Merge tag 'docs-6.5' of git://git.lwn.net/linux

[platform/kernel/linux-rpi.git] / Documentation / admin-guide / kernel-parameters.txt

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 2836780..e7b4e64 100644 (file)
--- 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.