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-rw-r--r--Documentation/admin-guide/kernel-parameters.txt63
1 files changed, 39 insertions, 24 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 2836780618a8..e7b4e64e3fd3 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2112,6 +2112,16 @@
disable
Do not enable intel_pstate as the default
scaling driver for the supported processors
+ active
+ Use intel_pstate driver to bypass the scaling
+ governors layer of cpufreq and provides it own
+ algorithms for p-state selection. There are two
+ P-state selection algorithms provided by
+ intel_pstate in the active mode: powersave and
+ performance. The way they both operate depends
+ on whether or not the hardware managed P-states
+ (HWP) feature has been enabled in the processor
+ and possibly on the processor model.
passive
Use intel_pstate as a scaling driver, but configure it
to work with generic cpufreq governors (instead of
@@ -2546,12 +2556,13 @@
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)
+ kvm-amd.nested= [KVM,AMD] Control nested virtualization feature in
+ KVM/SVM. Default is 1 (enabled).
- kvm-amd.npt= [KVM,AMD] Disable nested paging (virtualized MMU)
- for all guests.
- Default is 1 (enabled) if in 64-bit or 32-bit PAE mode.
+ kvm-amd.npt= [KVM,AMD] Control KVM's use of Nested Page Tables,
+ a.k.a. Two-Dimensional Page Tables. Default is 1
+ (enabled). Disable by KVM if hardware lacks support
+ for NPT.
kvm-arm.mode=
[KVM,ARM] Select one of KVM/arm64's modes of operation.
@@ -2597,30 +2608,33 @@
Format: <integer>
Default: 5
- kvm-intel.ept= [KVM,Intel] Disable extended page tables
- (virtualized MMU) support on capable Intel chips.
- Default is 1 (enabled)
+ kvm-intel.ept= [KVM,Intel] Control KVM's use of Extended Page Tables,
+ a.k.a. Two-Dimensional Page Tables. Default is 1
+ (enabled). Disable by KVM if hardware lacks support
+ for EPT.
kvm-intel.emulate_invalid_guest_state=
- [KVM,Intel] Disable emulation of invalid guest state.
- Ignored if kvm-intel.enable_unrestricted_guest=1, as
- guest state is never invalid for unrestricted guests.
- This param doesn't apply to nested guests (L2), as KVM
- never emulates invalid L2 guest state.
- Default is 1 (enabled)
+ [KVM,Intel] Control whether to emulate invalid guest
+ state. Ignored if kvm-intel.enable_unrestricted_guest=1,
+ as guest state is never invalid for unrestricted
+ guests. This param doesn't apply to nested guests (L2),
+ as KVM never emulates invalid L2 guest state.
+ Default is 1 (enabled).
kvm-intel.flexpriority=
- [KVM,Intel] Disable FlexPriority feature (TPR shadow).
- Default is 1 (enabled)
+ [KVM,Intel] Control KVM's use of FlexPriority feature
+ (TPR shadow). Default is 1 (enabled). Disalbe by KVM if
+ hardware lacks support for it.
kvm-intel.nested=
- [KVM,Intel] Enable VMX nesting (nVMX).
- Default is 0 (disabled)
+ [KVM,Intel] Control nested virtualization feature in
+ KVM/VMX. Default is 1 (enabled).
kvm-intel.unrestricted_guest=
- [KVM,Intel] Disable unrestricted guest feature
- (virtualized real and unpaged mode) on capable
- Intel chips. Default is 1 (enabled)
+ [KVM,Intel] Control KVM's use of unrestricted guest
+ feature (virtualized real and unpaged mode). Default
+ is 1 (enabled). Disable by KVM if EPT is disabled or
+ hardware lacks support for it.
kvm-intel.vmentry_l1d_flush=[KVM,Intel] Mitigation for L1 Terminal Fault
CVE-2018-3620.
@@ -2634,9 +2648,10 @@
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)
+ kvm-intel.vpid= [KVM,Intel] Control KVM's use of Virtual Processor
+ Identification feature (tagged TLBs). Default is 1
+ (enabled). Disable by KVM if hardware lacks support
+ for it.
l1d_flush= [X86,INTEL]
Control mitigation for L1D based snooping vulnerability.