summaryrefslogtreecommitdiffstats
path: root/Documentation/admin-guide/kernel-parameters.txt
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/admin-guide/kernel-parameters.txt')
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt59
1 files changed, 48 insertions, 11 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index af7104aaffd9..02045e0b50a5 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -114,7 +114,6 @@
This facility can be used to prevent such uncontrolled
GPE floodings.
Format: <int>
- Support masking of GPEs numbered from 0x00 to 0x7f.
acpi_no_auto_serialize [HW,ACPI]
Disable auto-serialization of AML methods
@@ -713,9 +712,6 @@
It will be ignored when crashkernel=X,high is not used
or memory reserved is below 4G.
- crossrelease_fullstack
- [KNL] Allow to record full stack trace in cross-release
-
cryptomgr.notests
[KNL] Disable crypto self-tests
@@ -2626,6 +2622,11 @@
nosmt [KNL,S390] Disable symmetric multithreading (SMT).
Equivalent to smt=1.
+ 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
+ to spectre_v2=off.
+
noxsave [BUGS=X86] Disables x86 extended register state save
and restore using xsave. The kernel will fallback to
enabling legacy floating-point and sse state.
@@ -2712,8 +2713,6 @@
steal time is computed, but won't influence scheduler
behaviour
- nopti [X86-64] Disable kernel page table isolation
-
nolapic [X86-32,APIC] Do not enable or use the local APIC.
nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
@@ -3100,6 +3099,12 @@
pcie_scan_all Scan all possible PCIe devices. Otherwise we
only look for one device below a PCIe downstream
port.
+ big_root_window Try to add a big 64bit memory window to the PCIe
+ root complex on AMD CPUs. Some GFX hardware
+ can resize a BAR to allow access to all VRAM.
+ Adding the window is slightly risky (it may
+ conflict with unreported devices), so this
+ taints the kernel.
pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power
Management.
@@ -3288,11 +3293,20 @@
pt. [PARIDE]
See Documentation/blockdev/paride.txt.
- pti= [X86_64]
- Control user/kernel address space isolation:
- on - enable
- off - disable
- auto - default setting
+ pti= [X86_64] Control Page Table Isolation of user and
+ kernel address spaces. Disabling this feature
+ removes hardening, but improves performance of
+ system calls and interrupts.
+
+ on - unconditionally enable
+ off - unconditionally disable
+ auto - kernel detects whether your CPU model is
+ vulnerable to issues that PTI mitigates
+
+ Not specifying this option is equivalent to pti=auto.
+
+ nopti [X86_64]
+ Equivalent to pti=off
pty.legacy_count=
[KNL] Number of legacy pty's. Overwrites compiled-in
@@ -3943,6 +3957,29 @@
sonypi.*= [HW] Sony Programmable I/O Control Device driver
See Documentation/laptops/sonypi.txt
+ spectre_v2= [X86] Control mitigation of Spectre variant 2
+ (indirect branch speculation) vulnerability.
+
+ on - unconditionally enable
+ off - unconditionally disable
+ auto - kernel detects whether your CPU model is
+ vulnerable
+
+ Selecting 'on' will, and 'auto' may, choose a
+ mitigation method at run time according to the
+ CPU, the available microcode, the setting of the
+ CONFIG_RETPOLINE configuration option, and the
+ compiler with which the kernel was built.
+
+ Specific mitigations can also be selected manually:
+
+ retpoline - replace indirect branches
+ retpoline,generic - google's original retpoline
+ retpoline,amd - AMD-specific minimal thunk
+
+ Not specifying this option is equivalent to
+ spectre_v2=auto.
+
spia_io_base= [HW,MTD]
spia_fio_base=
spia_pedr=