1# SPDX-License-Identifier: GPL-2.0 2config MMU 3 def_bool y 4 5config CPU_BIG_ENDIAN 6 def_bool y 7 8config LOCKDEP_SUPPORT 9 def_bool y 10 11config STACKTRACE_SUPPORT 12 def_bool y 13 14config ARCH_HAS_ILOG2_U32 15 def_bool n 16 17config ARCH_HAS_ILOG2_U64 18 def_bool n 19 20config ARCH_PROC_KCORE_TEXT 21 def_bool y 22 23config GENERIC_HWEIGHT 24 def_bool !HAVE_MARCH_Z196_FEATURES 25 26config GENERIC_BUG 27 def_bool y if BUG 28 29config GENERIC_BUG_RELATIVE_POINTERS 30 def_bool y 31 32config GENERIC_LOCKBREAK 33 def_bool y if PREEMPTION 34 35config PGSTE 36 def_bool y if KVM 37 38config AUDIT_ARCH 39 def_bool y 40 41config NO_IOPORT_MAP 42 def_bool y 43 44config PCI_QUIRKS 45 def_bool n 46 47config ARCH_SUPPORTS_UPROBES 48 def_bool y 49 50config KASAN_SHADOW_OFFSET 51 hex 52 depends on KASAN 53 default 0x1C000000000000 54 55config S390 56 def_bool y 57 # 58 # Note: keep this list sorted alphabetically 59 # 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 78 select ARCH_HAS_KCOV 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 89 select ARCH_HAS_UBSAN 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_DEVICES 146 select GENERIC_CPU_AUTOPROBE 147 select GENERIC_CPU_VULNERABILITIES 148 select GENERIC_ENTRY 149 select GENERIC_GETTIMEOFDAY 150 select GENERIC_PTDUMP 151 select GENERIC_SMP_IDLE_THREAD 152 select GENERIC_TIME_VSYSCALL 153 select GENERIC_VDSO_TIME_NS 154 select GENERIC_IOREMAP if PCI 155 select HAVE_ALIGNED_STRUCT_PAGE 156 select HAVE_ARCH_AUDITSYSCALL 157 select HAVE_ARCH_JUMP_LABEL 158 select HAVE_ARCH_JUMP_LABEL_RELATIVE 159 select HAVE_ARCH_KASAN 160 select HAVE_ARCH_KASAN_VMALLOC 161 select HAVE_ARCH_KCSAN 162 select HAVE_ARCH_KMSAN 163 select HAVE_ARCH_KFENCE 164 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 165 select HAVE_ARCH_SECCOMP_FILTER 166 select HAVE_ARCH_SOFT_DIRTY 167 select HAVE_ARCH_STACKLEAK 168 select HAVE_ARCH_TRACEHOOK 169 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 170 select HAVE_ARCH_VMAP_STACK 171 select HAVE_ASM_MODVERSIONS 172 select HAVE_CMPXCHG_DOUBLE 173 select HAVE_CMPXCHG_LOCAL 174 select HAVE_DEBUG_KMEMLEAK 175 select HAVE_DMA_CONTIGUOUS 176 select HAVE_DYNAMIC_FTRACE 177 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 178 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 179 select HAVE_DYNAMIC_FTRACE_WITH_REGS 180 select HAVE_EBPF_JIT if HAVE_MARCH_Z196_FEATURES 181 select HAVE_EFFICIENT_UNALIGNED_ACCESS 182 select HAVE_GUP_FAST 183 select HAVE_FENTRY 184 select HAVE_FTRACE_MCOUNT_RECORD 185 select HAVE_FUNCTION_ARG_ACCESS_API 186 select HAVE_FUNCTION_ERROR_INJECTION 187 select HAVE_FUNCTION_GRAPH_RETVAL 188 select HAVE_FUNCTION_GRAPH_TRACER 189 select HAVE_FUNCTION_TRACER 190 select HAVE_GCC_PLUGINS 191 select HAVE_GENERIC_VDSO 192 select HAVE_IOREMAP_PROT if PCI 193 select HAVE_KERNEL_BZIP2 194 select HAVE_KERNEL_GZIP 195 select HAVE_KERNEL_LZ4 196 select HAVE_KERNEL_LZMA 197 select HAVE_KERNEL_LZO 198 select HAVE_KERNEL_UNCOMPRESSED 199 select HAVE_KERNEL_XZ 200 select HAVE_KERNEL_ZSTD 201 select HAVE_KPROBES 202 select HAVE_KPROBES_ON_FTRACE 203 select HAVE_KRETPROBES 204 select HAVE_LIVEPATCH 205 select HAVE_MEMBLOCK_PHYS_MAP 206 select HAVE_MOD_ARCH_SPECIFIC 207 select HAVE_NMI 208 select HAVE_NOP_MCOUNT 209 select HAVE_PAGE_SIZE_4KB 210 select HAVE_PCI 211 select HAVE_PERF_EVENTS 212 select HAVE_PERF_REGS 213 select HAVE_PERF_USER_STACK_DUMP 214 select HAVE_REGS_AND_STACK_ACCESS_API 215 select HAVE_RELIABLE_STACKTRACE 216 select HAVE_RETHOOK 217 select HAVE_RSEQ 218 select HAVE_SAMPLE_FTRACE_DIRECT 219 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 220 select HAVE_SETUP_PER_CPU_AREA 221 select HAVE_SOFTIRQ_ON_OWN_STACK 222 select HAVE_SYSCALL_TRACEPOINTS 223 select HAVE_VIRT_CPU_ACCOUNTING 224 select HAVE_VIRT_CPU_ACCOUNTING_IDLE 225 select IOMMU_HELPER if PCI 226 select IOMMU_SUPPORT if PCI 227 select MMU_GATHER_MERGE_VMAS 228 select MMU_GATHER_NO_GATHER 229 select MMU_GATHER_RCU_TABLE_FREE 230 select MODULES_USE_ELF_RELA 231 select NEED_DMA_MAP_STATE if PCI 232 select NEED_PER_CPU_EMBED_FIRST_CHUNK 233 select NEED_SG_DMA_LENGTH if PCI 234 select OLD_SIGACTION 235 select OLD_SIGSUSPEND3 236 select PCI_DOMAINS if PCI 237 select PCI_MSI if PCI 238 select PCI_MSI_ARCH_FALLBACKS if PCI_MSI 239 select SPARSE_IRQ 240 select SWIOTLB 241 select SYSCTL_EXCEPTION_TRACE 242 select THREAD_INFO_IN_TASK 243 select TRACE_IRQFLAGS_SUPPORT 244 select TTY 245 select USER_STACKTRACE_SUPPORT 246 select VIRT_CPU_ACCOUNTING 247 select ZONE_DMA 248 # Note: keep the above list sorted alphabetically 249 250config SCHED_OMIT_FRAME_POINTER 251 def_bool y 252 253config PGTABLE_LEVELS 254 int 255 default 5 256 257source "kernel/livepatch/Kconfig" 258 259config ARCH_SUPPORTS_KEXEC 260 def_bool y 261 262config ARCH_SUPPORTS_KEXEC_FILE 263 def_bool y 264 265config ARCH_SUPPORTS_KEXEC_SIG 266 def_bool MODULE_SIG_FORMAT 267 268config ARCH_SUPPORTS_KEXEC_PURGATORY 269 def_bool y 270 271config ARCH_SUPPORTS_CRASH_DUMP 272 def_bool y 273 help 274 Refer to <file:Documentation/arch/s390/zfcpdump.rst> for more details on this. 275 This option also enables s390 zfcpdump. 276 See also <file:Documentation/arch/s390/zfcpdump.rst> 277 278menu "Processor type and features" 279 280config HAVE_MARCH_Z10_FEATURES 281 def_bool n 282 283config HAVE_MARCH_Z196_FEATURES 284 def_bool n 285 select HAVE_MARCH_Z10_FEATURES 286 287config HAVE_MARCH_ZEC12_FEATURES 288 def_bool n 289 select HAVE_MARCH_Z196_FEATURES 290 291config HAVE_MARCH_Z13_FEATURES 292 def_bool n 293 select HAVE_MARCH_ZEC12_FEATURES 294 295config HAVE_MARCH_Z14_FEATURES 296 def_bool n 297 select HAVE_MARCH_Z13_FEATURES 298 299config HAVE_MARCH_Z15_FEATURES 300 def_bool n 301 select HAVE_MARCH_Z14_FEATURES 302 303config HAVE_MARCH_Z16_FEATURES 304 def_bool n 305 select HAVE_MARCH_Z15_FEATURES 306 307choice 308 prompt "Processor type" 309 default MARCH_Z196 310 311config MARCH_Z10 312 bool "IBM System z10" 313 select HAVE_MARCH_Z10_FEATURES 314 depends on $(cc-option,-march=z10) 315 help 316 Select this to enable optimizations for IBM System z10 (2097 and 2098 317 series). This is the oldest machine generation currently supported. 318 319config MARCH_Z196 320 bool "IBM zEnterprise 114 and 196" 321 select HAVE_MARCH_Z196_FEATURES 322 depends on $(cc-option,-march=z196) 323 help 324 Select this to enable optimizations for IBM zEnterprise 114 and 196 325 (2818 and 2817 series). The kernel will be slightly faster but will 326 not work on older machines. 327 328config MARCH_ZEC12 329 bool "IBM zBC12 and zEC12" 330 select HAVE_MARCH_ZEC12_FEATURES 331 depends on $(cc-option,-march=zEC12) 332 help 333 Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and 334 2827 series). The kernel will be slightly faster but will not work on 335 older machines. 336 337config MARCH_Z13 338 bool "IBM z13s and z13" 339 select HAVE_MARCH_Z13_FEATURES 340 depends on $(cc-option,-march=z13) 341 help 342 Select this to enable optimizations for IBM z13s and z13 (2965 and 343 2964 series). The kernel will be slightly faster but will not work on 344 older machines. 345 346config MARCH_Z14 347 bool "IBM z14 ZR1 and z14" 348 select HAVE_MARCH_Z14_FEATURES 349 depends on $(cc-option,-march=z14) 350 help 351 Select this to enable optimizations for IBM z14 ZR1 and z14 (3907 352 and 3906 series). The kernel will be slightly faster but will not 353 work on older machines. 354 355config MARCH_Z15 356 bool "IBM z15" 357 select HAVE_MARCH_Z15_FEATURES 358 depends on $(cc-option,-march=z15) 359 help 360 Select this to enable optimizations for IBM z15 (8562 361 and 8561 series). The kernel will be slightly faster but will not 362 work on older machines. 363 364config MARCH_Z16 365 bool "IBM z16" 366 select HAVE_MARCH_Z16_FEATURES 367 depends on $(cc-option,-march=z16) 368 help 369 Select this to enable optimizations for IBM z16 (3931 and 370 3932 series). 371 372endchoice 373 374config MARCH_Z10_TUNE 375 def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT 376 377config MARCH_Z196_TUNE 378 def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT 379 380config MARCH_ZEC12_TUNE 381 def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT 382 383config MARCH_Z13_TUNE 384 def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT 385 386config MARCH_Z14_TUNE 387 def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT 388 389config MARCH_Z15_TUNE 390 def_bool TUNE_Z15 || MARCH_Z15 && TUNE_DEFAULT 391 392config MARCH_Z16_TUNE 393 def_bool TUNE_Z16 || MARCH_Z16 && TUNE_DEFAULT 394 395choice 396 prompt "Tune code generation" 397 default TUNE_DEFAULT 398 help 399 Cause the compiler to tune (-mtune) the generated code for a machine. 400 This will make the code run faster on the selected machine but 401 somewhat slower on other machines. 402 This option only changes how the compiler emits instructions, not the 403 selection of instructions itself, so the resulting kernel will run on 404 all other machines. 405 406config TUNE_DEFAULT 407 bool "Default" 408 help 409 Tune the generated code for the target processor for which the kernel 410 will be compiled. 411 412config TUNE_Z10 413 bool "IBM System z10" 414 415config TUNE_Z196 416 bool "IBM zEnterprise 114 and 196" 417 depends on $(cc-option,-mtune=z196) 418 419config TUNE_ZEC12 420 bool "IBM zBC12 and zEC12" 421 depends on $(cc-option,-mtune=zEC12) 422 423config TUNE_Z13 424 bool "IBM z13s and z13" 425 depends on $(cc-option,-mtune=z13) 426 427config TUNE_Z14 428 bool "IBM z14 ZR1 and z14" 429 depends on $(cc-option,-mtune=z14) 430 431config TUNE_Z15 432 bool "IBM z15" 433 depends on $(cc-option,-mtune=z15) 434 435config TUNE_Z16 436 bool "IBM z16" 437 depends on $(cc-option,-mtune=z16) 438 439endchoice 440 441config 64BIT 442 def_bool y 443 444config COMMAND_LINE_SIZE 445 int "Maximum size of kernel command line" 446 default 4096 447 range 896 1048576 448 help 449 This allows you to specify the maximum length of the kernel command 450 line. 451 452config COMPAT 453 def_bool n 454 prompt "Kernel support for 31 bit emulation" 455 select ARCH_WANT_OLD_COMPAT_IPC 456 select COMPAT_OLD_SIGACTION 457 select HAVE_UID16 458 depends on MULTIUSER 459 depends on !CC_IS_CLANG && !LD_IS_LLD 460 help 461 Select this option if you want to enable your system kernel to 462 handle system-calls from ELF binaries for 31 bit ESA. This option 463 (and some other stuff like libraries and such) is needed for 464 executing 31 bit applications. 465 466 If unsure say N. 467 468config SMP 469 def_bool y 470 471config NR_CPUS 472 int "Maximum number of CPUs (2-512)" 473 range 2 512 474 default "64" 475 help 476 This allows you to specify the maximum number of CPUs which this 477 kernel will support. The maximum supported value is 512 and the 478 minimum value which makes sense is 2. 479 480 This is purely to save memory - each supported CPU adds 481 approximately sixteen kilobytes to the kernel image. 482 483config HOTPLUG_CPU 484 def_bool y 485 486config NUMA 487 bool "NUMA support" 488 depends on SCHED_TOPOLOGY 489 default n 490 help 491 Enable NUMA support 492 493 This option adds NUMA support to the kernel. 494 495config NODES_SHIFT 496 int 497 depends on NUMA 498 default "1" 499 500config SCHED_SMT 501 def_bool n 502 503config SCHED_MC 504 def_bool n 505 506config SCHED_TOPOLOGY 507 def_bool y 508 prompt "Topology scheduler support" 509 select SCHED_SMT 510 select SCHED_MC 511 help 512 Topology scheduler support improves the CPU scheduler's decision 513 making when dealing with machines that have multi-threading, 514 multiple cores or multiple books. 515 516source "kernel/Kconfig.hz" 517 518config CERT_STORE 519 bool "Get user certificates via DIAG320" 520 depends on KEYS 521 select CRYPTO_LIB_SHA256 522 help 523 Enable this option if you want to access user-provided secure boot 524 certificates via DIAG 0x320. 525 526 These certificates will be made available via the keyring named 527 'cert_store'. 528 529config KERNEL_NOBP 530 def_bool n 531 prompt "Enable modified branch prediction for the kernel by default" 532 help 533 If this option is selected the kernel will switch to a modified 534 branch prediction mode if the firmware interface is available. 535 The modified branch prediction mode improves the behaviour in 536 regard to speculative execution. 537 538 With the option enabled the kernel parameter "nobp=0" or "nospec" 539 can be used to run the kernel in the normal branch prediction mode. 540 541 With the option disabled the modified branch prediction mode is 542 enabled with the "nobp=1" kernel parameter. 543 544 If unsure, say N. 545 546config EXPOLINE 547 def_bool n 548 depends on $(cc-option,-mindirect-branch=thunk) 549 prompt "Avoid speculative indirect branches in the kernel" 550 help 551 Compile the kernel with the expoline compiler options to guard 552 against kernel-to-user data leaks by avoiding speculative indirect 553 branches. 554 Requires a compiler with -mindirect-branch=thunk support for full 555 protection. The kernel may run slower. 556 557 If unsure, say N. 558 559config EXPOLINE_EXTERN 560 def_bool y if EXPOLINE 561 depends on EXPOLINE 562 depends on CC_IS_GCC && GCC_VERSION >= 110200 563 depends on $(success,$(srctree)/arch/s390/tools/gcc-thunk-extern.sh $(CC)) 564 prompt "Generate expolines as extern functions." 565 help 566 This option is required for some tooling like kpatch. The kernel is 567 compiled with -mindirect-branch=thunk-extern and requires a newer 568 compiler. 569 570 If unsure, say N. 571 572choice 573 prompt "Expoline default" 574 depends on EXPOLINE 575 default EXPOLINE_FULL 576 577config EXPOLINE_OFF 578 bool "spectre_v2=off" 579 580config EXPOLINE_AUTO 581 bool "spectre_v2=auto" 582 583config EXPOLINE_FULL 584 bool "spectre_v2=on" 585 586endchoice 587 588config RELOCATABLE 589 def_bool y 590 help 591 This builds a kernel image that retains relocation information 592 so it can be loaded at an arbitrary address. 593 The relocations make the kernel image about 15% larger (compressed 594 10%), but are discarded at runtime. 595 Note: this option exists only for documentation purposes, please do 596 not remove it. 597 598config RANDOMIZE_BASE 599 bool "Randomize the address of the kernel image (KASLR)" 600 default y 601 help 602 In support of Kernel Address Space Layout Randomization (KASLR), 603 this randomizes the address at which the kernel image is loaded, 604 as a security feature that deters exploit attempts relying on 605 knowledge of the location of kernel internals. 606 607config RANDOMIZE_IDENTITY_BASE 608 bool "Randomize the address of the identity mapping base" 609 depends on RANDOMIZE_BASE 610 default DEBUG_VM 611 help 612 The identity mapping base address is pinned to zero by default. 613 Allow randomization of that base to expose otherwise missed 614 notion of physical and virtual addresses of data structures. 615 That does not have any impact on the base address at which the 616 kernel image is loaded. 617 618 If unsure, say N 619 620config KERNEL_IMAGE_BASE 621 hex "Kernel image base address" 622 range 0x100000 0x1FFFFFE0000000 if !KASAN 623 range 0x100000 0x1BFFFFE0000000 if KASAN 624 default 0x3FFE0000000 if !KASAN 625 default 0x7FFFE0000000 if KASAN 626 help 627 This is the address at which the kernel image is loaded in case 628 Kernel Address Space Layout Randomization (KASLR) is disabled. 629 630 In case the Protected virtualization guest support is enabled the 631 Ultravisor imposes a virtual address limit. If the value of this 632 option leads to the kernel image exceeding the Ultravisor limit, 633 this option is ignored and the image is loaded below the limit. 634 635 If the value of this option leads to the kernel image overlapping 636 the virtual memory where other data structures are located, this 637 option is ignored and the image is loaded above the structures. 638 639endmenu 640 641menu "Memory setup" 642 643config ARCH_SPARSEMEM_ENABLE 644 def_bool y 645 select SPARSEMEM_VMEMMAP_ENABLE 646 select SPARSEMEM_VMEMMAP 647 648config ARCH_SPARSEMEM_DEFAULT 649 def_bool y 650 651config MAX_PHYSMEM_BITS 652 int "Maximum size of supported physical memory in bits (42-53)" 653 range 42 53 654 default "46" 655 help 656 This option specifies the maximum supported size of physical memory 657 in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB). 658 Increasing the number of bits also increases the kernel image size. 659 By default 46 bits (64TB) are supported. 660 661config CHECK_STACK 662 def_bool y 663 depends on !VMAP_STACK 664 prompt "Detect kernel stack overflow" 665 help 666 This option enables the compiler option -mstack-guard and 667 -mstack-size if they are available. If the compiler supports them 668 it will emit additional code to each function prolog to trigger 669 an illegal operation if the kernel stack is about to overflow. 670 671 Say N if you are unsure. 672 673config STACK_GUARD 674 int "Size of the guard area (128-1024)" 675 range 128 1024 676 depends on CHECK_STACK 677 default "256" 678 help 679 This allows you to specify the size of the guard area at the lower 680 end of the kernel stack. If the kernel stack points into the guard 681 area on function entry an illegal operation is triggered. The size 682 needs to be a power of 2. Please keep in mind that the size of an 683 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit. 684 The minimum size for the stack guard should be 256 for 31 bit and 685 512 for 64 bit. 686 687endmenu 688 689menu "I/O subsystem" 690 691config QDIO 692 def_tristate y 693 prompt "QDIO support" 694 help 695 This driver provides the Queued Direct I/O base support for 696 IBM System z. 697 698 To compile this driver as a module, choose M here: the 699 module will be called qdio. 700 701 If unsure, say Y. 702 703if PCI 704 705config PCI_NR_FUNCTIONS 706 int "Maximum number of PCI functions (1-4096)" 707 range 1 4096 708 default "512" 709 help 710 This allows you to specify the maximum number of PCI functions which 711 this kernel will support. 712 713endif # PCI 714 715config HAS_IOMEM 716 def_bool PCI 717 718config CHSC_SCH 719 def_tristate m 720 prompt "Support for CHSC subchannels" 721 help 722 This driver allows usage of CHSC subchannels. A CHSC subchannel 723 is usually present on LPAR only. 724 The driver creates a device /dev/chsc, which may be used to 725 obtain I/O configuration information about the machine and 726 to issue asynchronous chsc commands (DANGEROUS). 727 You will usually only want to use this interface on a special 728 LPAR designated for system management. 729 730 To compile this driver as a module, choose M here: the 731 module will be called chsc_sch. 732 733 If unsure, say N. 734 735config SCM_BUS 736 def_bool y 737 prompt "SCM bus driver" 738 help 739 Bus driver for Storage Class Memory. 740 741config EADM_SCH 742 def_tristate m 743 prompt "Support for EADM subchannels" 744 depends on SCM_BUS 745 help 746 This driver allows usage of EADM subchannels. EADM subchannels act 747 as a communication vehicle for SCM increments. 748 749 To compile this driver as a module, choose M here: the 750 module will be called eadm_sch. 751 752config AP 753 def_tristate y 754 prompt "Support for Adjunct Processors (ap)" 755 help 756 This driver allows usage to Adjunct Processor (AP) devices via 757 the ap bus, cards and queues. Supported Adjunct Processors are 758 the CryptoExpress Cards (CEX). 759 760 To compile this driver as a module, choose M here: the 761 module will be called ap. 762 763 If unsure, say Y (default). 764 765config AP_DEBUG 766 def_bool n 767 prompt "Enable debug features for Adjunct Processor (ap) devices" 768 depends on AP 769 help 770 Say 'Y' here to enable some additional debug features for Adjunct 771 Processor (ap) devices. 772 773 There will be some more sysfs attributes displayed for ap queues. 774 775 Do not enable on production level kernel build. 776 777 If unsure, say N. 778 779config VFIO_CCW 780 def_tristate n 781 prompt "Support for VFIO-CCW subchannels" 782 depends on VFIO 783 select VFIO_MDEV 784 help 785 This driver allows usage of I/O subchannels via VFIO-CCW. 786 787 To compile this driver as a module, choose M here: the 788 module will be called vfio_ccw. 789 790config VFIO_AP 791 def_tristate n 792 prompt "VFIO support for AP devices" 793 depends on KVM 794 depends on VFIO 795 depends on AP 796 select VFIO_MDEV 797 help 798 This driver grants access to Adjunct Processor (AP) devices 799 via the VFIO mediated device interface. 800 801 To compile this driver as a module, choose M here: the module 802 will be called vfio_ap. 803 804endmenu 805 806config CCW 807 def_bool y 808 809config HAVE_PNETID 810 tristate 811 default (SMC || CCWGROUP) 812 813menu "Virtualization" 814 815config PFAULT 816 def_bool y 817 prompt "Pseudo page fault support" 818 help 819 Select this option, if you want to use PFAULT pseudo page fault 820 handling under VM. If running native or in LPAR, this option 821 has no effect. If your VM does not support PFAULT, PAGEEX 822 pseudo page fault handling will be used. 823 Note that VM 4.2 supports PFAULT but has a bug in its 824 implementation that causes some problems. 825 Everybody who wants to run Linux under VM != VM4.2 should select 826 this option. 827 828config CMM 829 def_tristate n 830 prompt "Cooperative memory management" 831 help 832 Select this option, if you want to enable the kernel interface 833 to reduce the memory size of the system. This is accomplished 834 by allocating pages of memory and put them "on hold". This only 835 makes sense for a system running under VM where the unused pages 836 will be reused by VM for other guest systems. The interface 837 allows an external monitor to balance memory of many systems. 838 Everybody who wants to run Linux under VM should select this 839 option. 840 841config CMM_IUCV 842 def_bool y 843 prompt "IUCV special message interface to cooperative memory management" 844 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV) 845 help 846 Select this option to enable the special message interface to 847 the cooperative memory management. 848 849config APPLDATA_BASE 850 def_bool n 851 prompt "Linux - VM Monitor Stream, base infrastructure" 852 depends on PROC_SYSCTL 853 help 854 This provides a kernel interface for creating and updating z/VM APPLDATA 855 monitor records. The monitor records are updated at certain time 856 intervals, once the timer is started. 857 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer, 858 i.e. enables or disables monitoring on the Linux side. 859 A custom interval value (in seconds) can be written to 860 /proc/appldata/interval. 861 862 Defaults are 60 seconds interval and timer off. 863 The /proc entries can also be read from, showing the current settings. 864 865config APPLDATA_MEM 866 def_tristate m 867 prompt "Monitor memory management statistics" 868 depends on APPLDATA_BASE && VM_EVENT_COUNTERS 869 help 870 This provides memory management related data to the Linux - VM Monitor 871 Stream, like paging/swapping rate, memory utilisation, etc. 872 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM 873 APPLDATA monitor record, i.e. enables or disables monitoring this record 874 on the z/VM side. 875 876 Default is disabled. 877 The /proc entry can also be read from, showing the current settings. 878 879 This can also be compiled as a module, which will be called 880 appldata_mem.o. 881 882config APPLDATA_OS 883 def_tristate m 884 prompt "Monitor OS statistics" 885 depends on APPLDATA_BASE 886 help 887 This provides OS related data to the Linux - VM Monitor Stream, like 888 CPU utilisation, etc. 889 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM 890 APPLDATA monitor record, i.e. enables or disables monitoring this record 891 on the z/VM side. 892 893 Default is disabled. 894 This can also be compiled as a module, which will be called 895 appldata_os.o. 896 897config APPLDATA_NET_SUM 898 def_tristate m 899 prompt "Monitor overall network statistics" 900 depends on APPLDATA_BASE && NET 901 help 902 This provides network related data to the Linux - VM Monitor Stream, 903 currently there is only a total sum of network I/O statistics, no 904 per-interface data. 905 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM 906 APPLDATA monitor record, i.e. enables or disables monitoring this record 907 on the z/VM side. 908 909 Default is disabled. 910 This can also be compiled as a module, which will be called 911 appldata_net_sum.o. 912 913config S390_HYPFS 914 def_bool y 915 prompt "s390 hypervisor information" 916 help 917 This provides several binary files at (debugfs)/s390_hypfs/ to 918 provide accounting information in an s390 hypervisor environment. 919 920config S390_HYPFS_FS 921 def_bool n 922 prompt "s390 hypervisor file system support" 923 select SYS_HYPERVISOR 924 depends on S390_HYPFS 925 help 926 This is a virtual file system intended to provide accounting 927 information in an s390 hypervisor environment. This file system 928 is deprecated and should not be used. 929 930 Say N if you are unsure. 931 932source "arch/s390/kvm/Kconfig" 933 934config S390_GUEST 935 def_bool y 936 prompt "s390 support for virtio devices" 937 select TTY 938 select VIRTUALIZATION 939 select VIRTIO 940 help 941 Enabling this option adds support for virtio based paravirtual device 942 drivers on s390. 943 944 Select this option if you want to run the kernel as a guest under 945 the KVM hypervisor. 946 947endmenu 948 949config S390_MODULES_SANITY_TEST_HELPERS 950 def_bool n 951 952menu "Selftests" 953 954config S390_UNWIND_SELFTEST 955 def_tristate n 956 depends on KUNIT 957 default KUNIT_ALL_TESTS 958 prompt "Test unwind functions" 959 help 960 This option enables s390 specific stack unwinder testing kernel 961 module. This option is not useful for distributions or general 962 kernels, but only for kernel developers working on architecture code. 963 964 Say N if you are unsure. 965 966config S390_KPROBES_SANITY_TEST 967 def_tristate n 968 prompt "Enable s390 specific kprobes tests" 969 depends on KPROBES 970 depends on KUNIT 971 help 972 This option enables an s390 specific kprobes test module. This option 973 is not useful for distributions or general kernels, but only for kernel 974 developers working on architecture code. 975 976 Say N if you are unsure. 977 978config S390_MODULES_SANITY_TEST 979 def_tristate n 980 depends on KUNIT 981 default KUNIT_ALL_TESTS 982 prompt "Enable s390 specific modules tests" 983 select S390_MODULES_SANITY_TEST_HELPERS 984 help 985 This option enables an s390 specific modules test. This option is 986 not useful for distributions or general kernels, but only for 987 kernel developers working on architecture code. 988 989 Say N if you are unsure. 990endmenu 991