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 AUDIT_ARCH 33 def_bool y 34 35config NO_IOPORT_MAP 36 def_bool y 37 38config ARCH_SUPPORTS_UPROBES 39 def_bool y 40 41config KASAN_SHADOW_OFFSET 42 hex 43 depends on KASAN 44 default 0x1C000000000000 45 46config CC_HAS_BUILTIN_FFS 47 def_bool !(CC_IS_GCC && GCC_VERSION < 160000) 48 help 49 GCC versions before 16.0.0 generate library calls to ffs() 50 for __builtin_ffs() even when __has_builtin(__builtin_ffs) 51 is true. 52 53config CC_ASM_FLAG_OUTPUT_BROKEN 54 def_bool CC_IS_GCC && GCC_VERSION < 140200 55 help 56 GCC versions before 14.2.0 may die with an internal 57 compiler error in some configurations if flag output 58 operands are used within inline assemblies. 59 60config CC_HAS_ASM_AOR_FORMAT_FLAGS 61 def_bool !(CC_IS_CLANG && CLANG_VERSION < 190100) 62 help 63 Clang versions before 19.1.0 do not support A, 64 O, and R inline assembly format flags. 65 66config CC_HAS_ASM_IMMEDIATE_STRINGS 67 def_bool !(CC_IS_GCC && GCC_VERSION < 90000) 68 help 69 GCC versions before 9.0.0 cannot handle strings as immediate 70 input operands in inline assemblies. 71 72config CC_HAS_STACKPROTECTOR_GLOBAL 73 def_bool $(cc-option, -mstack-protector-guard=global -mstack-protector-guard-record) 74 75config S390 76 def_bool y 77 # 78 # Note: keep this list sorted alphabetically 79 # 80 select ALTERNATE_USER_ADDRESS_SPACE 81 select ARCH_32BIT_USTAT_F_TINODE 82 select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE 83 select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM 84 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 85 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE 86 select ARCH_HAS_CC_CAN_LINK 87 select ARCH_HAS_CPU_FINALIZE_INIT 88 select ARCH_HAS_CURRENT_STACK_POINTER 89 select ARCH_HAS_DEBUG_VIRTUAL 90 select ARCH_HAS_DEBUG_VM_PGTABLE 91 select ARCH_HAS_DEBUG_WX 92 select ARCH_HAS_DEVMEM_IS_ALLOWED 93 select ARCH_HAS_DMA_OPS if PCI 94 select ARCH_HAS_ELF_RANDOMIZE 95 select ARCH_HAS_FORCE_DMA_UNENCRYPTED 96 select ARCH_HAS_FORTIFY_SOURCE 97 select ARCH_HAS_GCOV_PROFILE_ALL 98 select ARCH_HAS_GIGANTIC_PAGE 99 select ARCH_HAS_KCOV 100 select ARCH_HAS_MEMBARRIER_SYNC_CORE 101 select ARCH_HAS_MEM_ENCRYPT 102 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS 103 select ARCH_HAS_PREEMPT_LAZY 104 select ARCH_HAS_PTDUMP 105 select ARCH_HAS_PTE_SPECIAL 106 select ARCH_HAS_SCALED_CPUTIME 107 select ARCH_HAS_SET_DIRECT_MAP 108 select ARCH_HAS_SET_MEMORY 109 select ARCH_HAS_STRICT_KERNEL_RWX 110 select ARCH_HAS_STRICT_MODULE_RWX 111 select ARCH_HAS_SYSCALL_WRAPPER 112 select ARCH_HAS_UBSAN 113 select ARCH_HAS_VDSO_TIME_DATA 114 select ARCH_HAVE_NMI_SAFE_CMPXCHG 115 select ARCH_HAVE_TRACE_MMIO_ACCESS 116 select ARCH_INLINE_READ_LOCK 117 select ARCH_INLINE_READ_LOCK_BH 118 select ARCH_INLINE_READ_LOCK_IRQ 119 select ARCH_INLINE_READ_LOCK_IRQSAVE 120 select ARCH_INLINE_READ_TRYLOCK 121 select ARCH_INLINE_READ_UNLOCK 122 select ARCH_INLINE_READ_UNLOCK_BH 123 select ARCH_INLINE_READ_UNLOCK_IRQ 124 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE 125 select ARCH_INLINE_SPIN_LOCK 126 select ARCH_INLINE_SPIN_LOCK_BH 127 select ARCH_INLINE_SPIN_LOCK_IRQ 128 select ARCH_INLINE_SPIN_LOCK_IRQSAVE 129 select ARCH_INLINE_SPIN_TRYLOCK 130 select ARCH_INLINE_SPIN_TRYLOCK_BH 131 select ARCH_INLINE_SPIN_UNLOCK 132 select ARCH_INLINE_SPIN_UNLOCK_BH 133 select ARCH_INLINE_SPIN_UNLOCK_IRQ 134 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE 135 select ARCH_INLINE_WRITE_LOCK 136 select ARCH_INLINE_WRITE_LOCK_BH 137 select ARCH_INLINE_WRITE_LOCK_IRQ 138 select ARCH_INLINE_WRITE_LOCK_IRQSAVE 139 select ARCH_INLINE_WRITE_TRYLOCK 140 select ARCH_INLINE_WRITE_UNLOCK 141 select ARCH_INLINE_WRITE_UNLOCK_BH 142 select ARCH_INLINE_WRITE_UNLOCK_IRQ 143 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE 144 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 145 select ARCH_STACKWALK 146 select ARCH_SUPPORTS_ATOMIC_RMW 147 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 148 select ARCH_SUPPORTS_HUGETLBFS 149 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && CC_IS_CLANG 150 select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS 151 select ARCH_SUPPORTS_NUMA_BALANCING 152 select ARCH_SUPPORTS_PAGE_TABLE_CHECK 153 select ARCH_SUPPORTS_PER_VMA_LOCK 154 select ARCH_USE_BUILTIN_BSWAP 155 select ARCH_USE_CMPXCHG_LOCKREF 156 select ARCH_USE_SYM_ANNOTATIONS 157 select ARCH_WANTS_NO_INSTR 158 select ARCH_WANT_DEFAULT_BPF_JIT 159 select ARCH_WANT_IPC_PARSE_VERSION 160 select ARCH_WANT_IRQS_OFF_ACTIVATE_MM 161 select ARCH_WANT_KERNEL_PMD_MKWRITE 162 select ARCH_WANT_LD_ORPHAN_WARN 163 select ARCH_WANTS_THP_SWAP 164 select BUILDTIME_TABLE_SORT 165 select CLONE_BACKWARDS2 166 select DYNAMIC_FTRACE if FUNCTION_TRACER 167 select FUNCTION_ALIGNMENT_8B if CC_IS_GCC 168 select FUNCTION_ALIGNMENT_16B if !CC_IS_GCC 169 select GENERIC_ALLOCATOR 170 select GENERIC_CPU_DEVICES 171 select GENERIC_CPU_AUTOPROBE 172 select GENERIC_CPU_VULNERABILITIES 173 select GENERIC_ENTRY 174 select GENERIC_GETTIMEOFDAY 175 select GENERIC_SMP_IDLE_THREAD 176 select GENERIC_IOREMAP if PCI 177 select GLOB 178 select HAVE_ALIGNED_STRUCT_PAGE 179 select HAVE_ARCH_AUDITSYSCALL 180 select HAVE_ARCH_GET_SECUREBOOT 181 select HAVE_ARCH_JUMP_LABEL 182 select HAVE_ARCH_JUMP_LABEL_RELATIVE 183 select HAVE_ARCH_KASAN 184 select HAVE_ARCH_KASAN_VMALLOC 185 select HAVE_ARCH_KCSAN 186 select HAVE_ARCH_KMSAN 187 select HAVE_ARCH_KFENCE 188 select HAVE_ARCH_KSTACK_ERASE 189 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 190 select HAVE_ARCH_SECCOMP_FILTER 191 select HAVE_ARCH_SOFT_DIRTY 192 select HAVE_ARCH_TRACEHOOK 193 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 194 select HAVE_ARCH_VMAP_STACK 195 select HAVE_ASM_MODVERSIONS 196 select HAVE_BUILDTIME_MCOUNT_SORT 197 select HAVE_CMPXCHG_DOUBLE 198 select HAVE_CMPXCHG_LOCAL 199 select HAVE_DEBUG_KMEMLEAK 200 select HAVE_DMA_CONTIGUOUS 201 select HAVE_DYNAMIC_FTRACE 202 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 203 select HAVE_FTRACE_REGS_HAVING_PT_REGS 204 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 205 select HAVE_DYNAMIC_FTRACE_WITH_REGS 206 select HAVE_EBPF_JIT if HAVE_MARCH_Z196_FEATURES 207 select HAVE_EFFICIENT_UNALIGNED_ACCESS 208 select HAVE_GENERIC_TIF_BITS 209 select HAVE_GUP_FAST 210 select HAVE_FENTRY 211 select HAVE_FTRACE_GRAPH_FUNC 212 select HAVE_FUNCTION_ARG_ACCESS_API 213 select HAVE_FUNCTION_ERROR_INJECTION 214 select HAVE_FUNCTION_GRAPH_FREGS 215 select HAVE_FUNCTION_GRAPH_TRACER 216 select HAVE_FUNCTION_TRACER 217 select HAVE_GCC_PLUGINS 218 select HAVE_GENERIC_VDSO 219 select HAVE_IOREMAP_PROT if PCI 220 select HAVE_KERNEL_BZIP2 221 select HAVE_KERNEL_GZIP 222 select HAVE_KERNEL_LZ4 223 select HAVE_KERNEL_LZMA 224 select HAVE_KERNEL_LZO 225 select HAVE_KERNEL_UNCOMPRESSED 226 select HAVE_KERNEL_XZ 227 select HAVE_KERNEL_ZSTD 228 select HAVE_KPROBES 229 select HAVE_KPROBES_ON_FTRACE 230 select HAVE_KRETPROBES 231 select HAVE_LIVEPATCH 232 select HAVE_MEMBLOCK_PHYS_MAP 233 select HAVE_MOD_ARCH_SPECIFIC 234 select HAVE_NMI 235 select HAVE_NOP_MCOUNT 236 select HAVE_PAGE_SIZE_4KB 237 select HAVE_PCI 238 select HAVE_PERF_EVENTS 239 select HAVE_PERF_REGS 240 select HAVE_PERF_USER_STACK_DUMP 241 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 242 select HAVE_PREEMPT_DYNAMIC_KEY 243 select HAVE_REGS_AND_STACK_ACCESS_API 244 select HAVE_RELIABLE_STACKTRACE 245 select HAVE_RETHOOK 246 select HAVE_RSEQ 247 select HAVE_RUST if !EXPOLINE 248 select HAVE_SAMPLE_FTRACE_DIRECT 249 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 250 select HAVE_SETUP_PER_CPU_AREA 251 select HAVE_SOFTIRQ_ON_OWN_STACK 252 select HAVE_STACKPROTECTOR if CC_HAS_STACKPROTECTOR_GLOBAL 253 select HAVE_SYSCALL_TRACEPOINTS 254 select HAVE_VIRT_CPU_ACCOUNTING 255 select HAVE_VIRT_CPU_ACCOUNTING_IDLE 256 select HOTPLUG_SMT 257 select IOMMU_HELPER if PCI 258 select IOMMU_SUPPORT if PCI 259 select IRQ_MSI_LIB if PCI 260 select KASAN_VMALLOC if KASAN 261 select LOCK_MM_AND_FIND_VMA 262 select MMU_GATHER_MERGE_VMAS 263 select MMU_GATHER_NO_GATHER 264 select MMU_GATHER_RCU_TABLE_FREE 265 select MODULES_USE_ELF_RELA 266 select NEED_DMA_MAP_STATE if PCI 267 select NEED_PER_CPU_EMBED_FIRST_CHUNK 268 select NEED_PROC_VMCORE_DEVICE_RAM if PROC_VMCORE 269 select NEED_SG_DMA_LENGTH if PCI 270 select OLD_SIGACTION 271 select OLD_SIGSUSPEND3 272 select PCI_DOMAINS if PCI 273 select PCI_MSI if PCI 274 select PCI_MSI_ARCH_FALLBACKS if PCI_MSI 275 select PCI_QUIRKS if PCI 276 select SPARSE_IRQ 277 select SWIOTLB 278 select SYSCTL_EXCEPTION_TRACE 279 select SYSTEM_DATA_VERIFICATION if KEXEC_SIG 280 select THREAD_INFO_IN_TASK 281 select TRACE_IRQFLAGS_SUPPORT 282 select TTY 283 select USER_STACKTRACE_SUPPORT 284 select VDSO_GETRANDOM 285 select VIRT_CPU_ACCOUNTING 286 select VMAP_STACK 287 select ZONE_DMA 288 # Note: keep the above list sorted alphabetically 289 290config SCHED_OMIT_FRAME_POINTER 291 def_bool y 292 293config PGTABLE_LEVELS 294 int 295 default 5 296 297source "kernel/livepatch/Kconfig" 298 299config ARCH_CC_CAN_LINK 300 bool 301 default $(cc_can_link_user,-m64) 302 303config ARCH_USERFLAGS 304 string 305 default "-m64" 306 307config ARCH_SUPPORTS_KEXEC 308 def_bool y 309 310config ARCH_SUPPORTS_KEXEC_FILE 311 def_bool y 312 313config ARCH_SUPPORTS_KEXEC_SIG 314 def_bool y 315 316config ARCH_SUPPORTS_KEXEC_PURGATORY 317 def_bool y 318 319config ARCH_SUPPORTS_CRASH_DUMP 320 def_bool y 321 help 322 Refer to <file:Documentation/arch/s390/zfcpdump.rst> for more details on this. 323 This option also enables s390 zfcpdump. 324 See also <file:Documentation/arch/s390/zfcpdump.rst> 325 326config ARCH_DEFAULT_CRASH_DUMP 327 def_bool y 328 329menu "Processor type and features" 330 331config HAVE_MARCH_Z10_FEATURES 332 def_bool n 333 334config HAVE_MARCH_Z196_FEATURES 335 def_bool n 336 select HAVE_MARCH_Z10_FEATURES 337 338config HAVE_MARCH_ZEC12_FEATURES 339 def_bool n 340 select HAVE_MARCH_Z196_FEATURES 341 342config HAVE_MARCH_Z13_FEATURES 343 def_bool n 344 select HAVE_MARCH_ZEC12_FEATURES 345 346config HAVE_MARCH_Z14_FEATURES 347 def_bool n 348 select HAVE_MARCH_Z13_FEATURES 349 350config HAVE_MARCH_Z15_FEATURES 351 def_bool n 352 select HAVE_MARCH_Z14_FEATURES 353 354config HAVE_MARCH_Z16_FEATURES 355 def_bool n 356 select HAVE_MARCH_Z15_FEATURES 357 358config HAVE_MARCH_Z17_FEATURES 359 def_bool n 360 select HAVE_MARCH_Z16_FEATURES 361 362choice 363 prompt "Processor type" 364 default MARCH_Z196 365 366config MARCH_Z10 367 bool "IBM System z10" 368 select HAVE_MARCH_Z10_FEATURES 369 depends on $(cc-option,-march=z10) 370 help 371 Select this to enable optimizations for IBM System z10 (2097 and 2098 372 series). This is the oldest machine generation currently supported. 373 374config MARCH_Z196 375 bool "IBM zEnterprise 114 and 196" 376 select HAVE_MARCH_Z196_FEATURES 377 depends on $(cc-option,-march=z196) 378 help 379 Select this to enable optimizations for IBM zEnterprise 114 and 196 380 (2818 and 2817 series). The kernel will be slightly faster but will 381 not work on older machines. 382 383config MARCH_ZEC12 384 bool "IBM zBC12 and zEC12" 385 select HAVE_MARCH_ZEC12_FEATURES 386 depends on $(cc-option,-march=zEC12) 387 help 388 Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and 389 2827 series). The kernel will be slightly faster but will not work on 390 older machines. 391 392config MARCH_Z13 393 bool "IBM z13s and z13" 394 select HAVE_MARCH_Z13_FEATURES 395 depends on $(cc-option,-march=z13) 396 help 397 Select this to enable optimizations for IBM z13s and z13 (2965 and 398 2964 series). The kernel will be slightly faster but will not work on 399 older machines. 400 401config MARCH_Z14 402 bool "IBM z14 ZR1 and z14" 403 select HAVE_MARCH_Z14_FEATURES 404 depends on $(cc-option,-march=z14) 405 help 406 Select this to enable optimizations for IBM z14 ZR1 and z14 (3907 407 and 3906 series). The kernel will be slightly faster but will not 408 work on older machines. 409 410config MARCH_Z15 411 bool "IBM z15" 412 select HAVE_MARCH_Z15_FEATURES 413 depends on $(cc-option,-march=z15) 414 help 415 Select this to enable optimizations for IBM z15 (8562 416 and 8561 series). The kernel will be slightly faster but will not 417 work on older machines. 418 419config MARCH_Z16 420 bool "IBM z16" 421 select HAVE_MARCH_Z16_FEATURES 422 depends on $(cc-option,-march=z16) 423 help 424 Select this to enable optimizations for IBM z16 (3931 and 425 3932 series). 426 427config MARCH_Z17 428 bool "IBM z17" 429 select HAVE_MARCH_Z17_FEATURES 430 depends on $(cc-option,-march=z17) 431 help 432 Select this to enable optimizations for IBM z17 (9175 and 433 9176 series). 434 435endchoice 436 437config MARCH_Z10_TUNE 438 def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT 439 440config MARCH_Z196_TUNE 441 def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT 442 443config MARCH_ZEC12_TUNE 444 def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT 445 446config MARCH_Z13_TUNE 447 def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT 448 449config MARCH_Z14_TUNE 450 def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT 451 452config MARCH_Z15_TUNE 453 def_bool TUNE_Z15 || MARCH_Z15 && TUNE_DEFAULT 454 455config MARCH_Z16_TUNE 456 def_bool TUNE_Z16 || MARCH_Z16 && TUNE_DEFAULT 457 458config MARCH_Z17_TUNE 459 def_bool TUNE_Z17 || MARCH_Z17 && TUNE_DEFAULT 460 461choice 462 prompt "Tune code generation" 463 default TUNE_DEFAULT 464 help 465 Cause the compiler to tune (-mtune) the generated code for a machine. 466 This will make the code run faster on the selected machine but 467 somewhat slower on other machines. 468 This option only changes how the compiler emits instructions, not the 469 selection of instructions itself, so the resulting kernel will run on 470 all other machines. 471 472config TUNE_DEFAULT 473 bool "Default" 474 help 475 Tune the generated code for the target processor for which the kernel 476 will be compiled. 477 478config TUNE_Z10 479 bool "IBM System z10" 480 481config TUNE_Z196 482 bool "IBM zEnterprise 114 and 196" 483 depends on $(cc-option,-mtune=z196) 484 485config TUNE_ZEC12 486 bool "IBM zBC12 and zEC12" 487 depends on $(cc-option,-mtune=zEC12) 488 489config TUNE_Z13 490 bool "IBM z13s and z13" 491 depends on $(cc-option,-mtune=z13) 492 493config TUNE_Z14 494 bool "IBM z14 ZR1 and z14" 495 depends on $(cc-option,-mtune=z14) 496 497config TUNE_Z15 498 bool "IBM z15" 499 depends on $(cc-option,-mtune=z15) 500 501config TUNE_Z16 502 bool "IBM z16" 503 depends on $(cc-option,-mtune=z16) 504 505config TUNE_Z17 506 bool "IBM z17" 507 depends on $(cc-option,-mtune=z17) 508 509endchoice 510 511config 64BIT 512 def_bool y 513 514config COMMAND_LINE_SIZE 515 int "Maximum size of kernel command line" 516 default 4096 517 range 896 1048576 518 help 519 This allows you to specify the maximum length of the kernel command 520 line. 521 522config SMP 523 def_bool y 524 525config NR_CPUS 526 int "Maximum number of CPUs (2-512)" 527 range 2 512 528 default "64" 529 help 530 This allows you to specify the maximum number of CPUs which this 531 kernel will support. The maximum supported value is 512 and the 532 minimum value which makes sense is 2. 533 534 This is purely to save memory - each supported CPU adds 535 approximately sixteen kilobytes to the kernel image. 536 537config HOTPLUG_CPU 538 def_bool y 539 540config NUMA 541 bool "NUMA support" 542 depends on SCHED_TOPOLOGY 543 default n 544 help 545 Enable NUMA support 546 547 This option adds NUMA support to the kernel. 548 549config NODES_SHIFT 550 int 551 depends on NUMA 552 default "1" 553 554config SCHED_TOPOLOGY 555 def_bool y 556 prompt "Topology scheduler support" 557 select ARCH_SUPPORTS_SCHED_SMT 558 select ARCH_SUPPORTS_SCHED_MC 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 ILLEGAL_POINTER_VALUE 718 hex 719 default 0xdead000000000000 720 721config MAX_PHYSMEM_BITS 722 int "Maximum size of supported physical memory in bits (42-53)" 723 range 42 53 724 default "46" 725 help 726 This option specifies the maximum supported size of physical memory 727 in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB). 728 Increasing the number of bits also increases the kernel image size. 729 By default 46 bits (64TB) are supported. 730 731endmenu 732 733menu "I/O subsystem" 734 735config QDIO 736 def_tristate y 737 prompt "QDIO support" 738 help 739 This driver provides the Queued Direct I/O base support for 740 IBM System z. 741 742 To compile this driver as a module, choose M here: the 743 module will be called qdio. 744 745 If unsure, say Y. 746 747if PCI 748 749config PCI_NR_FUNCTIONS 750 int "Maximum number of PCI functions (1-4096)" 751 range 1 4096 752 default "512" 753 help 754 This allows you to specify the maximum number of PCI functions which 755 this kernel will support. 756 757endif # PCI 758 759config HAS_IOMEM 760 def_bool PCI 761 762config CHSC_SCH 763 def_tristate m 764 prompt "Support for CHSC subchannels" 765 help 766 This driver allows usage of CHSC subchannels. A CHSC subchannel 767 is usually present on LPAR only. 768 The driver creates a device /dev/chsc, which may be used to 769 obtain I/O configuration information about the machine and 770 to issue asynchronous chsc commands (DANGEROUS). 771 You will usually only want to use this interface on a special 772 LPAR designated for system management. 773 774 To compile this driver as a module, choose M here: the 775 module will be called chsc_sch. 776 777 If unsure, say N. 778 779config SCM_BUS 780 def_bool y 781 prompt "SCM bus driver" 782 help 783 Bus driver for Storage Class Memory. 784 785config EADM_SCH 786 def_tristate m 787 prompt "Support for EADM subchannels" 788 depends on SCM_BUS 789 help 790 This driver allows usage of EADM subchannels. EADM subchannels act 791 as a communication vehicle for SCM increments. 792 793 To compile this driver as a module, choose M here: the 794 module will be called eadm_sch. 795 796config AP 797 def_tristate y 798 prompt "Support for Adjunct Processors (ap)" 799 help 800 This driver allows usage to Adjunct Processor (AP) devices via 801 the ap bus, cards and queues. Supported Adjunct Processors are 802 the CryptoExpress Cards (CEX). 803 804 To compile this driver as a module, choose M here: the 805 module will be called ap. 806 807 If unsure, say Y (default). 808 809config AP_DEBUG 810 def_bool n 811 prompt "Enable debug features for Adjunct Processor (ap) devices" 812 depends on AP 813 help 814 Say 'Y' here to enable some additional debug features for Adjunct 815 Processor (ap) devices. 816 817 There will be some more sysfs attributes displayed for ap queues. 818 819 Do not enable on production level kernel build. 820 821 If unsure, say N. 822 823config VFIO_CCW 824 def_tristate n 825 prompt "Support for VFIO-CCW subchannels" 826 depends on VFIO 827 select VFIO_MDEV 828 help 829 This driver allows usage of I/O subchannels via VFIO-CCW. 830 831 To compile this driver as a module, choose M here: the 832 module will be called vfio_ccw. 833 834config VFIO_AP 835 def_tristate n 836 prompt "VFIO support for AP devices" 837 depends on KVM 838 depends on VFIO 839 depends on AP 840 select VFIO_MDEV 841 help 842 This driver grants access to Adjunct Processor (AP) devices 843 via the VFIO mediated device interface. 844 845 To compile this driver as a module, choose M here: the module 846 will be called vfio_ap. 847 848endmenu 849 850config CCW 851 def_bool y 852 853config HAVE_PNETID 854 tristate 855 default (SMC || CCWGROUP) 856 857menu "Virtualization" 858 859config PFAULT 860 def_bool y 861 prompt "Pseudo page fault support" 862 help 863 Select this option, if you want to use PFAULT pseudo page fault 864 handling under VM. If running native or in LPAR, this option 865 has no effect. If your VM does not support PFAULT, PAGEEX 866 pseudo page fault handling will be used. 867 Note that VM 4.2 supports PFAULT but has a bug in its 868 implementation that causes some problems. 869 Everybody who wants to run Linux under VM != VM4.2 should select 870 this option. 871 872config CMM 873 def_tristate n 874 prompt "Cooperative memory management" 875 help 876 Select this option, if you want to enable the kernel interface 877 to reduce the memory size of the system. This is accomplished 878 by allocating pages of memory and put them "on hold". This only 879 makes sense for a system running under VM where the unused pages 880 will be reused by VM for other guest systems. The interface 881 allows an external monitor to balance memory of many systems. 882 Everybody who wants to run Linux under VM should select this 883 option. 884 885config CMM_IUCV 886 def_bool y 887 prompt "IUCV special message interface to cooperative memory management" 888 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV) 889 help 890 Select this option to enable the special message interface to 891 the cooperative memory management. 892 893config APPLDATA_BASE 894 def_bool n 895 prompt "Linux - VM Monitor Stream, base infrastructure" 896 depends on PROC_SYSCTL 897 help 898 This provides a kernel interface for creating and updating z/VM APPLDATA 899 monitor records. The monitor records are updated at certain time 900 intervals, once the timer is started. 901 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer, 902 i.e. enables or disables monitoring on the Linux side. 903 A custom interval value (in seconds) can be written to 904 /proc/appldata/interval. 905 906 Defaults are 60 seconds interval and timer off. 907 The /proc entries can also be read from, showing the current settings. 908 909config APPLDATA_MEM 910 def_tristate m 911 prompt "Monitor memory management statistics" 912 depends on APPLDATA_BASE && VM_EVENT_COUNTERS 913 help 914 This provides memory management related data to the Linux - VM Monitor 915 Stream, like paging/swapping rate, memory utilisation, etc. 916 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM 917 APPLDATA monitor record, i.e. enables or disables monitoring this record 918 on the z/VM side. 919 920 Default is disabled. 921 The /proc entry can also be read from, showing the current settings. 922 923 This can also be compiled as a module, which will be called 924 appldata_mem.o. 925 926config APPLDATA_OS 927 def_tristate m 928 prompt "Monitor OS statistics" 929 depends on APPLDATA_BASE 930 help 931 This provides OS related data to the Linux - VM Monitor Stream, like 932 CPU utilisation, etc. 933 Writing 1 or 0 to /proc/appldata/os 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_os.o. 940 941config APPLDATA_NET_SUM 942 def_tristate m 943 prompt "Monitor overall network statistics" 944 depends on APPLDATA_BASE && NET 945 help 946 This provides network related data to the Linux - VM Monitor Stream, 947 currently there is only a total sum of network I/O statistics, no 948 per-interface data. 949 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM 950 APPLDATA monitor record, i.e. enables or disables monitoring this record 951 on the z/VM side. 952 953 Default is disabled. 954 This can also be compiled as a module, which will be called 955 appldata_net_sum.o. 956 957config S390_HYPFS 958 def_bool y 959 prompt "s390 hypervisor information" 960 help 961 This provides several binary files at (debugfs)/s390_hypfs/ to 962 provide accounting information in an s390 hypervisor environment. 963 964config S390_HYPFS_FS 965 def_bool n 966 prompt "s390 hypervisor file system support" 967 select SYS_HYPERVISOR 968 depends on S390_HYPFS 969 help 970 This is a virtual file system intended to provide accounting 971 information in an s390 hypervisor environment. This file system 972 is deprecated and should not be used. 973 974 Say N if you are unsure. 975 976source "arch/s390/kvm/Kconfig" 977 978config S390_GUEST 979 def_bool y 980 prompt "s390 support for virtio devices" 981 select TTY 982 select VIRTUALIZATION 983 select VIRTIO 984 help 985 Enabling this option adds support for virtio based paravirtual device 986 drivers on s390. 987 988 Select this option if you want to run the kernel as a guest under 989 the KVM hypervisor. 990 991endmenu 992 993config S390_MODULES_SANITY_TEST_HELPERS 994 def_bool n 995 996menu "Selftests" 997 998config S390_UNWIND_SELFTEST 999 def_tristate KUNIT_ALL_TESTS 1000 depends on KUNIT 1001 prompt "Test unwind functions" 1002 help 1003 This option enables s390 specific stack unwinder testing kernel 1004 module. This option is not useful for distributions or general 1005 kernels, but only for kernel developers working on architecture code. 1006 1007 Say N if you are unsure. 1008 1009config S390_KPROBES_SANITY_TEST 1010 def_tristate KUNIT_ALL_TESTS 1011 prompt "Enable s390 specific kprobes tests" 1012 depends on KPROBES 1013 depends on KUNIT 1014 help 1015 This option enables an s390 specific kprobes test module. This option 1016 is not useful for distributions or general kernels, but only for kernel 1017 developers working on architecture code. 1018 1019 Say N if you are unsure. 1020 1021config S390_MODULES_SANITY_TEST 1022 def_tristate KUNIT_ALL_TESTS 1023 depends on KUNIT && m 1024 prompt "Enable s390 specific modules tests" 1025 select S390_MODULES_SANITY_TEST_HELPERS 1026 help 1027 This option enables an s390 specific modules test. This option is 1028 not useful for distributions or general kernels, but only for 1029 kernel developers working on architecture code. 1030 1031 Say N if you are unsure. 1032endmenu 1033