1# SPDX-License-Identifier: GPL-2.0 2config MMU 3 def_bool y 4 5config CPU_BIG_ENDIAN 6 def_bool y 7 8config LOCKDEP_SUPPORT 9 def_bool y 10 11config STACKTRACE_SUPPORT 12 def_bool y 13 14config ARCH_HAS_ILOG2_U32 15 def_bool n 16 17config ARCH_HAS_ILOG2_U64 18 def_bool n 19 20config ARCH_PROC_KCORE_TEXT 21 def_bool y 22 23config GENERIC_HWEIGHT 24 def_bool !HAVE_MARCH_Z196_FEATURES 25 26config GENERIC_BUG 27 def_bool y if BUG 28 29config GENERIC_BUG_RELATIVE_POINTERS 30 def_bool y 31 32config GENERIC_LOCKBREAK 33 def_bool y if PREEMPTION 34 35config PGSTE 36 def_bool y if KVM 37 38config AUDIT_ARCH 39 def_bool y 40 41config NO_IOPORT_MAP 42 def_bool y 43 44config ARCH_SUPPORTS_UPROBES 45 def_bool y 46 47config KASAN_SHADOW_OFFSET 48 hex 49 depends on KASAN 50 default 0x1C000000000000 51 52config CC_ASM_FLAG_OUTPUT_BROKEN 53 def_bool CC_IS_GCC && GCC_VERSION < 140200 54 help 55 GCC versions before 14.2.0 may die with an internal 56 compiler error in some configurations if flag output 57 operands are used within inline assemblies. 58 59config CC_HAS_ASM_AOR_FORMAT_FLAGS 60 def_bool !(CC_IS_CLANG && CLANG_VERSION < 190100) 61 help 62 Clang versions before 19.1.0 do not support A, 63 O, and R inline assembly format flags. 64 65config S390 66 def_bool y 67 # 68 # Note: keep this list sorted alphabetically 69 # 70 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 71 select ALTERNATE_USER_ADDRESS_SPACE 72 select ARCH_32BIT_USTAT_F_TINODE 73 select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE 74 select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM 75 select ARCH_ENABLE_MEMORY_HOTREMOVE 76 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 77 select ARCH_HAS_CPU_FINALIZE_INIT 78 select ARCH_HAS_CRC32 79 select ARCH_HAS_CURRENT_STACK_POINTER 80 select ARCH_HAS_DEBUG_VIRTUAL 81 select ARCH_HAS_DEBUG_VM_PGTABLE 82 select ARCH_HAS_DEBUG_WX 83 select ARCH_HAS_DEVMEM_IS_ALLOWED 84 select ARCH_HAS_DMA_OPS if PCI 85 select ARCH_HAS_ELF_RANDOMIZE 86 select ARCH_HAS_FORCE_DMA_UNENCRYPTED 87 select ARCH_HAS_FORTIFY_SOURCE 88 select ARCH_HAS_GCOV_PROFILE_ALL 89 select ARCH_HAS_GIGANTIC_PAGE 90 select ARCH_HAS_KCOV 91 select ARCH_HAS_MEMBARRIER_SYNC_CORE 92 select ARCH_HAS_MEM_ENCRYPT 93 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS 94 select ARCH_HAS_PREEMPT_LAZY 95 select ARCH_HAS_PTDUMP 96 select ARCH_HAS_PTE_SPECIAL 97 select ARCH_HAS_SCALED_CPUTIME 98 select ARCH_HAS_SET_DIRECT_MAP 99 select ARCH_HAS_SET_MEMORY 100 select ARCH_HAS_STRICT_KERNEL_RWX 101 select ARCH_HAS_STRICT_MODULE_RWX 102 select ARCH_HAS_SYSCALL_WRAPPER 103 select ARCH_HAS_UBSAN 104 select ARCH_HAS_VDSO_TIME_DATA 105 select ARCH_HAVE_NMI_SAFE_CMPXCHG 106 select ARCH_INLINE_READ_LOCK 107 select ARCH_INLINE_READ_LOCK_BH 108 select ARCH_INLINE_READ_LOCK_IRQ 109 select ARCH_INLINE_READ_LOCK_IRQSAVE 110 select ARCH_INLINE_READ_TRYLOCK 111 select ARCH_INLINE_READ_UNLOCK 112 select ARCH_INLINE_READ_UNLOCK_BH 113 select ARCH_INLINE_READ_UNLOCK_IRQ 114 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE 115 select ARCH_INLINE_SPIN_LOCK 116 select ARCH_INLINE_SPIN_LOCK_BH 117 select ARCH_INLINE_SPIN_LOCK_IRQ 118 select ARCH_INLINE_SPIN_LOCK_IRQSAVE 119 select ARCH_INLINE_SPIN_TRYLOCK 120 select ARCH_INLINE_SPIN_TRYLOCK_BH 121 select ARCH_INLINE_SPIN_UNLOCK 122 select ARCH_INLINE_SPIN_UNLOCK_BH 123 select ARCH_INLINE_SPIN_UNLOCK_IRQ 124 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE 125 select ARCH_INLINE_WRITE_LOCK 126 select ARCH_INLINE_WRITE_LOCK_BH 127 select ARCH_INLINE_WRITE_LOCK_IRQ 128 select ARCH_INLINE_WRITE_LOCK_IRQSAVE 129 select ARCH_INLINE_WRITE_TRYLOCK 130 select ARCH_INLINE_WRITE_UNLOCK 131 select ARCH_INLINE_WRITE_UNLOCK_BH 132 select ARCH_INLINE_WRITE_UNLOCK_IRQ 133 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE 134 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 135 select ARCH_STACKWALK 136 select ARCH_SUPPORTS_ATOMIC_RMW 137 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 138 select ARCH_SUPPORTS_HUGETLBFS 139 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && CC_IS_CLANG 140 select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS 141 select ARCH_SUPPORTS_NUMA_BALANCING 142 select ARCH_SUPPORTS_PER_VMA_LOCK 143 select ARCH_USE_BUILTIN_BSWAP 144 select ARCH_USE_CMPXCHG_LOCKREF 145 select ARCH_USE_SYM_ANNOTATIONS 146 select ARCH_WANTS_NO_INSTR 147 select ARCH_WANT_DEFAULT_BPF_JIT 148 select ARCH_WANT_IPC_PARSE_VERSION 149 select ARCH_WANT_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_RANDOMIZE_KSTACK_OFFSET 179 select HAVE_ARCH_SECCOMP_FILTER 180 select HAVE_ARCH_SOFT_DIRTY 181 select HAVE_ARCH_STACKLEAK 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_FTRACE_MCOUNT_RECORD 202 select HAVE_FUNCTION_ARG_ACCESS_API 203 select HAVE_FUNCTION_ERROR_INJECTION 204 select HAVE_FUNCTION_GRAPH_FREGS 205 select HAVE_FUNCTION_GRAPH_TRACER 206 select HAVE_FUNCTION_TRACER 207 select HAVE_GCC_PLUGINS 208 select HAVE_GENERIC_VDSO 209 select HAVE_IOREMAP_PROT if PCI 210 select HAVE_KERNEL_BZIP2 211 select HAVE_KERNEL_GZIP 212 select HAVE_KERNEL_LZ4 213 select HAVE_KERNEL_LZMA 214 select HAVE_KERNEL_LZO 215 select HAVE_KERNEL_UNCOMPRESSED 216 select HAVE_KERNEL_XZ 217 select HAVE_KERNEL_ZSTD 218 select HAVE_KPROBES 219 select HAVE_KPROBES_ON_FTRACE 220 select HAVE_KRETPROBES 221 select HAVE_LIVEPATCH 222 select HAVE_MEMBLOCK_PHYS_MAP 223 select HAVE_MOD_ARCH_SPECIFIC 224 select HAVE_NMI 225 select HAVE_NOP_MCOUNT 226 select HAVE_PAGE_SIZE_4KB 227 select HAVE_PCI 228 select HAVE_PERF_EVENTS 229 select HAVE_PERF_REGS 230 select HAVE_PERF_USER_STACK_DUMP 231 select HAVE_PREEMPT_DYNAMIC_KEY 232 select HAVE_REGS_AND_STACK_ACCESS_API 233 select HAVE_RELIABLE_STACKTRACE 234 select HAVE_RETHOOK 235 select HAVE_RSEQ 236 select HAVE_SAMPLE_FTRACE_DIRECT 237 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 238 select HAVE_SETUP_PER_CPU_AREA 239 select HAVE_SOFTIRQ_ON_OWN_STACK 240 select HAVE_SYSCALL_TRACEPOINTS 241 select HAVE_VIRT_CPU_ACCOUNTING 242 select HAVE_VIRT_CPU_ACCOUNTING_IDLE 243 select HOTPLUG_SMT 244 select IOMMU_HELPER if PCI 245 select IOMMU_SUPPORT if PCI 246 select KASAN_VMALLOC if KASAN 247 select LOCK_MM_AND_FIND_VMA 248 select MMU_GATHER_MERGE_VMAS 249 select MMU_GATHER_NO_GATHER 250 select MMU_GATHER_RCU_TABLE_FREE 251 select MODULES_USE_ELF_RELA 252 select NEED_DMA_MAP_STATE if PCI 253 select NEED_PER_CPU_EMBED_FIRST_CHUNK 254 select NEED_PROC_VMCORE_DEVICE_RAM if PROC_VMCORE 255 select NEED_SG_DMA_LENGTH if PCI 256 select OLD_SIGACTION 257 select OLD_SIGSUSPEND3 258 select PCI_DOMAINS if PCI 259 select PCI_MSI if PCI 260 select PCI_MSI_ARCH_FALLBACKS if PCI_MSI 261 select PCI_QUIRKS if PCI 262 select SPARSE_IRQ 263 select SWIOTLB 264 select SYSCTL_EXCEPTION_TRACE 265 select THREAD_INFO_IN_TASK 266 select TRACE_IRQFLAGS_SUPPORT 267 select TTY 268 select USER_STACKTRACE_SUPPORT 269 select VDSO_GETRANDOM 270 select VIRT_CPU_ACCOUNTING 271 select VMAP_STACK 272 select ZONE_DMA 273 # Note: keep the above list sorted alphabetically 274 275config SCHED_OMIT_FRAME_POINTER 276 def_bool y 277 278config PGTABLE_LEVELS 279 int 280 default 5 281 282source "kernel/livepatch/Kconfig" 283 284config ARCH_SUPPORTS_KEXEC 285 def_bool y 286 287config ARCH_SUPPORTS_KEXEC_FILE 288 def_bool y 289 290config ARCH_SUPPORTS_KEXEC_SIG 291 def_bool MODULE_SIG_FORMAT 292 293config ARCH_SUPPORTS_KEXEC_PURGATORY 294 def_bool y 295 296config ARCH_SUPPORTS_CRASH_DUMP 297 def_bool y 298 help 299 Refer to <file:Documentation/arch/s390/zfcpdump.rst> for more details on this. 300 This option also enables s390 zfcpdump. 301 See also <file:Documentation/arch/s390/zfcpdump.rst> 302 303config ARCH_DEFAULT_CRASH_DUMP 304 def_bool y 305 306menu "Processor type and features" 307 308config HAVE_MARCH_Z10_FEATURES 309 def_bool n 310 311config HAVE_MARCH_Z196_FEATURES 312 def_bool n 313 select HAVE_MARCH_Z10_FEATURES 314 315config HAVE_MARCH_ZEC12_FEATURES 316 def_bool n 317 select HAVE_MARCH_Z196_FEATURES 318 319config HAVE_MARCH_Z13_FEATURES 320 def_bool n 321 select HAVE_MARCH_ZEC12_FEATURES 322 323config HAVE_MARCH_Z14_FEATURES 324 def_bool n 325 select HAVE_MARCH_Z13_FEATURES 326 327config HAVE_MARCH_Z15_FEATURES 328 def_bool n 329 select HAVE_MARCH_Z14_FEATURES 330 331config HAVE_MARCH_Z16_FEATURES 332 def_bool n 333 select HAVE_MARCH_Z15_FEATURES 334 335config HAVE_MARCH_Z17_FEATURES 336 def_bool n 337 select HAVE_MARCH_Z16_FEATURES 338 339choice 340 prompt "Processor type" 341 default MARCH_Z196 342 343config MARCH_Z10 344 bool "IBM System z10" 345 select HAVE_MARCH_Z10_FEATURES 346 depends on $(cc-option,-march=z10) 347 help 348 Select this to enable optimizations for IBM System z10 (2097 and 2098 349 series). This is the oldest machine generation currently supported. 350 351config MARCH_Z196 352 bool "IBM zEnterprise 114 and 196" 353 select HAVE_MARCH_Z196_FEATURES 354 depends on $(cc-option,-march=z196) 355 help 356 Select this to enable optimizations for IBM zEnterprise 114 and 196 357 (2818 and 2817 series). The kernel will be slightly faster but will 358 not work on older machines. 359 360config MARCH_ZEC12 361 bool "IBM zBC12 and zEC12" 362 select HAVE_MARCH_ZEC12_FEATURES 363 depends on $(cc-option,-march=zEC12) 364 help 365 Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and 366 2827 series). The kernel will be slightly faster but will not work on 367 older machines. 368 369config MARCH_Z13 370 bool "IBM z13s and z13" 371 select HAVE_MARCH_Z13_FEATURES 372 depends on $(cc-option,-march=z13) 373 help 374 Select this to enable optimizations for IBM z13s and z13 (2965 and 375 2964 series). The kernel will be slightly faster but will not work on 376 older machines. 377 378config MARCH_Z14 379 bool "IBM z14 ZR1 and z14" 380 select HAVE_MARCH_Z14_FEATURES 381 depends on $(cc-option,-march=z14) 382 help 383 Select this to enable optimizations for IBM z14 ZR1 and z14 (3907 384 and 3906 series). The kernel will be slightly faster but will not 385 work on older machines. 386 387config MARCH_Z15 388 bool "IBM z15" 389 select HAVE_MARCH_Z15_FEATURES 390 depends on $(cc-option,-march=z15) 391 help 392 Select this to enable optimizations for IBM z15 (8562 393 and 8561 series). The kernel will be slightly faster but will not 394 work on older machines. 395 396config MARCH_Z16 397 bool "IBM z16" 398 select HAVE_MARCH_Z16_FEATURES 399 depends on $(cc-option,-march=z16) 400 help 401 Select this to enable optimizations for IBM z16 (3931 and 402 3932 series). 403 404config MARCH_Z17 405 bool "IBM z17" 406 select HAVE_MARCH_Z17_FEATURES 407 depends on $(cc-option,-march=z17) 408 help 409 Select this to enable optimizations for IBM z17 (9175 and 410 9176 series). 411 412endchoice 413 414config MARCH_Z10_TUNE 415 def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT 416 417config MARCH_Z196_TUNE 418 def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT 419 420config MARCH_ZEC12_TUNE 421 def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT 422 423config MARCH_Z13_TUNE 424 def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT 425 426config MARCH_Z14_TUNE 427 def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT 428 429config MARCH_Z15_TUNE 430 def_bool TUNE_Z15 || MARCH_Z15 && TUNE_DEFAULT 431 432config MARCH_Z16_TUNE 433 def_bool TUNE_Z16 || MARCH_Z16 && TUNE_DEFAULT 434 435config MARCH_Z17_TUNE 436 def_bool TUNE_Z17 || MARCH_Z17 && TUNE_DEFAULT 437 438choice 439 prompt "Tune code generation" 440 default TUNE_DEFAULT 441 help 442 Cause the compiler to tune (-mtune) the generated code for a machine. 443 This will make the code run faster on the selected machine but 444 somewhat slower on other machines. 445 This option only changes how the compiler emits instructions, not the 446 selection of instructions itself, so the resulting kernel will run on 447 all other machines. 448 449config TUNE_DEFAULT 450 bool "Default" 451 help 452 Tune the generated code for the target processor for which the kernel 453 will be compiled. 454 455config TUNE_Z10 456 bool "IBM System z10" 457 458config TUNE_Z196 459 bool "IBM zEnterprise 114 and 196" 460 depends on $(cc-option,-mtune=z196) 461 462config TUNE_ZEC12 463 bool "IBM zBC12 and zEC12" 464 depends on $(cc-option,-mtune=zEC12) 465 466config TUNE_Z13 467 bool "IBM z13s and z13" 468 depends on $(cc-option,-mtune=z13) 469 470config TUNE_Z14 471 bool "IBM z14 ZR1 and z14" 472 depends on $(cc-option,-mtune=z14) 473 474config TUNE_Z15 475 bool "IBM z15" 476 depends on $(cc-option,-mtune=z15) 477 478config TUNE_Z16 479 bool "IBM z16" 480 depends on $(cc-option,-mtune=z16) 481 482config TUNE_Z17 483 bool "IBM z17" 484 depends on $(cc-option,-mtune=z17) 485 486endchoice 487 488config 64BIT 489 def_bool y 490 491config COMMAND_LINE_SIZE 492 int "Maximum size of kernel command line" 493 default 4096 494 range 896 1048576 495 help 496 This allows you to specify the maximum length of the kernel command 497 line. 498 499config COMPAT 500 def_bool n 501 prompt "Kernel support for 31 bit emulation" 502 select ARCH_WANT_OLD_COMPAT_IPC 503 select COMPAT_OLD_SIGACTION 504 select HAVE_UID16 505 depends on MULTIUSER 506 depends on !CC_IS_CLANG && !LD_IS_LLD 507 help 508 Select this option if you want to enable your system kernel to 509 handle system-calls from ELF binaries for 31 bit ESA. This option 510 (and some other stuff like libraries and such) is needed for 511 executing 31 bit applications. 512 513 If unsure say N. 514 515config SMP 516 def_bool y 517 518config NR_CPUS 519 int "Maximum number of CPUs (2-512)" 520 range 2 512 521 default "64" 522 help 523 This allows you to specify the maximum number of CPUs which this 524 kernel will support. The maximum supported value is 512 and the 525 minimum value which makes sense is 2. 526 527 This is purely to save memory - each supported CPU adds 528 approximately sixteen kilobytes to the kernel image. 529 530config HOTPLUG_CPU 531 def_bool y 532 533config NUMA 534 bool "NUMA support" 535 depends on SCHED_TOPOLOGY 536 default n 537 help 538 Enable NUMA support 539 540 This option adds NUMA support to the kernel. 541 542config NODES_SHIFT 543 int 544 depends on NUMA 545 default "1" 546 547config SCHED_SMT 548 def_bool n 549 550config SCHED_MC 551 def_bool n 552 553config SCHED_TOPOLOGY 554 def_bool y 555 prompt "Topology scheduler support" 556 select SCHED_SMT 557 select SCHED_MC 558 help 559 Topology scheduler support improves the CPU scheduler's decision 560 making when dealing with machines that have multi-threading, 561 multiple cores or multiple books. 562 563config SCHED_TOPOLOGY_VERTICAL 564 def_bool y 565 bool "Use vertical CPU polarization by default" 566 depends on SCHED_TOPOLOGY 567 help 568 Use vertical CPU polarization by default if available. 569 The default CPU polarization is horizontal. 570 571config HIPERDISPATCH_ON 572 def_bool y 573 bool "Use hiperdispatch on vertical polarization by default" 574 depends on SCHED_TOPOLOGY 575 depends on PROC_SYSCTL 576 help 577 Hiperdispatch aims to improve the CPU scheduler's decision 578 making when using vertical polarization by adjusting CPU 579 capacities dynamically. Set this option to use hiperdispatch 580 on vertical polarization by default. This can be overwritten 581 by sysctl's s390.hiperdispatch attribute later on. 582 583source "kernel/Kconfig.hz" 584 585config CERT_STORE 586 bool "Get user certificates via DIAG320" 587 depends on KEYS 588 select CRYPTO_LIB_SHA256 589 help 590 Enable this option if you want to access user-provided secure boot 591 certificates via DIAG 0x320. 592 593 These certificates will be made available via the keyring named 594 'cert_store'. 595 596config KERNEL_NOBP 597 def_bool n 598 prompt "Enable modified branch prediction for the kernel by default" 599 help 600 If this option is selected the kernel will switch to a modified 601 branch prediction mode if the firmware interface is available. 602 The modified branch prediction mode improves the behaviour in 603 regard to speculative execution. 604 605 With the option enabled the kernel parameter "nobp=0" or "nospec" 606 can be used to run the kernel in the normal branch prediction mode. 607 608 With the option disabled the modified branch prediction mode is 609 enabled with the "nobp=1" kernel parameter. 610 611 If unsure, say N. 612 613config EXPOLINE 614 def_bool n 615 depends on $(cc-option,-mindirect-branch=thunk) 616 prompt "Avoid speculative indirect branches in the kernel" 617 help 618 Compile the kernel with the expoline compiler options to guard 619 against kernel-to-user data leaks by avoiding speculative indirect 620 branches. 621 Requires a compiler with -mindirect-branch=thunk support for full 622 protection. The kernel may run slower. 623 624 If unsure, say N. 625 626config EXPOLINE_EXTERN 627 def_bool EXPOLINE && CC_IS_GCC && GCC_VERSION >= 110200 && \ 628 $(success,$(srctree)/arch/s390/tools/gcc-thunk-extern.sh $(CC)) 629 help 630 Generate expolines as external functions if the compiler supports it. 631 This option is required for some tooling like kpatch, if expolines 632 are enabled. The kernel is compiled with 633 -mindirect-branch=thunk-extern, which requires a newer compiler. 634 635choice 636 prompt "Expoline default" 637 depends on EXPOLINE 638 default EXPOLINE_FULL 639 640config EXPOLINE_OFF 641 bool "spectre_v2=off" 642 643config EXPOLINE_AUTO 644 bool "spectre_v2=auto" 645 646config EXPOLINE_FULL 647 bool "spectre_v2=on" 648 649endchoice 650 651config RELOCATABLE 652 def_bool y 653 select ARCH_VMLINUX_NEEDS_RELOCS 654 help 655 This builds a kernel image that retains relocation information 656 so it can be loaded at an arbitrary address. 657 The relocations make the kernel image about 15% larger (compressed 658 10%), but are discarded at runtime. 659 Note: this option exists only for documentation purposes, please do 660 not remove it. 661 662config RANDOMIZE_BASE 663 bool "Randomize the address of the kernel image (KASLR)" 664 default y 665 help 666 In support of Kernel Address Space Layout Randomization (KASLR), 667 this randomizes the address at which the kernel image is loaded, 668 as a security feature that deters exploit attempts relying on 669 knowledge of the location of kernel internals. 670 671config RANDOMIZE_IDENTITY_BASE 672 bool "Randomize the address of the identity mapping base" 673 depends on RANDOMIZE_BASE 674 default DEBUG_VM 675 help 676 The identity mapping base address is pinned to zero by default. 677 Allow randomization of that base to expose otherwise missed 678 notion of physical and virtual addresses of data structures. 679 That does not have any impact on the base address at which the 680 kernel image is loaded. 681 682 If unsure, say N 683 684config KERNEL_IMAGE_BASE 685 hex "Kernel image base address" 686 range 0x100000 0x1FFFFFE0000000 if !KASAN 687 range 0x100000 0x1BFFFFE0000000 if KASAN 688 default 0x3FFE0000000 if !KASAN 689 default 0x7FFFE0000000 if KASAN 690 help 691 This is the address at which the kernel image is loaded in case 692 Kernel Address Space Layout Randomization (KASLR) is disabled. 693 694 In case the Protected virtualization guest support is enabled the 695 Ultravisor imposes a virtual address limit. If the value of this 696 option leads to the kernel image exceeding the Ultravisor limit, 697 this option is ignored and the image is loaded below the limit. 698 699 If the value of this option leads to the kernel image overlapping 700 the virtual memory where other data structures are located, this 701 option is ignored and the image is loaded above the structures. 702 703endmenu 704 705menu "Memory setup" 706 707config ARCH_SPARSEMEM_ENABLE 708 def_bool y 709 select SPARSEMEM_VMEMMAP_ENABLE 710 select SPARSEMEM_VMEMMAP 711 712config ARCH_SPARSEMEM_DEFAULT 713 def_bool y 714 715config MAX_PHYSMEM_BITS 716 int "Maximum size of supported physical memory in bits (42-53)" 717 range 42 53 718 default "46" 719 help 720 This option specifies the maximum supported size of physical memory 721 in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB). 722 Increasing the number of bits also increases the kernel image size. 723 By default 46 bits (64TB) are supported. 724 725endmenu 726 727menu "I/O subsystem" 728 729config QDIO 730 def_tristate y 731 prompt "QDIO support" 732 help 733 This driver provides the Queued Direct I/O base support for 734 IBM System z. 735 736 To compile this driver as a module, choose M here: the 737 module will be called qdio. 738 739 If unsure, say Y. 740 741if PCI 742 743config PCI_NR_FUNCTIONS 744 int "Maximum number of PCI functions (1-4096)" 745 range 1 4096 746 default "512" 747 help 748 This allows you to specify the maximum number of PCI functions which 749 this kernel will support. 750 751endif # PCI 752 753config HAS_IOMEM 754 def_bool PCI 755 756config CHSC_SCH 757 def_tristate m 758 prompt "Support for CHSC subchannels" 759 help 760 This driver allows usage of CHSC subchannels. A CHSC subchannel 761 is usually present on LPAR only. 762 The driver creates a device /dev/chsc, which may be used to 763 obtain I/O configuration information about the machine and 764 to issue asynchronous chsc commands (DANGEROUS). 765 You will usually only want to use this interface on a special 766 LPAR designated for system management. 767 768 To compile this driver as a module, choose M here: the 769 module will be called chsc_sch. 770 771 If unsure, say N. 772 773config SCM_BUS 774 def_bool y 775 prompt "SCM bus driver" 776 help 777 Bus driver for Storage Class Memory. 778 779config EADM_SCH 780 def_tristate m 781 prompt "Support for EADM subchannels" 782 depends on SCM_BUS 783 help 784 This driver allows usage of EADM subchannels. EADM subchannels act 785 as a communication vehicle for SCM increments. 786 787 To compile this driver as a module, choose M here: the 788 module will be called eadm_sch. 789 790config AP 791 def_tristate y 792 prompt "Support for Adjunct Processors (ap)" 793 help 794 This driver allows usage to Adjunct Processor (AP) devices via 795 the ap bus, cards and queues. Supported Adjunct Processors are 796 the CryptoExpress Cards (CEX). 797 798 To compile this driver as a module, choose M here: the 799 module will be called ap. 800 801 If unsure, say Y (default). 802 803config AP_DEBUG 804 def_bool n 805 prompt "Enable debug features for Adjunct Processor (ap) devices" 806 depends on AP 807 help 808 Say 'Y' here to enable some additional debug features for Adjunct 809 Processor (ap) devices. 810 811 There will be some more sysfs attributes displayed for ap queues. 812 813 Do not enable on production level kernel build. 814 815 If unsure, say N. 816 817config VFIO_CCW 818 def_tristate n 819 prompt "Support for VFIO-CCW subchannels" 820 depends on VFIO 821 select VFIO_MDEV 822 help 823 This driver allows usage of I/O subchannels via VFIO-CCW. 824 825 To compile this driver as a module, choose M here: the 826 module will be called vfio_ccw. 827 828config VFIO_AP 829 def_tristate n 830 prompt "VFIO support for AP devices" 831 depends on KVM 832 depends on VFIO 833 depends on AP 834 select VFIO_MDEV 835 help 836 This driver grants access to Adjunct Processor (AP) devices 837 via the VFIO mediated device interface. 838 839 To compile this driver as a module, choose M here: the module 840 will be called vfio_ap. 841 842endmenu 843 844config CCW 845 def_bool y 846 847config HAVE_PNETID 848 tristate 849 default (SMC || CCWGROUP) 850 851menu "Virtualization" 852 853config PFAULT 854 def_bool y 855 prompt "Pseudo page fault support" 856 help 857 Select this option, if you want to use PFAULT pseudo page fault 858 handling under VM. If running native or in LPAR, this option 859 has no effect. If your VM does not support PFAULT, PAGEEX 860 pseudo page fault handling will be used. 861 Note that VM 4.2 supports PFAULT but has a bug in its 862 implementation that causes some problems. 863 Everybody who wants to run Linux under VM != VM4.2 should select 864 this option. 865 866config CMM 867 def_tristate n 868 prompt "Cooperative memory management" 869 help 870 Select this option, if you want to enable the kernel interface 871 to reduce the memory size of the system. This is accomplished 872 by allocating pages of memory and put them "on hold". This only 873 makes sense for a system running under VM where the unused pages 874 will be reused by VM for other guest systems. The interface 875 allows an external monitor to balance memory of many systems. 876 Everybody who wants to run Linux under VM should select this 877 option. 878 879config CMM_IUCV 880 def_bool y 881 prompt "IUCV special message interface to cooperative memory management" 882 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV) 883 help 884 Select this option to enable the special message interface to 885 the cooperative memory management. 886 887config APPLDATA_BASE 888 def_bool n 889 prompt "Linux - VM Monitor Stream, base infrastructure" 890 depends on PROC_SYSCTL 891 help 892 This provides a kernel interface for creating and updating z/VM APPLDATA 893 monitor records. The monitor records are updated at certain time 894 intervals, once the timer is started. 895 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer, 896 i.e. enables or disables monitoring on the Linux side. 897 A custom interval value (in seconds) can be written to 898 /proc/appldata/interval. 899 900 Defaults are 60 seconds interval and timer off. 901 The /proc entries can also be read from, showing the current settings. 902 903config APPLDATA_MEM 904 def_tristate m 905 prompt "Monitor memory management statistics" 906 depends on APPLDATA_BASE && VM_EVENT_COUNTERS 907 help 908 This provides memory management related data to the Linux - VM Monitor 909 Stream, like paging/swapping rate, memory utilisation, etc. 910 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM 911 APPLDATA monitor record, i.e. enables or disables monitoring this record 912 on the z/VM side. 913 914 Default is disabled. 915 The /proc entry can also be read from, showing the current settings. 916 917 This can also be compiled as a module, which will be called 918 appldata_mem.o. 919 920config APPLDATA_OS 921 def_tristate m 922 prompt "Monitor OS statistics" 923 depends on APPLDATA_BASE 924 help 925 This provides OS related data to the Linux - VM Monitor Stream, like 926 CPU utilisation, etc. 927 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM 928 APPLDATA monitor record, i.e. enables or disables monitoring this record 929 on the z/VM side. 930 931 Default is disabled. 932 This can also be compiled as a module, which will be called 933 appldata_os.o. 934 935config APPLDATA_NET_SUM 936 def_tristate m 937 prompt "Monitor overall network statistics" 938 depends on APPLDATA_BASE && NET 939 help 940 This provides network related data to the Linux - VM Monitor Stream, 941 currently there is only a total sum of network I/O statistics, no 942 per-interface data. 943 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM 944 APPLDATA monitor record, i.e. enables or disables monitoring this record 945 on the z/VM side. 946 947 Default is disabled. 948 This can also be compiled as a module, which will be called 949 appldata_net_sum.o. 950 951config S390_HYPFS 952 def_bool y 953 prompt "s390 hypervisor information" 954 help 955 This provides several binary files at (debugfs)/s390_hypfs/ to 956 provide accounting information in an s390 hypervisor environment. 957 958config S390_HYPFS_FS 959 def_bool n 960 prompt "s390 hypervisor file system support" 961 select SYS_HYPERVISOR 962 depends on S390_HYPFS 963 help 964 This is a virtual file system intended to provide accounting 965 information in an s390 hypervisor environment. This file system 966 is deprecated and should not be used. 967 968 Say N if you are unsure. 969 970source "arch/s390/kvm/Kconfig" 971 972config S390_GUEST 973 def_bool y 974 prompt "s390 support for virtio devices" 975 select TTY 976 select VIRTUALIZATION 977 select VIRTIO 978 help 979 Enabling this option adds support for virtio based paravirtual device 980 drivers on s390. 981 982 Select this option if you want to run the kernel as a guest under 983 the KVM hypervisor. 984 985endmenu 986 987config S390_MODULES_SANITY_TEST_HELPERS 988 def_bool n 989 990menu "Selftests" 991 992config S390_UNWIND_SELFTEST 993 def_tristate n 994 depends on KUNIT 995 default KUNIT_ALL_TESTS 996 prompt "Test unwind functions" 997 help 998 This option enables s390 specific stack unwinder testing kernel 999 module. This option is not useful for distributions or general 1000 kernels, but only for kernel developers working on architecture code. 1001 1002 Say N if you are unsure. 1003 1004config S390_KPROBES_SANITY_TEST 1005 def_tristate n 1006 prompt "Enable s390 specific kprobes tests" 1007 depends on KPROBES 1008 depends on KUNIT 1009 help 1010 This option enables an s390 specific kprobes test module. This option 1011 is not useful for distributions or general kernels, but only for kernel 1012 developers working on architecture code. 1013 1014 Say N if you are unsure. 1015 1016config S390_MODULES_SANITY_TEST 1017 def_tristate n 1018 depends on KUNIT 1019 default KUNIT_ALL_TESTS 1020 prompt "Enable s390 specific modules tests" 1021 select S390_MODULES_SANITY_TEST_HELPERS 1022 help 1023 This option enables an s390 specific modules test. This option is 1024 not useful for distributions or general kernels, but only for 1025 kernel developers working on architecture code. 1026 1027 Say N if you are unsure. 1028endmenu 1029