MARCH_Z14_FEATURES
295 select HAVE_MARCH_Z13_FEATURES
297 config HAVE_MARCH_Z15_FEATURES
299 select HAVE_MARCH_Z14_FEATURES
301 config HAVE_MARCH_Z16_FEATURES
303 select HAVE_MARCH_Z15_FEATURES
306 prompt "Processor type"
310 bool "IBM System z10"
311 select HAVE_MARCH_Z10_FEATURES
312 depends on $(cc-option,-march=z10)
314 Select this to enable optimizations for IBM System z10 (2097 and 2098
315 series). This is the oldest machine generation currently supported.
318 bool "IBM zEnterprise 114 and 196"
319 select HAVE_MARCH_Z196_FEATURES
320 depends on $(cc-option,-march=z196)
322 Select this to enable optimizations for IBM zEnterprise 114 and 196
323 (2818 and 2817 series). The kernel will be slightly faster but will
324 not work on older machines.
327 bool "IBM zBC12 and zEC12"
328 select HAVE_MARCH_ZEC12_FEATURES
329 depends on $(cc-option,-march=zEC12)
331 Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
332 2827 series). The kernel will be slightly faster but will not work on
336 bool "IBM z13s and z13"
337 select HAVE_MARCH_Z13_FEATURES
338 depends on $(cc-option,-march=z13)
340 Select this to enable optimizations for IBM z13s and z13 (2965 and
341 2964 series). The kernel will be slightly faster but will not work on
345 bool "IBM z14 ZR1 and z14"
346 select HAVE_MARCH_Z14_FEATURES
347 depends on $(cc-option,-march=z14)
349 Select this to enable optimizations for IBM z14 ZR1 and z14 (3907
350 and 3906 series). The kernel will be slightly faster but will not
351 work on older machines.
355 select HAVE_MARCH_Z15_FEATURES
356 depends on $(cc-option,-march=z15)
358 Select this to enable optimizations for IBM z15 (8562
359 and 8561 series). The kernel will be slightly faster but will not
360 work on older machines.
364 select HAVE_MARCH_Z16_FEATURES
365 depends on $(cc-option,-march=z16)
367 Select this to enable optimizations for IBM z16 (3931 and
372 config MARCH_Z10_TUNE
373 def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
375 config MARCH_Z196_TUNE
376 def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
378 config MARCH_ZEC12_TUNE
379 def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
381 config MARCH_Z13_TUNE
382 def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT
384 config MARCH_Z14_TUNE
385 def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT
387 config MARCH_Z15_TUNE
388 def_bool TUNE_Z15 || MARCH_Z15 && TUNE_DEFAULT
390 config MARCH_Z16_TUNE
391 def_bool TUNE_Z16 || MARCH_Z16 && TUNE_DEFAULT
394 prompt "Tune code generation"
397 Cause the compiler to tune (-mtune) the generated code for a machine.
398 This will make the code run faster on the selected machine but
399 somewhat slower on other machines.
400 This option only changes how the compiler emits instructions, not the
401 selection of instructions itself, so the resulting kernel will run on
407 Tune the generated code for the target processor for which the kernel
411 bool "IBM System z10"
414 bool "IBM zEnterprise 114 and 196"
415 depends on $(cc-option,-mtune=z196)
418 bool "IBM zBC12 and zEC12"
419 depends on $(cc-option,-mtune=zEC12)
422 bool "IBM z13s and z13"
423 depends on $(cc-option,-mtune=z13)
426 bool "IBM z14 ZR1 and z14"
427 depends on $(cc-option,-mtune=z14)
431 depends on $(cc-option,-mtune=z15)
435 depends on $(cc-option,-mtune=z16)
442 config COMMAND_LINE_SIZE
443 int "Maximum size of kernel command line"
447 This allows you to specify the maximum length of the kernel command
452 prompt "Kernel support for 31 bit emulation"
453 select ARCH_WANT_OLD_COMPAT_IPC
454 select COMPAT_OLD_SIGACTION
457 depends on !CC_IS_CLANG && !LD_IS_LLD
459 Select this option if you want to enable your system kernel to
460 handle system-calls from ELF binaries for 31 bit ESA. This option
461 (and some other stuff like libraries and such) is needed for
462 executing 31 bit applications.
470 int "Maximum number of CPUs (2-512)"
474 This allows you to specify the maximum number of CPUs which this
475 kernel will support. The maximum supported value is 512 and the
476 minimum value which makes sense is 2.
478 This is purely to save memory - each supported CPU adds
479 approximately sixteen kilobytes to the kernel image.
486 depends on SCHED_TOPOLOGY
491 This option adds NUMA support to the kernel.
504 config SCHED_TOPOLOGY
506 prompt "Topology scheduler support"
510 Topology scheduler support improves the CPU scheduler's decision
511 making when dealing with machines that have multi-threading,
512 multiple cores or multiple books.
514 source "kernel/Kconfig.hz"
517 bool "Get user certificates via DIAG320"
519 select CRYPTO_LIB_SHA256
521 Enable this option if you want to access user-provided secure boot
522 certificates via DIAG 0x320.
524 These certificates will be made available via the keyring named
529 prompt "Enable modified branch prediction for the kernel by default"
531 If this option is selected the kernel will switch to a modified
532 branch prediction mode if the firmware interface is available.
533 The modified branch prediction mode improves the behaviour in
534 regard to speculative execution.
536 With the option enabled the kernel parameter "nobp=0" or "nospec"
537 can be used to run the kernel in the normal branch prediction mode.
539 With the option disabled the modified branch prediction mode is
540 enabled with the "nobp=1" kernel parameter.
546 depends on $(cc-option,-mindirect-branch=thunk)
547 prompt "Avoid speculative indirect branches in the kernel"
549 Compile the kernel with the expoline compiler options to guard
550 against kernel-to-user data leaks by avoiding speculative indirect
552 Requires a compiler with -mindirect-branch=thunk support for full
553 protection. The kernel may run slower.
557 config EXPOLINE_EXTERN
558 def_bool y if EXPOLINE
560 depends on CC_IS_GCC && GCC_VERSION >= 110200
561 depends on $(success,$(srctree)/arch/s390/tools/gcc-thunk-extern.sh $(CC))
562 prompt "Generate expolines as extern functions."
564 This option is required for some tooling like kpatch. The kernel is
565 compiled with -mindirect-branch=thunk-extern and requires a newer
571 prompt "Expoline default"
573 default EXPOLINE_FULL
576 bool "spectre_v2=off"
579 bool "spectre_v2=auto"
589 This builds a kernel image that retains relocation information
590 so it can be loaded at an arbitrary address.
591 The relocations make the kernel image about 15% larger (compressed
592 10%), but are discarded at runtime.
593 Note: this option exists only for documentation purposes, please do
596 config RANDOMIZE_BASE
597 bool "Randomize the address of the kernel image (KASLR)"
600 In support of Kernel Address Space Layout Randomization (KASLR),
601 this randomizes the address at which the kernel image is loaded,
602 as a security feature that deters exploit attempts relying on
603 knowledge of the location of kernel internals.
605 config KERNEL_IMAGE_BASE
606 hex "Kernel image base address"
607 range 0x100000 0x1FFFFFE0000000 if !KASAN
608 range 0x100000 0x1BFFFFE0000000 if KASAN
609 default 0x3FFE0000000 if !KASAN
610 default 0x7FFFE0000000 if KASAN
612 This is the address at which the kernel image is loaded in case
613 Kernel Address Space Layout Randomization (KASLR) is disabled.
615 In case the Protected virtualization guest support is enabled the
616 Ultravisor imposes a virtual address limit. If the value of this
617 option leads to the kernel image exceeding the Ultravisor limit,
618 this option is ignored and the image is loaded below the limit.
620 If the value of this option leads to the kernel image overlapping
621 the virtual memory where other data structures are located, this
622 option is ignored and the image is loaded above the structures.
628 config ARCH_SPARSEMEM_ENABLE
630 select SPARSEMEM_VMEMMAP_ENABLE
631 select SPARSEMEM_VMEMMAP
633 config ARCH_SPARSEMEM_DEFAULT
636 config MAX_PHYSMEM_BITS
637 int "Maximum size of supported physical memory in bits (42-53)"
641 This option specifies the maximum supported size of physical memory
642 in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB).
643 Increasing the number of bits also increases the kernel image size.
644 By default 46 bits (64TB) are supported.
648 depends on !VMAP_STACK
649 prompt "Detect kernel stack overflow"
651 This option enables the compiler option -mstack-guard and
652 -mstack-size if they are available. If the compiler supports them
653 it will emit additional code to each function prolog to trigger
654 an illegal operation if the kernel stack is about to overflow.
656 Say N if you are unsure.
659 int "Size of the guard area (128-1024)"
661 depends on CHECK_STACK
664 This allows you to specify the size of the guard area at the lower
665 end of the kernel stack. If the kernel stack points into the guard
666 area on function entry an illegal operation is triggered. The size
667 needs to be a power of 2. Please keep in mind that the size of an
668 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
669 The minimum size for the stack guard should be 256 for 31 bit and
678 prompt "QDIO support"
680 This driver provides the Queued Direct I/O base support for
683 To compile this driver as a module, choose M here: the
684 module will be called qdio.
690 config PCI_NR_FUNCTIONS
691 int "Maximum number of PCI functions (1-4096)"
695 This allows you to specify the maximum number of PCI functions which
696 this kernel will support.
705 prompt "Support for CHSC subchannels"
707 This driver allows usage of CHSC subchannels. A CHSC subchannel
708 is usually present on LPAR only.
709 The driver creates a device /dev/chsc, which may be used to
710 obtain I/O configuration information about the machine and
711 to issue asynchronous chsc commands (DANGEROUS).
712 You will usually only want to use this interface on a special
713 LPAR designated for system management.
715 To compile this driver as a module, choose M here: the
716 module will be called chsc_sch.
722 prompt "SCM bus driver"
724 Bus driver for Storage Class Memory.
728 prompt "Support for EADM subchannels"
731 This driver allows usage of EADM subchannels. EADM subchannels act
732 as a communication vehicle for SCM increments.
734 To compile this driver as a module, choose M here: the
735 module will be called eadm_sch.
739 prompt "Support for Adjunct Processors (ap)"
741 This driver allows usage to Adjunct Processor (AP) devices via
742 the ap bus, cards and queues. Supported Adjunct Processors are
743 the CryptoExpress Cards (CEX).
745 To compile this driver as a module, choose M here: the
746 module will be called ap.
748 If unsure, say Y (default).
752 prompt "Enable debug features for Adjunct Processor (ap) devices"
755 Say 'Y' here to enable some additional debug features for Adjunct
756 Processor (ap) devices.
758 There will be some more sysfs attributes displayed for ap queues.
760 Do not enable on production level kernel build.
766 prompt "Support for VFIO-CCW subchannels"
770 This driver allows usage of I/O subchannels via VFIO-CCW.
772 To compile this driver as a module, choose M here: the
773 module will be called vfio_ccw.
777 prompt "VFIO support for AP devices"
783 This driver grants access to Adjunct Processor (AP) devices
784 via the VFIO mediated device interface.
786 To compile this driver as a module, choose M here: the module
787 will be called vfio_ap.
796 default (SMC || CCWGROUP)
798 menu "Virtualization"
800 config PROTECTED_VIRTUALIZATION_GUEST
802 prompt "Protected virtualization guest support"
804 Select this option, if you want to be able to run this
805 kernel as a protected virtualization KVM guest.
806 Protected virtualization capable machines have a mini hypervisor
807 located at machine level (an ultravisor). With help of the
808 Ultravisor, KVM will be able to run "protected" VMs, special
809 VMs whose memory and management data are unavailable to KVM.
813 prompt "Pseudo page fault support"
815 Select this option, if you want to use PFAULT pseudo page fault
816 handling under VM. If running native or in LPAR, this option
817 has no effect. If your VM does not support PFAULT, PAGEEX
818 pseudo page fault handling will be used.
819 Note that VM 4.2 supports PFAULT but has a bug in its
820 implementation that causes some problems.
821 Everybody who wants to run Linux under VM != VM4.2 should select
826 prompt "Cooperative memory management"
828 Select this option, if you want to enable the kernel interface
829 to reduce the memory size of the system. This is accomplished
830 by allocating pages of memory and put them "on hold". This only
831 makes sense for a system running under VM where the unused pages
832 will be reused by VM for other guest systems. The interface
833 allows an external monitor to balance memory of many systems.
834 Everybody who wants to run Linux under VM should select this
839 prompt "IUCV special message interface to cooperative memory management"
840 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
842 Select this option to enable the special message interface to
843 the cooperative memory management.
847 prompt "Linux - VM Monitor Stream, base infrastructure"
848 depends on PROC_SYSCTL
850 This provides a kernel interface for creating and updating z/VM APPLDATA
851 monitor records. The monitor records are updated at certain time
852 intervals, once the timer is started.
853 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
854 i.e. enables or disables monitoring on the Linux side.
855 A custom interval value (in seconds) can be written to
856 /proc/appldata/interval.
858 Defaults are 60 seconds interval and timer off.
859 The /proc entries can also be read from, showing the current settings.
863 prompt "Monitor memory management statistics"
864 depends on APPLDATA_BASE && VM_EVENT_COUNTERS
866 This provides memory management related data to the Linux - VM Monitor
867 Stream, like paging/swapping rate, memory utilisation, etc.
868 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
869 APPLDATA monitor record, i.e. enables or disables monitoring this record
873 The /proc entry can also be read from, showing the current settings.
875 This can also be compiled as a module, which will be called
880 prompt "Monitor OS statistics"
881 depends on APPLDATA_BASE
883 This provides OS related data to the Linux - VM Monitor Stream, like
884 CPU utilisation, etc.
885 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
886 APPLDATA monitor record, i.e. enables or disables monitoring this record
890 This can also be compiled as a module, which will be called
893 config APPLDATA_NET_SUM
895 prompt "Monitor overall network statistics"
896 depends on APPLDATA_BASE && NET
898 This provides network related data to the Linux - VM Monitor Stream,
899 currently there is only a total sum of network I/O statistics, no
901 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
902 APPLDATA monitor record, i.e. enables or disables monitoring this record
906 This can also be compiled as a module, which will be called
911 prompt "s390 hypervisor information"
913 This provides several binary files at (debugfs)/s390_hypfs/ to
914 provide accounting information in an s390 hypervisor environment.
918 prompt "s390 hypervisor file system support"
919 select SYS_HYPERVISOR
920 depends on S390_HYPFS
922 This is a virtual file system intended to provide accounting
923 information in an s390 hypervisor environment. This file system
924 is deprecated and should not be used.
926 Say N if you are unsure.
928 source "arch/s390/kvm/Kconfig"
932 prompt "s390 support for virtio devices"
934 select VIRTUALIZATION
937 Enabling this option adds support for virtio based paravirtual device
940 Select this option if you want to run the kernel as a guest under
945 config S390_MODULES_SANITY_TEST_HELPERS
950 config S390_UNWIND_SELFTEST
953 default KUNIT_ALL_TESTS
954 prompt "Test unwind functions"
956 This option enables s390 specific stack unwinder testing kernel
957 module. This option is not useful for distributions or general
958 kernels, but only for kernel developers working on architecture code.
960 Say N if you are unsure.
962 config S390_KPROBES_SANITY_TEST
964 prompt "Enable s390 specific kprobes tests"
968 This option enables an s390 specific kprobes test module. This option
969 is not useful for distributions or general kernels, but only for kernel
970 developers working on architecture code.
972 Say N if you are unsure.
974 config S390_MODULES_SANITY_TEST
977 default KUNIT_ALL_TESTS
978 prompt "Enable s390 specific modules tests"
979 select S390_MODULES_SANITY_TEST_HELPERS
981 This option enables an s390 specific modules test. This option is
982 not useful for distributions or general kernels, but only for
983 kernel developers working on architecture code.
985 Say N if you are unsure.