1# SPDX-License-Identifier: GPL-2.0 2config MMU 3 def_bool y 4 5config CPU_BIG_ENDIAN 6 def_bool y 7 8config LOCKDEP_SUPPORT 9 def_bool y 10 11config STACKTRACE_SUPPORT 12 def_bool y 13 14config ARCH_HAS_ILOG2_U32 15 def_bool n 16 17config ARCH_HAS_ILOG2_U64 18 def_bool n 19 20config ARCH_PROC_KCORE_TEXT 21 def_bool y 22 23config GENERIC_HWEIGHT 24 def_bool !HAVE_MARCH_Z196_FEATURES 25 26config GENERIC_BUG 27 def_bool y if BUG 28 29config GENERIC_BUG_RELATIVE_POINTERS 30 def_bool y 31 32config GENERIC_LOCKBREAK 33 def_bool y if PREEMPTION 34 35config PGSTE 36 def_bool y if KVM 37 38config AUDIT_ARCH 39 def_bool y 40 41config NO_IOPORT_MAP 42 def_bool y 43 44config PCI_QUIRKS 45 def_bool n 46 47config ARCH_SUPPORTS_UPROBES 48 def_bool y 49 50config KASAN_SHADOW_OFFSET 51 hex 52 depends on KASAN 53 default 0x1C000000000000 54 55config GCC_ASM_FLAG_OUTPUT_BROKEN 56 def_bool CC_IS_GCC && GCC_VERSION < 140200 57 help 58 GCC versions before 14.2.0 may die with an internal 59 compiler error in some configurations if flag output 60 operands are used within inline assemblies. 61 62config S390 63 def_bool y 64 # 65 # Note: keep this list sorted alphabetically 66 # 67 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 68 select ALTERNATE_USER_ADDRESS_SPACE 69 select ARCH_32BIT_USTAT_F_TINODE 70 select ARCH_BINFMT_ELF_STATE 71 select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE 72 select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM 73 select ARCH_ENABLE_MEMORY_HOTREMOVE 74 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 75 select ARCH_HAS_CRC32 76 select ARCH_HAS_CURRENT_STACK_POINTER 77 select ARCH_HAS_DEBUG_VIRTUAL 78 select ARCH_HAS_DEBUG_VM_PGTABLE 79 select ARCH_HAS_DEBUG_WX 80 select ARCH_HAS_DEVMEM_IS_ALLOWED 81 select ARCH_HAS_DMA_OPS if PCI 82 select ARCH_HAS_ELF_RANDOMIZE 83 select ARCH_HAS_FORCE_DMA_UNENCRYPTED 84 select ARCH_HAS_FORTIFY_SOURCE 85 select ARCH_HAS_GCOV_PROFILE_ALL 86 select ARCH_HAS_GIGANTIC_PAGE 87 select ARCH_HAS_KCOV 88 select ARCH_HAS_MEMBARRIER_SYNC_CORE 89 select ARCH_HAS_MEM_ENCRYPT 90 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS 91 select ARCH_HAS_PREEMPT_LAZY 92 select ARCH_HAS_PTE_SPECIAL 93 select ARCH_HAS_SCALED_CPUTIME 94 select ARCH_HAS_SET_DIRECT_MAP 95 select ARCH_HAS_SET_MEMORY 96 select ARCH_HAS_STRICT_KERNEL_RWX 97 select ARCH_HAS_STRICT_MODULE_RWX 98 select ARCH_HAS_SYSCALL_WRAPPER 99 select ARCH_HAS_UBSAN 100 select ARCH_HAS_VDSO_TIME_DATA 101 select ARCH_HAVE_NMI_SAFE_CMPXCHG 102 select ARCH_INLINE_READ_LOCK 103 select ARCH_INLINE_READ_LOCK_BH 104 select ARCH_INLINE_READ_LOCK_IRQ 105 select ARCH_INLINE_READ_LOCK_IRQSAVE 106 select ARCH_INLINE_READ_TRYLOCK 107 select ARCH_INLINE_READ_UNLOCK 108 select ARCH_INLINE_READ_UNLOCK_BH 109 select ARCH_INLINE_READ_UNLOCK_IRQ 110 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE 111 select ARCH_INLINE_SPIN_LOCK 112 select ARCH_INLINE_SPIN_LOCK_BH 113 select ARCH_INLINE_SPIN_LOCK_IRQ 114 select ARCH_INLINE_SPIN_LOCK_IRQSAVE 115 select ARCH_INLINE_SPIN_TRYLOCK 116 select ARCH_INLINE_SPIN_TRYLOCK_BH 117 select ARCH_INLINE_SPIN_UNLOCK 118 select ARCH_INLINE_SPIN_UNLOCK_BH 119 select ARCH_INLINE_SPIN_UNLOCK_IRQ 120 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE 121 select ARCH_INLINE_WRITE_LOCK 122 select ARCH_INLINE_WRITE_LOCK_BH 123 select ARCH_INLINE_WRITE_LOCK_IRQ 124 select ARCH_INLINE_WRITE_LOCK_IRQSAVE 125 select ARCH_INLINE_WRITE_TRYLOCK 126 select ARCH_INLINE_WRITE_UNLOCK 127 select ARCH_INLINE_WRITE_UNLOCK_BH 128 select ARCH_INLINE_WRITE_UNLOCK_IRQ 129 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE 130 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 131 select ARCH_STACKWALK 132 select ARCH_SUPPORTS_ATOMIC_RMW 133 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 134 select ARCH_SUPPORTS_HUGETLBFS 135 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && CC_IS_CLANG 136 select ARCH_SUPPORTS_NUMA_BALANCING 137 select ARCH_SUPPORTS_PER_VMA_LOCK 138 select ARCH_USE_BUILTIN_BSWAP 139 select ARCH_USE_CMPXCHG_LOCKREF 140 select ARCH_USE_SYM_ANNOTATIONS 141 select ARCH_WANTS_NO_INSTR 142 select ARCH_WANT_DEFAULT_BPF_JIT 143 select ARCH_WANT_IPC_PARSE_VERSION 144 select ARCH_WANT_KERNEL_PMD_MKWRITE 145 select ARCH_WANT_LD_ORPHAN_WARN 146 select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP 147 select BUILDTIME_TABLE_SORT 148 select CLONE_BACKWARDS2 149 select DCACHE_WORD_ACCESS if !KMSAN 150 select DYNAMIC_FTRACE if FUNCTION_TRACER 151 select FUNCTION_ALIGNMENT_8B if CC_IS_GCC 152 select FUNCTION_ALIGNMENT_16B if !CC_IS_GCC 153 select GENERIC_ALLOCATOR 154 select GENERIC_CPU_DEVICES 155 select GENERIC_CPU_AUTOPROBE 156 select GENERIC_CPU_VULNERABILITIES 157 select GENERIC_ENTRY 158 select GENERIC_GETTIMEOFDAY 159 select GENERIC_PTDUMP 160 select GENERIC_SMP_IDLE_THREAD 161 select GENERIC_TIME_VSYSCALL 162 select GENERIC_VDSO_TIME_NS 163 select GENERIC_IOREMAP if PCI 164 select HAVE_ALIGNED_STRUCT_PAGE 165 select HAVE_ARCH_AUDITSYSCALL 166 select HAVE_ARCH_JUMP_LABEL 167 select HAVE_ARCH_JUMP_LABEL_RELATIVE 168 select HAVE_ARCH_KASAN 169 select HAVE_ARCH_KASAN_VMALLOC 170 select HAVE_ARCH_KCSAN 171 select HAVE_ARCH_KMSAN 172 select HAVE_ARCH_KFENCE 173 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 174 select HAVE_ARCH_SECCOMP_FILTER 175 select HAVE_ARCH_SOFT_DIRTY 176 select HAVE_ARCH_STACKLEAK 177 select HAVE_ARCH_TRACEHOOK 178 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 179 select HAVE_ARCH_VMAP_STACK 180 select HAVE_ASM_MODVERSIONS 181 select HAVE_CMPXCHG_DOUBLE 182 select HAVE_CMPXCHG_LOCAL 183 select HAVE_DEBUG_KMEMLEAK 184 select HAVE_DMA_CONTIGUOUS 185 select HAVE_DYNAMIC_FTRACE 186 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 187 select HAVE_FTRACE_REGS_HAVING_PT_REGS 188 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 189 select HAVE_DYNAMIC_FTRACE_WITH_REGS 190 select HAVE_EBPF_JIT if HAVE_MARCH_Z196_FEATURES 191 select HAVE_EFFICIENT_UNALIGNED_ACCESS 192 select HAVE_GUP_FAST 193 select HAVE_FENTRY 194 select HAVE_FTRACE_GRAPH_FUNC 195 select HAVE_FTRACE_MCOUNT_RECORD 196 select HAVE_FUNCTION_ARG_ACCESS_API 197 select HAVE_FUNCTION_ERROR_INJECTION 198 select HAVE_FUNCTION_GRAPH_FREGS 199 select HAVE_FUNCTION_GRAPH_TRACER 200 select HAVE_FUNCTION_TRACER 201 select HAVE_GCC_PLUGINS 202 select HAVE_GENERIC_VDSO 203 select HAVE_IOREMAP_PROT if PCI 204 select HAVE_KERNEL_BZIP2 205 select HAVE_KERNEL_GZIP 206 select HAVE_KERNEL_LZ4 207 select HAVE_KERNEL_LZMA 208 select HAVE_KERNEL_LZO 209 select HAVE_KERNEL_UNCOMPRESSED 210 select HAVE_KERNEL_XZ 211 select HAVE_KERNEL_ZSTD 212 select HAVE_KPROBES 213 select HAVE_KPROBES_ON_FTRACE 214 select HAVE_KRETPROBES 215 select HAVE_LIVEPATCH 216 select HAVE_MEMBLOCK_PHYS_MAP 217 select HAVE_MOD_ARCH_SPECIFIC 218 select HAVE_NMI 219 select HAVE_NOP_MCOUNT 220 select HAVE_PAGE_SIZE_4KB 221 select HAVE_PCI 222 select HAVE_PERF_EVENTS 223 select HAVE_PERF_REGS 224 select HAVE_PERF_USER_STACK_DUMP 225 select HAVE_PREEMPT_DYNAMIC_KEY 226 select HAVE_REGS_AND_STACK_ACCESS_API 227 select HAVE_RELIABLE_STACKTRACE 228 select HAVE_RETHOOK 229 select HAVE_RSEQ 230 select HAVE_SAMPLE_FTRACE_DIRECT 231 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 232 select HAVE_SETUP_PER_CPU_AREA 233 select HAVE_SOFTIRQ_ON_OWN_STACK 234 select HAVE_SYSCALL_TRACEPOINTS 235 select HAVE_VIRT_CPU_ACCOUNTING 236 select HAVE_VIRT_CPU_ACCOUNTING_IDLE 237 select IOMMU_HELPER if PCI 238 select IOMMU_SUPPORT if PCI 239 select KASAN_VMALLOC if KASAN 240 select LOCK_MM_AND_FIND_VMA 241 select MMU_GATHER_MERGE_VMAS 242 select MMU_GATHER_NO_GATHER 243 select MMU_GATHER_RCU_TABLE_FREE 244 select MODULES_USE_ELF_RELA 245 select NEED_DMA_MAP_STATE if PCI 246 select NEED_PER_CPU_EMBED_FIRST_CHUNK 247 select NEED_PROC_VMCORE_DEVICE_RAM if PROC_VMCORE 248 select NEED_SG_DMA_LENGTH if PCI 249 select OLD_SIGACTION 250 select OLD_SIGSUSPEND3 251 select PCI_DOMAINS if PCI 252 select PCI_MSI if PCI 253 select PCI_MSI_ARCH_FALLBACKS if PCI_MSI 254 select SPARSE_IRQ 255 select SWIOTLB 256 select SYSCTL_EXCEPTION_TRACE 257 select THREAD_INFO_IN_TASK 258 select TRACE_IRQFLAGS_SUPPORT 259 select TTY 260 select USER_STACKTRACE_SUPPORT 261 select VDSO_GETRANDOM 262 select VIRT_CPU_ACCOUNTING 263 select VMAP_STACK 264 select ZONE_DMA 265 # Note: keep the above list sorted alphabetically 266 267config SCHED_OMIT_FRAME_POINTER 268 def_bool y 269 270config PGTABLE_LEVELS 271 int 272 default 5 273 274source "kernel/livepatch/Kconfig" 275 276config ARCH_SUPPORTS_KEXEC 277 def_bool y 278 279config ARCH_SUPPORTS_KEXEC_FILE 280 def_bool y 281 282config ARCH_SUPPORTS_KEXEC_SIG 283 def_bool MODULE_SIG_FORMAT 284 285config ARCH_SUPPORTS_KEXEC_PURGATORY 286 def_bool y 287 288config ARCH_SUPPORTS_CRASH_DUMP 289 def_bool y 290 help 291 Refer to <file:Documentation/arch/s390/zfcpdump.rst> for more details on this. 292 This option also enables s390 zfcpdump. 293 See also <file:Documentation/arch/s390/zfcpdump.rst> 294 295config ARCH_DEFAULT_CRASH_DUMP 296 def_bool y 297 298menu "Processor type and features" 299 300config HAVE_MARCH_Z10_FEATURES 301 def_bool n 302 303config HAVE_MARCH_Z196_FEATURES 304 def_bool n 305 select HAVE_MARCH_Z10_FEATURES 306 307config HAVE_MARCH_ZEC12_FEATURES 308 def_bool n 309 select HAVE_MARCH_Z196_FEATURES 310 311config HAVE_MARCH_Z13_FEATURES 312 def_bool n 313 select HAVE_MARCH_ZEC12_FEATURES 314 315config HAVE_MARCH_Z14_FEATURES 316 def_bool n 317 select HAVE_MARCH_Z13_FEATURES 318 319config HAVE_MARCH_Z15_FEATURES 320 def_bool n 321 select HAVE_MARCH_Z14_FEATURES 322 323config HAVE_MARCH_Z16_FEATURES 324 def_bool n 325 select HAVE_MARCH_Z15_FEATURES 326 327choice 328 prompt "Processor type" 329 default MARCH_Z196 330 331config MARCH_Z10 332 bool "IBM System z10" 333 select HAVE_MARCH_Z10_FEATURES 334 depends on $(cc-option,-march=z10) 335 help 336 Select this to enable optimizations for IBM System z10 (2097 and 2098 337 series). This is the oldest machine generation currently supported. 338 339config MARCH_Z196 340 bool "IBM zEnterprise 114 and 196" 341 select HAVE_MARCH_Z196_FEATURES 342 depends on $(cc-option,-march=z196) 343 help 344 Select this to enable optimizations for IBM zEnterprise 114 and 196 345 (2818 and 2817 series). The kernel will be slightly faster but will 346 not work on older machines. 347 348config MARCH_ZEC12 349 bool "IBM zBC12 and zEC12" 350 select HAVE_MARCH_ZEC12_FEATURES 351 depends on $(cc-option,-march=zEC12) 352 help 353 Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and 354 2827 series). The kernel will be slightly faster but will not work on 355 older machines. 356 357config MARCH_Z13 358 bool "IBM z13s and z13" 359 select HAVE_MARCH_Z13_FEATURES 360 depends on $(cc-option,-march=z13) 361 help 362 Select this to enable optimizations for IBM z13s and z13 (2965 and 363 2964 series). The kernel will be slightly faster but will not work on 364 older machines. 365 366config MARCH_Z14 367 bool "IBM z14 ZR1 and z14" 368 select HAVE_MARCH_Z14_FEATURES 369 depends on $(cc-option,-march=z14) 370 help 371 Select this to enable optimizations for IBM z14 ZR1 and z14 (3907 372 and 3906 series). The kernel will be slightly faster but will not 373 work on older machines. 374 375config MARCH_Z15 376 bool "IBM z15" 377 select HAVE_MARCH_Z15_FEATURES 378 depends on $(cc-option,-march=z15) 379 help 380 Select this to enable optimizations for IBM z15 (8562 381 and 8561 series). The kernel will be slightly faster but will not 382 work on older machines. 383 384config MARCH_Z16 385 bool "IBM z16" 386 select HAVE_MARCH_Z16_FEATURES 387 depends on $(cc-option,-march=z16) 388 help 389 Select this to enable optimizations for IBM z16 (3931 and 390 3932 series). 391 392endchoice 393 394config MARCH_Z10_TUNE 395 def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT 396 397config MARCH_Z196_TUNE 398 def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT 399 400config MARCH_ZEC12_TUNE 401 def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT 402 403config MARCH_Z13_TUNE 404 def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT 405 406config MARCH_Z14_TUNE 407 def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT 408 409config MARCH_Z15_TUNE 410 def_bool TUNE_Z15 || MARCH_Z15 && TUNE_DEFAULT 411 412config MARCH_Z16_TUNE 413 def_bool TUNE_Z16 || MARCH_Z16 && TUNE_DEFAULT 414 415choice 416 prompt "Tune code generation" 417 default TUNE_DEFAULT 418 help 419 Cause the compiler to tune (-mtune) the generated code for a machine. 420 This will make the code run faster on the selected machine but 421 somewhat slower on other machines. 422 This option only changes how the compiler emits instructions, not the 423 selection of instructions itself, so the resulting kernel will run on 424 all other machines. 425 426config TUNE_DEFAULT 427 bool "Default" 428 help 429 Tune the generated code for the target processor for which the kernel 430 will be compiled. 431 432config TUNE_Z10 433 bool "IBM System z10" 434 435config TUNE_Z196 436 bool "IBM zEnterprise 114 and 196" 437 depends on $(cc-option,-mtune=z196) 438 439config TUNE_ZEC12 440 bool "IBM zBC12 and zEC12" 441 depends on $(cc-option,-mtune=zEC12) 442 443config TUNE_Z13 444 bool "IBM z13s and z13" 445 depends on $(cc-option,-mtune=z13) 446 447config TUNE_Z14 448 bool "IBM z14 ZR1 and z14" 449 depends on $(cc-option,-mtune=z14) 450 451config TUNE_Z15 452 bool "IBM z15" 453 depends on $(cc-option,-mtune=z15) 454 455config TUNE_Z16 456 bool "IBM z16" 457 depends on $(cc-option,-mtune=z16) 458 459endchoice 460 461config 64BIT 462 def_bool y 463 464config COMMAND_LINE_SIZE 465 int "Maximum size of kernel command line" 466 default 4096 467 range 896 1048576 468 help 469 This allows you to specify the maximum length of the kernel command 470 line. 471 472config COMPAT 473 def_bool n 474 prompt "Kernel support for 31 bit emulation" 475 select ARCH_WANT_OLD_COMPAT_IPC 476 select COMPAT_OLD_SIGACTION 477 select HAVE_UID16 478 depends on MULTIUSER 479 depends on !CC_IS_CLANG && !LD_IS_LLD 480 help 481 Select this option if you want to enable your system kernel to 482 handle system-calls from ELF binaries for 31 bit ESA. This option 483 (and some other stuff like libraries and such) is needed for 484 executing 31 bit applications. 485 486 If unsure say N. 487 488config SMP 489 def_bool y 490 491config NR_CPUS 492 int "Maximum number of CPUs (2-512)" 493 range 2 512 494 default "64" 495 help 496 This allows you to specify the maximum number of CPUs which this 497 kernel will support. The maximum supported value is 512 and the 498 minimum value which makes sense is 2. 499 500 This is purely to save memory - each supported CPU adds 501 approximately sixteen kilobytes to the kernel image. 502 503config HOTPLUG_CPU 504 def_bool y 505 506config NUMA 507 bool "NUMA support" 508 depends on SCHED_TOPOLOGY 509 default n 510 help 511 Enable NUMA support 512 513 This option adds NUMA support to the kernel. 514 515config NODES_SHIFT 516 int 517 depends on NUMA 518 default "1" 519 520config SCHED_SMT 521 def_bool n 522 523config SCHED_MC 524 def_bool n 525 526config SCHED_TOPOLOGY 527 def_bool y 528 prompt "Topology scheduler support" 529 select SCHED_SMT 530 select SCHED_MC 531 help 532 Topology scheduler support improves the CPU scheduler's decision 533 making when dealing with machines that have multi-threading, 534 multiple cores or multiple books. 535 536config SCHED_TOPOLOGY_VERTICAL 537 def_bool y 538 bool "Use vertical CPU polarization by default" 539 depends on SCHED_TOPOLOGY 540 help 541 Use vertical CPU polarization by default if available. 542 The default CPU polarization is horizontal. 543 544config HIPERDISPATCH_ON 545 def_bool y 546 bool "Use hiperdispatch on vertical polarization by default" 547 depends on SCHED_TOPOLOGY 548 depends on PROC_SYSCTL 549 help 550 Hiperdispatch aims to improve the CPU scheduler's decision 551 making when using vertical polarization by adjusting CPU 552 capacities dynamically. Set this option to use hiperdispatch 553 on vertical polarization by default. This can be overwritten 554 by sysctl's s390.hiperdispatch attribute later on. 555 556source "kernel/Kconfig.hz" 557 558config CERT_STORE 559 bool "Get user certificates via DIAG320" 560 depends on KEYS 561 select CRYPTO_LIB_SHA256 562 help 563 Enable this option if you want to access user-provided secure boot 564 certificates via DIAG 0x320. 565 566 These certificates will be made available via the keyring named 567 'cert_store'. 568 569config KERNEL_NOBP 570 def_bool n 571 prompt "Enable modified branch prediction for the kernel by default" 572 help 573 If this option is selected the kernel will switch to a modified 574 branch prediction mode if the firmware interface is available. 575 The modified branch prediction mode improves the behaviour in 576 regard to speculative execution. 577 578 With the option enabled the kernel parameter "nobp=0" or "nospec" 579 can be used to run the kernel in the normal branch prediction mode. 580 581 With the option disabled the modified branch prediction mode is 582 enabled with the "nobp=1" kernel parameter. 583 584 If unsure, say N. 585 586config EXPOLINE 587 def_bool n 588 depends on $(cc-option,-mindirect-branch=thunk) 589 prompt "Avoid speculative indirect branches in the kernel" 590 help 591 Compile the kernel with the expoline compiler options to guard 592 against kernel-to-user data leaks by avoiding speculative indirect 593 branches. 594 Requires a compiler with -mindirect-branch=thunk support for full 595 protection. The kernel may run slower. 596 597 If unsure, say N. 598 599config EXPOLINE_EXTERN 600 def_bool EXPOLINE && CC_IS_GCC && GCC_VERSION >= 110200 && \ 601 $(success,$(srctree)/arch/s390/tools/gcc-thunk-extern.sh $(CC)) 602 help 603 Generate expolines as external functions if the compiler supports it. 604 This option is required for some tooling like kpatch, if expolines 605 are enabled. The kernel is compiled with 606 -mindirect-branch=thunk-extern, which requires a newer compiler. 607 608choice 609 prompt "Expoline default" 610 depends on EXPOLINE 611 default EXPOLINE_FULL 612 613config EXPOLINE_OFF 614 bool "spectre_v2=off" 615 616config EXPOLINE_AUTO 617 bool "spectre_v2=auto" 618 619config EXPOLINE_FULL 620 bool "spectre_v2=on" 621 622endchoice 623 624config RELOCATABLE 625 def_bool y 626 help 627 This builds a kernel image that retains relocation information 628 so it can be loaded at an arbitrary address. 629 The relocations make the kernel image about 15% larger (compressed 630 10%), but are discarded at runtime. 631 Note: this option exists only for documentation purposes, please do 632 not remove it. 633 634config RANDOMIZE_BASE 635 bool "Randomize the address of the kernel image (KASLR)" 636 default y 637 help 638 In support of Kernel Address Space Layout Randomization (KASLR), 639 this randomizes the address at which the kernel image is loaded, 640 as a security feature that deters exploit attempts relying on 641 knowledge of the location of kernel internals. 642 643config RANDOMIZE_IDENTITY_BASE 644 bool "Randomize the address of the identity mapping base" 645 depends on RANDOMIZE_BASE 646 default DEBUG_VM 647 help 648 The identity mapping base address is pinned to zero by default. 649 Allow randomization of that base to expose otherwise missed 650 notion of physical and virtual addresses of data structures. 651 That does not have any impact on the base address at which the 652 kernel image is loaded. 653 654 If unsure, say N 655 656config KERNEL_IMAGE_BASE 657 hex "Kernel image base address" 658 range 0x100000 0x1FFFFFE0000000 if !KASAN 659 range 0x100000 0x1BFFFFE0000000 if KASAN 660 default 0x3FFE0000000 if !KASAN 661 default 0x7FFFE0000000 if KASAN 662 help 663 This is the address at which the kernel image is loaded in case 664 Kernel Address Space Layout Randomization (KASLR) is disabled. 665 666 In case the Protected virtualization guest support is enabled the 667 Ultravisor imposes a virtual address limit. If the value of this 668 option leads to the kernel image exceeding the Ultravisor limit, 669 this option is ignored and the image is loaded below the limit. 670 671 If the value of this option leads to the kernel image overlapping 672 the virtual memory where other data structures are located, this 673 option is ignored and the image is loaded above the structures. 674 675endmenu 676 677menu "Memory setup" 678 679config ARCH_SPARSEMEM_ENABLE 680 def_bool y 681 select SPARSEMEM_VMEMMAP_ENABLE 682 select SPARSEMEM_VMEMMAP 683 684config ARCH_SPARSEMEM_DEFAULT 685 def_bool y 686 687config MAX_PHYSMEM_BITS 688 int "Maximum size of supported physical memory in bits (42-53)" 689 range 42 53 690 default "46" 691 help 692 This option specifies the maximum supported size of physical memory 693 in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB). 694 Increasing the number of bits also increases the kernel image size. 695 By default 46 bits (64TB) are supported. 696 697endmenu 698 699menu "I/O subsystem" 700 701config QDIO 702 def_tristate y 703 prompt "QDIO support" 704 help 705 This driver provides the Queued Direct I/O base support for 706 IBM System z. 707 708 To compile this driver as a module, choose M here: the 709 module will be called qdio. 710 711 If unsure, say Y. 712 713if PCI 714 715config PCI_NR_FUNCTIONS 716 int "Maximum number of PCI functions (1-4096)" 717 range 1 4096 718 default "512" 719 help 720 This allows you to specify the maximum number of PCI functions which 721 this kernel will support. 722 723endif # PCI 724 725config HAS_IOMEM 726 def_bool PCI 727 728config CHSC_SCH 729 def_tristate m 730 prompt "Support for CHSC subchannels" 731 help 732 This driver allows usage of CHSC subchannels. A CHSC subchannel 733 is usually present on LPAR only. 734 The driver creates a device /dev/chsc, which may be used to 735 obtain I/O configuration information about the machine and 736 to issue asynchronous chsc commands (DANGEROUS). 737 You will usually only want to use this interface on a special 738 LPAR designated for system management. 739 740 To compile this driver as a module, choose M here: the 741 module will be called chsc_sch. 742 743 If unsure, say N. 744 745config SCM_BUS 746 def_bool y 747 prompt "SCM bus driver" 748 help 749 Bus driver for Storage Class Memory. 750 751config EADM_SCH 752 def_tristate m 753 prompt "Support for EADM subchannels" 754 depends on SCM_BUS 755 help 756 This driver allows usage of EADM subchannels. EADM subchannels act 757 as a communication vehicle for SCM increments. 758 759 To compile this driver as a module, choose M here: the 760 module will be called eadm_sch. 761 762config AP 763 def_tristate y 764 prompt "Support for Adjunct Processors (ap)" 765 help 766 This driver allows usage to Adjunct Processor (AP) devices via 767 the ap bus, cards and queues. Supported Adjunct Processors are 768 the CryptoExpress Cards (CEX). 769 770 To compile this driver as a module, choose M here: the 771 module will be called ap. 772 773 If unsure, say Y (default). 774 775config AP_DEBUG 776 def_bool n 777 prompt "Enable debug features for Adjunct Processor (ap) devices" 778 depends on AP 779 help 780 Say 'Y' here to enable some additional debug features for Adjunct 781 Processor (ap) devices. 782 783 There will be some more sysfs attributes displayed for ap queues. 784 785 Do not enable on production level kernel build. 786 787 If unsure, say N. 788 789config VFIO_CCW 790 def_tristate n 791 prompt "Support for VFIO-CCW subchannels" 792 depends on VFIO 793 select VFIO_MDEV 794 help 795 This driver allows usage of I/O subchannels via VFIO-CCW. 796 797 To compile this driver as a module, choose M here: the 798 module will be called vfio_ccw. 799 800config VFIO_AP 801 def_tristate n 802 prompt "VFIO support for AP devices" 803 depends on KVM 804 depends on VFIO 805 depends on AP 806 select VFIO_MDEV 807 help 808 This driver grants access to Adjunct Processor (AP) devices 809 via the VFIO mediated device interface. 810 811 To compile this driver as a module, choose M here: the module 812 will be called vfio_ap. 813 814endmenu 815 816config CCW 817 def_bool y 818 819config HAVE_PNETID 820 tristate 821 default (SMC || CCWGROUP) 822 823menu "Virtualization" 824 825config PFAULT 826 def_bool y 827 prompt "Pseudo page fault support" 828 help 829 Select this option, if you want to use PFAULT pseudo page fault 830 handling under VM. If running native or in LPAR, this option 831 has no effect. If your VM does not support PFAULT, PAGEEX 832 pseudo page fault handling will be used. 833 Note that VM 4.2 supports PFAULT but has a bug in its 834 implementation that causes some problems. 835 Everybody who wants to run Linux under VM != VM4.2 should select 836 this option. 837 838config CMM 839 def_tristate n 840 prompt "Cooperative memory management" 841 help 842 Select this option, if you want to enable the kernel interface 843 to reduce the memory size of the system. This is accomplished 844 by allocating pages of memory and put them "on hold". This only 845 makes sense for a system running under VM where the unused pages 846 will be reused by VM for other guest systems. The interface 847 allows an external monitor to balance memory of many systems. 848 Everybody who wants to run Linux under VM should select this 849 option. 850 851config CMM_IUCV 852 def_bool y 853 prompt "IUCV special message interface to cooperative memory management" 854 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV) 855 help 856 Select this option to enable the special message interface to 857 the cooperative memory management. 858 859config APPLDATA_BASE 860 def_bool n 861 prompt "Linux - VM Monitor Stream, base infrastructure" 862 depends on PROC_SYSCTL 863 help 864 This provides a kernel interface for creating and updating z/VM APPLDATA 865 monitor records. The monitor records are updated at certain time 866 intervals, once the timer is started. 867 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer, 868 i.e. enables or disables monitoring on the Linux side. 869 A custom interval value (in seconds) can be written to 870 /proc/appldata/interval. 871 872 Defaults are 60 seconds interval and timer off. 873 The /proc entries can also be read from, showing the current settings. 874 875config APPLDATA_MEM 876 def_tristate m 877 prompt "Monitor memory management statistics" 878 depends on APPLDATA_BASE && VM_EVENT_COUNTERS 879 help 880 This provides memory management related data to the Linux - VM Monitor 881 Stream, like paging/swapping rate, memory utilisation, etc. 882 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM 883 APPLDATA monitor record, i.e. enables or disables monitoring this record 884 on the z/VM side. 885 886 Default is disabled. 887 The /proc entry can also be read from, showing the current settings. 888 889 This can also be compiled as a module, which will be called 890 appldata_mem.o. 891 892config APPLDATA_OS 893 def_tristate m 894 prompt "Monitor OS statistics" 895 depends on APPLDATA_BASE 896 help 897 This provides OS related data to the Linux - VM Monitor Stream, like 898 CPU utilisation, etc. 899 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM 900 APPLDATA monitor record, i.e. enables or disables monitoring this record 901 on the z/VM side. 902 903 Default is disabled. 904 This can also be compiled as a module, which will be called 905 appldata_os.o. 906 907config APPLDATA_NET_SUM 908 def_tristate m 909 prompt "Monitor overall network statistics" 910 depends on APPLDATA_BASE && NET 911 help 912 This provides network related data to the Linux - VM Monitor Stream, 913 currently there is only a total sum of network I/O statistics, no 914 per-interface data. 915 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM 916 APPLDATA monitor record, i.e. enables or disables monitoring this record 917 on the z/VM side. 918 919 Default is disabled. 920 This can also be compiled as a module, which will be called 921 appldata_net_sum.o. 922 923config S390_HYPFS 924 def_bool y 925 prompt "s390 hypervisor information" 926 help 927 This provides several binary files at (debugfs)/s390_hypfs/ to 928 provide accounting information in an s390 hypervisor environment. 929 930config S390_HYPFS_FS 931 def_bool n 932 prompt "s390 hypervisor file system support" 933 select SYS_HYPERVISOR 934 depends on S390_HYPFS 935 help 936 This is a virtual file system intended to provide accounting 937 information in an s390 hypervisor environment. This file system 938 is deprecated and should not be used. 939 940 Say N if you are unsure. 941 942source "arch/s390/kvm/Kconfig" 943 944config S390_GUEST 945 def_bool y 946 prompt "s390 support for virtio devices" 947 select TTY 948 select VIRTUALIZATION 949 select VIRTIO 950 help 951 Enabling this option adds support for virtio based paravirtual device 952 drivers on s390. 953 954 Select this option if you want to run the kernel as a guest under 955 the KVM hypervisor. 956 957endmenu 958 959config S390_MODULES_SANITY_TEST_HELPERS 960 def_bool n 961 962menu "Selftests" 963 964config S390_UNWIND_SELFTEST 965 def_tristate n 966 depends on KUNIT 967 default KUNIT_ALL_TESTS 968 prompt "Test unwind functions" 969 help 970 This option enables s390 specific stack unwinder testing kernel 971 module. This option is not useful for distributions or general 972 kernels, but only for kernel developers working on architecture code. 973 974 Say N if you are unsure. 975 976config S390_KPROBES_SANITY_TEST 977 def_tristate n 978 prompt "Enable s390 specific kprobes tests" 979 depends on KPROBES 980 depends on KUNIT 981 help 982 This option enables an s390 specific kprobes test module. This option 983 is not useful for distributions or general kernels, but only for kernel 984 developers working on architecture code. 985 986 Say N if you are unsure. 987 988config S390_MODULES_SANITY_TEST 989 def_tristate n 990 depends on KUNIT 991 default KUNIT_ALL_TESTS 992 prompt "Enable s390 specific modules tests" 993 select S390_MODULES_SANITY_TEST_HELPERS 994 help 995 This option enables an s390 specific modules test. This option is 996 not useful for distributions or general kernels, but only for 997 kernel developers working on architecture code. 998 999 Say N if you are unsure. 1000endmenu 1001