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 ARCH_SUPPORTS_UPROBES 45 def_bool y 46 47config KASAN_SHADOW_OFFSET 48 hex 49 depends on KASAN 50 default 0x1C000000000000 51 52config CC_ASM_FLAG_OUTPUT_BROKEN 53 def_bool CC_IS_GCC && GCC_VERSION < 140200 54 help 55 GCC versions before 14.2.0 may die with an internal 56 compiler error in some configurations if flag output 57 operands are used within inline assemblies. 58 59config CC_HAS_ASM_AOR_FORMAT_FLAGS 60 def_bool !(CC_IS_CLANG && CLANG_VERSION < 190100) 61 help 62 Clang versions before 19.1.0 do not support A, 63 O, and R inline assembly format flags. 64 65config S390 66 def_bool y 67 # 68 # Note: keep this list sorted alphabetically 69 # 70 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 71 select ALTERNATE_USER_ADDRESS_SPACE 72 select ARCH_32BIT_USTAT_F_TINODE 73 select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE 74 select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM 75 select ARCH_ENABLE_MEMORY_HOTREMOVE 76 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 77 select ARCH_HAS_CPU_FINALIZE_INIT 78 select ARCH_HAS_CRC32 79 select ARCH_HAS_CURRENT_STACK_POINTER 80 select ARCH_HAS_DEBUG_VIRTUAL 81 select ARCH_HAS_DEBUG_VM_PGTABLE 82 select ARCH_HAS_DEBUG_WX 83 select ARCH_HAS_DEVMEM_IS_ALLOWED 84 select ARCH_HAS_DMA_OPS if PCI 85 select ARCH_HAS_ELF_RANDOMIZE 86 select ARCH_HAS_FORCE_DMA_UNENCRYPTED 87 select ARCH_HAS_FORTIFY_SOURCE 88 select ARCH_HAS_GCOV_PROFILE_ALL 89 select ARCH_HAS_GIGANTIC_PAGE 90 select ARCH_HAS_KCOV 91 select ARCH_HAS_MEMBARRIER_SYNC_CORE 92 select ARCH_HAS_MEM_ENCRYPT 93 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS 94 select ARCH_HAS_PREEMPT_LAZY 95 select ARCH_HAS_PTDUMP 96 select ARCH_HAS_PTE_SPECIAL 97 select ARCH_HAS_SCALED_CPUTIME 98 select ARCH_HAS_SET_DIRECT_MAP 99 select ARCH_HAS_SET_MEMORY 100 select ARCH_HAS_STRICT_KERNEL_RWX 101 select ARCH_HAS_STRICT_MODULE_RWX 102 select ARCH_HAS_SYSCALL_WRAPPER 103 select ARCH_HAS_UBSAN 104 select ARCH_HAS_VDSO_TIME_DATA 105 select ARCH_HAVE_NMI_SAFE_CMPXCHG 106 select ARCH_INLINE_READ_LOCK 107 select ARCH_INLINE_READ_LOCK_BH 108 select ARCH_INLINE_READ_LOCK_IRQ 109 select ARCH_INLINE_READ_LOCK_IRQSAVE 110 select ARCH_INLINE_READ_TRYLOCK 111 select ARCH_INLINE_READ_UNLOCK 112 select ARCH_INLINE_READ_UNLOCK_BH 113 select ARCH_INLINE_READ_UNLOCK_IRQ 114 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE 115 select ARCH_INLINE_SPIN_LOCK 116 select ARCH_INLINE_SPIN_LOCK_BH 117 select ARCH_INLINE_SPIN_LOCK_IRQ 118 select ARCH_INLINE_SPIN_LOCK_IRQSAVE 119 select ARCH_INLINE_SPIN_TRYLOCK 120 select ARCH_INLINE_SPIN_TRYLOCK_BH 121 select ARCH_INLINE_SPIN_UNLOCK 122 select ARCH_INLINE_SPIN_UNLOCK_BH 123 select ARCH_INLINE_SPIN_UNLOCK_IRQ 124 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE 125 select ARCH_INLINE_WRITE_LOCK 126 select ARCH_INLINE_WRITE_LOCK_BH 127 select ARCH_INLINE_WRITE_LOCK_IRQ 128 select ARCH_INLINE_WRITE_LOCK_IRQSAVE 129 select ARCH_INLINE_WRITE_TRYLOCK 130 select ARCH_INLINE_WRITE_UNLOCK 131 select ARCH_INLINE_WRITE_UNLOCK_BH 132 select ARCH_INLINE_WRITE_UNLOCK_IRQ 133 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE 134 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 135 select ARCH_STACKWALK 136 select ARCH_SUPPORTS_ATOMIC_RMW 137 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 138 select ARCH_SUPPORTS_HUGETLBFS 139 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && CC_IS_CLANG 140 select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS 141 select ARCH_SUPPORTS_NUMA_BALANCING 142 select ARCH_SUPPORTS_PER_VMA_LOCK 143 select ARCH_USE_BUILTIN_BSWAP 144 select ARCH_USE_CMPXCHG_LOCKREF 145 select ARCH_USE_SYM_ANNOTATIONS 146 select ARCH_WANTS_NO_INSTR 147 select ARCH_WANT_DEFAULT_BPF_JIT 148 select ARCH_WANT_IPC_PARSE_VERSION 149 select ARCH_WANT_IRQS_OFF_ACTIVATE_MM 150 select ARCH_WANT_KERNEL_PMD_MKWRITE 151 select ARCH_WANT_LD_ORPHAN_WARN 152 select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP 153 select BUILDTIME_TABLE_SORT 154 select CLONE_BACKWARDS2 155 select DCACHE_WORD_ACCESS if !KMSAN 156 select DYNAMIC_FTRACE if FUNCTION_TRACER 157 select FUNCTION_ALIGNMENT_8B if CC_IS_GCC 158 select FUNCTION_ALIGNMENT_16B if !CC_IS_GCC 159 select GENERIC_ALLOCATOR 160 select GENERIC_CPU_DEVICES 161 select GENERIC_CPU_AUTOPROBE 162 select GENERIC_CPU_VULNERABILITIES 163 select GENERIC_ENTRY 164 select GENERIC_GETTIMEOFDAY 165 select GENERIC_SMP_IDLE_THREAD 166 select GENERIC_TIME_VSYSCALL 167 select GENERIC_VDSO_DATA_STORE 168 select GENERIC_VDSO_TIME_NS 169 select GENERIC_IOREMAP if PCI 170 select HAVE_ALIGNED_STRUCT_PAGE 171 select HAVE_ARCH_AUDITSYSCALL 172 select HAVE_ARCH_JUMP_LABEL 173 select HAVE_ARCH_JUMP_LABEL_RELATIVE 174 select HAVE_ARCH_KASAN 175 select HAVE_ARCH_KASAN_VMALLOC 176 select HAVE_ARCH_KCSAN 177 select HAVE_ARCH_KMSAN 178 select HAVE_ARCH_KFENCE 179 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 180 select HAVE_ARCH_SECCOMP_FILTER 181 select HAVE_ARCH_SOFT_DIRTY 182 select HAVE_ARCH_STACKLEAK 183 select HAVE_ARCH_TRACEHOOK 184 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 185 select HAVE_ARCH_VMAP_STACK 186 select HAVE_ASM_MODVERSIONS 187 select HAVE_BUILDTIME_MCOUNT_SORT 188 select HAVE_CMPXCHG_DOUBLE 189 select HAVE_CMPXCHG_LOCAL 190 select HAVE_DEBUG_KMEMLEAK 191 select HAVE_DMA_CONTIGUOUS 192 select HAVE_DYNAMIC_FTRACE 193 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 194 select HAVE_FTRACE_REGS_HAVING_PT_REGS 195 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 196 select HAVE_DYNAMIC_FTRACE_WITH_REGS 197 select HAVE_EBPF_JIT if HAVE_MARCH_Z196_FEATURES 198 select HAVE_EFFICIENT_UNALIGNED_ACCESS 199 select HAVE_GUP_FAST 200 select HAVE_FENTRY 201 select HAVE_FTRACE_GRAPH_FUNC 202 select HAVE_FTRACE_MCOUNT_RECORD 203 select HAVE_FUNCTION_ARG_ACCESS_API 204 select HAVE_FUNCTION_ERROR_INJECTION 205 select HAVE_FUNCTION_GRAPH_FREGS 206 select HAVE_FUNCTION_GRAPH_TRACER 207 select HAVE_FUNCTION_TRACER 208 select HAVE_GCC_PLUGINS 209 select HAVE_GENERIC_VDSO 210 select HAVE_IOREMAP_PROT if PCI 211 select HAVE_KERNEL_BZIP2 212 select HAVE_KERNEL_GZIP 213 select HAVE_KERNEL_LZ4 214 select HAVE_KERNEL_LZMA 215 select HAVE_KERNEL_LZO 216 select HAVE_KERNEL_UNCOMPRESSED 217 select HAVE_KERNEL_XZ 218 select HAVE_KERNEL_ZSTD 219 select HAVE_KPROBES 220 select HAVE_KPROBES_ON_FTRACE 221 select HAVE_KRETPROBES 222 select HAVE_LIVEPATCH 223 select HAVE_MEMBLOCK_PHYS_MAP 224 select HAVE_MOD_ARCH_SPECIFIC 225 select HAVE_NMI 226 select HAVE_NOP_MCOUNT 227 select HAVE_PAGE_SIZE_4KB 228 select HAVE_PCI 229 select HAVE_PERF_EVENTS 230 select HAVE_PERF_REGS 231 select HAVE_PERF_USER_STACK_DUMP 232 select HAVE_PREEMPT_DYNAMIC_KEY 233 select HAVE_REGS_AND_STACK_ACCESS_API 234 select HAVE_RELIABLE_STACKTRACE 235 select HAVE_RETHOOK 236 select HAVE_RSEQ 237 select HAVE_SAMPLE_FTRACE_DIRECT 238 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 239 select HAVE_SETUP_PER_CPU_AREA 240 select HAVE_SOFTIRQ_ON_OWN_STACK 241 select HAVE_SYSCALL_TRACEPOINTS 242 select HAVE_VIRT_CPU_ACCOUNTING 243 select HAVE_VIRT_CPU_ACCOUNTING_IDLE 244 select HOTPLUG_SMT 245 select IOMMU_HELPER if PCI 246 select IOMMU_SUPPORT if PCI 247 select KASAN_VMALLOC if KASAN 248 select LOCK_MM_AND_FIND_VMA 249 select MMU_GATHER_MERGE_VMAS 250 select MMU_GATHER_NO_GATHER 251 select MMU_GATHER_RCU_TABLE_FREE 252 select MODULES_USE_ELF_RELA 253 select NEED_DMA_MAP_STATE if PCI 254 select NEED_PER_CPU_EMBED_FIRST_CHUNK 255 select NEED_PROC_VMCORE_DEVICE_RAM if PROC_VMCORE 256 select NEED_SG_DMA_LENGTH if PCI 257 select OLD_SIGACTION 258 select OLD_SIGSUSPEND3 259 select PCI_DOMAINS if PCI 260 select PCI_MSI if PCI 261 select PCI_MSI_ARCH_FALLBACKS if PCI_MSI 262 select PCI_QUIRKS if PCI 263 select SPARSE_IRQ 264 select SWIOTLB 265 select SYSCTL_EXCEPTION_TRACE 266 select THREAD_INFO_IN_TASK 267 select TRACE_IRQFLAGS_SUPPORT 268 select TTY 269 select USER_STACKTRACE_SUPPORT 270 select VDSO_GETRANDOM 271 select VIRT_CPU_ACCOUNTING 272 select VMAP_STACK 273 select ZONE_DMA 274 # Note: keep the above list sorted alphabetically 275 276config SCHED_OMIT_FRAME_POINTER 277 def_bool y 278 279config PGTABLE_LEVELS 280 int 281 default 5 282 283source "kernel/livepatch/Kconfig" 284 285config ARCH_SUPPORTS_KEXEC 286 def_bool y 287 288config ARCH_SUPPORTS_KEXEC_FILE 289 def_bool y 290 291config ARCH_SUPPORTS_KEXEC_SIG 292 def_bool MODULE_SIG_FORMAT 293 294config ARCH_SUPPORTS_KEXEC_PURGATORY 295 def_bool y 296 297config ARCH_SUPPORTS_CRASH_DUMP 298 def_bool y 299 help 300 Refer to <file:Documentation/arch/s390/zfcpdump.rst> for more details on this. 301 This option also enables s390 zfcpdump. 302 See also <file:Documentation/arch/s390/zfcpdump.rst> 303 304config ARCH_DEFAULT_CRASH_DUMP 305 def_bool y 306 307menu "Processor type and features" 308 309config HAVE_MARCH_Z10_FEATURES 310 def_bool n 311 312config HAVE_MARCH_Z196_FEATURES 313 def_bool n 314 select HAVE_MARCH_Z10_FEATURES 315 316config HAVE_MARCH_ZEC12_FEATURES 317 def_bool n 318 select HAVE_MARCH_Z196_FEATURES 319 320config HAVE_MARCH_Z13_FEATURES 321 def_bool n 322 select HAVE_MARCH_ZEC12_FEATURES 323 324config HAVE_MARCH_Z14_FEATURES 325 def_bool n 326 select HAVE_MARCH_Z13_FEATURES 327 328config HAVE_MARCH_Z15_FEATURES 329 def_bool n 330 select HAVE_MARCH_Z14_FEATURES 331 332config HAVE_MARCH_Z16_FEATURES 333 def_bool n 334 select HAVE_MARCH_Z15_FEATURES 335 336config HAVE_MARCH_Z17_FEATURES 337 def_bool n 338 select HAVE_MARCH_Z16_FEATURES 339 340choice 341 prompt "Processor type" 342 default MARCH_Z196 343 344config MARCH_Z10 345 bool "IBM System z10" 346 select HAVE_MARCH_Z10_FEATURES 347 depends on $(cc-option,-march=z10) 348 help 349 Select this to enable optimizations for IBM System z10 (2097 and 2098 350 series). This is the oldest machine generation currently supported. 351 352config MARCH_Z196 353 bool "IBM zEnterprise 114 and 196" 354 select HAVE_MARCH_Z196_FEATURES 355 depends on $(cc-option,-march=z196) 356 help 357 Select this to enable optimizations for IBM zEnterprise 114 and 196 358 (2818 and 2817 series). The kernel will be slightly faster but will 359 not work on older machines. 360 361config MARCH_ZEC12 362 bool "IBM zBC12 and zEC12" 363 select HAVE_MARCH_ZEC12_FEATURES 364 depends on $(cc-option,-march=zEC12) 365 help 366 Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and 367 2827 series). The kernel will be slightly faster but will not work on 368 older machines. 369 370config MARCH_Z13 371 bool "IBM z13s and z13" 372 select HAVE_MARCH_Z13_FEATURES 373 depends on $(cc-option,-march=z13) 374 help 375 Select this to enable optimizations for IBM z13s and z13 (2965 and 376 2964 series). The kernel will be slightly faster but will not work on 377 older machines. 378 379config MARCH_Z14 380 bool "IBM z14 ZR1 and z14" 381 select HAVE_MARCH_Z14_FEATURES 382 depends on $(cc-option,-march=z14) 383 help 384 Select this to enable optimizations for IBM z14 ZR1 and z14 (3907 385 and 3906 series). The kernel will be slightly faster but will not 386 work on older machines. 387 388config MARCH_Z15 389 bool "IBM z15" 390 select HAVE_MARCH_Z15_FEATURES 391 depends on $(cc-option,-march=z15) 392 help 393 Select this to enable optimizations for IBM z15 (8562 394 and 8561 series). The kernel will be slightly faster but will not 395 work on older machines. 396 397config MARCH_Z16 398 bool "IBM z16" 399 select HAVE_MARCH_Z16_FEATURES 400 depends on $(cc-option,-march=z16) 401 help 402 Select this to enable optimizations for IBM z16 (3931 and 403 3932 series). 404 405config MARCH_Z17 406 bool "IBM z17" 407 select HAVE_MARCH_Z17_FEATURES 408 depends on $(cc-option,-march=z17) 409 help 410 Select this to enable optimizations for IBM z17 (9175 and 411 9176 series). 412 413endchoice 414 415config MARCH_Z10_TUNE 416 def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT 417 418config MARCH_Z196_TUNE 419 def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT 420 421config MARCH_ZEC12_TUNE 422 def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT 423 424config MARCH_Z13_TUNE 425 def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT 426 427config MARCH_Z14_TUNE 428 def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT 429 430config MARCH_Z15_TUNE 431 def_bool TUNE_Z15 || MARCH_Z15 && TUNE_DEFAULT 432 433config MARCH_Z16_TUNE 434 def_bool TUNE_Z16 || MARCH_Z16 && TUNE_DEFAULT 435 436config MARCH_Z17_TUNE 437 def_bool TUNE_Z17 || MARCH_Z17 && TUNE_DEFAULT 438 439choice 440 prompt "Tune code generation" 441 default TUNE_DEFAULT 442 help 443 Cause the compiler to tune (-mtune) the generated code for a machine. 444 This will make the code run faster on the selected machine but 445 somewhat slower on other machines. 446 This option only changes how the compiler emits instructions, not the 447 selection of instructions itself, so the resulting kernel will run on 448 all other machines. 449 450config TUNE_DEFAULT 451 bool "Default" 452 help 453 Tune the generated code for the target processor for which the kernel 454 will be compiled. 455 456config TUNE_Z10 457 bool "IBM System z10" 458 459config TUNE_Z196 460 bool "IBM zEnterprise 114 and 196" 461 depends on $(cc-option,-mtune=z196) 462 463config TUNE_ZEC12 464 bool "IBM zBC12 and zEC12" 465 depends on $(cc-option,-mtune=zEC12) 466 467config TUNE_Z13 468 bool "IBM z13s and z13" 469 depends on $(cc-option,-mtune=z13) 470 471config TUNE_Z14 472 bool "IBM z14 ZR1 and z14" 473 depends on $(cc-option,-mtune=z14) 474 475config TUNE_Z15 476 bool "IBM z15" 477 depends on $(cc-option,-mtune=z15) 478 479config TUNE_Z16 480 bool "IBM z16" 481 depends on $(cc-option,-mtune=z16) 482 483config TUNE_Z17 484 bool "IBM z17" 485 depends on $(cc-option,-mtune=z17) 486 487endchoice 488 489config 64BIT 490 def_bool y 491 492config COMMAND_LINE_SIZE 493 int "Maximum size of kernel command line" 494 default 4096 495 range 896 1048576 496 help 497 This allows you to specify the maximum length of the kernel command 498 line. 499 500config COMPAT 501 def_bool n 502 prompt "Kernel support for 31 bit emulation" 503 select ARCH_WANT_OLD_COMPAT_IPC 504 select COMPAT_OLD_SIGACTION 505 select HAVE_UID16 506 depends on MULTIUSER 507 depends on !CC_IS_CLANG && !LD_IS_LLD 508 help 509 Select this option if you want to enable your system kernel to 510 handle system-calls from ELF binaries for 31 bit ESA. This option 511 (and some other stuff like libraries and such) is needed for 512 executing 31 bit applications. 513 514 If unsure say N. 515 516config SMP 517 def_bool y 518 519config NR_CPUS 520 int "Maximum number of CPUs (2-512)" 521 range 2 512 522 default "64" 523 help 524 This allows you to specify the maximum number of CPUs which this 525 kernel will support. The maximum supported value is 512 and the 526 minimum value which makes sense is 2. 527 528 This is purely to save memory - each supported CPU adds 529 approximately sixteen kilobytes to the kernel image. 530 531config HOTPLUG_CPU 532 def_bool y 533 534config NUMA 535 bool "NUMA support" 536 depends on SCHED_TOPOLOGY 537 default n 538 help 539 Enable NUMA support 540 541 This option adds NUMA support to the kernel. 542 543config NODES_SHIFT 544 int 545 depends on NUMA 546 default "1" 547 548config SCHED_SMT 549 def_bool n 550 551config SCHED_MC 552 def_bool n 553 554config SCHED_TOPOLOGY 555 def_bool y 556 prompt "Topology scheduler support" 557 select SCHED_SMT 558 select SCHED_MC 559 help 560 Topology scheduler support improves the CPU scheduler's decision 561 making when dealing with machines that have multi-threading, 562 multiple cores or multiple books. 563 564config SCHED_TOPOLOGY_VERTICAL 565 def_bool y 566 bool "Use vertical CPU polarization by default" 567 depends on SCHED_TOPOLOGY 568 help 569 Use vertical CPU polarization by default if available. 570 The default CPU polarization is horizontal. 571 572config HIPERDISPATCH_ON 573 def_bool y 574 bool "Use hiperdispatch on vertical polarization by default" 575 depends on SCHED_TOPOLOGY 576 depends on PROC_SYSCTL 577 help 578 Hiperdispatch aims to improve the CPU scheduler's decision 579 making when using vertical polarization by adjusting CPU 580 capacities dynamically. Set this option to use hiperdispatch 581 on vertical polarization by default. This can be overwritten 582 by sysctl's s390.hiperdispatch attribute later on. 583 584source "kernel/Kconfig.hz" 585 586config CERT_STORE 587 bool "Get user certificates via DIAG320" 588 depends on KEYS 589 select CRYPTO_LIB_SHA256 590 help 591 Enable this option if you want to access user-provided secure boot 592 certificates via DIAG 0x320. 593 594 These certificates will be made available via the keyring named 595 'cert_store'. 596 597config KERNEL_NOBP 598 def_bool n 599 prompt "Enable modified branch prediction for the kernel by default" 600 help 601 If this option is selected the kernel will switch to a modified 602 branch prediction mode if the firmware interface is available. 603 The modified branch prediction mode improves the behaviour in 604 regard to speculative execution. 605 606 With the option enabled the kernel parameter "nobp=0" or "nospec" 607 can be used to run the kernel in the normal branch prediction mode. 608 609 With the option disabled the modified branch prediction mode is 610 enabled with the "nobp=1" kernel parameter. 611 612 If unsure, say N. 613 614config EXPOLINE 615 def_bool n 616 depends on $(cc-option,-mindirect-branch=thunk) 617 prompt "Avoid speculative indirect branches in the kernel" 618 help 619 Compile the kernel with the expoline compiler options to guard 620 against kernel-to-user data leaks by avoiding speculative indirect 621 branches. 622 Requires a compiler with -mindirect-branch=thunk support for full 623 protection. The kernel may run slower. 624 625 If unsure, say N. 626 627config EXPOLINE_EXTERN 628 def_bool EXPOLINE && CC_IS_GCC && GCC_VERSION >= 110200 && \ 629 $(success,$(srctree)/arch/s390/tools/gcc-thunk-extern.sh $(CC)) 630 help 631 Generate expolines as external functions if the compiler supports it. 632 This option is required for some tooling like kpatch, if expolines 633 are enabled. The kernel is compiled with 634 -mindirect-branch=thunk-extern, which requires a newer compiler. 635 636choice 637 prompt "Expoline default" 638 depends on EXPOLINE 639 default EXPOLINE_FULL 640 641config EXPOLINE_OFF 642 bool "spectre_v2=off" 643 644config EXPOLINE_AUTO 645 bool "spectre_v2=auto" 646 647config EXPOLINE_FULL 648 bool "spectre_v2=on" 649 650endchoice 651 652config RELOCATABLE 653 def_bool y 654 select ARCH_VMLINUX_NEEDS_RELOCS 655 help 656 This builds a kernel image that retains relocation information 657 so it can be loaded at an arbitrary address. 658 The relocations make the kernel image about 15% larger (compressed 659 10%), but are discarded at runtime. 660 Note: this option exists only for documentation purposes, please do 661 not remove it. 662 663config RANDOMIZE_BASE 664 bool "Randomize the address of the kernel image (KASLR)" 665 default y 666 help 667 In support of Kernel Address Space Layout Randomization (KASLR), 668 this randomizes the address at which the kernel image is loaded, 669 as a security feature that deters exploit attempts relying on 670 knowledge of the location of kernel internals. 671 672config RANDOMIZE_IDENTITY_BASE 673 bool "Randomize the address of the identity mapping base" 674 depends on RANDOMIZE_BASE 675 default DEBUG_VM 676 help 677 The identity mapping base address is pinned to zero by default. 678 Allow randomization of that base to expose otherwise missed 679 notion of physical and virtual addresses of data structures. 680 That does not have any impact on the base address at which the 681 kernel image is loaded. 682 683 If unsure, say N 684 685config KERNEL_IMAGE_BASE 686 hex "Kernel image base address" 687 range 0x100000 0x1FFFFFE0000000 if !KASAN 688 range 0x100000 0x1BFFFFE0000000 if KASAN 689 default 0x3FFE0000000 if !KASAN 690 default 0x7FFFE0000000 if KASAN 691 help 692 This is the address at which the kernel image is loaded in case 693 Kernel Address Space Layout Randomization (KASLR) is disabled. 694 695 In case the Protected virtualization guest support is enabled the 696 Ultravisor imposes a virtual address limit. If the value of this 697 option leads to the kernel image exceeding the Ultravisor limit, 698 this option is ignored and the image is loaded below the limit. 699 700 If the value of this option leads to the kernel image overlapping 701 the virtual memory where other data structures are located, this 702 option is ignored and the image is loaded above the structures. 703 704endmenu 705 706menu "Memory setup" 707 708config ARCH_SPARSEMEM_ENABLE 709 def_bool y 710 select SPARSEMEM_VMEMMAP_ENABLE 711 select SPARSEMEM_VMEMMAP 712 713config ARCH_SPARSEMEM_DEFAULT 714 def_bool y 715 716config MAX_PHYSMEM_BITS 717 int "Maximum size of supported physical memory in bits (42-53)" 718 range 42 53 719 default "46" 720 help 721 This option specifies the maximum supported size of physical memory 722 in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB). 723 Increasing the number of bits also increases the kernel image size. 724 By default 46 bits (64TB) are supported. 725 726endmenu 727 728menu "I/O subsystem" 729 730config QDIO 731 def_tristate y 732 prompt "QDIO support" 733 help 734 This driver provides the Queued Direct I/O base support for 735 IBM System z. 736 737 To compile this driver as a module, choose M here: the 738 module will be called qdio. 739 740 If unsure, say Y. 741 742if PCI 743 744config PCI_NR_FUNCTIONS 745 int "Maximum number of PCI functions (1-4096)" 746 range 1 4096 747 default "512" 748 help 749 This allows you to specify the maximum number of PCI functions which 750 this kernel will support. 751 752endif # PCI 753 754config HAS_IOMEM 755 def_bool PCI 756 757config CHSC_SCH 758 def_tristate m 759 prompt "Support for CHSC subchannels" 760 help 761 This driver allows usage of CHSC subchannels. A CHSC subchannel 762 is usually present on LPAR only. 763 The driver creates a device /dev/chsc, which may be used to 764 obtain I/O configuration information about the machine and 765 to issue asynchronous chsc commands (DANGEROUS). 766 You will usually only want to use this interface on a special 767 LPAR designated for system management. 768 769 To compile this driver as a module, choose M here: the 770 module will be called chsc_sch. 771 772 If unsure, say N. 773 774config SCM_BUS 775 def_bool y 776 prompt "SCM bus driver" 777 help 778 Bus driver for Storage Class Memory. 779 780config EADM_SCH 781 def_tristate m 782 prompt "Support for EADM subchannels" 783 depends on SCM_BUS 784 help 785 This driver allows usage of EADM subchannels. EADM subchannels act 786 as a communication vehicle for SCM increments. 787 788 To compile this driver as a module, choose M here: the 789 module will be called eadm_sch. 790 791config AP 792 def_tristate y 793 prompt "Support for Adjunct Processors (ap)" 794 help 795 This driver allows usage to Adjunct Processor (AP) devices via 796 the ap bus, cards and queues. Supported Adjunct Processors are 797 the CryptoExpress Cards (CEX). 798 799 To compile this driver as a module, choose M here: the 800 module will be called ap. 801 802 If unsure, say Y (default). 803 804config AP_DEBUG 805 def_bool n 806 prompt "Enable debug features for Adjunct Processor (ap) devices" 807 depends on AP 808 help 809 Say 'Y' here to enable some additional debug features for Adjunct 810 Processor (ap) devices. 811 812 There will be some more sysfs attributes displayed for ap queues. 813 814 Do not enable on production level kernel build. 815 816 If unsure, say N. 817 818config VFIO_CCW 819 def_tristate n 820 prompt "Support for VFIO-CCW subchannels" 821 depends on VFIO 822 select VFIO_MDEV 823 help 824 This driver allows usage of I/O subchannels via VFIO-CCW. 825 826 To compile this driver as a module, choose M here: the 827 module will be called vfio_ccw. 828 829config VFIO_AP 830 def_tristate n 831 prompt "VFIO support for AP devices" 832 depends on KVM 833 depends on VFIO 834 depends on AP 835 select VFIO_MDEV 836 help 837 This driver grants access to Adjunct Processor (AP) devices 838 via the VFIO mediated device interface. 839 840 To compile this driver as a module, choose M here: the module 841 will be called vfio_ap. 842 843endmenu 844 845config CCW 846 def_bool y 847 848config HAVE_PNETID 849 tristate 850 default (SMC || CCWGROUP) 851 852menu "Virtualization" 853 854config PFAULT 855 def_bool y 856 prompt "Pseudo page fault support" 857 help 858 Select this option, if you want to use PFAULT pseudo page fault 859 handling under VM. If running native or in LPAR, this option 860 has no effect. If your VM does not support PFAULT, PAGEEX 861 pseudo page fault handling will be used. 862 Note that VM 4.2 supports PFAULT but has a bug in its 863 implementation that causes some problems. 864 Everybody who wants to run Linux under VM != VM4.2 should select 865 this option. 866 867config CMM 868 def_tristate n 869 prompt "Cooperative memory management" 870 help 871 Select this option, if you want to enable the kernel interface 872 to reduce the memory size of the system. This is accomplished 873 by allocating pages of memory and put them "on hold". This only 874 makes sense for a system running under VM where the unused pages 875 will be reused by VM for other guest systems. The interface 876 allows an external monitor to balance memory of many systems. 877 Everybody who wants to run Linux under VM should select this 878 option. 879 880config CMM_IUCV 881 def_bool y 882 prompt "IUCV special message interface to cooperative memory management" 883 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV) 884 help 885 Select this option to enable the special message interface to 886 the cooperative memory management. 887 888config APPLDATA_BASE 889 def_bool n 890 prompt "Linux - VM Monitor Stream, base infrastructure" 891 depends on PROC_SYSCTL 892 help 893 This provides a kernel interface for creating and updating z/VM APPLDATA 894 monitor records. The monitor records are updated at certain time 895 intervals, once the timer is started. 896 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer, 897 i.e. enables or disables monitoring on the Linux side. 898 A custom interval value (in seconds) can be written to 899 /proc/appldata/interval. 900 901 Defaults are 60 seconds interval and timer off. 902 The /proc entries can also be read from, showing the current settings. 903 904config APPLDATA_MEM 905 def_tristate m 906 prompt "Monitor memory management statistics" 907 depends on APPLDATA_BASE && VM_EVENT_COUNTERS 908 help 909 This provides memory management related data to the Linux - VM Monitor 910 Stream, like paging/swapping rate, memory utilisation, etc. 911 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM 912 APPLDATA monitor record, i.e. enables or disables monitoring this record 913 on the z/VM side. 914 915 Default is disabled. 916 The /proc entry can also be read from, showing the current settings. 917 918 This can also be compiled as a module, which will be called 919 appldata_mem.o. 920 921config APPLDATA_OS 922 def_tristate m 923 prompt "Monitor OS statistics" 924 depends on APPLDATA_BASE 925 help 926 This provides OS related data to the Linux - VM Monitor Stream, like 927 CPU utilisation, etc. 928 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM 929 APPLDATA monitor record, i.e. enables or disables monitoring this record 930 on the z/VM side. 931 932 Default is disabled. 933 This can also be compiled as a module, which will be called 934 appldata_os.o. 935 936config APPLDATA_NET_SUM 937 def_tristate m 938 prompt "Monitor overall network statistics" 939 depends on APPLDATA_BASE && NET 940 help 941 This provides network related data to the Linux - VM Monitor Stream, 942 currently there is only a total sum of network I/O statistics, no 943 per-interface data. 944 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM 945 APPLDATA monitor record, i.e. enables or disables monitoring this record 946 on the z/VM side. 947 948 Default is disabled. 949 This can also be compiled as a module, which will be called 950 appldata_net_sum.o. 951 952config S390_HYPFS 953 def_bool y 954 prompt "s390 hypervisor information" 955 help 956 This provides several binary files at (debugfs)/s390_hypfs/ to 957 provide accounting information in an s390 hypervisor environment. 958 959config S390_HYPFS_FS 960 def_bool n 961 prompt "s390 hypervisor file system support" 962 select SYS_HYPERVISOR 963 depends on S390_HYPFS 964 help 965 This is a virtual file system intended to provide accounting 966 information in an s390 hypervisor environment. This file system 967 is deprecated and should not be used. 968 969 Say N if you are unsure. 970 971source "arch/s390/kvm/Kconfig" 972 973config S390_GUEST 974 def_bool y 975 prompt "s390 support for virtio devices" 976 select TTY 977 select VIRTUALIZATION 978 select VIRTIO 979 help 980 Enabling this option adds support for virtio based paravirtual device 981 drivers on s390. 982 983 Select this option if you want to run the kernel as a guest under 984 the KVM hypervisor. 985 986endmenu 987 988config S390_MODULES_SANITY_TEST_HELPERS 989 def_bool n 990 991menu "Selftests" 992 993config S390_UNWIND_SELFTEST 994 def_tristate n 995 depends on KUNIT 996 default KUNIT_ALL_TESTS 997 prompt "Test unwind functions" 998 help 999 This option enables s390 specific stack unwinder testing kernel 1000 module. This option is not useful for distributions or general 1001 kernels, but only for kernel developers working on architecture code. 1002 1003 Say N if you are unsure. 1004 1005config S390_KPROBES_SANITY_TEST 1006 def_tristate n 1007 prompt "Enable s390 specific kprobes tests" 1008 depends on KPROBES 1009 depends on KUNIT 1010 help 1011 This option enables an s390 specific kprobes test module. This option 1012 is not useful for distributions or general kernels, but only for kernel 1013 developers working on architecture code. 1014 1015 Say N if you are unsure. 1016 1017config S390_MODULES_SANITY_TEST 1018 def_tristate n 1019 depends on KUNIT 1020 default KUNIT_ALL_TESTS 1021 prompt "Enable s390 specific modules tests" 1022 select S390_MODULES_SANITY_TEST_HELPERS 1023 help 1024 This option enables an s390 specific modules test. This option is 1025 not useful for distributions or general kernels, but only for 1026 kernel developers working on architecture code. 1027 1028 Say N if you are unsure. 1029endmenu 1030