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