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 GCC_ASM_FLAG_OUTPUT_BROKEN 56 def_bool CC_IS_GCC && GCC_VERSION < 140200 57 help 58 GCC versions before 14.2.0 may die with an internal 59 compiler error in some configurations if flag output 60 operands are used within inline assemblies. 61 62config S390 63 def_bool y 64 # 65 # Note: keep this list sorted alphabetically 66 # 67 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 68 select ALTERNATE_USER_ADDRESS_SPACE 69 select ARCH_32BIT_USTAT_F_TINODE 70 select ARCH_BINFMT_ELF_STATE 71 select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE 72 select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM 73 select ARCH_ENABLE_MEMORY_HOTREMOVE 74 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 75 select ARCH_HAS_CURRENT_STACK_POINTER 76 select ARCH_HAS_DEBUG_VIRTUAL 77 select ARCH_HAS_DEBUG_VM_PGTABLE 78 select ARCH_HAS_DEBUG_WX 79 select ARCH_HAS_DEVMEM_IS_ALLOWED 80 select ARCH_HAS_DMA_OPS if PCI 81 select ARCH_HAS_ELF_RANDOMIZE 82 select ARCH_HAS_FORCE_DMA_UNENCRYPTED 83 select ARCH_HAS_FORTIFY_SOURCE 84 select ARCH_HAS_GCOV_PROFILE_ALL 85 select ARCH_HAS_GIGANTIC_PAGE 86 select ARCH_HAS_KCOV 87 select ARCH_HAS_MEMBARRIER_SYNC_CORE 88 select ARCH_HAS_MEM_ENCRYPT 89 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS 90 select ARCH_HAS_PTE_SPECIAL 91 select ARCH_HAS_SCALED_CPUTIME 92 select ARCH_HAS_SET_DIRECT_MAP 93 select ARCH_HAS_SET_MEMORY 94 select ARCH_HAS_STRICT_KERNEL_RWX 95 select ARCH_HAS_STRICT_MODULE_RWX 96 select ARCH_HAS_SYSCALL_WRAPPER 97 select ARCH_HAS_UBSAN 98 select ARCH_HAS_VDSO_TIME_DATA 99 select ARCH_HAVE_NMI_SAFE_CMPXCHG 100 select ARCH_INLINE_READ_LOCK 101 select ARCH_INLINE_READ_LOCK_BH 102 select ARCH_INLINE_READ_LOCK_IRQ 103 select ARCH_INLINE_READ_LOCK_IRQSAVE 104 select ARCH_INLINE_READ_TRYLOCK 105 select ARCH_INLINE_READ_UNLOCK 106 select ARCH_INLINE_READ_UNLOCK_BH 107 select ARCH_INLINE_READ_UNLOCK_IRQ 108 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE 109 select ARCH_INLINE_SPIN_LOCK 110 select ARCH_INLINE_SPIN_LOCK_BH 111 select ARCH_INLINE_SPIN_LOCK_IRQ 112 select ARCH_INLINE_SPIN_LOCK_IRQSAVE 113 select ARCH_INLINE_SPIN_TRYLOCK 114 select ARCH_INLINE_SPIN_TRYLOCK_BH 115 select ARCH_INLINE_SPIN_UNLOCK 116 select ARCH_INLINE_SPIN_UNLOCK_BH 117 select ARCH_INLINE_SPIN_UNLOCK_IRQ 118 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE 119 select ARCH_INLINE_WRITE_LOCK 120 select ARCH_INLINE_WRITE_LOCK_BH 121 select ARCH_INLINE_WRITE_LOCK_IRQ 122 select ARCH_INLINE_WRITE_LOCK_IRQSAVE 123 select ARCH_INLINE_WRITE_TRYLOCK 124 select ARCH_INLINE_WRITE_UNLOCK 125 select ARCH_INLINE_WRITE_UNLOCK_BH 126 select ARCH_INLINE_WRITE_UNLOCK_IRQ 127 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE 128 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 129 select ARCH_STACKWALK 130 select ARCH_SUPPORTS_ATOMIC_RMW 131 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 132 select ARCH_SUPPORTS_HUGETLBFS 133 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && CC_IS_CLANG 134 select ARCH_SUPPORTS_NUMA_BALANCING 135 select ARCH_SUPPORTS_PER_VMA_LOCK 136 select ARCH_USE_BUILTIN_BSWAP 137 select ARCH_USE_CMPXCHG_LOCKREF 138 select ARCH_USE_SYM_ANNOTATIONS 139 select ARCH_WANTS_NO_INSTR 140 select ARCH_WANT_DEFAULT_BPF_JIT 141 select ARCH_WANT_IPC_PARSE_VERSION 142 select ARCH_WANT_KERNEL_PMD_MKWRITE 143 select ARCH_WANT_LD_ORPHAN_WARN 144 select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP 145 select BUILDTIME_TABLE_SORT 146 select CLONE_BACKWARDS2 147 select DCACHE_WORD_ACCESS if !KMSAN 148 select DYNAMIC_FTRACE if FUNCTION_TRACER 149 select FUNCTION_ALIGNMENT_8B if CC_IS_GCC 150 select FUNCTION_ALIGNMENT_16B if !CC_IS_GCC 151 select GENERIC_ALLOCATOR 152 select GENERIC_CPU_DEVICES 153 select GENERIC_CPU_AUTOPROBE 154 select GENERIC_CPU_VULNERABILITIES 155 select GENERIC_ENTRY 156 select GENERIC_GETTIMEOFDAY 157 select GENERIC_PTDUMP 158 select GENERIC_SMP_IDLE_THREAD 159 select GENERIC_TIME_VSYSCALL 160 select GENERIC_VDSO_TIME_NS 161 select GENERIC_IOREMAP if PCI 162 select HAVE_ALIGNED_STRUCT_PAGE 163 select HAVE_ARCH_AUDITSYSCALL 164 select HAVE_ARCH_JUMP_LABEL 165 select HAVE_ARCH_JUMP_LABEL_RELATIVE 166 select HAVE_ARCH_KASAN 167 select HAVE_ARCH_KASAN_VMALLOC 168 select HAVE_ARCH_KCSAN 169 select HAVE_ARCH_KMSAN 170 select HAVE_ARCH_KFENCE 171 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 172 select HAVE_ARCH_SECCOMP_FILTER 173 select HAVE_ARCH_SOFT_DIRTY 174 select HAVE_ARCH_STACKLEAK 175 select HAVE_ARCH_TRACEHOOK 176 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 177 select HAVE_ARCH_VMAP_STACK 178 select HAVE_ASM_MODVERSIONS 179 select HAVE_CMPXCHG_DOUBLE 180 select HAVE_CMPXCHG_LOCAL 181 select HAVE_DEBUG_KMEMLEAK 182 select HAVE_DMA_CONTIGUOUS 183 select HAVE_DYNAMIC_FTRACE 184 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 185 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 186 select HAVE_DYNAMIC_FTRACE_WITH_REGS 187 select HAVE_EBPF_JIT if HAVE_MARCH_Z196_FEATURES 188 select HAVE_EFFICIENT_UNALIGNED_ACCESS 189 select HAVE_GUP_FAST 190 select HAVE_FENTRY 191 select HAVE_FTRACE_MCOUNT_RECORD 192 select HAVE_FUNCTION_ARG_ACCESS_API 193 select HAVE_FUNCTION_ERROR_INJECTION 194 select HAVE_FUNCTION_GRAPH_RETVAL 195 select HAVE_FUNCTION_GRAPH_TRACER 196 select HAVE_FUNCTION_TRACER 197 select HAVE_GCC_PLUGINS 198 select HAVE_GENERIC_VDSO 199 select HAVE_IOREMAP_PROT if PCI 200 select HAVE_KERNEL_BZIP2 201 select HAVE_KERNEL_GZIP 202 select HAVE_KERNEL_LZ4 203 select HAVE_KERNEL_LZMA 204 select HAVE_KERNEL_LZO 205 select HAVE_KERNEL_UNCOMPRESSED 206 select HAVE_KERNEL_XZ 207 select HAVE_KERNEL_ZSTD 208 select HAVE_KPROBES 209 select HAVE_KPROBES_ON_FTRACE 210 select HAVE_KRETPROBES 211 select HAVE_LIVEPATCH 212 select HAVE_MEMBLOCK_PHYS_MAP 213 select HAVE_MOD_ARCH_SPECIFIC 214 select HAVE_NMI 215 select HAVE_NOP_MCOUNT 216 select HAVE_PAGE_SIZE_4KB 217 select HAVE_PCI 218 select HAVE_PERF_EVENTS 219 select HAVE_PERF_REGS 220 select HAVE_PERF_USER_STACK_DUMP 221 select HAVE_REGS_AND_STACK_ACCESS_API 222 select HAVE_RELIABLE_STACKTRACE 223 select HAVE_RETHOOK 224 select HAVE_RSEQ 225 select HAVE_SAMPLE_FTRACE_DIRECT 226 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 227 select HAVE_SETUP_PER_CPU_AREA 228 select HAVE_SOFTIRQ_ON_OWN_STACK 229 select HAVE_SYSCALL_TRACEPOINTS 230 select HAVE_VIRT_CPU_ACCOUNTING 231 select HAVE_VIRT_CPU_ACCOUNTING_IDLE 232 select IOMMU_HELPER if PCI 233 select IOMMU_SUPPORT if PCI 234 select LOCK_MM_AND_FIND_VMA 235 select MMU_GATHER_MERGE_VMAS 236 select MMU_GATHER_NO_GATHER 237 select MMU_GATHER_RCU_TABLE_FREE 238 select MODULES_USE_ELF_RELA 239 select NEED_DMA_MAP_STATE if PCI 240 select NEED_PER_CPU_EMBED_FIRST_CHUNK 241 select NEED_SG_DMA_LENGTH if PCI 242 select OLD_SIGACTION 243 select OLD_SIGSUSPEND3 244 select PCI_DOMAINS if PCI 245 select PCI_MSI if PCI 246 select PCI_MSI_ARCH_FALLBACKS if PCI_MSI 247 select SPARSE_IRQ 248 select SWIOTLB 249 select SYSCTL_EXCEPTION_TRACE 250 select THREAD_INFO_IN_TASK 251 select TRACE_IRQFLAGS_SUPPORT 252 select TTY 253 select USER_STACKTRACE_SUPPORT 254 select VDSO_GETRANDOM 255 select VIRT_CPU_ACCOUNTING 256 select ZONE_DMA 257 # Note: keep the above list sorted alphabetically 258 259config SCHED_OMIT_FRAME_POINTER 260 def_bool y 261 262config PGTABLE_LEVELS 263 int 264 default 5 265 266source "kernel/livepatch/Kconfig" 267 268config ARCH_SUPPORTS_KEXEC 269 def_bool y 270 271config ARCH_SUPPORTS_KEXEC_FILE 272 def_bool y 273 274config ARCH_SUPPORTS_KEXEC_SIG 275 def_bool MODULE_SIG_FORMAT 276 277config ARCH_SUPPORTS_KEXEC_PURGATORY 278 def_bool y 279 280config ARCH_SUPPORTS_CRASH_DUMP 281 def_bool y 282 help 283 Refer to <file:Documentation/arch/s390/zfcpdump.rst> for more details on this. 284 This option also enables s390 zfcpdump. 285 See also <file:Documentation/arch/s390/zfcpdump.rst> 286 287config ARCH_DEFAULT_CRASH_DUMP 288 def_bool y 289 290menu "Processor type and features" 291 292config HAVE_MARCH_Z10_FEATURES 293 def_bool n 294 295config HAVE_MARCH_Z196_FEATURES 296 def_bool n 297 select HAVE_MARCH_Z10_FEATURES 298 299config HAVE_MARCH_ZEC12_FEATURES 300 def_bool n 301 select HAVE_MARCH_Z196_FEATURES 302 303config HAVE_MARCH_Z13_FEATURES 304 def_bool n 305 select HAVE_MARCH_ZEC12_FEATURES 306 307config HAVE_MARCH_Z14_FEATURES 308 def_bool n 309 select HAVE_MARCH_Z13_FEATURES 310 311config HAVE_MARCH_Z15_FEATURES 312 def_bool n 313 select HAVE_MARCH_Z14_FEATURES 314 315config HAVE_MARCH_Z16_FEATURES 316 def_bool n 317 select HAVE_MARCH_Z15_FEATURES 318 319choice 320 prompt "Processor type" 321 default MARCH_Z196 322 323config MARCH_Z10 324 bool "IBM System z10" 325 select HAVE_MARCH_Z10_FEATURES 326 depends on $(cc-option,-march=z10) 327 help 328 Select this to enable optimizations for IBM System z10 (2097 and 2098 329 series). This is the oldest machine generation currently supported. 330 331config MARCH_Z196 332 bool "IBM zEnterprise 114 and 196" 333 select HAVE_MARCH_Z196_FEATURES 334 depends on $(cc-option,-march=z196) 335 help 336 Select this to enable optimizations for IBM zEnterprise 114 and 196 337 (2818 and 2817 series). The kernel will be slightly faster but will 338 not work on older machines. 339 340config MARCH_ZEC12 341 bool "IBM zBC12 and zEC12" 342 select HAVE_MARCH_ZEC12_FEATURES 343 depends on $(cc-option,-march=zEC12) 344 help 345 Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and 346 2827 series). The kernel will be slightly faster but will not work on 347 older machines. 348 349config MARCH_Z13 350 bool "IBM z13s and z13" 351 select HAVE_MARCH_Z13_FEATURES 352 depends on $(cc-option,-march=z13) 353 help 354 Select this to enable optimizations for IBM z13s and z13 (2965 and 355 2964 series). The kernel will be slightly faster but will not work on 356 older machines. 357 358config MARCH_Z14 359 bool "IBM z14 ZR1 and z14" 360 select HAVE_MARCH_Z14_FEATURES 361 depends on $(cc-option,-march=z14) 362 help 363 Select this to enable optimizations for IBM z14 ZR1 and z14 (3907 364 and 3906 series). The kernel will be slightly faster but will not 365 work on older machines. 366 367config MARCH_Z15 368 bool "IBM z15" 369 select HAVE_MARCH_Z15_FEATURES 370 depends on $(cc-option,-march=z15) 371 help 372 Select this to enable optimizations for IBM z15 (8562 373 and 8561 series). The kernel will be slightly faster but will not 374 work on older machines. 375 376config MARCH_Z16 377 bool "IBM z16" 378 select HAVE_MARCH_Z16_FEATURES 379 depends on $(cc-option,-march=z16) 380 help 381 Select this to enable optimizations for IBM z16 (3931 and 382 3932 series). 383 384endchoice 385 386config MARCH_Z10_TUNE 387 def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT 388 389config MARCH_Z196_TUNE 390 def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT 391 392config MARCH_ZEC12_TUNE 393 def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT 394 395config MARCH_Z13_TUNE 396 def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT 397 398config MARCH_Z14_TUNE 399 def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT 400 401config MARCH_Z15_TUNE 402 def_bool TUNE_Z15 || MARCH_Z15 && TUNE_DEFAULT 403 404config MARCH_Z16_TUNE 405 def_bool TUNE_Z16 || MARCH_Z16 && TUNE_DEFAULT 406 407choice 408 prompt "Tune code generation" 409 default TUNE_DEFAULT 410 help 411 Cause the compiler to tune (-mtune) the generated code for a machine. 412 This will make the code run faster on the selected machine but 413 somewhat slower on other machines. 414 This option only changes how the compiler emits instructions, not the 415 selection of instructions itself, so the resulting kernel will run on 416 all other machines. 417 418config TUNE_DEFAULT 419 bool "Default" 420 help 421 Tune the generated code for the target processor for which the kernel 422 will be compiled. 423 424config TUNE_Z10 425 bool "IBM System z10" 426 427config TUNE_Z196 428 bool "IBM zEnterprise 114 and 196" 429 depends on $(cc-option,-mtune=z196) 430 431config TUNE_ZEC12 432 bool "IBM zBC12 and zEC12" 433 depends on $(cc-option,-mtune=zEC12) 434 435config TUNE_Z13 436 bool "IBM z13s and z13" 437 depends on $(cc-option,-mtune=z13) 438 439config TUNE_Z14 440 bool "IBM z14 ZR1 and z14" 441 depends on $(cc-option,-mtune=z14) 442 443config TUNE_Z15 444 bool "IBM z15" 445 depends on $(cc-option,-mtune=z15) 446 447config TUNE_Z16 448 bool "IBM z16" 449 depends on $(cc-option,-mtune=z16) 450 451endchoice 452 453config 64BIT 454 def_bool y 455 456config COMMAND_LINE_SIZE 457 int "Maximum size of kernel command line" 458 default 4096 459 range 896 1048576 460 help 461 This allows you to specify the maximum length of the kernel command 462 line. 463 464config COMPAT 465 def_bool n 466 prompt "Kernel support for 31 bit emulation" 467 select ARCH_WANT_OLD_COMPAT_IPC 468 select COMPAT_OLD_SIGACTION 469 select HAVE_UID16 470 depends on MULTIUSER 471 depends on !CC_IS_CLANG && !LD_IS_LLD 472 help 473 Select this option if you want to enable your system kernel to 474 handle system-calls from ELF binaries for 31 bit ESA. This option 475 (and some other stuff like libraries and such) is needed for 476 executing 31 bit applications. 477 478 If unsure say N. 479 480config SMP 481 def_bool y 482 483config NR_CPUS 484 int "Maximum number of CPUs (2-512)" 485 range 2 512 486 default "64" 487 help 488 This allows you to specify the maximum number of CPUs which this 489 kernel will support. The maximum supported value is 512 and the 490 minimum value which makes sense is 2. 491 492 This is purely to save memory - each supported CPU adds 493 approximately sixteen kilobytes to the kernel image. 494 495config HOTPLUG_CPU 496 def_bool y 497 498config NUMA 499 bool "NUMA support" 500 depends on SCHED_TOPOLOGY 501 default n 502 help 503 Enable NUMA support 504 505 This option adds NUMA support to the kernel. 506 507config NODES_SHIFT 508 int 509 depends on NUMA 510 default "1" 511 512config SCHED_SMT 513 def_bool n 514 515config SCHED_MC 516 def_bool n 517 518config SCHED_TOPOLOGY 519 def_bool y 520 prompt "Topology scheduler support" 521 select SCHED_SMT 522 select SCHED_MC 523 help 524 Topology scheduler support improves the CPU scheduler's decision 525 making when dealing with machines that have multi-threading, 526 multiple cores or multiple books. 527 528config SCHED_TOPOLOGY_VERTICAL 529 def_bool y 530 bool "Use vertical CPU polarization by default" 531 depends on SCHED_TOPOLOGY 532 help 533 Use vertical CPU polarization by default if available. 534 The default CPU polarization is horizontal. 535 536config HIPERDISPATCH_ON 537 def_bool y 538 bool "Use hiperdispatch on vertical polarization by default" 539 depends on SCHED_TOPOLOGY 540 depends on PROC_SYSCTL 541 help 542 Hiperdispatch aims to improve the CPU scheduler's decision 543 making when using vertical polarization by adjusting CPU 544 capacities dynamically. Set this option to use hiperdispatch 545 on vertical polarization by default. This can be overwritten 546 by sysctl's s390.hiperdispatch attribute later on. 547 548source "kernel/Kconfig.hz" 549 550config CERT_STORE 551 bool "Get user certificates via DIAG320" 552 depends on KEYS 553 select CRYPTO_LIB_SHA256 554 help 555 Enable this option if you want to access user-provided secure boot 556 certificates via DIAG 0x320. 557 558 These certificates will be made available via the keyring named 559 'cert_store'. 560 561config KERNEL_NOBP 562 def_bool n 563 prompt "Enable modified branch prediction for the kernel by default" 564 help 565 If this option is selected the kernel will switch to a modified 566 branch prediction mode if the firmware interface is available. 567 The modified branch prediction mode improves the behaviour in 568 regard to speculative execution. 569 570 With the option enabled the kernel parameter "nobp=0" or "nospec" 571 can be used to run the kernel in the normal branch prediction mode. 572 573 With the option disabled the modified branch prediction mode is 574 enabled with the "nobp=1" kernel parameter. 575 576 If unsure, say N. 577 578config EXPOLINE 579 def_bool n 580 depends on $(cc-option,-mindirect-branch=thunk) 581 prompt "Avoid speculative indirect branches in the kernel" 582 help 583 Compile the kernel with the expoline compiler options to guard 584 against kernel-to-user data leaks by avoiding speculative indirect 585 branches. 586 Requires a compiler with -mindirect-branch=thunk support for full 587 protection. The kernel may run slower. 588 589 If unsure, say N. 590 591config EXPOLINE_EXTERN 592 def_bool EXPOLINE && CC_IS_GCC && GCC_VERSION >= 110200 && \ 593 $(success,$(srctree)/arch/s390/tools/gcc-thunk-extern.sh $(CC)) 594 help 595 Generate expolines as external functions if the compiler supports it. 596 This option is required for some tooling like kpatch, if expolines 597 are enabled. The kernel is compiled with 598 -mindirect-branch=thunk-extern, which requires a newer compiler. 599 600choice 601 prompt "Expoline default" 602 depends on EXPOLINE 603 default EXPOLINE_FULL 604 605config EXPOLINE_OFF 606 bool "spectre_v2=off" 607 608config EXPOLINE_AUTO 609 bool "spectre_v2=auto" 610 611config EXPOLINE_FULL 612 bool "spectre_v2=on" 613 614endchoice 615 616config RELOCATABLE 617 def_bool y 618 help 619 This builds a kernel image that retains relocation information 620 so it can be loaded at an arbitrary address. 621 The relocations make the kernel image about 15% larger (compressed 622 10%), but are discarded at runtime. 623 Note: this option exists only for documentation purposes, please do 624 not remove it. 625 626config RANDOMIZE_BASE 627 bool "Randomize the address of the kernel image (KASLR)" 628 default y 629 help 630 In support of Kernel Address Space Layout Randomization (KASLR), 631 this randomizes the address at which the kernel image is loaded, 632 as a security feature that deters exploit attempts relying on 633 knowledge of the location of kernel internals. 634 635config RANDOMIZE_IDENTITY_BASE 636 bool "Randomize the address of the identity mapping base" 637 depends on RANDOMIZE_BASE 638 default DEBUG_VM 639 help 640 The identity mapping base address is pinned to zero by default. 641 Allow randomization of that base to expose otherwise missed 642 notion of physical and virtual addresses of data structures. 643 That does not have any impact on the base address at which the 644 kernel image is loaded. 645 646 If unsure, say N 647 648config KERNEL_IMAGE_BASE 649 hex "Kernel image base address" 650 range 0x100000 0x1FFFFFE0000000 if !KASAN 651 range 0x100000 0x1BFFFFE0000000 if KASAN 652 default 0x3FFE0000000 if !KASAN 653 default 0x7FFFE0000000 if KASAN 654 help 655 This is the address at which the kernel image is loaded in case 656 Kernel Address Space Layout Randomization (KASLR) is disabled. 657 658 In case the Protected virtualization guest support is enabled the 659 Ultravisor imposes a virtual address limit. If the value of this 660 option leads to the kernel image exceeding the Ultravisor limit, 661 this option is ignored and the image is loaded below the limit. 662 663 If the value of this option leads to the kernel image overlapping 664 the virtual memory where other data structures are located, this 665 option is ignored and the image is loaded above the structures. 666 667endmenu 668 669menu "Memory setup" 670 671config ARCH_SPARSEMEM_ENABLE 672 def_bool y 673 select SPARSEMEM_VMEMMAP_ENABLE 674 select SPARSEMEM_VMEMMAP 675 676config ARCH_SPARSEMEM_DEFAULT 677 def_bool y 678 679config MAX_PHYSMEM_BITS 680 int "Maximum size of supported physical memory in bits (42-53)" 681 range 42 53 682 default "46" 683 help 684 This option specifies the maximum supported size of physical memory 685 in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB). 686 Increasing the number of bits also increases the kernel image size. 687 By default 46 bits (64TB) are supported. 688 689config CHECK_STACK 690 def_bool y 691 depends on !VMAP_STACK 692 prompt "Detect kernel stack overflow" 693 help 694 This option enables the compiler option -mstack-guard and 695 -mstack-size if they are available. If the compiler supports them 696 it will emit additional code to each function prolog to trigger 697 an illegal operation if the kernel stack is about to overflow. 698 699 Say N if you are unsure. 700 701config STACK_GUARD 702 int "Size of the guard area (128-1024)" 703 range 128 1024 704 depends on CHECK_STACK 705 default "256" 706 help 707 This allows you to specify the size of the guard area at the lower 708 end of the kernel stack. If the kernel stack points into the guard 709 area on function entry an illegal operation is triggered. The size 710 needs to be a power of 2. Please keep in mind that the size of an 711 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit. 712 The minimum size for the stack guard should be 256 for 31 bit and 713 512 for 64 bit. 714 715endmenu 716 717menu "I/O subsystem" 718 719config QDIO 720 def_tristate y 721 prompt "QDIO support" 722 help 723 This driver provides the Queued Direct I/O base support for 724 IBM System z. 725 726 To compile this driver as a module, choose M here: the 727 module will be called qdio. 728 729 If unsure, say Y. 730 731if PCI 732 733config PCI_NR_FUNCTIONS 734 int "Maximum number of PCI functions (1-4096)" 735 range 1 4096 736 default "512" 737 help 738 This allows you to specify the maximum number of PCI functions which 739 this kernel will support. 740 741endif # PCI 742 743config HAS_IOMEM 744 def_bool PCI 745 746config CHSC_SCH 747 def_tristate m 748 prompt "Support for CHSC subchannels" 749 help 750 This driver allows usage of CHSC subchannels. A CHSC subchannel 751 is usually present on LPAR only. 752 The driver creates a device /dev/chsc, which may be used to 753 obtain I/O configuration information about the machine and 754 to issue asynchronous chsc commands (DANGEROUS). 755 You will usually only want to use this interface on a special 756 LPAR designated for system management. 757 758 To compile this driver as a module, choose M here: the 759 module will be called chsc_sch. 760 761 If unsure, say N. 762 763config SCM_BUS 764 def_bool y 765 prompt "SCM bus driver" 766 help 767 Bus driver for Storage Class Memory. 768 769config EADM_SCH 770 def_tristate m 771 prompt "Support for EADM subchannels" 772 depends on SCM_BUS 773 help 774 This driver allows usage of EADM subchannels. EADM subchannels act 775 as a communication vehicle for SCM increments. 776 777 To compile this driver as a module, choose M here: the 778 module will be called eadm_sch. 779 780config AP 781 def_tristate y 782 prompt "Support for Adjunct Processors (ap)" 783 help 784 This driver allows usage to Adjunct Processor (AP) devices via 785 the ap bus, cards and queues. Supported Adjunct Processors are 786 the CryptoExpress Cards (CEX). 787 788 To compile this driver as a module, choose M here: the 789 module will be called ap. 790 791 If unsure, say Y (default). 792 793config AP_DEBUG 794 def_bool n 795 prompt "Enable debug features for Adjunct Processor (ap) devices" 796 depends on AP 797 help 798 Say 'Y' here to enable some additional debug features for Adjunct 799 Processor (ap) devices. 800 801 There will be some more sysfs attributes displayed for ap queues. 802 803 Do not enable on production level kernel build. 804 805 If unsure, say N. 806 807config VFIO_CCW 808 def_tristate n 809 prompt "Support for VFIO-CCW subchannels" 810 depends on VFIO 811 select VFIO_MDEV 812 help 813 This driver allows usage of I/O subchannels via VFIO-CCW. 814 815 To compile this driver as a module, choose M here: the 816 module will be called vfio_ccw. 817 818config VFIO_AP 819 def_tristate n 820 prompt "VFIO support for AP devices" 821 depends on KVM 822 depends on VFIO 823 depends on AP 824 select VFIO_MDEV 825 help 826 This driver grants access to Adjunct Processor (AP) devices 827 via the VFIO mediated device interface. 828 829 To compile this driver as a module, choose M here: the module 830 will be called vfio_ap. 831 832endmenu 833 834config CCW 835 def_bool y 836 837config HAVE_PNETID 838 tristate 839 default (SMC || CCWGROUP) 840 841menu "Virtualization" 842 843config PFAULT 844 def_bool y 845 prompt "Pseudo page fault support" 846 help 847 Select this option, if you want to use PFAULT pseudo page fault 848 handling under VM. If running native or in LPAR, this option 849 has no effect. If your VM does not support PFAULT, PAGEEX 850 pseudo page fault handling will be used. 851 Note that VM 4.2 supports PFAULT but has a bug in its 852 implementation that causes some problems. 853 Everybody who wants to run Linux under VM != VM4.2 should select 854 this option. 855 856config CMM 857 def_tristate n 858 prompt "Cooperative memory management" 859 help 860 Select this option, if you want to enable the kernel interface 861 to reduce the memory size of the system. This is accomplished 862 by allocating pages of memory and put them "on hold". This only 863 makes sense for a system running under VM where the unused pages 864 will be reused by VM for other guest systems. The interface 865 allows an external monitor to balance memory of many systems. 866 Everybody who wants to run Linux under VM should select this 867 option. 868 869config CMM_IUCV 870 def_bool y 871 prompt "IUCV special message interface to cooperative memory management" 872 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV) 873 help 874 Select this option to enable the special message interface to 875 the cooperative memory management. 876 877config APPLDATA_BASE 878 def_bool n 879 prompt "Linux - VM Monitor Stream, base infrastructure" 880 depends on PROC_SYSCTL 881 help 882 This provides a kernel interface for creating and updating z/VM APPLDATA 883 monitor records. The monitor records are updated at certain time 884 intervals, once the timer is started. 885 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer, 886 i.e. enables or disables monitoring on the Linux side. 887 A custom interval value (in seconds) can be written to 888 /proc/appldata/interval. 889 890 Defaults are 60 seconds interval and timer off. 891 The /proc entries can also be read from, showing the current settings. 892 893config APPLDATA_MEM 894 def_tristate m 895 prompt "Monitor memory management statistics" 896 depends on APPLDATA_BASE && VM_EVENT_COUNTERS 897 help 898 This provides memory management related data to the Linux - VM Monitor 899 Stream, like paging/swapping rate, memory utilisation, etc. 900 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM 901 APPLDATA monitor record, i.e. enables or disables monitoring this record 902 on the z/VM side. 903 904 Default is disabled. 905 The /proc entry can also be read from, showing the current settings. 906 907 This can also be compiled as a module, which will be called 908 appldata_mem.o. 909 910config APPLDATA_OS 911 def_tristate m 912 prompt "Monitor OS statistics" 913 depends on APPLDATA_BASE 914 help 915 This provides OS related data to the Linux - VM Monitor Stream, like 916 CPU utilisation, etc. 917 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM 918 APPLDATA monitor record, i.e. enables or disables monitoring this record 919 on the z/VM side. 920 921 Default is disabled. 922 This can also be compiled as a module, which will be called 923 appldata_os.o. 924 925config APPLDATA_NET_SUM 926 def_tristate m 927 prompt "Monitor overall network statistics" 928 depends on APPLDATA_BASE && NET 929 help 930 This provides network related data to the Linux - VM Monitor Stream, 931 currently there is only a total sum of network I/O statistics, no 932 per-interface data. 933 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM 934 APPLDATA monitor record, i.e. enables or disables monitoring this record 935 on the z/VM side. 936 937 Default is disabled. 938 This can also be compiled as a module, which will be called 939 appldata_net_sum.o. 940 941config S390_HYPFS 942 def_bool y 943 prompt "s390 hypervisor information" 944 help 945 This provides several binary files at (debugfs)/s390_hypfs/ to 946 provide accounting information in an s390 hypervisor environment. 947 948config S390_HYPFS_FS 949 def_bool n 950 prompt "s390 hypervisor file system support" 951 select SYS_HYPERVISOR 952 depends on S390_HYPFS 953 help 954 This is a virtual file system intended to provide accounting 955 information in an s390 hypervisor environment. This file system 956 is deprecated and should not be used. 957 958 Say N if you are unsure. 959 960source "arch/s390/kvm/Kconfig" 961 962config S390_GUEST 963 def_bool y 964 prompt "s390 support for virtio devices" 965 select TTY 966 select VIRTUALIZATION 967 select VIRTIO 968 help 969 Enabling this option adds support for virtio based paravirtual device 970 drivers on s390. 971 972 Select this option if you want to run the kernel as a guest under 973 the KVM hypervisor. 974 975endmenu 976 977config S390_MODULES_SANITY_TEST_HELPERS 978 def_bool n 979 980menu "Selftests" 981 982config S390_UNWIND_SELFTEST 983 def_tristate n 984 depends on KUNIT 985 default KUNIT_ALL_TESTS 986 prompt "Test unwind functions" 987 help 988 This option enables s390 specific stack unwinder testing kernel 989 module. This option is not useful for distributions or general 990 kernels, but only for kernel developers working on architecture code. 991 992 Say N if you are unsure. 993 994config S390_KPROBES_SANITY_TEST 995 def_tristate n 996 prompt "Enable s390 specific kprobes tests" 997 depends on KPROBES 998 depends on KUNIT 999 help 1000 This option enables an s390 specific kprobes test module. This option 1001 is not useful for distributions or general kernels, but only for kernel 1002 developers working on architecture code. 1003 1004 Say N if you are unsure. 1005 1006config S390_MODULES_SANITY_TEST 1007 def_tristate n 1008 depends on KUNIT 1009 default KUNIT_ALL_TESTS 1010 prompt "Enable s390 specific modules tests" 1011 select S390_MODULES_SANITY_TEST_HELPERS 1012 help 1013 This option enables an s390 specific modules test. This option is 1014 not useful for distributions or general kernels, but only for 1015 kernel developers working on architecture code. 1016 1017 Say N if you are unsure. 1018endmenu 1019