diff options
Diffstat (limited to 'Documentation/admin-guide/kernel-parameters.txt')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 62 |
1 files changed, 46 insertions, 16 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 91ba391f9b32..0905d2cdb2d5 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -841,11 +841,6 @@ Format: <port#>,<type> See also Documentation/input/devices/joystick-parport.rst - ddebug_query= [KNL,DYNAMIC_DEBUG] Enable debug messages at early boot - time. See - Documentation/admin-guide/dynamic-debug-howto.rst for - details. Deprecated, see dyndbg. - debug [KNL] Enable kernel debugging (events log level). debug_boot_weak_hash @@ -1266,7 +1261,7 @@ The VGA and EFI output is eventually overwritten by the real console. - The xen output can only be used by Xen PV guests. + The xen option can only be used in Xen domains. The sclp output can only be used on s390. @@ -1587,8 +1582,10 @@ registers. Default set by CONFIG_HPET_MMAP_DEFAULT. hugetlb_cma= [HW,CMA] The size of a CMA area used for allocation - of gigantic hugepages. - Format: nn[KMGTPE] + of gigantic hugepages. Or using node format, the size + of a CMA area per node can be specified. + Format: nn[KMGTPE] or (node format) + <node>:nn[KMGTPE][,<node>:nn[KMGTPE]] Reserve a CMA area of given size and allocate gigantic hugepages using the CMA allocator. If enabled, the @@ -1599,9 +1596,11 @@ the number of pages of hugepagesz to be allocated. If this is the first HugeTLB parameter on the command line, it specifies the number of pages to allocate for - the default huge page size. See also - Documentation/admin-guide/mm/hugetlbpage.rst. - Format: <integer> + the default huge page size. If using node format, the + number of pages to allocate per-node can be specified. + See also Documentation/admin-guide/mm/hugetlbpage.rst. + Format: <integer> or (node format) + <node>:<integer>[,<node>:<integer>] hugepagesz= [HW] The size of the HugeTLB pages. This is used in @@ -2353,7 +2352,14 @@ [KVM] Controls how many 4KiB pages are periodically zapped back to huge pages. 0 disables the recovery, otherwise if the value is N KVM will zap 1/Nth of the 4KiB pages every - minute. The default is 60. + period (see below). The default is 60. + + kvm.nx_huge_pages_recovery_period_ms= + [KVM] Controls the time period at which KVM zaps 4KiB pages + back to huge pages. If the value is a non-zero N, KVM will + zap a portion (see ratio above) of the pages every N msecs. + If the value is 0 (the default), KVM will pick a period based + on the ratio, such that a page is zapped after 1 hour on average. kvm-amd.nested= [KVM,AMD] Allow nested virtualization in KVM/SVM. Default is 1 (enabled) @@ -2365,6 +2371,8 @@ kvm-arm.mode= [KVM,ARM] Select one of KVM/arm64's modes of operation. + none: Forcefully disable KVM. + nvhe: Standard nVHE-based mode, without support for protected guests. @@ -2372,7 +2380,9 @@ state is kept private from the host. Not valid if the kernel is running in EL2. - Defaults to VHE/nVHE based on hardware support. + Defaults to VHE/nVHE based on hardware support. Setting + mode to "protected" will disable kexec and hibernation + for the host. kvm-arm.vgic_v3_group0_trap= [KVM,ARM] Trap guest accesses to GICv3 group-0 @@ -4982,6 +4992,18 @@ an IOTLB flush. Default is lazy flushing before reuse, which is faster. + s390_iommu_aperture= [KNL,S390] + Specifies the size of the per device DMA address space + accessible through the DMA and IOMMU APIs as a decimal + factor of the size of main memory. + The default is 1 meaning that one can concurrently use + as many DMA addresses as physical memory is installed, + if supported by hardware, and thus map all of memory + once. With a value of 2 one can map all of memory twice + and so on. As a special case a factor of 0 imposes no + restrictions other than those given by hardware at the + cost of significant additional memory use for tables. + sa1100ir [NET] See drivers/net/irda/sa1100_ir.c. @@ -5303,8 +5325,7 @@ auto - Kernel selects the mitigation depending on the available CPU features and vulnerability. - Default mitigation: - If CONFIG_SECCOMP=y then "seccomp", otherwise "prctl" + Default mitigation: "prctl" Not specifying this option is equivalent to spectre_v2_user=auto. @@ -5348,7 +5369,7 @@ will disable SSB unless they explicitly opt out. Default mitigations: - X86: If CONFIG_SECCOMP=y "seccomp", otherwise "prctl" + X86: "prctl" On powerpc the options are: @@ -5497,6 +5518,15 @@ stifb= [HW] Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]] + strict_sas_size= + [X86] + Format: <bool> + Enable or disable strict sigaltstack size checks + against the required signal frame size which + depends on the supported FPU features. This can + be used to filter out binaries which have + not yet been made aware of AT_MINSIGSTKSZ. + sunrpc.min_resvport= sunrpc.max_resvport= [NFS,SUNRPC] |