1# SPDX-License-Identifier: GPL-2.0 2config MMU 3 def_bool y 4 5config ZONE_DMA 6 def_bool y 7 8config CPU_BIG_ENDIAN 9 def_bool y 10 11config LOCKDEP_SUPPORT 12 def_bool y 13 14config STACKTRACE_SUPPORT 15 def_bool y 16 17config ARCH_HAS_ILOG2_U32 18 def_bool n 19 20config ARCH_HAS_ILOG2_U64 21 def_bool n 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 0x18000000000000 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 ARCH_32BIT_USTAT_F_TINODE 62 select ARCH_BINFMT_ELF_STATE 63 select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM 64 select ARCH_ENABLE_MEMORY_HOTREMOVE 65 select ARCH_ENABLE_SPLIT_PMD_PTLOCK 66 select ARCH_HAS_DEBUG_VM_PGTABLE 67 select ARCH_HAS_DEBUG_WX 68 select ARCH_HAS_DEVMEM_IS_ALLOWED 69 select ARCH_HAS_ELF_RANDOMIZE 70 select ARCH_HAS_FORCE_DMA_UNENCRYPTED 71 select ARCH_HAS_FORTIFY_SOURCE 72 select ARCH_HAS_GCOV_PROFILE_ALL 73 select ARCH_HAS_GIGANTIC_PAGE 74 select ARCH_HAS_KCOV 75 select ARCH_HAS_MEM_ENCRYPT 76 select ARCH_HAS_PTE_SPECIAL 77 select ARCH_HAS_SCALED_CPUTIME 78 select ARCH_HAS_SET_MEMORY 79 select ARCH_HAS_STRICT_KERNEL_RWX 80 select ARCH_HAS_STRICT_MODULE_RWX 81 select ARCH_HAS_SYSCALL_WRAPPER 82 select ARCH_HAS_UBSAN_SANITIZE_ALL 83 select ARCH_HAS_VDSO_DATA 84 select ARCH_HAVE_NMI_SAFE_CMPXCHG 85 select ARCH_INLINE_READ_LOCK 86 select ARCH_INLINE_READ_LOCK_BH 87 select ARCH_INLINE_READ_LOCK_IRQ 88 select ARCH_INLINE_READ_LOCK_IRQSAVE 89 select ARCH_INLINE_READ_TRYLOCK 90 select ARCH_INLINE_READ_UNLOCK 91 select ARCH_INLINE_READ_UNLOCK_BH 92 select ARCH_INLINE_READ_UNLOCK_IRQ 93 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE 94 select ARCH_INLINE_SPIN_LOCK 95 select ARCH_INLINE_SPIN_LOCK_BH 96 select ARCH_INLINE_SPIN_LOCK_IRQ 97 select ARCH_INLINE_SPIN_LOCK_IRQSAVE 98 select ARCH_INLINE_SPIN_TRYLOCK 99 select ARCH_INLINE_SPIN_TRYLOCK_BH 100 select ARCH_INLINE_SPIN_UNLOCK 101 select ARCH_INLINE_SPIN_UNLOCK_BH 102 select ARCH_INLINE_SPIN_UNLOCK_IRQ 103 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE 104 select ARCH_INLINE_WRITE_LOCK 105 select ARCH_INLINE_WRITE_LOCK_BH 106 select ARCH_INLINE_WRITE_LOCK_IRQ 107 select ARCH_INLINE_WRITE_LOCK_IRQSAVE 108 select ARCH_INLINE_WRITE_TRYLOCK 109 select ARCH_INLINE_WRITE_UNLOCK 110 select ARCH_INLINE_WRITE_UNLOCK_BH 111 select ARCH_INLINE_WRITE_UNLOCK_IRQ 112 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE 113 select ARCH_STACKWALK 114 select ARCH_SUPPORTS_ATOMIC_RMW 115 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 116 select ARCH_SUPPORTS_NUMA_BALANCING 117 select ARCH_USE_BUILTIN_BSWAP 118 select ARCH_USE_CMPXCHG_LOCKREF 119 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 120 select ARCH_WANT_DEFAULT_BPF_JIT 121 select ARCH_WANT_IPC_PARSE_VERSION 122 select BUILDTIME_TABLE_SORT 123 select CLONE_BACKWARDS2 124 select CPU_NO_EFFICIENT_FFS if !HAVE_MARCH_Z9_109_FEATURES 125 select DMA_OPS if PCI 126 select DYNAMIC_FTRACE if FUNCTION_TRACER 127 select GENERIC_ALLOCATOR 128 select GENERIC_CPU_AUTOPROBE 129 select GENERIC_CPU_VULNERABILITIES 130 select GENERIC_ENTRY 131 select GENERIC_FIND_FIRST_BIT 132 select GENERIC_GETTIMEOFDAY 133 select GENERIC_PTDUMP 134 select GENERIC_SMP_IDLE_THREAD 135 select GENERIC_TIME_VSYSCALL 136 select GENERIC_VDSO_TIME_NS 137 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 138 select HAVE_ARCH_AUDITSYSCALL 139 select HAVE_ARCH_JUMP_LABEL 140 select HAVE_ARCH_JUMP_LABEL_RELATIVE 141 select HAVE_ARCH_KASAN 142 select HAVE_ARCH_KASAN_VMALLOC 143 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 144 select HAVE_ARCH_SECCOMP_FILTER 145 select HAVE_ARCH_SOFT_DIRTY 146 select HAVE_ARCH_TRACEHOOK 147 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 148 select HAVE_ARCH_VMAP_STACK 149 select HAVE_ASM_MODVERSIONS 150 select HAVE_CMPXCHG_DOUBLE 151 select HAVE_CMPXCHG_LOCAL 152 select HAVE_DEBUG_KMEMLEAK 153 select HAVE_DMA_CONTIGUOUS 154 select HAVE_DYNAMIC_FTRACE 155 select HAVE_DYNAMIC_FTRACE_WITH_REGS 156 select HAVE_EBPF_JIT if PACK_STACK && HAVE_MARCH_Z196_FEATURES 157 select HAVE_EFFICIENT_UNALIGNED_ACCESS 158 select HAVE_FAST_GUP 159 select HAVE_FENTRY 160 select HAVE_FTRACE_MCOUNT_RECORD 161 select HAVE_FUNCTION_ERROR_INJECTION 162 select HAVE_FUNCTION_GRAPH_TRACER 163 select HAVE_FUNCTION_TRACER 164 select HAVE_FUTEX_CMPXCHG if FUTEX 165 select HAVE_GCC_PLUGINS 166 select HAVE_GENERIC_VDSO 167 select HAVE_IOREMAP_PROT if PCI 168 select HAVE_IRQ_EXIT_ON_IRQ_STACK 169 select HAVE_KERNEL_BZIP2 170 select HAVE_KERNEL_GZIP 171 select HAVE_KERNEL_LZ4 172 select HAVE_KERNEL_LZMA 173 select HAVE_KERNEL_LZO 174 select HAVE_KERNEL_UNCOMPRESSED 175 select HAVE_KERNEL_XZ 176 select HAVE_KERNEL_ZSTD 177 select HAVE_KPROBES 178 select HAVE_KPROBES_ON_FTRACE 179 select HAVE_KRETPROBES 180 select HAVE_KVM 181 select HAVE_LIVEPATCH 182 select HAVE_MEMBLOCK_PHYS_MAP 183 select HAVE_MOD_ARCH_SPECIFIC 184 select HAVE_NMI 185 select HAVE_NOP_MCOUNT 186 select HAVE_PCI 187 select HAVE_PERF_EVENTS 188 select HAVE_PERF_REGS 189 select HAVE_PERF_USER_STACK_DUMP 190 select HAVE_REGS_AND_STACK_ACCESS_API 191 select HAVE_RELIABLE_STACKTRACE 192 select HAVE_RSEQ 193 select HAVE_SOFTIRQ_ON_OWN_STACK 194 select HAVE_SYSCALL_TRACEPOINTS 195 select HAVE_VIRT_CPU_ACCOUNTING 196 select HAVE_VIRT_CPU_ACCOUNTING_IDLE 197 select IOMMU_HELPER if PCI 198 select IOMMU_SUPPORT if PCI 199 select MMU_GATHER_NO_GATHER 200 select MMU_GATHER_RCU_TABLE_FREE 201 select MODULES_USE_ELF_RELA 202 select NEED_DMA_MAP_STATE if PCI 203 select NEED_SG_DMA_LENGTH if PCI 204 select OLD_SIGACTION 205 select OLD_SIGSUSPEND3 206 select PCI_DOMAINS if PCI 207 select PCI_MSI if PCI 208 select PCI_MSI_ARCH_FALLBACKS if PCI_MSI 209 select SPARSE_IRQ 210 select SWIOTLB 211 select SYSCTL_EXCEPTION_TRACE 212 select THREAD_INFO_IN_TASK 213 select TTY 214 select VIRT_CPU_ACCOUNTING 215 # Note: keep the above list sorted alphabetically 216 217config SCHED_OMIT_FRAME_POINTER 218 def_bool y 219 220config PGTABLE_LEVELS 221 int 222 default 5 223 224source "kernel/livepatch/Kconfig" 225 226menu "Processor type and features" 227 228config HAVE_MARCH_Z900_FEATURES 229 def_bool n 230 231config HAVE_MARCH_Z990_FEATURES 232 def_bool n 233 select HAVE_MARCH_Z900_FEATURES 234 235config HAVE_MARCH_Z9_109_FEATURES 236 def_bool n 237 select HAVE_MARCH_Z990_FEATURES 238 239config HAVE_MARCH_Z10_FEATURES 240 def_bool n 241 select HAVE_MARCH_Z9_109_FEATURES 242 243config HAVE_MARCH_Z196_FEATURES 244 def_bool n 245 select HAVE_MARCH_Z10_FEATURES 246 247config HAVE_MARCH_ZEC12_FEATURES 248 def_bool n 249 select HAVE_MARCH_Z196_FEATURES 250 251config HAVE_MARCH_Z13_FEATURES 252 def_bool n 253 select HAVE_MARCH_ZEC12_FEATURES 254 255config HAVE_MARCH_Z14_FEATURES 256 def_bool n 257 select HAVE_MARCH_Z13_FEATURES 258 259config HAVE_MARCH_Z15_FEATURES 260 def_bool n 261 select HAVE_MARCH_Z14_FEATURES 262 263choice 264 prompt "Processor type" 265 default MARCH_Z196 266 267config MARCH_Z900 268 bool "IBM zSeries model z800 and z900" 269 select HAVE_MARCH_Z900_FEATURES 270 depends on $(cc-option,-march=z900) 271 help 272 Select this to enable optimizations for model z800/z900 (2064 and 273 2066 series). This will enable some optimizations that are not 274 available on older ESA/390 (31 Bit) only CPUs. 275 276config MARCH_Z990 277 bool "IBM zSeries model z890 and z990" 278 select HAVE_MARCH_Z990_FEATURES 279 depends on $(cc-option,-march=z990) 280 help 281 Select this to enable optimizations for model z890/z990 (2084 and 282 2086 series). The kernel will be slightly faster but will not work 283 on older machines. 284 285config MARCH_Z9_109 286 bool "IBM System z9" 287 select HAVE_MARCH_Z9_109_FEATURES 288 depends on $(cc-option,-march=z9-109) 289 help 290 Select this to enable optimizations for IBM System z9 (2094 and 291 2096 series). The kernel will be slightly faster but will not work 292 on older machines. 293 294config MARCH_Z10 295 bool "IBM System z10" 296 select HAVE_MARCH_Z10_FEATURES 297 depends on $(cc-option,-march=z10) 298 help 299 Select this to enable optimizations for IBM System z10 (2097 and 300 2098 series). The kernel will be slightly faster but will not work 301 on older machines. 302 303config MARCH_Z196 304 bool "IBM zEnterprise 114 and 196" 305 select HAVE_MARCH_Z196_FEATURES 306 depends on $(cc-option,-march=z196) 307 help 308 Select this to enable optimizations for IBM zEnterprise 114 and 196 309 (2818 and 2817 series). The kernel will be slightly faster but will 310 not work on older machines. 311 312config MARCH_ZEC12 313 bool "IBM zBC12 and zEC12" 314 select HAVE_MARCH_ZEC12_FEATURES 315 depends on $(cc-option,-march=zEC12) 316 help 317 Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and 318 2827 series). The kernel will be slightly faster but will not work on 319 older machines. 320 321config MARCH_Z13 322 bool "IBM z13s and z13" 323 select HAVE_MARCH_Z13_FEATURES 324 depends on $(cc-option,-march=z13) 325 help 326 Select this to enable optimizations for IBM z13s and z13 (2965 and 327 2964 series). The kernel will be slightly faster but will not work on 328 older machines. 329 330config MARCH_Z14 331 bool "IBM z14 ZR1 and z14" 332 select HAVE_MARCH_Z14_FEATURES 333 depends on $(cc-option,-march=z14) 334 help 335 Select this to enable optimizations for IBM z14 ZR1 and z14 (3907 336 and 3906 series). The kernel will be slightly faster but will not 337 work on older machines. 338 339config MARCH_Z15 340 bool "IBM z15" 341 select HAVE_MARCH_Z15_FEATURES 342 depends on $(cc-option,-march=z15) 343 help 344 Select this to enable optimizations for IBM z15 (8562 345 and 8561 series). The kernel will be slightly faster but will not 346 work on older machines. 347 348endchoice 349 350config MARCH_Z900_TUNE 351 def_bool TUNE_Z900 || MARCH_Z900 && TUNE_DEFAULT 352 353config MARCH_Z990_TUNE 354 def_bool TUNE_Z990 || MARCH_Z990 && TUNE_DEFAULT 355 356config MARCH_Z9_109_TUNE 357 def_bool TUNE_Z9_109 || MARCH_Z9_109 && TUNE_DEFAULT 358 359config MARCH_Z10_TUNE 360 def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT 361 362config MARCH_Z196_TUNE 363 def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT 364 365config MARCH_ZEC12_TUNE 366 def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT 367 368config MARCH_Z13_TUNE 369 def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT 370 371config MARCH_Z14_TUNE 372 def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT 373 374config MARCH_Z15_TUNE 375 def_bool TUNE_Z15 || MARCH_Z15 && TUNE_DEFAULT 376 377choice 378 prompt "Tune code generation" 379 default TUNE_DEFAULT 380 help 381 Cause the compiler to tune (-mtune) the generated code for a machine. 382 This will make the code run faster on the selected machine but 383 somewhat slower on other machines. 384 This option only changes how the compiler emits instructions, not the 385 selection of instructions itself, so the resulting kernel will run on 386 all other machines. 387 388config TUNE_DEFAULT 389 bool "Default" 390 help 391 Tune the generated code for the target processor for which the kernel 392 will be compiled. 393 394config TUNE_Z900 395 bool "IBM zSeries model z800 and z900" 396 depends on $(cc-option,-mtune=z900) 397 398config TUNE_Z990 399 bool "IBM zSeries model z890 and z990" 400 depends on $(cc-option,-mtune=z990) 401 402config TUNE_Z9_109 403 bool "IBM System z9" 404 depends on $(cc-option,-mtune=z9-109) 405 406config TUNE_Z10 407 bool "IBM System z10" 408 depends on $(cc-option,-mtune=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 430endchoice 431 432config 64BIT 433 def_bool y 434 435config COMPAT 436 def_bool y 437 prompt "Kernel support for 31 bit emulation" 438 select ARCH_WANT_OLD_COMPAT_IPC 439 select COMPAT_OLD_SIGACTION 440 select HAVE_UID16 441 depends on MULTIUSER 442 help 443 Select this option if you want to enable your system kernel to 444 handle system-calls from ELF binaries for 31 bit ESA. This option 445 (and some other stuff like libraries and such) is needed for 446 executing 31 bit applications. It is safe to say "Y". 447 448config SYSVIPC_COMPAT 449 def_bool y if COMPAT && SYSVIPC 450 451config SMP 452 def_bool y 453 454config NR_CPUS 455 int "Maximum number of CPUs (2-512)" 456 range 2 512 457 default "64" 458 help 459 This allows you to specify the maximum number of CPUs which this 460 kernel will support. The maximum supported value is 512 and the 461 minimum value which makes sense is 2. 462 463 This is purely to save memory - each supported CPU adds 464 approximately sixteen kilobytes to the kernel image. 465 466config HOTPLUG_CPU 467 def_bool y 468 469config NUMA 470 bool "NUMA support" 471 depends on SCHED_TOPOLOGY 472 default n 473 help 474 Enable NUMA support 475 476 This option adds NUMA support to the kernel. 477 478config NODES_SHIFT 479 int 480 depends on NEED_MULTIPLE_NODES 481 default "1" 482 483config SCHED_SMT 484 def_bool n 485 486config SCHED_MC 487 def_bool n 488 489config SCHED_BOOK 490 def_bool n 491 492config SCHED_DRAWER 493 def_bool n 494 495config SCHED_TOPOLOGY 496 def_bool y 497 prompt "Topology scheduler support" 498 select SCHED_SMT 499 select SCHED_MC 500 select SCHED_BOOK 501 select SCHED_DRAWER 502 help 503 Topology scheduler support improves the CPU scheduler's decision 504 making when dealing with machines that have multi-threading, 505 multiple cores or multiple books. 506 507source "kernel/Kconfig.hz" 508 509config KEXEC 510 def_bool y 511 select KEXEC_CORE 512 513config KEXEC_FILE 514 bool "kexec file based system call" 515 select KEXEC_CORE 516 select BUILD_BIN2C 517 depends on CRYPTO 518 depends on CRYPTO_SHA256 519 depends on CRYPTO_SHA256_S390 520 help 521 Enable the kexec file based system call. In contrast to the normal 522 kexec system call this system call takes file descriptors for the 523 kernel and initramfs as arguments. 524 525config ARCH_HAS_KEXEC_PURGATORY 526 def_bool y 527 depends on KEXEC_FILE 528 529config KEXEC_SIG 530 bool "Verify kernel signature during kexec_file_load() syscall" 531 depends on KEXEC_FILE && MODULE_SIG_FORMAT 532 help 533 This option makes kernel signature verification mandatory for 534 the kexec_file_load() syscall. 535 536 In addition to that option, you need to enable signature 537 verification for the corresponding kernel image type being 538 loaded in order for this to work. 539 540config ARCH_RANDOM 541 def_bool y 542 prompt "s390 architectural random number generation API" 543 help 544 Enable the s390 architectural random number generation API 545 to provide random data for all consumers within the Linux 546 kernel. 547 548 When enabled the arch_random_* functions declared in linux/random.h 549 are implemented. The implementation is based on the s390 CPACF 550 instruction subfunction TRNG which provides a real true random 551 number generator. 552 553 If unsure, say Y. 554 555config KERNEL_NOBP 556 def_bool n 557 prompt "Enable modified branch prediction for the kernel by default" 558 help 559 If this option is selected the kernel will switch to a modified 560 branch prediction mode if the firmware interface is available. 561 The modified branch prediction mode improves the behaviour in 562 regard to speculative execution. 563 564 With the option enabled the kernel parameter "nobp=0" or "nospec" 565 can be used to run the kernel in the normal branch prediction mode. 566 567 With the option disabled the modified branch prediction mode is 568 enabled with the "nobp=1" kernel parameter. 569 570 If unsure, say N. 571 572config EXPOLINE 573 def_bool n 574 prompt "Avoid speculative indirect branches in the kernel" 575 help 576 Compile the kernel with the expoline compiler options to guard 577 against kernel-to-user data leaks by avoiding speculative indirect 578 branches. 579 Requires a compiler with -mindirect-branch=thunk support for full 580 protection. The kernel may run slower. 581 582 If unsure, say N. 583 584choice 585 prompt "Expoline default" 586 depends on EXPOLINE 587 default EXPOLINE_FULL 588 589config EXPOLINE_OFF 590 bool "spectre_v2=off" 591 592config EXPOLINE_AUTO 593 bool "spectre_v2=auto" 594 595config EXPOLINE_FULL 596 bool "spectre_v2=on" 597 598endchoice 599 600config RELOCATABLE 601 bool "Build a relocatable kernel" 602 select MODULE_REL_CRCS if MODVERSIONS 603 default y 604 help 605 This builds a kernel image that retains relocation information 606 so it can be loaded at an arbitrary address. 607 The kernel is linked as a position-independent executable (PIE) 608 and contains dynamic relocations which are processed early in the 609 bootup process. 610 The relocations make the kernel image about 15% larger (compressed 611 10%), but are discarded at runtime. 612 613config RANDOMIZE_BASE 614 bool "Randomize the address of the kernel image (KASLR)" 615 depends on RELOCATABLE 616 default y 617 help 618 In support of Kernel Address Space Layout Randomization (KASLR), 619 this randomizes the address at which the kernel image is loaded, 620 as a security feature that deters exploit attempts relying on 621 knowledge of the location of kernel internals. 622 623endmenu 624 625menu "Memory setup" 626 627config ARCH_SPARSEMEM_ENABLE 628 def_bool y 629 select SPARSEMEM_VMEMMAP_ENABLE 630 select SPARSEMEM_VMEMMAP 631 632config ARCH_SPARSEMEM_DEFAULT 633 def_bool y 634 635config MAX_PHYSMEM_BITS 636 int "Maximum size of supported physical memory in bits (42-53)" 637 range 42 53 638 default "46" 639 help 640 This option specifies the maximum supported size of physical memory 641 in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB). 642 Increasing the number of bits also increases the kernel image size. 643 By default 46 bits (64TB) are supported. 644 645config PACK_STACK 646 def_bool y 647 prompt "Pack kernel stack" 648 help 649 This option enables the compiler option -mkernel-backchain if it 650 is available. If the option is available the compiler supports 651 the new stack layout which dramatically reduces the minimum stack 652 frame size. With an old compiler a non-leaf function needs a 653 minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With 654 -mkernel-backchain the minimum size drops to 16 byte on 31 bit 655 and 24 byte on 64 bit. 656 657 Say Y if you are unsure. 658 659config CHECK_STACK 660 def_bool y 661 depends on !VMAP_STACK 662 prompt "Detect kernel stack overflow" 663 help 664 This option enables the compiler option -mstack-guard and 665 -mstack-size if they are available. If the compiler supports them 666 it will emit additional code to each function prolog to trigger 667 an illegal operation if the kernel stack is about to overflow. 668 669 Say N if you are unsure. 670 671config STACK_GUARD 672 int "Size of the guard area (128-1024)" 673 range 128 1024 674 depends on CHECK_STACK 675 default "256" 676 help 677 This allows you to specify the size of the guard area at the lower 678 end of the kernel stack. If the kernel stack points into the guard 679 area on function entry an illegal operation is triggered. The size 680 needs to be a power of 2. Please keep in mind that the size of an 681 interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit. 682 The minimum size for the stack guard should be 256 for 31 bit and 683 512 for 64 bit. 684 685config WARN_DYNAMIC_STACK 686 def_bool n 687 prompt "Emit compiler warnings for function with dynamic stack usage" 688 help 689 This option enables the compiler option -mwarn-dynamicstack. If the 690 compiler supports this options generates warnings for functions 691 that dynamically allocate stack space using alloca. 692 693 Say N if you are unsure. 694 695endmenu 696 697menu "I/O subsystem" 698 699config QDIO 700 def_tristate y 701 prompt "QDIO support" 702 help 703 This driver provides the Queued Direct I/O base support for 704 IBM System z. 705 706 To compile this driver as a module, choose M here: the 707 module will be called qdio. 708 709 If unsure, say Y. 710 711if PCI 712 713config PCI_NR_FUNCTIONS 714 int "Maximum number of PCI functions (1-4096)" 715 range 1 4096 716 default "512" 717 help 718 This allows you to specify the maximum number of PCI functions which 719 this kernel will support. 720 721endif # PCI 722 723config HAS_IOMEM 724 def_bool PCI 725 726config CHSC_SCH 727 def_tristate m 728 prompt "Support for CHSC subchannels" 729 help 730 This driver allows usage of CHSC subchannels. A CHSC subchannel 731 is usually present on LPAR only. 732 The driver creates a device /dev/chsc, which may be used to 733 obtain I/O configuration information about the machine and 734 to issue asynchronous chsc commands (DANGEROUS). 735 You will usually only want to use this interface on a special 736 LPAR designated for system management. 737 738 To compile this driver as a module, choose M here: the 739 module will be called chsc_sch. 740 741 If unsure, say N. 742 743config SCM_BUS 744 def_bool y 745 prompt "SCM bus driver" 746 help 747 Bus driver for Storage Class Memory. 748 749config EADM_SCH 750 def_tristate m 751 prompt "Support for EADM subchannels" 752 depends on SCM_BUS 753 help 754 This driver allows usage of EADM subchannels. EADM subchannels act 755 as a communication vehicle for SCM increments. 756 757 To compile this driver as a module, choose M here: the 758 module will be called eadm_sch. 759 760config VFIO_CCW 761 def_tristate n 762 prompt "Support for VFIO-CCW subchannels" 763 depends on S390_CCW_IOMMU && VFIO_MDEV 764 help 765 This driver allows usage of I/O subchannels via VFIO-CCW. 766 767 To compile this driver as a module, choose M here: the 768 module will be called vfio_ccw. 769 770config VFIO_AP 771 def_tristate n 772 prompt "VFIO support for AP devices" 773 depends on S390_AP_IOMMU && VFIO_MDEV_DEVICE && KVM 774 depends on ZCRYPT 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 784menu "Dump support" 785 786config CRASH_DUMP 787 bool "kernel crash dumps" 788 select KEXEC 789 help 790 Generate crash dump after being started by kexec. 791 Crash dump kernels are loaded in the main kernel with kexec-tools 792 into a specially reserved region and then later executed after 793 a crash by kdump/kexec. 794 Refer to <file:Documentation/s390/zfcpdump.rst> for more details on this. 795 This option also enables s390 zfcpdump. 796 See also <file:Documentation/s390/zfcpdump.rst> 797 798endmenu 799 800config CCW 801 def_bool y 802 803config HAVE_PNETID 804 tristate 805 default (SMC || CCWGROUP) 806 807menu "Virtualization" 808 809config PROTECTED_VIRTUALIZATION_GUEST 810 def_bool n 811 prompt "Protected virtualization guest support" 812 select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS 813 help 814 Select this option, if you want to be able to run this 815 kernel as a protected virtualization KVM guest. 816 Protected virtualization capable machines have a mini hypervisor 817 located at machine level (an ultravisor). With help of the 818 Ultravisor, KVM will be able to run "protected" VMs, special 819 VMs whose memory and management data are unavailable to KVM. 820 821config PFAULT 822 def_bool y 823 prompt "Pseudo page fault support" 824 help 825 Select this option, if you want to use PFAULT pseudo page fault 826 handling under VM. If running native or in LPAR, this option 827 has no effect. If your VM does not support PFAULT, PAGEEX 828 pseudo page fault handling will be used. 829 Note that VM 4.2 supports PFAULT but has a bug in its 830 implementation that causes some problems. 831 Everybody who wants to run Linux under VM != VM4.2 should select 832 this option. 833 834config CMM 835 def_tristate n 836 prompt "Cooperative memory management" 837 help 838 Select this option, if you want to enable the kernel interface 839 to reduce the memory size of the system. This is accomplished 840 by allocating pages of memory and put them "on hold". This only 841 makes sense for a system running under VM where the unused pages 842 will be reused by VM for other guest systems. The interface 843 allows an external monitor to balance memory of many systems. 844 Everybody who wants to run Linux under VM should select this 845 option. 846 847config CMM_IUCV 848 def_bool y 849 prompt "IUCV special message interface to cooperative memory management" 850 depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV) 851 help 852 Select this option to enable the special message interface to 853 the cooperative memory management. 854 855config APPLDATA_BASE 856 def_bool n 857 prompt "Linux - VM Monitor Stream, base infrastructure" 858 depends on PROC_SYSCTL 859 help 860 This provides a kernel interface for creating and updating z/VM APPLDATA 861 monitor records. The monitor records are updated at certain time 862 intervals, once the timer is started. 863 Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer, 864 i.e. enables or disables monitoring on the Linux side. 865 A custom interval value (in seconds) can be written to 866 /proc/appldata/interval. 867 868 Defaults are 60 seconds interval and timer off. 869 The /proc entries can also be read from, showing the current settings. 870 871config APPLDATA_MEM 872 def_tristate m 873 prompt "Monitor memory management statistics" 874 depends on APPLDATA_BASE && VM_EVENT_COUNTERS 875 help 876 This provides memory management related data to the Linux - VM Monitor 877 Stream, like paging/swapping rate, memory utilisation, etc. 878 Writing 1 or 0 to /proc/appldata/memory 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 The /proc entry can also be read from, showing the current settings. 884 885 This can also be compiled as a module, which will be called 886 appldata_mem.o. 887 888config APPLDATA_OS 889 def_tristate m 890 prompt "Monitor OS statistics" 891 depends on APPLDATA_BASE 892 help 893 This provides OS related data to the Linux - VM Monitor Stream, like 894 CPU utilisation, etc. 895 Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM 896 APPLDATA monitor record, i.e. enables or disables monitoring this record 897 on the z/VM side. 898 899 Default is disabled. 900 This can also be compiled as a module, which will be called 901 appldata_os.o. 902 903config APPLDATA_NET_SUM 904 def_tristate m 905 prompt "Monitor overall network statistics" 906 depends on APPLDATA_BASE && NET 907 help 908 This provides network related data to the Linux - VM Monitor Stream, 909 currently there is only a total sum of network I/O statistics, no 910 per-interface data. 911 Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM 912 APPLDATA monitor record, i.e. enables or disables monitoring this record 913 on the z/VM side. 914 915 Default is disabled. 916 This can also be compiled as a module, which will be called 917 appldata_net_sum.o. 918 919config S390_HYPFS_FS 920 def_bool y 921 prompt "s390 hypervisor file system support" 922 select SYS_HYPERVISOR 923 help 924 This is a virtual file system intended to provide accounting 925 information in an s390 hypervisor environment. 926 927source "arch/s390/kvm/Kconfig" 928 929config S390_GUEST 930 def_bool y 931 prompt "s390 support for virtio devices" 932 select TTY 933 select VIRTUALIZATION 934 select VIRTIO 935 help 936 Enabling this option adds support for virtio based paravirtual device 937 drivers on s390. 938 939 Select this option if you want to run the kernel as a guest under 940 the KVM hypervisor. 941 942endmenu 943 944menu "Selftests" 945 946config S390_UNWIND_SELFTEST 947 def_tristate n 948 prompt "Test unwind functions" 949 help 950 This option enables s390 specific stack unwinder testing kernel 951 module. This option is not useful for distributions or general 952 kernels, but only for kernel developers working on architecture code. 953 954 Say N if you are unsure. 955 956endmenu 957