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