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 S390 56 def_bool y 57 # 58 # Note: keep this list sorted alphabetically 59 # 60 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 61 select ALTERNATE_USER_ADDRESS_SPACE 62 select ARCH_32BIT_USTAT_F_TINODE 63 select ARCH_BINFMT_ELF_STATE 64 select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE 65 select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM 66 select ARCH_ENABLE_MEMORY_HOTREMOVE 67 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 68 select ARCH_HAS_CURRENT_STACK_POINTER 69 select ARCH_HAS_DEBUG_VIRTUAL 70 select ARCH_HAS_DEBUG_VM_PGTABLE 71 select ARCH_HAS_DEBUG_WX 72 select ARCH_HAS_DEVMEM_IS_ALLOWED 73 select ARCH_HAS_ELF_RANDOMIZE 74 select ARCH_HAS_FORCE_DMA_UNENCRYPTED 75 select ARCH_HAS_FORTIFY_SOURCE 76 select ARCH_HAS_GCOV_PROFILE_ALL 77 select ARCH_HAS_GIGANTIC_PAGE 78 select ARCH_HAS_KCOV 79 select ARCH_HAS_MEMBARRIER_SYNC_CORE 80 select ARCH_HAS_MEM_ENCRYPT 81 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS 82 select ARCH_HAS_PTE_SPECIAL 83 select ARCH_HAS_SCALED_CPUTIME 84 select ARCH_HAS_SET_DIRECT_MAP 85 select ARCH_HAS_SET_MEMORY 86 select ARCH_HAS_STRICT_KERNEL_RWX 87 select ARCH_HAS_STRICT_MODULE_RWX 88 select ARCH_HAS_SYSCALL_WRAPPER 89 select ARCH_HAS_UBSAN 90 select ARCH_HAS_VDSO_DATA 91 select ARCH_HAVE_NMI_SAFE_CMPXCHG 92 select ARCH_INLINE_READ_LOCK 93 select ARCH_INLINE_READ_LOCK_BH 94 select ARCH_INLINE_READ_LOCK_IRQ 95 select ARCH_INLINE_READ_LOCK_IRQSAVE 96 select ARCH_INLINE_READ_TRYLOCK 97 select ARCH_INLINE_READ_UNLOCK 98 select ARCH_INLINE_READ_UNLOCK_BH 99 select ARCH_INLINE_READ_UNLOCK_IRQ 100 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE 101 select ARCH_INLINE_SPIN_LOCK 102 select ARCH_INLINE_SPIN_LOCK_BH 103 select ARCH_INLINE_SPIN_LOCK_IRQ 104 select ARCH_INLINE_SPIN_LOCK_IRQSAVE 105 select ARCH_INLINE_SPIN_TRYLOCK 106 select ARCH_INLINE_SPIN_TRYLOCK_BH 107 select ARCH_INLINE_SPIN_UNLOCK 108 select ARCH_INLINE_SPIN_UNLOCK_BH 109 select ARCH_INLINE_SPIN_UNLOCK_IRQ 110 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE 111 select ARCH_INLINE_WRITE_LOCK 112 select ARCH_INLINE_WRITE_LOCK_BH 113 select ARCH_INLINE_WRITE_LOCK_IRQ 114 select ARCH_INLINE_WRITE_LOCK_IRQSAVE 115 select ARCH_INLINE_WRITE_TRYLOCK 116 select ARCH_INLINE_WRITE_UNLOCK 117 select ARCH_INLINE_WRITE_UNLOCK_BH 118 select ARCH_INLINE_WRITE_UNLOCK_IRQ 119 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE 120 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 121 select ARCH_STACKWALK 122 select ARCH_SUPPORTS_ATOMIC_RMW 123 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 124 select ARCH_SUPPORTS_HUGETLBFS 125 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && CC_IS_CLANG 126 select ARCH_SUPPORTS_NUMA_BALANCING 127 select ARCH_SUPPORTS_PER_VMA_LOCK 128 select ARCH_USE_BUILTIN_BSWAP 129 select ARCH_USE_CMPXCHG_LOCKREF 130 select ARCH_USE_SYM_ANNOTATIONS 131 select ARCH_WANTS_NO_INSTR 132 select ARCH_WANT_DEFAULT_BPF_JIT 133 select ARCH_WANT_IPC_PARSE_VERSION 134 select ARCH_WANT_KERNEL_PMD_MKWRITE 135 select ARCH_WANT_LD_ORPHAN_WARN 136 select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP 137 select BUILDTIME_TABLE_SORT 138 select CLONE_BACKWARDS2 139 select DCACHE_WORD_ACCESS if !KMSAN 140 select DMA_OPS if PCI 141 select DYNAMIC_FTRACE if FUNCTION_TRACER 142 select FUNCTION_ALIGNMENT_8B if CC_IS_GCC 143 select FUNCTION_ALIGNMENT_16B if !CC_IS_GCC 144 select GENERIC_ALLOCATOR 145 select GENERIC_CPU_DEVICES 146 select GENERIC_CPU_AUTOPROBE 147 select GENERIC_CPU_VULNERABILITIES 148 select GENERIC_ENTRY 149 select GENERIC_GETTIMEOFDAY 150 select GENERIC_PTDUMP 151 select GENERIC_SMP_IDLE_THREAD 152 select GENERIC_TIME_VSYSCALL 153 select GENERIC_VDSO_TIME_NS 154 select GENERIC_IOREMAP if PCI 155 select HAVE_ALIGNED_STRUCT_PAGE 156 select HAVE_ARCH_AUDITSYSCALL 157 select HAVE_ARCH_JUMP_LABEL 158 select HAVE_ARCH_JUMP_LABEL_RELATIVE 159 select HAVE_ARCH_KASAN 160 select HAVE_ARCH_KASAN_VMALLOC 161 select HAVE_ARCH_KCSAN 162 select HAVE_ARCH_KMSAN 163 select HAVE_ARCH_KFENCE 164 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 165 select HAVE_ARCH_SECCOMP_FILTER 166 select HAVE_ARCH_SOFT_DIRTY 167 select HAVE_ARCH_STACKLEAK 168 select HAVE_ARCH_TRACEHOOK 169 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 170 select HAVE_ARCH_VMAP_STACK 171 select HAVE_ASM_MODVERSIONS 172 select HAVE_CMPXCHG_DOUBLE 173 select HAVE_CMPXCHG_LOCAL 174 select HAVE_DEBUG_KMEMLEAK 175 select HAVE_DMA_CONTIGUOUS 176 select HAVE_DYNAMIC_FTRACE 177 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 178 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 179 select HAVE_DYNAMIC_FTRACE_WITH_REGS 180 select HAVE_EBPF_JIT if HAVE_MARCH_Z196_FEATURES 181 select HAVE_EFFICIENT_UNALIGNED_ACCESS 182 select HAVE_GUP_FAST 183 select HAVE_FENTRY 184 select HAVE_FTRACE_MCOUNT_RECORD 185 select HAVE_FUNCTION_ARG_ACCESS_API 186 select HAVE_FUNCTION_ERROR_INJECTION 187 select HAVE_FUNCTION_GRAPH_RETVAL 188 select HAVE_FUNCTION_GRAPH_TRACER 189 select HAVE_FUNCTION_TRACER 190 select HAVE_GCC_PLUGINS 191 select HAVE_GENERIC_VDSO 192 select HAVE_IOREMAP_PROT if PCI 193 select HAVE_KERNEL_BZIP2 194 select HAVE_KERNEL_GZIP 195 select HAVE_KERNEL_LZ4 196 select HAVE_KERNEL_LZMA 197 select HAVE_KERNEL_LZO 198 select HAVE_KERNEL_UNCOMPRESSED 199 select HAVE_KERNEL_XZ 200 select HAVE_KERNEL_ZSTD 201 select HAVE_KPROBES 202 select HAVE_KPROBES_ON_FTRACE 203 select HAVE_KRETPROBES 204 select HAVE_LIVEPATCH 205 select HAVE_MEMBLOCK_PHYS_MAP 206 select HAVE_MOD_ARCH_SPECIFIC 207 select HAVE_NMI 208 select HAVE_NOP_MCOUNT 209 select HAVE_PAGE_SIZE_4KB 210 select HAVE_PCI 211 select HAVE_PERF_EVENTS 212 select HAVE_PERF_REGS 213 select HAVE_PERF_USER_STACK_DUMP 214 select HAVE_REGS_AND_STACK_ACCESS_API 215 select HAVE_RELIABLE_STACKTRACE 216 select HAVE_RETHOOK 217 select HAVE_RSEQ 218 select HAVE_SAMPLE_FTRACE_DIRECT 219 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 220 select HAVE_SETUP_PER_CPU_AREA 221 select HAVE_SOFTIRQ_ON_OWN_STACK 222 select HAVE_SYSCALL_TRACEPOINTS 223 select HAVE_VIRT_CPU_ACCOUNTING 224 select HAVE_VIRT_CPU_ACCOUNTING_IDLE 225 select IOMMU_HELPER if PCI 226 select IOMMU_SUPPORT if PCI 227 select MMU_GATHER_MERGE_VMAS 228 select MMU_GATHER_NO_GATHER 229 select MMU_GATHER_RCU_TABLE_FREE 230 select MODULES_USE_ELF_RELA 231 select NEED_DMA_MAP_STATE if PCI 232 select NEED_PER_CPU_EMBED_FIRST_CHUNK 233 select NEED_SG_DMA_LENGTH if PCI 234 select OLD_SIGACTION 235 select OLD_SIGSUSPEND3 236 select PCI_DOMAINS if PCI 237 select PCI_MSI if PCI 238 select PCI_MSI_ARCH_FALLBACKS if PCI_MSI 239 select SPARSE_IRQ 240 select SWIOTLB 241 select SYSCTL_EXCEPTION_TRACE 242 select THREAD_INFO_IN_TASK 243 select TRACE_IRQFLAGS_SUPPORT 244 select TTY 245 select USER_STACKTRACE_SUPPORT 246 select VDSO_GETRANDOM 247 select VIRT_CPU_ACCOUNTING 248 select ZONE_DMA 249 # Note: keep the above list sorted alphabetically 250 251config SCHED_OMIT_FRAME_POINTER 252 def_bool y 253 254config PGTABLE_LEVELS 255 int 256 default 5 257 258source "kernel/livepatch/Kconfig" 259 260config ARCH_SUPPORTS_KEXEC 261 def_bool y 262 263config ARCH_SUPPORTS_KEXEC_FILE 264 def_bool y 265 266config ARCH_SUPPORTS_KEXEC_SIG 267 def_bool MODULE_SIG_FORMAT 268 269config ARCH_SUPPORTS_KEXEC_PURGATORY 270 def_bool y 271 272config ARCH_SUPPORTS_CRASH_DUMP 273 def_bool y 274 help 275 Refer to <file:Documentation/arch/s390/zfcpdump.rst> for more details on this. 276 This option also enables s390 zfcpdump. 277 See also <file:Documentation/arch/s390/zfcpdump.rst> 278 279menu "Processor type and features" 280 281config HAVE_MARCH_Z10_FEATURES 282 def_bool n 283 284config HAVE_MARCH_Z196_FEATURES 285 def_bool n 286 select HAVE_MARCH_Z10_FEATURES 287 288config HAVE_MARCH_ZEC12_FEATURES 289 def_bool n 290 select HAVE_MARCH_Z196_FEATURES 291 292config HAVE_MARCH_Z13_FEATURES 293 def_bool n 294 select HAVE_MARCH_ZEC12_FEATURES 295 296config HAVE_MARCH_Z14_FEATURES 297 def_bool n 298 select HAVE_MARCH_Z13_FEATURES 299 300config HAVE_MARCH_Z15_FEATURES 301 def_bool n 302 select HAVE_MARCH_Z14_FEATURES 303 304config HAVE_MARCH_Z16_FEATURES 305 def_bool n 306 select HAVE_MARCH_Z15_FEATURES 307 308choice 309 prompt "Processor type" 310 default MARCH_Z196 311 312config MARCH_Z10 313 bool "IBM System z10" 314 select HAVE_MARCH_Z10_FEATURES 315 depends on $(cc-option,-march=z10) 316 help 317 Select this to enable optimizations for IBM System z10 (2097 and 2098 318 series). This is the oldest machine generation currently supported. 319 320config MARCH_Z196 321 bool "IBM zEnterprise 114 and 196" 322 select HAVE_MARCH_Z196_FEATURES 323 depends on $(cc-option,-march=z196) 324 help 325 Select this to enable optimizations for IBM zEnterprise 114 and 196 326 (2818 and 2817 series). The kernel will be slightly faster but will 327 not work on older machines. 328 329config MARCH_ZEC12 330 bool "IBM zBC12 and zEC12" 331 select HAVE_MARCH_ZEC12_FEATURES 332 depends on $(cc-option,-march=zEC12) 333 help 334 Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and 335 2827 series). The kernel will be slightly faster but will not work on 336 older machines. 337 338config MARCH_Z13 339 bool "IBM z13s and z13" 340 select HAVE_MARCH_Z13_FEATURES 341 depends on $(cc-option,-march=z13) 342 help 343 Select this to enable optimizations for IBM z13s and z13 (2965 and 344 2964 series). The kernel will be slightly faster but will not work on 345 older machines. 346 347config MARCH_Z14 348 bool "IBM z14 ZR1 and z14" 349 select HAVE_MARCH_Z14_FEATURES 350 depends on $(cc-option,-march=z14) 351 help 352 Select this to enable optimizations for IBM z14 ZR1 and z14 (3907 353 and 3906 series). The kernel will be slightly faster but will not 354 work on older machines. 355 356config MARCH_Z15 357 bool "IBM z15" 358 select HAVE_MARCH_Z15_FEATURES 359 depends on $(cc-option,-march=z15) 360 help 361 Select this to enable optimizations for IBM z15 (8562 362 and 8561 series). The kernel will be slightly faster but will not 363 work on older machines. 364 365config MARCH_Z16 366 bool "IBM z16" 367 select HAVE_MARCH_Z16_FEATURES 368 depends on $(cc-option,-march=z16) 369 help 370 Select this to enable optimizations for IBM z16 (3931 and 371 3932 series). 372 373endchoice 374 375config MARCH_Z10_TUNE 376 def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT 377 378config MARCH_Z196_TUNE 379 def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT 380 381config MARCH_ZEC12_TUNE 382 def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT 383 384config MARCH_Z13_TUNE 385 def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT 386 387config MARCH_Z14_TUNE 388 def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT 389 390config MARCH_Z15_TUNE 391 def_bool TUNE_Z15 || MARCH_Z15 && TUNE_DEFAULT 392 393config MARCH_Z16_TUNE 394 def_bool TUNE_Z16 || MARCH_Z16 && TUNE_DEFAULT 395 396choice 397 prompt "Tune code generation" 398 default TUNE_DEFAULT 399 help 400 Cause the compiler to tune (-mtune) the generated code for a machine. 401 This will make the code run faster on the selected machine but 402 somewhat slower on other machines. 403 This option only changes how the compiler emits instructions, not the 404 selection of instructions itself, so the resulting kernel will run on 405 all other machines. 406 407config TUNE_DEFAULT 408 bool "Default" 409 help 410 Tune the generated code for the target processor for which the kernel 411 will be compiled. 412 413config TUNE_Z10 414 bool "IBM System z10" 415 416config TUNE_Z196 417 bool "IBM zEnterprise 114 and 196" 418 depends on $(cc-option,-mtune=z196) 419 420config TUNE_ZEC12 421 bool "IBM zBC12 and zEC12" 422 depends on $(cc-option,-mtune=zEC12) 423 424config TUNE_Z13 425 bool "IBM z13s and z13" 426 depends on $(cc-option,-mtune=z13) 427 428config TUNE_Z14 429 bool "IBM z14 ZR1 and z14" 430 depends on $(cc-option,-mtune=z14) 431 432config TUNE_Z15 433 bool "IBM z15" 434 depends on $(cc-option,-mtune=z15) 435 436config TUNE_Z16 437 bool "IBM z16" 438 depends on $(cc-option,-mtune=z16) 439 440endchoice 441 442config 64BIT 443 def_bool y 444 445config COMMAND_LINE_SIZE 446 int "Maximum size of kernel command line" 447 default 4096 448 range 896 1048576 449 help 450 This allows you to specify the maximum length of the kernel command 451 line. 452 453config COMPAT 454 def_bool n 455 prompt "Kernel support for 31 bit emulation" 456 select ARCH_WANT_OLD_COMPAT_IPC 457 select COMPAT_OLD_SIGACTION 458 select HAVE_UID16 459 depends on MULTIUSER 460 depends on !CC_IS_CLANG && !LD_IS_LLD 461 help 462 Select this option if you want to enable your system kernel to 463 handle system-calls from ELF binaries for 31 bit ESA. This option 464 (and some other stuff like libraries and such) is needed for 465 executing 31 bit applications. 466 467 If unsure say N. 468 469config SMP 470 def_bool y 471 472config NR_CPUS 473 int "Maximum number of CPUs (2-512)" 474 range 2 512 475 default "64" 476 help 477 This allows you to specify the maximum number of CPUs which this 478 kernel will support. The maximum supported value is 512 and the 479 minimum value which makes sense is 2. 480 481 This is purely to save memory - each supported CPU adds 482 approximately sixteen kilobytes to the kernel image. 483 484config HOTPLUG_CPU 485 def_bool y 486 487config NUMA 488 bool "NUMA support" 489 depends on SCHED_TOPOLOGY 490 default n 491 help 492 Enable NUMA support 493 494 This option adds NUMA support to the kernel. 495 496config NODES_SHIFT 497 int 498 depends on NUMA 499 default "1" 500 501config SCHED_SMT 502 def_bool n 503 504config SCHED_MC 505 def_bool n 506 507config SCHED_TOPOLOGY 508 def_bool y 509 prompt "Topology scheduler support" 510 select SCHED_SMT 511 select SCHED_MC 512 help 513 Topology scheduler support improves the CPU scheduler's decision 514 making when dealing with machines that have multi-threading, 515 multiple cores or multiple books. 516 517source "kernel/Kconfig.hz" 518 519config CERT_STORE 520 bool "Get user certificates via DIAG320" 521 depends on KEYS 522 select CRYPTO_LIB_SHA256 523 help 524 Enable this option if you want to access user-provided secure boot 525 certificates via DIAG 0x320. 526 527 These certificates will be made available via the keyring named 528 'cert_store'. 529 530config KERNEL_NOBP 531 def_bool n 532 prompt "Enable modified branch prediction for the kernel by default" 533 help 534 If this option is selected the kernel will switch to a modified 535 branch prediction mode if the firmware interface is available. 536 The modified branch prediction mode improves the behaviour in 537 regard to speculative execution. 538 539 With the option enabled the kernel parameter "nobp=0" or "nospec" 540 can be used to run the kernel in the normal branch prediction mode. 541 542 With the option disabled the modified branch prediction mode is 543 enabled with the "nobp=1" kernel parameter. 544 545 If unsure, say N. 546 547config EXPOLINE 548 def_bool n 549 depends on $(cc-option,-mindirect-branch=thunk) 550 prompt "Avoid speculative indirect branches in the kernel" 551 help 552 Compile the kernel with the expoline compiler options to guard 553 against kernel-to-user data leaks by avoiding speculative indirect 554 branches. 555 Requires a compiler with -mindirect-branch=thunk support for full 556 protection. The kernel may run slower. 557 558 If unsure, say N. 559 560config EXPOLINE_EXTERN 561 def_bool y if EXPOLINE 562 depends on EXPOLINE 563 depends on CC_IS_GCC && GCC_VERSION >= 110200 564 depends on $(success,$(srctree)/arch/s390/tools/gcc-thunk-extern.sh $(CC)) 565 prompt "Generate expolines as extern functions." 566 help 567 This option is required for some tooling like kpatch. The kernel is 568 compiled with -mindirect-branch=thunk-extern and requires a newer 569 compiler. 570 571 If unsure, say N. 572 573choice 574 prompt "Expoline default" 575 depends on EXPOLINE 576 default EXPOLINE_FULL 577 578config EXPOLINE_OFF 579 bool "spectre_v2=off" 580 581config EXPOLINE_AUTO 582 bool "spectre_v2=auto" 583 584config EXPOLINE_FULL 585 bool "spectre_v2=on" 586 587endchoice 588 589config RELOCATABLE 590 def_bool y 591 help 592 This builds a kernel image that retains relocation information 593 so it can be loaded at an arbitrary address. 594 The relocations make the kernel image about 15% larger (compressed 595 10%), but are discarded at runtime. 596 Note: this option exists only for documentation purposes, please do 597 not remove it. 598 599config RANDOMIZE_BASE 600 bool "Randomize the address of the kernel image (KASLR)" 601 default y 602 help 603 In support of Kernel Address Space Layout Randomization (KASLR), 604 this randomizes the address at which the kernel image is loaded, 605 as a security feature that deters exploit attempts relying on 606 knowledge of the location of kernel internals. 607 608config RANDOMIZE_IDENTITY_BASE 609 bool "Randomize the address of the identity mapping base" 610 depends on RANDOMIZE_BASE 611 default DEBUG_VM 612 help 613 The identity mapping base address is pinned to zero by default. 614 Allow randomization of that base to expose otherwise missed 615 notion of physical and virtual addresses of data structures. 616 That does not have any impact on the base address at which the 617 kernel image is loaded. 618 619 If unsure, say N 620 621config KERNEL_IMAGE_BASE 622 hex "Kernel image base address" 623 range 0x100000 0x1FFFFFE0000000 if !KASAN 624 range 0x100000 0x1BFFFFE0000000 if KASAN 625 default 0x3FFE0000000 if !KASAN 626 default 0x7FFFE0000000 if KASAN 627 help 628 This is the address at which the kernel image is loaded in case 629 Kernel Address Space Layout Randomization (KASLR) is disabled. 630 631 In case the Protected virtualization guest support is enabled the 632 Ultravisor imposes a virtual address limit. If the value of this 633 option leads to the kernel image exceeding the Ultravisor limit, 634 this option is ignored and the image is loaded below the limit. 635 636 If the value of this option leads to the kernel image overlapping 637 the virtual memory where other data structures are located, this 638 option is ignored and the image is loaded above the structures. 639 640endmenu 641 642menu "Memory setup" 643 644config ARCH_SPARSEMEM_ENABLE 645 def_bool y 646 select SPARSEMEM_VMEMMAP_ENABLE 647 select SPARSEMEM_VMEMMAP 648 649config ARCH_SPARSEMEM_DEFAULT 650 def_bool y 651 652config MAX_PHYSMEM_BITS 653 int "Maximum size of supported physical memory in bits (42-53)" 654 range 42 53 655 default "46" 656 help 657 This option specifies the maximum supported size of physical memory 658 in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB). 659 Increasing the number of bits also increases the kernel image size. 660 By default 46 bits (64TB) are supported. 661 662config CHECK_STACK 663 def_bool y 664 depends on !VMAP_STACK 665 prompt "Detect kernel stack overflow" 666 help 667 This option enables the compiler option -mstack-guard and 668 -mstack-size if they are available. If the compiler supports them 669 it will emit additional code to each function prolog to trigger 670 an illegal operation if the kernel stack is about to overflow. 671 672 Say N if you are unsure. 673 674config STACK_GUARD 675 int "Size of the guard area (128-1024)" 676 range 128 1024 677 depends on CHECK_STACK 678 default "256" 679 help 680 This allows you to specify the size of the guard area at the lower 681 end of the kernel stack. If the kernel stack points into the guard 682 area on function entry an illegal operation is triggered. The size 683 needs to be a power of 2. Please keep in mind that the size of an 684 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit. 685 The minimum size for the stack guard should be 256 for 31 bit and 686 512 for 64 bit. 687 688endmenu 689 690menu "I/O subsystem" 691 692config QDIO 693 def_tristate y 694 prompt "QDIO support" 695 help 696 This driver provides the Queued Direct I/O base support for 697 IBM System z. 698 699 To compile this driver as a module, choose M here: the 700 module will be called qdio. 701 702 If unsure, say Y. 703 704if PCI 705 706config PCI_NR_FUNCTIONS 707 int "Maximum number of PCI functions (1-4096)" 708 range 1 4096 709 default "512" 710 help 711 This allows you to specify the maximum number of PCI functions which 712 this kernel will support. 713 714endif # PCI 715 716config HAS_IOMEM 717 def_bool PCI 718 719config CHSC_SCH 720 def_tristate m 721 prompt "Support for CHSC subchannels" 722 help 723 This driver allows usage of CHSC subchannels. A CHSC subchannel 724 is usually present on LPAR only. 725 The driver creates a device /dev/chsc, which may be used to 726 obtain I/O configuration information about the machine and 727 to issue asynchronous chsc commands (DANGEROUS). 728 You will usually only want to use this interface on a special 729 LPAR designated for system management. 730 731 To compile this driver as a module, choose M here: the 732 module will be called chsc_sch. 733 734 If unsure, say N. 735 736config SCM_BUS 737 def_bool y 738 prompt "SCM bus driver" 739 help 740 Bus driver for Storage Class Memory. 741 742config EADM_SCH 743 def_tristate m 744 prompt "Support for EADM subchannels" 745 depends on SCM_BUS 746 help 747 This driver allows usage of EADM subchannels. EADM subchannels act 748 as a communication vehicle for SCM increments. 749 750 To compile this driver as a module, choose M here: the 751 module will be called eadm_sch. 752 753config AP 754 def_tristate y 755 prompt "Support for Adjunct Processors (ap)" 756 help 757 This driver allows usage to Adjunct Processor (AP) devices via 758 the ap bus, cards and queues. Supported Adjunct Processors are 759 the CryptoExpress Cards (CEX). 760 761 To compile this driver as a module, choose M here: the 762 module will be called ap. 763 764 If unsure, say Y (default). 765 766config AP_DEBUG 767 def_bool n 768 prompt "Enable debug features for Adjunct Processor (ap) devices" 769 depends on AP 770 help 771 Say 'Y' here to enable some additional debug features for Adjunct 772 Processor (ap) devices. 773 774 There will be some more sysfs attributes displayed for ap queues. 775 776 Do not enable on production level kernel build. 777 778 If unsure, say N. 779 780config VFIO_CCW 781 def_tristate n 782 prompt "Support for VFIO-CCW subchannels" 783 depends on VFIO 784 select VFIO_MDEV 785 help 786 This driver allows usage of I/O subchannels via VFIO-CCW. 787 788 To compile this driver as a module, choose M here: the 789 module will be called vfio_ccw. 790 791config VFIO_AP 792 def_tristate n 793 prompt "VFIO support for AP devices" 794 depends on KVM 795 depends on VFIO 796 depends on AP 797 select VFIO_MDEV 798 help 799 This driver grants access to Adjunct Processor (AP) devices 800 via the VFIO mediated device interface. 801 802 To compile this driver as a module, choose M here: the module 803 will be called vfio_ap. 804 805endmenu 806 807config CCW 808 def_bool y 809 810config HAVE_PNETID 811 tristate 812 default (SMC || CCWGROUP) 813 814menu "Virtualization" 815 816config PFAULT 817 def_bool y 818 prompt "Pseudo page fault support" 819 help 820 Select this option, if you want to use PFAULT pseudo page fault 821 handling under VM. If running native or in LPAR, this option 822 has no effect. If your VM does not support PFAULT, PAGEEX 823 pseudo page fault handling will be used. 824 Note that VM 4.2 supports PFAULT but has a bug in its 825 implementation that causes some problems. 826 Everybody who wants to run Linux under VM != VM4.2 should select 827 this option. 828 829config CMM 830 def_tristate n 831 prompt "Cooperative memory management" 832 help 833 Select this option, if you want to enable the kernel interface 834 to reduce the memory size of the system. This is accomplished 835 by allocating pages of memory and put them "on hold". This only 836 makes sense for a system running under VM where the unused pages 837 will be reused by VM for other guest systems. The interface 838 allows an external monitor to balance memory of many systems. 839 Everybody who wants to run Linux under VM should select this 840 option. 841 842config CMM_IUCV 843 def_bool y 844 prompt "IUCV special message interface to cooperative memory management" 845 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV) 846 help 847 Select this option to enable the special message interface to 848 the cooperative memory management. 849 850config APPLDATA_BASE 851 def_bool n 852 prompt "Linux - VM Monitor Stream, base infrastructure" 853 depends on PROC_SYSCTL 854 help 855 This provides a kernel interface for creating and updating z/VM APPLDATA 856 monitor records. The monitor records are updated at certain time 857 intervals, once the timer is started. 858 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer, 859 i.e. enables or disables monitoring on the Linux side. 860 A custom interval value (in seconds) can be written to 861 /proc/appldata/interval. 862 863 Defaults are 60 seconds interval and timer off. 864 The /proc entries can also be read from, showing the current settings. 865 866config APPLDATA_MEM 867 def_tristate m 868 prompt "Monitor memory management statistics" 869 depends on APPLDATA_BASE && VM_EVENT_COUNTERS 870 help 871 This provides memory management related data to the Linux - VM Monitor 872 Stream, like paging/swapping rate, memory utilisation, etc. 873 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM 874 APPLDATA monitor record, i.e. enables or disables monitoring this record 875 on the z/VM side. 876 877 Default is disabled. 878 The /proc entry can also be read from, showing the current settings. 879 880 This can also be compiled as a module, which will be called 881 appldata_mem.o. 882 883config APPLDATA_OS 884 def_tristate m 885 prompt "Monitor OS statistics" 886 depends on APPLDATA_BASE 887 help 888 This provides OS related data to the Linux - VM Monitor Stream, like 889 CPU utilisation, etc. 890 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM 891 APPLDATA monitor record, i.e. enables or disables monitoring this record 892 on the z/VM side. 893 894 Default is disabled. 895 This can also be compiled as a module, which will be called 896 appldata_os.o. 897 898config APPLDATA_NET_SUM 899 def_tristate m 900 prompt "Monitor overall network statistics" 901 depends on APPLDATA_BASE && NET 902 help 903 This provides network related data to the Linux - VM Monitor Stream, 904 currently there is only a total sum of network I/O statistics, no 905 per-interface data. 906 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM 907 APPLDATA monitor record, i.e. enables or disables monitoring this record 908 on the z/VM side. 909 910 Default is disabled. 911 This can also be compiled as a module, which will be called 912 appldata_net_sum.o. 913 914config S390_HYPFS 915 def_bool y 916 prompt "s390 hypervisor information" 917 help 918 This provides several binary files at (debugfs)/s390_hypfs/ to 919 provide accounting information in an s390 hypervisor environment. 920 921config S390_HYPFS_FS 922 def_bool n 923 prompt "s390 hypervisor file system support" 924 select SYS_HYPERVISOR 925 depends on S390_HYPFS 926 help 927 This is a virtual file system intended to provide accounting 928 information in an s390 hypervisor environment. This file system 929 is deprecated and should not be used. 930 931 Say N if you are unsure. 932 933source "arch/s390/kvm/Kconfig" 934 935config S390_GUEST 936 def_bool y 937 prompt "s390 support for virtio devices" 938 select TTY 939 select VIRTUALIZATION 940 select VIRTIO 941 help 942 Enabling this option adds support for virtio based paravirtual device 943 drivers on s390. 944 945 Select this option if you want to run the kernel as a guest under 946 the KVM hypervisor. 947 948endmenu 949 950config S390_MODULES_SANITY_TEST_HELPERS 951 def_bool n 952 953menu "Selftests" 954 955config S390_UNWIND_SELFTEST 956 def_tristate n 957 depends on KUNIT 958 default KUNIT_ALL_TESTS 959 prompt "Test unwind functions" 960 help 961 This option enables s390 specific stack unwinder testing kernel 962 module. This option is not useful for distributions or general 963 kernels, but only for kernel developers working on architecture code. 964 965 Say N if you are unsure. 966 967config S390_KPROBES_SANITY_TEST 968 def_tristate n 969 prompt "Enable s390 specific kprobes tests" 970 depends on KPROBES 971 depends on KUNIT 972 help 973 This option enables an s390 specific kprobes test module. This option 974 is not useful for distributions or general kernels, but only for kernel 975 developers working on architecture code. 976 977 Say N if you are unsure. 978 979config S390_MODULES_SANITY_TEST 980 def_tristate n 981 depends on KUNIT 982 default KUNIT_ALL_TESTS 983 prompt "Enable s390 specific modules tests" 984 select S390_MODULES_SANITY_TEST_HELPERS 985 help 986 This option enables an s390 specific modules test. This option is 987 not useful for distributions or general kernels, but only for 988 kernel developers working on architecture code. 989 990 Say N if you are unsure. 991endmenu 992