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_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE 78 select ARCH_HAS_CPU_FINALIZE_INIT 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_HAVE_TRACE_MMIO_ACCESS 107 select ARCH_INLINE_READ_LOCK 108 select ARCH_INLINE_READ_LOCK_BH 109 select ARCH_INLINE_READ_LOCK_IRQ 110 select ARCH_INLINE_READ_LOCK_IRQSAVE 111 select ARCH_INLINE_READ_TRYLOCK 112 select ARCH_INLINE_READ_UNLOCK 113 select ARCH_INLINE_READ_UNLOCK_BH 114 select ARCH_INLINE_READ_UNLOCK_IRQ 115 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE 116 select ARCH_INLINE_SPIN_LOCK 117 select ARCH_INLINE_SPIN_LOCK_BH 118 select ARCH_INLINE_SPIN_LOCK_IRQ 119 select ARCH_INLINE_SPIN_LOCK_IRQSAVE 120 select ARCH_INLINE_SPIN_TRYLOCK 121 select ARCH_INLINE_SPIN_TRYLOCK_BH 122 select ARCH_INLINE_SPIN_UNLOCK 123 select ARCH_INLINE_SPIN_UNLOCK_BH 124 select ARCH_INLINE_SPIN_UNLOCK_IRQ 125 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE 126 select ARCH_INLINE_WRITE_LOCK 127 select ARCH_INLINE_WRITE_LOCK_BH 128 select ARCH_INLINE_WRITE_LOCK_IRQ 129 select ARCH_INLINE_WRITE_LOCK_IRQSAVE 130 select ARCH_INLINE_WRITE_TRYLOCK 131 select ARCH_INLINE_WRITE_UNLOCK 132 select ARCH_INLINE_WRITE_UNLOCK_BH 133 select ARCH_INLINE_WRITE_UNLOCK_IRQ 134 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE 135 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 136 select ARCH_MODULE_NEEDS_WEAK_PER_CPU 137 select ARCH_STACKWALK 138 select ARCH_SUPPORTS_ATOMIC_RMW 139 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 140 select ARCH_SUPPORTS_HUGETLBFS 141 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && CC_IS_CLANG 142 select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS 143 select ARCH_SUPPORTS_NUMA_BALANCING 144 select ARCH_SUPPORTS_PER_VMA_LOCK 145 select ARCH_USE_BUILTIN_BSWAP 146 select ARCH_USE_CMPXCHG_LOCKREF 147 select ARCH_USE_SYM_ANNOTATIONS 148 select ARCH_WANTS_NO_INSTR 149 select ARCH_WANT_DEFAULT_BPF_JIT 150 select ARCH_WANT_IPC_PARSE_VERSION 151 select ARCH_WANT_IRQS_OFF_ACTIVATE_MM 152 select ARCH_WANT_KERNEL_PMD_MKWRITE 153 select ARCH_WANT_LD_ORPHAN_WARN 154 select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP 155 select ARCH_WANTS_THP_SWAP 156 select BUILDTIME_TABLE_SORT 157 select CLONE_BACKWARDS2 158 select DCACHE_WORD_ACCESS if !KMSAN 159 select DYNAMIC_FTRACE if FUNCTION_TRACER 160 select FUNCTION_ALIGNMENT_8B if CC_IS_GCC 161 select FUNCTION_ALIGNMENT_16B if !CC_IS_GCC 162 select GENERIC_ALLOCATOR 163 select GENERIC_CPU_DEVICES 164 select GENERIC_CPU_AUTOPROBE 165 select GENERIC_CPU_VULNERABILITIES 166 select GENERIC_ENTRY 167 select GENERIC_GETTIMEOFDAY 168 select GENERIC_SMP_IDLE_THREAD 169 select GENERIC_TIME_VSYSCALL 170 select GENERIC_VDSO_DATA_STORE 171 select GENERIC_VDSO_TIME_NS 172 select GENERIC_IOREMAP if PCI 173 select HAVE_ALIGNED_STRUCT_PAGE 174 select HAVE_ARCH_AUDITSYSCALL 175 select HAVE_ARCH_JUMP_LABEL 176 select HAVE_ARCH_JUMP_LABEL_RELATIVE 177 select HAVE_ARCH_KASAN 178 select HAVE_ARCH_KASAN_VMALLOC 179 select HAVE_ARCH_KCSAN 180 select HAVE_ARCH_KMSAN 181 select HAVE_ARCH_KFENCE 182 select HAVE_ARCH_KSTACK_ERASE 183 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 184 select HAVE_ARCH_SECCOMP_FILTER 185 select HAVE_ARCH_SOFT_DIRTY 186 select HAVE_ARCH_TRACEHOOK 187 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 188 select HAVE_ARCH_VMAP_STACK 189 select HAVE_ASM_MODVERSIONS 190 select HAVE_BUILDTIME_MCOUNT_SORT 191 select HAVE_CMPXCHG_DOUBLE 192 select HAVE_CMPXCHG_LOCAL 193 select HAVE_DEBUG_KMEMLEAK 194 select HAVE_DMA_CONTIGUOUS 195 select HAVE_DYNAMIC_FTRACE 196 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 197 select HAVE_FTRACE_REGS_HAVING_PT_REGS 198 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 199 select HAVE_DYNAMIC_FTRACE_WITH_REGS 200 select HAVE_EBPF_JIT if HAVE_MARCH_Z196_FEATURES 201 select HAVE_EFFICIENT_UNALIGNED_ACCESS 202 select HAVE_GUP_FAST 203 select HAVE_FENTRY 204 select HAVE_FTRACE_GRAPH_FUNC 205 select HAVE_FUNCTION_ARG_ACCESS_API 206 select HAVE_FUNCTION_ERROR_INJECTION 207 select HAVE_FUNCTION_GRAPH_FREGS 208 select HAVE_FUNCTION_GRAPH_TRACER 209 select HAVE_FUNCTION_TRACER 210 select HAVE_GCC_PLUGINS 211 select HAVE_GENERIC_VDSO 212 select HAVE_IOREMAP_PROT if PCI 213 select HAVE_KERNEL_BZIP2 214 select HAVE_KERNEL_GZIP 215 select HAVE_KERNEL_LZ4 216 select HAVE_KERNEL_LZMA 217 select HAVE_KERNEL_LZO 218 select HAVE_KERNEL_UNCOMPRESSED 219 select HAVE_KERNEL_XZ 220 select HAVE_KERNEL_ZSTD 221 select HAVE_KPROBES 222 select HAVE_KPROBES_ON_FTRACE 223 select HAVE_KRETPROBES 224 select HAVE_LIVEPATCH 225 select HAVE_MEMBLOCK_PHYS_MAP 226 select HAVE_MOD_ARCH_SPECIFIC 227 select HAVE_NMI 228 select HAVE_NOP_MCOUNT 229 select HAVE_PAGE_SIZE_4KB 230 select HAVE_PCI 231 select HAVE_PERF_EVENTS 232 select HAVE_PERF_REGS 233 select HAVE_PERF_USER_STACK_DUMP 234 select HAVE_PREEMPT_DYNAMIC_KEY 235 select HAVE_REGS_AND_STACK_ACCESS_API 236 select HAVE_RELIABLE_STACKTRACE 237 select HAVE_RETHOOK 238 select HAVE_RSEQ 239 select HAVE_SAMPLE_FTRACE_DIRECT 240 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 241 select HAVE_SETUP_PER_CPU_AREA 242 select HAVE_SOFTIRQ_ON_OWN_STACK 243 select HAVE_SYSCALL_TRACEPOINTS 244 select HAVE_VIRT_CPU_ACCOUNTING 245 select HAVE_VIRT_CPU_ACCOUNTING_IDLE 246 select HOTPLUG_SMT 247 select IOMMU_HELPER if PCI 248 select IOMMU_SUPPORT if PCI 249 select KASAN_VMALLOC if KASAN 250 select LOCK_MM_AND_FIND_VMA 251 select MMU_GATHER_MERGE_VMAS 252 select MMU_GATHER_NO_GATHER 253 select MMU_GATHER_RCU_TABLE_FREE 254 select MODULES_USE_ELF_RELA 255 select NEED_DMA_MAP_STATE if PCI 256 select NEED_PER_CPU_EMBED_FIRST_CHUNK 257 select NEED_PROC_VMCORE_DEVICE_RAM if PROC_VMCORE 258 select NEED_SG_DMA_LENGTH if PCI 259 select OLD_SIGACTION 260 select OLD_SIGSUSPEND3 261 select PCI_DOMAINS if PCI 262 select PCI_MSI if PCI 263 select PCI_MSI_ARCH_FALLBACKS if PCI_MSI 264 select PCI_QUIRKS if PCI 265 select SPARSE_IRQ 266 select SWIOTLB 267 select SYSCTL_EXCEPTION_TRACE 268 select THREAD_INFO_IN_TASK 269 select TRACE_IRQFLAGS_SUPPORT 270 select TTY 271 select USER_STACKTRACE_SUPPORT 272 select VDSO_GETRANDOM 273 select VIRT_CPU_ACCOUNTING 274 select VMAP_STACK 275 select ZONE_DMA 276 # Note: keep the above list sorted alphabetically 277 278config SCHED_OMIT_FRAME_POINTER 279 def_bool y 280 281config PGTABLE_LEVELS 282 int 283 default 5 284 285source "kernel/livepatch/Kconfig" 286 287config ARCH_SUPPORTS_KEXEC 288 def_bool y 289 290config ARCH_SUPPORTS_KEXEC_FILE 291 def_bool y 292 293config ARCH_SUPPORTS_KEXEC_SIG 294 def_bool MODULE_SIG_FORMAT 295 296config ARCH_SUPPORTS_KEXEC_PURGATORY 297 def_bool y 298 299config ARCH_SUPPORTS_CRASH_DUMP 300 def_bool y 301 help 302 Refer to <file:Documentation/arch/s390/zfcpdump.rst> for more details on this. 303 This option also enables s390 zfcpdump. 304 See also <file:Documentation/arch/s390/zfcpdump.rst> 305 306config ARCH_DEFAULT_CRASH_DUMP 307 def_bool y 308 309menu "Processor type and features" 310 311config HAVE_MARCH_Z10_FEATURES 312 def_bool n 313 314config HAVE_MARCH_Z196_FEATURES 315 def_bool n 316 select HAVE_MARCH_Z10_FEATURES 317 318config HAVE_MARCH_ZEC12_FEATURES 319 def_bool n 320 select HAVE_MARCH_Z196_FEATURES 321 322config HAVE_MARCH_Z13_FEATURES 323 def_bool n 324 select HAVE_MARCH_ZEC12_FEATURES 325 326config HAVE_MARCH_Z14_FEATURES 327 def_bool n 328 select HAVE_MARCH_Z13_FEATURES 329 330config HAVE_MARCH_Z15_FEATURES 331 def_bool n 332 select HAVE_MARCH_Z14_FEATURES 333 334config HAVE_MARCH_Z16_FEATURES 335 def_bool n 336 select HAVE_MARCH_Z15_FEATURES 337 338config HAVE_MARCH_Z17_FEATURES 339 def_bool n 340 select HAVE_MARCH_Z16_FEATURES 341 342choice 343 prompt "Processor type" 344 default MARCH_Z196 345 346config MARCH_Z10 347 bool "IBM System z10" 348 select HAVE_MARCH_Z10_FEATURES 349 depends on $(cc-option,-march=z10) 350 help 351 Select this to enable optimizations for IBM System z10 (2097 and 2098 352 series). This is the oldest machine generation currently supported. 353 354config MARCH_Z196 355 bool "IBM zEnterprise 114 and 196" 356 select HAVE_MARCH_Z196_FEATURES 357 depends on $(cc-option,-march=z196) 358 help 359 Select this to enable optimizations for IBM zEnterprise 114 and 196 360 (2818 and 2817 series). The kernel will be slightly faster but will 361 not work on older machines. 362 363config MARCH_ZEC12 364 bool "IBM zBC12 and zEC12" 365 select HAVE_MARCH_ZEC12_FEATURES 366 depends on $(cc-option,-march=zEC12) 367 help 368 Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and 369 2827 series). The kernel will be slightly faster but will not work on 370 older machines. 371 372config MARCH_Z13 373 bool "IBM z13s and z13" 374 select HAVE_MARCH_Z13_FEATURES 375 depends on $(cc-option,-march=z13) 376 help 377 Select this to enable optimizations for IBM z13s and z13 (2965 and 378 2964 series). The kernel will be slightly faster but will not work on 379 older machines. 380 381config MARCH_Z14 382 bool "IBM z14 ZR1 and z14" 383 select HAVE_MARCH_Z14_FEATURES 384 depends on $(cc-option,-march=z14) 385 help 386 Select this to enable optimizations for IBM z14 ZR1 and z14 (3907 387 and 3906 series). The kernel will be slightly faster but will not 388 work on older machines. 389 390config MARCH_Z15 391 bool "IBM z15" 392 select HAVE_MARCH_Z15_FEATURES 393 depends on $(cc-option,-march=z15) 394 help 395 Select this to enable optimizations for IBM z15 (8562 396 and 8561 series). The kernel will be slightly faster but will not 397 work on older machines. 398 399config MARCH_Z16 400 bool "IBM z16" 401 select HAVE_MARCH_Z16_FEATURES 402 depends on $(cc-option,-march=z16) 403 help 404 Select this to enable optimizations for IBM z16 (3931 and 405 3932 series). 406 407config MARCH_Z17 408 bool "IBM z17" 409 select HAVE_MARCH_Z17_FEATURES 410 depends on $(cc-option,-march=z17) 411 help 412 Select this to enable optimizations for IBM z17 (9175 and 413 9176 series). 414 415endchoice 416 417config MARCH_Z10_TUNE 418 def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT 419 420config MARCH_Z196_TUNE 421 def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT 422 423config MARCH_ZEC12_TUNE 424 def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT 425 426config MARCH_Z13_TUNE 427 def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT 428 429config MARCH_Z14_TUNE 430 def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT 431 432config MARCH_Z15_TUNE 433 def_bool TUNE_Z15 || MARCH_Z15 && TUNE_DEFAULT 434 435config MARCH_Z16_TUNE 436 def_bool TUNE_Z16 || MARCH_Z16 && TUNE_DEFAULT 437 438config MARCH_Z17_TUNE 439 def_bool TUNE_Z17 || MARCH_Z17 && TUNE_DEFAULT 440 441choice 442 prompt "Tune code generation" 443 default TUNE_DEFAULT 444 help 445 Cause the compiler to tune (-mtune) the generated code for a machine. 446 This will make the code run faster on the selected machine but 447 somewhat slower on other machines. 448 This option only changes how the compiler emits instructions, not the 449 selection of instructions itself, so the resulting kernel will run on 450 all other machines. 451 452config TUNE_DEFAULT 453 bool "Default" 454 help 455 Tune the generated code for the target processor for which the kernel 456 will be compiled. 457 458config TUNE_Z10 459 bool "IBM System z10" 460 461config TUNE_Z196 462 bool "IBM zEnterprise 114 and 196" 463 depends on $(cc-option,-mtune=z196) 464 465config TUNE_ZEC12 466 bool "IBM zBC12 and zEC12" 467 depends on $(cc-option,-mtune=zEC12) 468 469config TUNE_Z13 470 bool "IBM z13s and z13" 471 depends on $(cc-option,-mtune=z13) 472 473config TUNE_Z14 474 bool "IBM z14 ZR1 and z14" 475 depends on $(cc-option,-mtune=z14) 476 477config TUNE_Z15 478 bool "IBM z15" 479 depends on $(cc-option,-mtune=z15) 480 481config TUNE_Z16 482 bool "IBM z16" 483 depends on $(cc-option,-mtune=z16) 484 485config TUNE_Z17 486 bool "IBM z17" 487 depends on $(cc-option,-mtune=z17) 488 489endchoice 490 491config 64BIT 492 def_bool y 493 494config COMMAND_LINE_SIZE 495 int "Maximum size of kernel command line" 496 default 4096 497 range 896 1048576 498 help 499 This allows you to specify the maximum length of the kernel command 500 line. 501 502config COMPAT 503 def_bool n 504 prompt "Kernel support for 31 bit emulation" 505 select ARCH_WANT_OLD_COMPAT_IPC 506 select COMPAT_OLD_SIGACTION 507 select HAVE_UID16 508 depends on MULTIUSER 509 depends on !CC_IS_CLANG && !LD_IS_LLD 510 help 511 Select this option if you want to enable your system kernel to 512 handle system-calls from ELF binaries for 31 bit ESA. This option 513 (and some other stuff like libraries and such) is needed for 514 executing 31 bit applications. 515 516 If unsure say N. 517 518config SMP 519 def_bool y 520 521config NR_CPUS 522 int "Maximum number of CPUs (2-512)" 523 range 2 512 524 default "64" 525 help 526 This allows you to specify the maximum number of CPUs which this 527 kernel will support. The maximum supported value is 512 and the 528 minimum value which makes sense is 2. 529 530 This is purely to save memory - each supported CPU adds 531 approximately sixteen kilobytes to the kernel image. 532 533config HOTPLUG_CPU 534 def_bool y 535 536config NUMA 537 bool "NUMA support" 538 depends on SCHED_TOPOLOGY 539 default n 540 help 541 Enable NUMA support 542 543 This option adds NUMA support to the kernel. 544 545config NODES_SHIFT 546 int 547 depends on NUMA 548 default "1" 549 550config SCHED_SMT 551 def_bool n 552 553config SCHED_MC 554 def_bool n 555 556config SCHED_TOPOLOGY 557 def_bool y 558 prompt "Topology scheduler support" 559 select SCHED_SMT 560 select SCHED_MC 561 help 562 Topology scheduler support improves the CPU scheduler's decision 563 making when dealing with machines that have multi-threading, 564 multiple cores or multiple books. 565 566config SCHED_TOPOLOGY_VERTICAL 567 def_bool y 568 bool "Use vertical CPU polarization by default" 569 depends on SCHED_TOPOLOGY 570 help 571 Use vertical CPU polarization by default if available. 572 The default CPU polarization is horizontal. 573 574config HIPERDISPATCH_ON 575 def_bool y 576 bool "Use hiperdispatch on vertical polarization by default" 577 depends on SCHED_TOPOLOGY 578 depends on PROC_SYSCTL 579 help 580 Hiperdispatch aims to improve the CPU scheduler's decision 581 making when using vertical polarization by adjusting CPU 582 capacities dynamically. Set this option to use hiperdispatch 583 on vertical polarization by default. This can be overwritten 584 by sysctl's s390.hiperdispatch attribute later on. 585 586source "kernel/Kconfig.hz" 587 588config CERT_STORE 589 bool "Get user certificates via DIAG320" 590 depends on KEYS 591 select CRYPTO_LIB_SHA256 592 help 593 Enable this option if you want to access user-provided secure boot 594 certificates via DIAG 0x320. 595 596 These certificates will be made available via the keyring named 597 'cert_store'. 598 599config KERNEL_NOBP 600 def_bool n 601 prompt "Enable modified branch prediction for the kernel by default" 602 help 603 If this option is selected the kernel will switch to a modified 604 branch prediction mode if the firmware interface is available. 605 The modified branch prediction mode improves the behaviour in 606 regard to speculative execution. 607 608 With the option enabled the kernel parameter "nobp=0" or "nospec" 609 can be used to run the kernel in the normal branch prediction mode. 610 611 With the option disabled the modified branch prediction mode is 612 enabled with the "nobp=1" kernel parameter. 613 614 If unsure, say N. 615 616config EXPOLINE 617 def_bool n 618 depends on $(cc-option,-mindirect-branch=thunk) 619 prompt "Avoid speculative indirect branches in the kernel" 620 help 621 Compile the kernel with the expoline compiler options to guard 622 against kernel-to-user data leaks by avoiding speculative indirect 623 branches. 624 Requires a compiler with -mindirect-branch=thunk support for full 625 protection. The kernel may run slower. 626 627 If unsure, say N. 628 629config EXPOLINE_EXTERN 630 def_bool EXPOLINE && CC_IS_GCC && GCC_VERSION >= 110200 && \ 631 $(success,$(srctree)/arch/s390/tools/gcc-thunk-extern.sh $(CC)) 632 help 633 Generate expolines as external functions if the compiler supports it. 634 This option is required for some tooling like kpatch, if expolines 635 are enabled. The kernel is compiled with 636 -mindirect-branch=thunk-extern, which requires a newer compiler. 637 638choice 639 prompt "Expoline default" 640 depends on EXPOLINE 641 default EXPOLINE_FULL 642 643config EXPOLINE_OFF 644 bool "spectre_v2=off" 645 646config EXPOLINE_AUTO 647 bool "spectre_v2=auto" 648 649config EXPOLINE_FULL 650 bool "spectre_v2=on" 651 652endchoice 653 654config RELOCATABLE 655 def_bool y 656 select ARCH_VMLINUX_NEEDS_RELOCS 657 help 658 This builds a kernel image that retains relocation information 659 so it can be loaded at an arbitrary address. 660 The relocations make the kernel image about 15% larger (compressed 661 10%), but are discarded at runtime. 662 Note: this option exists only for documentation purposes, please do 663 not remove it. 664 665config RANDOMIZE_BASE 666 bool "Randomize the address of the kernel image (KASLR)" 667 default y 668 help 669 In support of Kernel Address Space Layout Randomization (KASLR), 670 this randomizes the address at which the kernel image is loaded, 671 as a security feature that deters exploit attempts relying on 672 knowledge of the location of kernel internals. 673 674config RANDOMIZE_IDENTITY_BASE 675 bool "Randomize the address of the identity mapping base" 676 depends on RANDOMIZE_BASE 677 default DEBUG_VM 678 help 679 The identity mapping base address is pinned to zero by default. 680 Allow randomization of that base to expose otherwise missed 681 notion of physical and virtual addresses of data structures. 682 That does not have any impact on the base address at which the 683 kernel image is loaded. 684 685 If unsure, say N 686 687config KERNEL_IMAGE_BASE 688 hex "Kernel image base address" 689 range 0x100000 0x1FFFFFE0000000 if !KASAN 690 range 0x100000 0x1BFFFFE0000000 if KASAN 691 default 0x3FFE0000000 if !KASAN 692 default 0x7FFFE0000000 if KASAN 693 help 694 This is the address at which the kernel image is loaded in case 695 Kernel Address Space Layout Randomization (KASLR) is disabled. 696 697 In case the Protected virtualization guest support is enabled the 698 Ultravisor imposes a virtual address limit. If the value of this 699 option leads to the kernel image exceeding the Ultravisor limit, 700 this option is ignored and the image is loaded below the limit. 701 702 If the value of this option leads to the kernel image overlapping 703 the virtual memory where other data structures are located, this 704 option is ignored and the image is loaded above the structures. 705 706endmenu 707 708menu "Memory setup" 709 710config ARCH_SPARSEMEM_ENABLE 711 def_bool y 712 select SPARSEMEM_VMEMMAP_ENABLE 713 714config ARCH_SPARSEMEM_DEFAULT 715 def_bool y 716 717config MAX_PHYSMEM_BITS 718 int "Maximum size of supported physical memory in bits (42-53)" 719 range 42 53 720 default "46" 721 help 722 This option specifies the maximum supported size of physical memory 723 in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB). 724 Increasing the number of bits also increases the kernel image size. 725 By default 46 bits (64TB) are supported. 726 727endmenu 728 729menu "I/O subsystem" 730 731config QDIO 732 def_tristate y 733 prompt "QDIO support" 734 help 735 This driver provides the Queued Direct I/O base support for 736 IBM System z. 737 738 To compile this driver as a module, choose M here: the 739 module will be called qdio. 740 741 If unsure, say Y. 742 743if PCI 744 745config PCI_NR_FUNCTIONS 746 int "Maximum number of PCI functions (1-4096)" 747 range 1 4096 748 default "512" 749 help 750 This allows you to specify the maximum number of PCI functions which 751 this kernel will support. 752 753endif # PCI 754 755config HAS_IOMEM 756 def_bool PCI 757 758config CHSC_SCH 759 def_tristate m 760 prompt "Support for CHSC subchannels" 761 help 762 This driver allows usage of CHSC subchannels. A CHSC subchannel 763 is usually present on LPAR only. 764 The driver creates a device /dev/chsc, which may be used to 765 obtain I/O configuration information about the machine and 766 to issue asynchronous chsc commands (DANGEROUS). 767 You will usually only want to use this interface on a special 768 LPAR designated for system management. 769 770 To compile this driver as a module, choose M here: the 771 module will be called chsc_sch. 772 773 If unsure, say N. 774 775config SCM_BUS 776 def_bool y 777 prompt "SCM bus driver" 778 help 779 Bus driver for Storage Class Memory. 780 781config EADM_SCH 782 def_tristate m 783 prompt "Support for EADM subchannels" 784 depends on SCM_BUS 785 help 786 This driver allows usage of EADM subchannels. EADM subchannels act 787 as a communication vehicle for SCM increments. 788 789 To compile this driver as a module, choose M here: the 790 module will be called eadm_sch. 791 792config AP 793 def_tristate y 794 prompt "Support for Adjunct Processors (ap)" 795 help 796 This driver allows usage to Adjunct Processor (AP) devices via 797 the ap bus, cards and queues. Supported Adjunct Processors are 798 the CryptoExpress Cards (CEX). 799 800 To compile this driver as a module, choose M here: the 801 module will be called ap. 802 803 If unsure, say Y (default). 804 805config AP_DEBUG 806 def_bool n 807 prompt "Enable debug features for Adjunct Processor (ap) devices" 808 depends on AP 809 help 810 Say 'Y' here to enable some additional debug features for Adjunct 811 Processor (ap) devices. 812 813 There will be some more sysfs attributes displayed for ap queues. 814 815 Do not enable on production level kernel build. 816 817 If unsure, say N. 818 819config VFIO_CCW 820 def_tristate n 821 prompt "Support for VFIO-CCW subchannels" 822 depends on VFIO 823 select VFIO_MDEV 824 help 825 This driver allows usage of I/O subchannels via VFIO-CCW. 826 827 To compile this driver as a module, choose M here: the 828 module will be called vfio_ccw. 829 830config VFIO_AP 831 def_tristate n 832 prompt "VFIO support for AP devices" 833 depends on KVM 834 depends on VFIO 835 depends on AP 836 select VFIO_MDEV 837 help 838 This driver grants access to Adjunct Processor (AP) devices 839 via the VFIO mediated device interface. 840 841 To compile this driver as a module, choose M here: the module 842 will be called vfio_ap. 843 844endmenu 845 846config CCW 847 def_bool y 848 849config HAVE_PNETID 850 tristate 851 default (SMC || CCWGROUP) 852 853menu "Virtualization" 854 855config PFAULT 856 def_bool y 857 prompt "Pseudo page fault support" 858 help 859 Select this option, if you want to use PFAULT pseudo page fault 860 handling under VM. If running native or in LPAR, this option 861 has no effect. If your VM does not support PFAULT, PAGEEX 862 pseudo page fault handling will be used. 863 Note that VM 4.2 supports PFAULT but has a bug in its 864 implementation that causes some problems. 865 Everybody who wants to run Linux under VM != VM4.2 should select 866 this option. 867 868config CMM 869 def_tristate n 870 prompt "Cooperative memory management" 871 help 872 Select this option, if you want to enable the kernel interface 873 to reduce the memory size of the system. This is accomplished 874 by allocating pages of memory and put them "on hold". This only 875 makes sense for a system running under VM where the unused pages 876 will be reused by VM for other guest systems. The interface 877 allows an external monitor to balance memory of many systems. 878 Everybody who wants to run Linux under VM should select this 879 option. 880 881config CMM_IUCV 882 def_bool y 883 prompt "IUCV special message interface to cooperative memory management" 884 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV) 885 help 886 Select this option to enable the special message interface to 887 the cooperative memory management. 888 889config APPLDATA_BASE 890 def_bool n 891 prompt "Linux - VM Monitor Stream, base infrastructure" 892 depends on PROC_SYSCTL 893 help 894 This provides a kernel interface for creating and updating z/VM APPLDATA 895 monitor records. The monitor records are updated at certain time 896 intervals, once the timer is started. 897 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer, 898 i.e. enables or disables monitoring on the Linux side. 899 A custom interval value (in seconds) can be written to 900 /proc/appldata/interval. 901 902 Defaults are 60 seconds interval and timer off. 903 The /proc entries can also be read from, showing the current settings. 904 905config APPLDATA_MEM 906 def_tristate m 907 prompt "Monitor memory management statistics" 908 depends on APPLDATA_BASE && VM_EVENT_COUNTERS 909 help 910 This provides memory management related data to the Linux - VM Monitor 911 Stream, like paging/swapping rate, memory utilisation, etc. 912 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM 913 APPLDATA monitor record, i.e. enables or disables monitoring this record 914 on the z/VM side. 915 916 Default is disabled. 917 The /proc entry can also be read from, showing the current settings. 918 919 This can also be compiled as a module, which will be called 920 appldata_mem.o. 921 922config APPLDATA_OS 923 def_tristate m 924 prompt "Monitor OS statistics" 925 depends on APPLDATA_BASE 926 help 927 This provides OS related data to the Linux - VM Monitor Stream, like 928 CPU utilisation, etc. 929 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM 930 APPLDATA monitor record, i.e. enables or disables monitoring this record 931 on the z/VM side. 932 933 Default is disabled. 934 This can also be compiled as a module, which will be called 935 appldata_os.o. 936 937config APPLDATA_NET_SUM 938 def_tristate m 939 prompt "Monitor overall network statistics" 940 depends on APPLDATA_BASE && NET 941 help 942 This provides network related data to the Linux - VM Monitor Stream, 943 currently there is only a total sum of network I/O statistics, no 944 per-interface data. 945 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM 946 APPLDATA monitor record, i.e. enables or disables monitoring this record 947 on the z/VM side. 948 949 Default is disabled. 950 This can also be compiled as a module, which will be called 951 appldata_net_sum.o. 952 953config S390_HYPFS 954 def_bool y 955 prompt "s390 hypervisor information" 956 help 957 This provides several binary files at (debugfs)/s390_hypfs/ to 958 provide accounting information in an s390 hypervisor environment. 959 960config S390_HYPFS_FS 961 def_bool n 962 prompt "s390 hypervisor file system support" 963 select SYS_HYPERVISOR 964 depends on S390_HYPFS 965 help 966 This is a virtual file system intended to provide accounting 967 information in an s390 hypervisor environment. This file system 968 is deprecated and should not be used. 969 970 Say N if you are unsure. 971 972source "arch/s390/kvm/Kconfig" 973 974config S390_GUEST 975 def_bool y 976 prompt "s390 support for virtio devices" 977 select TTY 978 select VIRTUALIZATION 979 select VIRTIO 980 help 981 Enabling this option adds support for virtio based paravirtual device 982 drivers on s390. 983 984 Select this option if you want to run the kernel as a guest under 985 the KVM hypervisor. 986 987endmenu 988 989config S390_MODULES_SANITY_TEST_HELPERS 990 def_bool n 991 992menu "Selftests" 993 994config S390_UNWIND_SELFTEST 995 def_tristate n 996 depends on KUNIT 997 default KUNIT_ALL_TESTS 998 prompt "Test unwind functions" 999 help 1000 This option enables s390 specific stack unwinder testing kernel 1001 module. This option is not useful for distributions or general 1002 kernels, but only for kernel developers working on architecture code. 1003 1004 Say N if you are unsure. 1005 1006config S390_KPROBES_SANITY_TEST 1007 def_tristate n 1008 prompt "Enable s390 specific kprobes tests" 1009 depends on KPROBES 1010 depends on KUNIT 1011 help 1012 This option enables an s390 specific kprobes test module. This option 1013 is not useful for distributions or general kernels, but only for kernel 1014 developers working on architecture code. 1015 1016 Say N if you are unsure. 1017 1018config S390_MODULES_SANITY_TEST 1019 def_tristate n 1020 depends on KUNIT 1021 default KUNIT_ALL_TESTS 1022 prompt "Enable s390 specific modules tests" 1023 select S390_MODULES_SANITY_TEST_HELPERS 1024 help 1025 This option enables an s390 specific modules test. This option is 1026 not useful for distributions or general kernels, but only for 1027 kernel developers working on architecture code. 1028 1029 Say N if you are unsure. 1030endmenu 1031