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authorJason Gunthorpe <jgg@mellanox.com>2018-08-16 23:13:03 +0300
committerJason Gunthorpe <jgg@mellanox.com>2018-08-16 23:21:29 +0300
commit0a3173a5f09bc58a3638ecfd0a80bdbae55e123c (patch)
treed6c0bc84863cca54dfbde3b7463e5d49c82af9f1 /Documentation/admin-guide/kernel-parameters.txt
parent92f4e77c85918eab5e5803d7e28ab89a7e6bd3a2 (diff)
parent5c60a7389d795e001c8748b458eb76e3a5b6008c (diff)
downloadlinux-0a3173a5f09bc58a3638ecfd0a80bdbae55e123c.tar.xz
Merge branch 'linus/master' into rdma.git for-next
rdma.git merge resolution for the 4.19 merge window Conflicts: drivers/infiniband/core/rdma_core.c - Use the rdma code and revise with the new spelling for atomic_fetch_add_unless drivers/nvme/host/rdma.c - Replace max_sge with max_send_sge in new blk code drivers/nvme/target/rdma.c - Use the blk code and revise to use NULL for ib_post_recv when appropriate - Replace max_sge with max_recv_sge in new blk code net/rds/ib_send.c - Use the net code and revise to use NULL for ib_post_recv when appropriate Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'Documentation/admin-guide/kernel-parameters.txt')
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt162
1 files changed, 149 insertions, 13 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 533ff5c68970..adafe47ac376 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -748,6 +748,14 @@
debug [KNL] Enable kernel debugging (events log level).
+ debug_boot_weak_hash
+ [KNL] Enable printing [hashed] pointers early in the
+ boot sequence. If enabled, we use a weak hash instead
+ of siphash to hash pointers. Use this option if you are
+ seeing instances of '(___ptrval___)') and need to see a
+ value (hashed pointer) instead. Cryptographically
+ insecure, please do not use on production kernels.
+
debug_locks_verbose=
[KNL] verbose self-tests
Format=<0|1>
@@ -816,6 +824,17 @@
disable= [IPV6]
See Documentation/networking/ipv6.txt.
+ hardened_usercopy=
+ [KNL] Under CONFIG_HARDENED_USERCOPY, whether
+ hardening is enabled for this boot. Hardened
+ usercopy checking is used to protect the kernel
+ from reading or writing beyond known memory
+ allocation boundaries as a proactive defense
+ against bounds-checking flaws in the kernel's
+ copy_to_user()/copy_from_user() interface.
+ on Perform hardened usercopy checks (default).
+ off Disable hardened usercopy checks.
+
disable_radix [PPC]
Disable RADIX MMU mode on POWER9
@@ -1967,10 +1986,84 @@
(virtualized real and unpaged mode) on capable
Intel chips. Default is 1 (enabled)
+ kvm-intel.vmentry_l1d_flush=[KVM,Intel] Mitigation for L1 Terminal Fault
+ CVE-2018-3620.
+
+ Valid arguments: never, cond, always
+
+ always: L1D cache flush on every VMENTER.
+ cond: Flush L1D on VMENTER only when the code between
+ VMEXIT and VMENTER can leak host memory.
+ never: Disables the mitigation
+
+ Default is cond (do L1 cache flush in specific instances)
+
kvm-intel.vpid= [KVM,Intel] Disable Virtual Processor Identification
feature (tagged TLBs) on capable Intel chips.
Default is 1 (enabled)
+ l1tf= [X86] Control mitigation of the L1TF vulnerability on
+ affected CPUs
+
+ The kernel PTE inversion protection is unconditionally
+ enabled and cannot be disabled.
+
+ full
+ Provides all available mitigations for the
+ L1TF vulnerability. Disables SMT and
+ enables all mitigations in the
+ hypervisors, i.e. unconditional L1D flush.
+
+ SMT control and L1D flush control via the
+ sysfs interface is still possible after
+ boot. Hypervisors will issue a warning
+ when the first VM is started in a
+ potentially insecure configuration,
+ i.e. SMT enabled or L1D flush disabled.
+
+ full,force
+ Same as 'full', but disables SMT and L1D
+ flush runtime control. Implies the
+ 'nosmt=force' command line option.
+ (i.e. sysfs control of SMT is disabled.)
+
+ flush
+ Leaves SMT enabled and enables the default
+ hypervisor mitigation, i.e. conditional
+ L1D flush.
+
+ SMT control and L1D flush control via the
+ sysfs interface is still possible after
+ boot. Hypervisors will issue a warning
+ when the first VM is started in a
+ potentially insecure configuration,
+ i.e. SMT enabled or L1D flush disabled.
+
+ flush,nosmt
+
+ Disables SMT and enables the default
+ hypervisor mitigation.
+
+ SMT control and L1D flush control via the
+ sysfs interface is still possible after
+ boot. Hypervisors will issue a warning
+ when the first VM is started in a
+ potentially insecure configuration,
+ i.e. SMT enabled or L1D flush disabled.
+
+ flush,nowarn
+ Same as 'flush', but hypervisors will not
+ warn when a VM is started in a potentially
+ insecure configuration.
+
+ off
+ Disables hypervisor mitigations and doesn't
+ emit any warnings.
+
+ Default is 'flush'.
+
+ For details see: Documentation/admin-guide/l1tf.rst
+
l2cr= [PPC]
l3cr= [PPC]
@@ -2687,6 +2780,10 @@
nosmt [KNL,S390] Disable symmetric multithreading (SMT).
Equivalent to smt=1.
+ [KNL,x86] Disable symmetric multithreading (SMT).
+ nosmt=force: Force disable SMT, cannot be undone
+ via the sysfs control file.
+
nospectre_v2 [X86] Disable all mitigations for the Spectre variant 2
(indirect branch prediction) vulnerability. System may
allow data leaks with this option, which is equivalent
@@ -2835,8 +2932,6 @@
nosync [HW,M68K] Disables sync negotiation for all devices.
- notsc [BUGS=X86-32] Disable Time Stamp Counter
-
nowatchdog [KNL] Disable both lockup detectors, i.e.
soft-lockup and NMI watchdog (hard-lockup).
@@ -2994,8 +3089,31 @@
See header of drivers/block/paride/pcd.c.
See also Documentation/blockdev/paride.txt.
- pci=option[,option...] [PCI] various PCI subsystem options:
- earlydump [X86] dump PCI config space before the kernel
+ pci=option[,option...] [PCI] various PCI subsystem options.
+
+ Some options herein operate on a specific device
+ or a set of devices (<pci_dev>). These are
+ specified in one of the following formats:
+
+ [<domain>:]<bus>:<dev>.<func>[/<dev>.<func>]*
+ pci:<vendor>:<device>[:<subvendor>:<subdevice>]
+
+ Note: the first format specifies a PCI
+ bus/device/function address which may change
+ if new hardware is inserted, if motherboard
+ firmware changes, or due to changes caused
+ by other kernel parameters. If the
+ domain is left unspecified, it is
+ taken to be zero. Optionally, a path
+ to a device through multiple device/function
+ addresses can be specified after the base
+ address (this is more robust against
+ renumbering issues). The second format
+ selects devices using IDs from the
+ configuration space which may match multiple
+ devices in the system.
+
+ earlydump dump PCI config space before the kernel
changes anything
off [X86] don't probe for the PCI bus
bios [X86-32] force use of PCI BIOS, don't access
@@ -3123,11 +3241,10 @@
window. The default value is 64 megabytes.
resource_alignment=
Format:
- [<order of align>@][<domain>:]<bus>:<slot>.<func>[; ...]
- [<order of align>@]pci:<vendor>:<device>\
- [:<subvendor>:<subdevice>][; ...]
+ [<order of align>@]<pci_dev>[; ...]
Specifies alignment and device to reassign
- aligned memory resources.
+ aligned memory resources. How to
+ specify the device is described above.
If <order of align> is not specified,
PAGE_SIZE is used as alignment.
PCI-PCI bridge can be specified, if resource
@@ -3170,6 +3287,15 @@
Adding the window is slightly risky (it may
conflict with unreported devices), so this
taints the kernel.
+ disable_acs_redir=<pci_dev>[; ...]
+ Specify one or more PCI devices (in the format
+ specified above) separated by semicolons.
+ Each device specified will have the PCI ACS
+ redirect capabilities forced off which will
+ allow P2P traffic between devices through
+ bridges without forcing it upstream. Note:
+ this removes isolation between devices and
+ may put more devices in an IOMMU group.
pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power
Management.
@@ -3632,8 +3758,8 @@
Set time (s) after boot for CPU-hotplug testing.
rcutorture.onoff_interval= [KNL]
- Set time (s) between CPU-hotplug operations, or
- zero to disable CPU-hotplug testing.
+ Set time (jiffies) between CPU-hotplug operations,
+ or zero to disable CPU-hotplug testing.
rcutorture.shuffle_interval= [KNL]
Set task-shuffle interval (s). Shuffling tasks
@@ -4060,6 +4186,8 @@
This parameter controls whether the Speculative Store
Bypass optimization is used.
+ On x86 the options are:
+
on - Unconditionally disable Speculative Store Bypass
off - Unconditionally enable Speculative Store Bypass
auto - Kernel detects whether the CPU model contains an
@@ -4075,12 +4203,20 @@
seccomp - Same as "prctl" above, but all seccomp threads
will disable SSB unless they explicitly opt out.
- Not specifying this option is equivalent to
- spec_store_bypass_disable=auto.
-
Default mitigations:
X86: If CONFIG_SECCOMP=y "seccomp", otherwise "prctl"
+ On powerpc the options are:
+
+ on,auto - On Power8 and Power9 insert a store-forwarding
+ barrier on kernel entry and exit. On Power7
+ perform a software flush on kernel entry and
+ exit.
+ off - No action.
+
+ Not specifying this option is equivalent to
+ spec_store_bypass_disable=auto.
+
spia_io_base= [HW,MTD]
spia_fio_base=
spia_pedr=