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 GENERIC_HWEIGHT 21 def_bool y 22 23config GENERIC_BUG 24 def_bool y if BUG 25 26config GENERIC_BUG_RELATIVE_POINTERS 27 def_bool y 28 29config GENERIC_LOCKBREAK 30 def_bool y if PREEMPTION 31 32config PGSTE 33 def_bool y if KVM 34 35config AUDIT_ARCH 36 def_bool y 37 38config NO_IOPORT_MAP 39 def_bool y 40 41config PCI_QUIRKS 42 def_bool n 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 S390 53 def_bool y 54 # 55 # Note: keep this list sorted alphabetically 56 # 57 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 58 select ALTERNATE_USER_ADDRESS_SPACE 59 select ARCH_32BIT_USTAT_F_TINODE 60 select ARCH_BINFMT_ELF_STATE 61 select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE 62 select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM 63 select ARCH_ENABLE_MEMORY_HOTREMOVE 64 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 65 select ARCH_HAS_CURRENT_STACK_POINTER 66 select ARCH_HAS_DEBUG_VIRTUAL 67 select ARCH_HAS_DEBUG_VM_PGTABLE 68 select ARCH_HAS_DEBUG_WX 69 select ARCH_HAS_DEVMEM_IS_ALLOWED 70 select ARCH_HAS_ELF_RANDOMIZE 71 select ARCH_HAS_FORCE_DMA_UNENCRYPTED 72 select ARCH_HAS_FORTIFY_SOURCE 73 select ARCH_HAS_GCOV_PROFILE_ALL 74 select ARCH_HAS_GIGANTIC_PAGE 75 select ARCH_HAS_KCOV 76 select ARCH_HAS_MEMBARRIER_SYNC_CORE 77 select ARCH_HAS_MEM_ENCRYPT 78 select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS 79 select ARCH_HAS_PTE_SPECIAL 80 select ARCH_HAS_SCALED_CPUTIME 81 select ARCH_HAS_SET_DIRECT_MAP 82 select ARCH_HAS_SET_MEMORY 83 select ARCH_HAS_STRICT_KERNEL_RWX 84 select ARCH_HAS_STRICT_MODULE_RWX 85 select ARCH_HAS_SYSCALL_WRAPPER 86 select ARCH_HAS_UBSAN 87 select ARCH_HAS_VDSO_DATA 88 select ARCH_HAVE_NMI_SAFE_CMPXCHG 89 select ARCH_INLINE_READ_LOCK 90 select ARCH_INLINE_READ_LOCK_BH 91 select ARCH_INLINE_READ_LOCK_IRQ 92 select ARCH_INLINE_READ_LOCK_IRQSAVE 93 select ARCH_INLINE_READ_TRYLOCK 94 select ARCH_INLINE_READ_UNLOCK 95 select ARCH_INLINE_READ_UNLOCK_BH 96 select ARCH_INLINE_READ_UNLOCK_IRQ 97 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE 98 select ARCH_INLINE_SPIN_LOCK 99 select ARCH_INLINE_SPIN_LOCK_BH 100 select ARCH_INLINE_SPIN_LOCK_IRQ 101 select ARCH_INLINE_SPIN_LOCK_IRQSAVE 102 select ARCH_INLINE_SPIN_TRYLOCK 103 select ARCH_INLINE_SPIN_TRYLOCK_BH 104 select ARCH_INLINE_SPIN_UNLOCK 105 select ARCH_INLINE_SPIN_UNLOCK_BH 106 select ARCH_INLINE_SPIN_UNLOCK_IRQ 107 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE 108 select ARCH_INLINE_WRITE_LOCK 109 select ARCH_INLINE_WRITE_LOCK_BH 110 select ARCH_INLINE_WRITE_LOCK_IRQ 111 select ARCH_INLINE_WRITE_LOCK_IRQSAVE 112 select ARCH_INLINE_WRITE_TRYLOCK 113 select ARCH_INLINE_WRITE_UNLOCK 114 select ARCH_INLINE_WRITE_UNLOCK_BH 115 select ARCH_INLINE_WRITE_UNLOCK_IRQ 116 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE 117 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE 118 select ARCH_STACKWALK 119 select ARCH_SUPPORTS_ATOMIC_RMW 120 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 121 select ARCH_SUPPORTS_HUGETLBFS 122 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && CC_IS_CLANG 123 select ARCH_SUPPORTS_NUMA_BALANCING 124 select ARCH_SUPPORTS_PER_VMA_LOCK 125 select ARCH_USE_BUILTIN_BSWAP 126 select ARCH_USE_CMPXCHG_LOCKREF 127 select ARCH_USE_SYM_ANNOTATIONS 128 select ARCH_WANTS_NO_INSTR 129 select ARCH_WANT_DEFAULT_BPF_JIT 130 select ARCH_WANT_IPC_PARSE_VERSION 131 select ARCH_WANT_KERNEL_PMD_MKWRITE 132 select ARCH_WANT_LD_ORPHAN_WARN 133 select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP 134 select BUILDTIME_TABLE_SORT 135 select CLONE_BACKWARDS2 136 select DCACHE_WORD_ACCESS if !KMSAN 137 select DMA_OPS if PCI 138 select DYNAMIC_FTRACE if FUNCTION_TRACER 139 select FUNCTION_ALIGNMENT_8B if CC_IS_GCC 140 select FUNCTION_ALIGNMENT_16B if !CC_IS_GCC 141 select GENERIC_ALLOCATOR 142 select GENERIC_CPU_AUTOPROBE 143 select GENERIC_CPU_VULNERABILITIES 144 select GENERIC_ENTRY 145 select GENERIC_GETTIMEOFDAY 146 select GENERIC_PTDUMP 147 select GENERIC_SMP_IDLE_THREAD 148 select GENERIC_TIME_VSYSCALL 149 select GENERIC_VDSO_TIME_NS 150 select GENERIC_IOREMAP if PCI 151 select HAVE_ALIGNED_STRUCT_PAGE 152 select HAVE_ARCH_AUDITSYSCALL 153 select HAVE_ARCH_JUMP_LABEL 154 select HAVE_ARCH_JUMP_LABEL_RELATIVE 155 select HAVE_ARCH_KASAN 156 select HAVE_ARCH_KASAN_VMALLOC 157 select HAVE_ARCH_KCSAN 158 select HAVE_ARCH_KFENCE 159 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 160 select HAVE_ARCH_SECCOMP_FILTER 161 select HAVE_ARCH_SOFT_DIRTY 162 select HAVE_ARCH_STACKLEAK 163 select HAVE_ARCH_TRACEHOOK 164 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 165 select HAVE_ARCH_VMAP_STACK 166 select HAVE_ASM_MODVERSIONS 167 select HAVE_CMPXCHG_DOUBLE 168 select HAVE_CMPXCHG_LOCAL 169 select HAVE_DEBUG_KMEMLEAK 170 select HAVE_DMA_CONTIGUOUS 171 select HAVE_DYNAMIC_FTRACE 172 select HAVE_DYNAMIC_FTRACE_WITH_ARGS 173 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 174 select HAVE_DYNAMIC_FTRACE_WITH_REGS 175 select HAVE_EBPF_JIT if HAVE_MARCH_Z196_FEATURES 176 select HAVE_EFFICIENT_UNALIGNED_ACCESS 177 select HAVE_FAST_GUP 178 select HAVE_FENTRY 179 select HAVE_FTRACE_MCOUNT_RECORD 180 select HAVE_FUNCTION_ARG_ACCESS_API 181 select HAVE_FUNCTION_ERROR_INJECTION 182 select HAVE_FUNCTION_GRAPH_RETVAL 183 select HAVE_FUNCTION_GRAPH_TRACER 184 select HAVE_FUNCTION_TRACER 185 select HAVE_GCC_PLUGINS 186 select HAVE_GENERIC_VDSO 187 select HAVE_IOREMAP_PROT if PCI 188 select HAVE_KERNEL_BZIP2 189 select HAVE_KERNEL_GZIP 190 select HAVE_KERNEL_LZ4 191 select HAVE_KERNEL_LZMA 192 select HAVE_KERNEL_LZO 193 select HAVE_KERNEL_UNCOMPRESSED 194 select HAVE_KERNEL_XZ 195 select HAVE_KERNEL_ZSTD 196 select HAVE_KPROBES 197 select HAVE_KPROBES_ON_FTRACE 198 select HAVE_KRETPROBES 199 select HAVE_LIVEPATCH 200 select HAVE_MEMBLOCK_PHYS_MAP 201 select HAVE_MOD_ARCH_SPECIFIC 202 select HAVE_NMI 203 select HAVE_NOP_MCOUNT 204 select HAVE_PAGE_SIZE_4KB 205 select HAVE_PCI 206 select HAVE_PERF_EVENTS 207 select HAVE_PERF_REGS 208 select HAVE_PERF_USER_STACK_DUMP 209 select HAVE_REGS_AND_STACK_ACCESS_API 210 select HAVE_RELIABLE_STACKTRACE 211 select HAVE_RETHOOK 212 select HAVE_RSEQ 213 select HAVE_SAMPLE_FTRACE_DIRECT 214 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 215 select HAVE_SETUP_PER_CPU_AREA 216 select HAVE_SOFTIRQ_ON_OWN_STACK 217 select HAVE_SYSCALL_TRACEPOINTS 218 select HAVE_VIRT_CPU_ACCOUNTING 219 select HAVE_VIRT_CPU_ACCOUNTING_IDLE 220 select IOMMU_HELPER if PCI 221 select IOMMU_SUPPORT if PCI 222 select MMU_GATHER_MERGE_VMAS 223 select MMU_GATHER_NO_GATHER 224 select MMU_GATHER_RCU_TABLE_FREE 225 select MODULES_USE_ELF_RELA 226 select NEED_DMA_MAP_STATE if PCI 227 select NEED_PER_CPU_EMBED_FIRST_CHUNK 228 select NEED_SG_DMA_LENGTH if PCI 229 select OLD_SIGACTION 230 select OLD_SIGSUSPEND3 231 select PCI_DOMAINS if PCI 232 select PCI_MSI if PCI 233 select PCI_MSI_ARCH_FALLBACKS if PCI_MSI 234 select SPARSE_IRQ 235 select SWIOTLB 236 select SYSCTL_EXCEPTION_TRACE 237 select THREAD_INFO_IN_TASK 238 select TRACE_IRQFLAGS_SUPPORT 239 select TTY 240 select USER_STACKTRACE_SUPPORT 241 select VIRT_CPU_ACCOUNTING 242 select ZONE_DMA 243 # Note: keep the above list sorted alphabetically 244 245config SCHED_OMIT_FRAME_POINTER 246 def_bool y 247 248config PGTABLE_LEVELS 249 int 250 default 5 251 252source "kernel/livepatch/Kconfig" 253 254config ARCH_SUPPORTS_KEXEC 255 def_bool y 256 257config ARCH_SUPPORTS_KEXEC_FILE 258 def_bool y 259 260config ARCH_SUPPORTS_KEXEC_SIG 261 def_bool MODULE_SIG_FORMAT 262 263config ARCH_SUPPORTS_KEXEC_PURGATORY 264 def_bool y 265 266config ARCH_SUPPORTS_CRASH_DUMP 267 def_bool y 268 help 269 Refer to <file:Documentation/arch/s390/zfcpdump.rst> for more details on this. 270 This option also enables s390 zfcpdump. 271 See also <file:Documentation/arch/s390/zfcpdump.rst> 272 273menu "Processor type and features" 274 275config HAVE_MARCH_Z10_FEATURES 276 def_bool n 277 278config HAVE_MARCH_Z196_FEATURES 279 def_bool n 280 select HAVE_MARCH_Z10_FEATURES 281 282config HAVE_MARCH_ZEC12_FEATURES 283 def_bool n 284 select HAVE_MARCH_Z196_FEATURES 285 286config HAVE_MARCH_Z13_FEATURES 287 def_bool n 288 select HAVE_MARCH_ZEC12_FEATURES 289 290config HAVE_MARCH_Z14_FEATURES 291 def_bool n 292 select HAVE_MARCH_Z13_FEATURES 293 294config HAVE_MARCH_Z15_FEATURES 295 def_bool n 296 select HAVE_MARCH_Z14_FEATURES 297 298config HAVE_MARCH_Z16_FEATURES 299 def_bool n 300 select HAVE_MARCH_Z15_FEATURES 301 302choice 303 prompt "Processor type" 304 default MARCH_Z196 305 306config MARCH_Z10 307 bool "IBM System z10" 308 select HAVE_MARCH_Z10_FEATURES 309 depends on $(cc-option,-march=z10) 310 help 311 Select this to enable optimizations for IBM System z10 (2097 and 2098 312 series). This is the oldest machine generation currently supported. 313 314config MARCH_Z196 315 bool "IBM zEnterprise 114 and 196" 316 select HAVE_MARCH_Z196_FEATURES 317 depends on $(cc-option,-march=z196) 318 help 319 Select this to enable optimizations for IBM zEnterprise 114 and 196 320 (2818 and 2817 series). The kernel will be slightly faster but will 321 not work on older machines. 322 323config MARCH_ZEC12 324 bool "IBM zBC12 and zEC12" 325 select HAVE_MARCH_ZEC12_FEATURES 326 depends on $(cc-option,-march=zEC12) 327 help 328 Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and 329 2827 series). The kernel will be slightly faster but will not work on 330 older machines. 331 332config MARCH_Z13 333 bool "IBM z13s and z13" 334 select HAVE_MARCH_Z13_FEATURES 335 depends on $(cc-option,-march=z13) 336 help 337 Select this to enable optimizations for IBM z13s and z13 (2965 and 338 2964 series). The kernel will be slightly faster but will not work on 339 older machines. 340 341config MARCH_Z14 342 bool "IBM z14 ZR1 and z14" 343 select HAVE_MARCH_Z14_FEATURES 344 depends on $(cc-option,-march=z14) 345 help 346 Select this to enable optimizations for IBM z14 ZR1 and z14 (3907 347 and 3906 series). The kernel will be slightly faster but will not 348 work on older machines. 349 350config MARCH_Z15 351 bool "IBM z15" 352 select HAVE_MARCH_Z15_FEATURES 353 depends on $(cc-option,-march=z15) 354 help 355 Select this to enable optimizations for IBM z15 (8562 356 and 8561 series). The kernel will be slightly faster but will not 357 work on older machines. 358 359config MARCH_Z16 360 bool "IBM z16" 361 select HAVE_MARCH_Z16_FEATURES 362 depends on $(cc-option,-march=z16) 363 help 364 Select this to enable optimizations for IBM z16 (3931 and 365 3932 series). 366 367endchoice 368 369config MARCH_Z10_TUNE 370 def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT 371 372config MARCH_Z196_TUNE 373 def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT 374 375config MARCH_ZEC12_TUNE 376 def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT 377 378config MARCH_Z13_TUNE 379 def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT 380 381config MARCH_Z14_TUNE 382 def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT 383 384config MARCH_Z15_TUNE 385 def_bool TUNE_Z15 || MARCH_Z15 && TUNE_DEFAULT 386 387config MARCH_Z16_TUNE 388 def_bool TUNE_Z16 || MARCH_Z16 && TUNE_DEFAULT 389 390choice 391 prompt "Tune code generation" 392 default TUNE_DEFAULT 393 help 394 Cause the compiler to tune (-mtune) the generated code for a machine. 395 This will make the code run faster on the selected machine but 396 somewhat slower on other machines. 397 This option only changes how the compiler emits instructions, not the 398 selection of instructions itself, so the resulting kernel will run on 399 all other machines. 400 401config TUNE_DEFAULT 402 bool "Default" 403 help 404 Tune the generated code for the target processor for which the kernel 405 will be compiled. 406 407config TUNE_Z10 408 bool "IBM System z10" 409 410config TUNE_Z196 411 bool "IBM zEnterprise 114 and 196" 412 depends on $(cc-option,-mtune=z196) 413 414config TUNE_ZEC12 415 bool "IBM zBC12 and zEC12" 416 depends on $(cc-option,-mtune=zEC12) 417 418config TUNE_Z13 419 bool "IBM z13s and z13" 420 depends on $(cc-option,-mtune=z13) 421 422config TUNE_Z14 423 bool "IBM z14 ZR1 and z14" 424 depends on $(cc-option,-mtune=z14) 425 426config TUNE_Z15 427 bool "IBM z15" 428 depends on $(cc-option,-mtune=z15) 429 430config TUNE_Z16 431 bool "IBM z16" 432 depends on $(cc-option,-mtune=z16) 433 434endchoice 435 436config 64BIT 437 def_bool y 438 439config COMMAND_LINE_SIZE 440 int "Maximum size of kernel command line" 441 default 4096 442 range 896 1048576 443 help 444 This allows you to specify the maximum length of the kernel command 445 line. 446 447config COMPAT 448 def_bool n 449 prompt "Kernel support for 31 bit emulation" 450 select ARCH_WANT_OLD_COMPAT_IPC 451 select COMPAT_OLD_SIGACTION 452 select HAVE_UID16 453 depends on MULTIUSER 454 depends on !CC_IS_CLANG && !LD_IS_LLD 455 help 456 Select this option if you want to enable your system kernel to 457 handle system-calls from ELF binaries for 31 bit ESA. This option 458 (and some other stuff like libraries and such) is needed for 459 executing 31 bit applications. 460 461 If unsure say N. 462 463config SMP 464 def_bool y 465 466config NR_CPUS 467 int "Maximum number of CPUs (2-512)" 468 range 2 512 469 default "64" 470 help 471 This allows you to specify the maximum number of CPUs which this 472 kernel will support. The maximum supported value is 512 and the 473 minimum value which makes sense is 2. 474 475 This is purely to save memory - each supported CPU adds 476 approximately sixteen kilobytes to the kernel image. 477 478config HOTPLUG_CPU 479 def_bool y 480 481config NUMA 482 bool "NUMA support" 483 depends on SCHED_TOPOLOGY 484 default n 485 help 486 Enable NUMA support 487 488 This option adds NUMA support to the kernel. 489 490config NODES_SHIFT 491 int 492 depends on NUMA 493 default "1" 494 495config SCHED_SMT 496 def_bool n 497 498config SCHED_MC 499 def_bool n 500 501config SCHED_TOPOLOGY 502 def_bool y 503 prompt "Topology scheduler support" 504 select SCHED_SMT 505 select SCHED_MC 506 help 507 Topology scheduler support improves the CPU scheduler's decision 508 making when dealing with machines that have multi-threading, 509 multiple cores or multiple books. 510 511source "kernel/Kconfig.hz" 512 513config CERT_STORE 514 bool "Get user certificates via DIAG320" 515 depends on KEYS 516 select CRYPTO_LIB_SHA256 517 help 518 Enable this option if you want to access user-provided secure boot 519 certificates via DIAG 0x320. 520 521 These certificates will be made available via the keyring named 522 'cert_store'. 523 524config KERNEL_NOBP 525 def_bool n 526 prompt "Enable modified branch prediction for the kernel by default" 527 help 528 If this option is selected the kernel will switch to a modified 529 branch prediction mode if the firmware interface is available. 530 The modified branch prediction mode improves the behaviour in 531 regard to speculative execution. 532 533 With the option enabled the kernel parameter "nobp=0" or "nospec" 534 can be used to run the kernel in the normal branch prediction mode. 535 536 With the option disabled the modified branch prediction mode is 537 enabled with the "nobp=1" kernel parameter. 538 539 If unsure, say N. 540 541config EXPOLINE 542 def_bool n 543 depends on $(cc-option,-mindirect-branch=thunk) 544 prompt "Avoid speculative indirect branches in the kernel" 545 help 546 Compile the kernel with the expoline compiler options to guard 547 against kernel-to-user data leaks by avoiding speculative indirect 548 branches. 549 Requires a compiler with -mindirect-branch=thunk support for full 550 protection. The kernel may run slower. 551 552 If unsure, say N. 553 554config EXPOLINE_EXTERN 555 def_bool n 556 depends on EXPOLINE 557 depends on CC_IS_GCC && GCC_VERSION >= 110200 558 depends on $(success,$(srctree)/arch/s390/tools/gcc-thunk-extern.sh $(CC)) 559 prompt "Generate expolines as extern functions." 560 help 561 This option is required for some tooling like kpatch. The kernel is 562 compiled with -mindirect-branch=thunk-extern and requires a newer 563 compiler. 564 565 If unsure, say N. 566 567choice 568 prompt "Expoline default" 569 depends on EXPOLINE 570 default EXPOLINE_FULL 571 572config EXPOLINE_OFF 573 bool "spectre_v2=off" 574 575config EXPOLINE_AUTO 576 bool "spectre_v2=auto" 577 578config EXPOLINE_FULL 579 bool "spectre_v2=on" 580 581endchoice 582 583config RELOCATABLE 584 def_bool y 585 help 586 This builds a kernel image that retains relocation information 587 so it can be loaded at an arbitrary address. 588 The relocations make the kernel image about 15% larger (compressed 589 10%), but are discarded at runtime. 590 Note: this option exists only for documentation purposes, please do 591 not remove it. 592 593config PIE_BUILD 594 def_bool CC_IS_CLANG && !$(cc-option,-munaligned-symbols) 595 help 596 If the compiler is unable to generate code that can manage unaligned 597 symbols, the kernel is linked as a position-independent executable 598 (PIE) and includes dynamic relocations that are processed early 599 during bootup. 600 601 For kpatch functionality, it is recommended to build the kernel 602 without the PIE_BUILD option. PIE_BUILD is only enabled when the 603 compiler lacks proper support for handling unaligned symbols. 604 605config RANDOMIZE_BASE 606 bool "Randomize the address of the kernel image (KASLR)" 607 default y 608 help 609 In support of Kernel Address Space Layout Randomization (KASLR), 610 this randomizes the address at which the kernel image is loaded, 611 as a security feature that deters exploit attempts relying on 612 knowledge of the location of kernel internals. 613 614endmenu 615 616menu "Memory setup" 617 618config ARCH_SPARSEMEM_ENABLE 619 def_bool y 620 select SPARSEMEM_VMEMMAP_ENABLE 621 select SPARSEMEM_VMEMMAP 622 623config ARCH_SPARSEMEM_DEFAULT 624 def_bool y 625 626config MAX_PHYSMEM_BITS 627 int "Maximum size of supported physical memory in bits (42-53)" 628 range 42 53 629 default "46" 630 help 631 This option specifies the maximum supported size of physical memory 632 in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB). 633 Increasing the number of bits also increases the kernel image size. 634 By default 46 bits (64TB) are supported. 635 636config CHECK_STACK 637 def_bool y 638 depends on !VMAP_STACK 639 prompt "Detect kernel stack overflow" 640 help 641 This option enables the compiler option -mstack-guard and 642 -mstack-size if they are available. If the compiler supports them 643 it will emit additional code to each function prolog to trigger 644 an illegal operation if the kernel stack is about to overflow. 645 646 Say N if you are unsure. 647 648config STACK_GUARD 649 int "Size of the guard area (128-1024)" 650 range 128 1024 651 depends on CHECK_STACK 652 default "256" 653 help 654 This allows you to specify the size of the guard area at the lower 655 end of the kernel stack. If the kernel stack points into the guard 656 area on function entry an illegal operation is triggered. The size 657 needs to be a power of 2. Please keep in mind that the size of an 658 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit. 659 The minimum size for the stack guard should be 256 for 31 bit and 660 512 for 64 bit. 661 662endmenu 663 664menu "I/O subsystem" 665 666config QDIO 667 def_tristate y 668 prompt "QDIO support" 669 help 670 This driver provides the Queued Direct I/O base support for 671 IBM System z. 672 673 To compile this driver as a module, choose M here: the 674 module will be called qdio. 675 676 If unsure, say Y. 677 678if PCI 679 680config PCI_NR_FUNCTIONS 681 int "Maximum number of PCI functions (1-4096)" 682 range 1 4096 683 default "512" 684 help 685 This allows you to specify the maximum number of PCI functions which 686 this kernel will support. 687 688endif # PCI 689 690config HAS_IOMEM 691 def_bool PCI 692 693config CHSC_SCH 694 def_tristate m 695 prompt "Support for CHSC subchannels" 696 help 697 This driver allows usage of CHSC subchannels. A CHSC subchannel 698 is usually present on LPAR only. 699 The driver creates a device /dev/chsc, which may be used to 700 obtain I/O configuration information about the machine and 701 to issue asynchronous chsc commands (DANGEROUS). 702 You will usually only want to use this interface on a special 703 LPAR designated for system management. 704 705 To compile this driver as a module, choose M here: the 706 module will be called chsc_sch. 707 708 If unsure, say N. 709 710config SCM_BUS 711 def_bool y 712 prompt "SCM bus driver" 713 help 714 Bus driver for Storage Class Memory. 715 716config EADM_SCH 717 def_tristate m 718 prompt "Support for EADM subchannels" 719 depends on SCM_BUS 720 help 721 This driver allows usage of EADM subchannels. EADM subchannels act 722 as a communication vehicle for SCM increments. 723 724 To compile this driver as a module, choose M here: the 725 module will be called eadm_sch. 726 727config VFIO_CCW 728 def_tristate n 729 prompt "Support for VFIO-CCW subchannels" 730 depends on VFIO 731 select VFIO_MDEV 732 help 733 This driver allows usage of I/O subchannels via VFIO-CCW. 734 735 To compile this driver as a module, choose M here: the 736 module will be called vfio_ccw. 737 738config VFIO_AP 739 def_tristate n 740 prompt "VFIO support for AP devices" 741 depends on KVM 742 depends on VFIO 743 depends on ZCRYPT 744 select VFIO_MDEV 745 help 746 This driver grants access to Adjunct Processor (AP) devices 747 via the VFIO mediated device interface. 748 749 To compile this driver as a module, choose M here: the module 750 will be called vfio_ap. 751 752endmenu 753 754config CCW 755 def_bool y 756 757config HAVE_PNETID 758 tristate 759 default (SMC || CCWGROUP) 760 761menu "Virtualization" 762 763config PROTECTED_VIRTUALIZATION_GUEST 764 def_bool n 765 prompt "Protected virtualization guest support" 766 help 767 Select this option, if you want to be able to run this 768 kernel as a protected virtualization KVM guest. 769 Protected virtualization capable machines have a mini hypervisor 770 located at machine level (an ultravisor). With help of the 771 Ultravisor, KVM will be able to run "protected" VMs, special 772 VMs whose memory and management data are unavailable to KVM. 773 774config PFAULT 775 def_bool y 776 prompt "Pseudo page fault support" 777 help 778 Select this option, if you want to use PFAULT pseudo page fault 779 handling under VM. If running native or in LPAR, this option 780 has no effect. If your VM does not support PFAULT, PAGEEX 781 pseudo page fault handling will be used. 782 Note that VM 4.2 supports PFAULT but has a bug in its 783 implementation that causes some problems. 784 Everybody who wants to run Linux under VM != VM4.2 should select 785 this option. 786 787config CMM 788 def_tristate n 789 prompt "Cooperative memory management" 790 help 791 Select this option, if you want to enable the kernel interface 792 to reduce the memory size of the system. This is accomplished 793 by allocating pages of memory and put them "on hold". This only 794 makes sense for a system running under VM where the unused pages 795 will be reused by VM for other guest systems. The interface 796 allows an external monitor to balance memory of many systems. 797 Everybody who wants to run Linux under VM should select this 798 option. 799 800config CMM_IUCV 801 def_bool y 802 prompt "IUCV special message interface to cooperative memory management" 803 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV) 804 help 805 Select this option to enable the special message interface to 806 the cooperative memory management. 807 808config APPLDATA_BASE 809 def_bool n 810 prompt "Linux - VM Monitor Stream, base infrastructure" 811 depends on PROC_SYSCTL 812 help 813 This provides a kernel interface for creating and updating z/VM APPLDATA 814 monitor records. The monitor records are updated at certain time 815 intervals, once the timer is started. 816 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer, 817 i.e. enables or disables monitoring on the Linux side. 818 A custom interval value (in seconds) can be written to 819 /proc/appldata/interval. 820 821 Defaults are 60 seconds interval and timer off. 822 The /proc entries can also be read from, showing the current settings. 823 824config APPLDATA_MEM 825 def_tristate m 826 prompt "Monitor memory management statistics" 827 depends on APPLDATA_BASE && VM_EVENT_COUNTERS 828 help 829 This provides memory management related data to the Linux - VM Monitor 830 Stream, like paging/swapping rate, memory utilisation, etc. 831 Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM 832 APPLDATA monitor record, i.e. enables or disables monitoring this record 833 on the z/VM side. 834 835 Default is disabled. 836 The /proc entry can also be read from, showing the current settings. 837 838 This can also be compiled as a module, which will be called 839 appldata_mem.o. 840 841config APPLDATA_OS 842 def_tristate m 843 prompt "Monitor OS statistics" 844 depends on APPLDATA_BASE 845 help 846 This provides OS related data to the Linux - VM Monitor Stream, like 847 CPU utilisation, etc. 848 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM 849 APPLDATA monitor record, i.e. enables or disables monitoring this record 850 on the z/VM side. 851 852 Default is disabled. 853 This can also be compiled as a module, which will be called 854 appldata_os.o. 855 856config APPLDATA_NET_SUM 857 def_tristate m 858 prompt "Monitor overall network statistics" 859 depends on APPLDATA_BASE && NET 860 help 861 This provides network related data to the Linux - VM Monitor Stream, 862 currently there is only a total sum of network I/O statistics, no 863 per-interface data. 864 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM 865 APPLDATA monitor record, i.e. enables or disables monitoring this record 866 on the z/VM side. 867 868 Default is disabled. 869 This can also be compiled as a module, which will be called 870 appldata_net_sum.o. 871 872config S390_HYPFS 873 def_bool y 874 prompt "s390 hypervisor information" 875 help 876 This provides several binary files at (debugfs)/s390_hypfs/ to 877 provide accounting information in an s390 hypervisor environment. 878 879config S390_HYPFS_FS 880 def_bool n 881 prompt "s390 hypervisor file system support" 882 select SYS_HYPERVISOR 883 depends on S390_HYPFS 884 help 885 This is a virtual file system intended to provide accounting 886 information in an s390 hypervisor environment. This file system 887 is deprecated and should not be used. 888 889 Say N if you are unsure. 890 891source "arch/s390/kvm/Kconfig" 892 893config S390_GUEST 894 def_bool y 895 prompt "s390 support for virtio devices" 896 select TTY 897 select VIRTUALIZATION 898 select VIRTIO 899 help 900 Enabling this option adds support for virtio based paravirtual device 901 drivers on s390. 902 903 Select this option if you want to run the kernel as a guest under 904 the KVM hypervisor. 905 906endmenu 907 908config S390_MODULES_SANITY_TEST_HELPERS 909 def_bool n 910 911menu "Selftests" 912 913config S390_UNWIND_SELFTEST 914 def_tristate n 915 depends on KUNIT 916 default KUNIT_ALL_TESTS 917 prompt "Test unwind functions" 918 help 919 This option enables s390 specific stack unwinder testing kernel 920 module. This option is not useful for distributions or general 921 kernels, but only for kernel developers working on architecture code. 922 923 Say N if you are unsure. 924 925config S390_KPROBES_SANITY_TEST 926 def_tristate n 927 prompt "Enable s390 specific kprobes tests" 928 depends on KPROBES 929 depends on KUNIT 930 help 931 This option enables an s390 specific kprobes test module. This option 932 is not useful for distributions or general kernels, but only for kernel 933 developers working on architecture code. 934 935 Say N if you are unsure. 936 937config S390_MODULES_SANITY_TEST 938 def_tristate n 939 depends on KUNIT 940 default KUNIT_ALL_TESTS 941 prompt "Enable s390 specific modules tests" 942 select S390_MODULES_SANITY_TEST_HELPERS 943 help 944 This option enables an s390 specific modules test. This option is 945 not useful for distributions or general kernels, but only for 946 kernel developers working on architecture code. 947 948 Say N if you are unsure. 949endmenu 950