X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=blobdiff_plain;f=Documentation%2Fadmin-guide%2Fkernel-parameters.txt;h=70384d8682eaac66fab163178d320ffe144a0e1a;hb=03ebe48e235f17d70f34890d34d8153b8a84c02e;hp=81d1d5a7472804e50a663480ef92dc67abc71ab5;hpb=a6906a8b0ebfbf6330847ba640c8dde8aca679be;p=linux.git

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 81d1d5a74728..70384d8682ea 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -856,7 +856,8 @@
 			causing system reset or hang due to sending
 			INIT from AP to BSP.
 
-	disable_counter_freezing [HW]
+	perf_v4_pmi=	[X86,INTEL]
+			Format: <bool>
 			Disable Intel PMU counter freezing feature.
 			The feature only exists starting from
 			Arch Perfmon v4 (Skylake and newer).
@@ -1682,12 +1683,12 @@
 			By default, super page will be supported if Intel IOMMU
 			has the capability. With this option, super page will
 			not be supported.
-		ecs_off [Default Off]
-			By default, extended context tables will be supported if
-			the hardware advertises that it has support both for the
-			extended tables themselves, and also PASID support. With
-			this option set, extended tables will not be used even
-			on hardware which claims to support them.
+		sm_off [Default Off]
+			By default, scalable mode will be supported if the
+			hardware advertises that it has support for the scalable
+			mode translation. With this option set, scalable mode
+			will not be used even on hardware which claims to support
+			it.
 		tboot_noforce [Default Off]
 			Do not force the Intel IOMMU enabled under tboot.
 			By default, tboot will force Intel IOMMU on, which
@@ -3504,6 +3505,10 @@
 			before loading.
 			See Documentation/blockdev/ramdisk.txt.
 
+	psi=		[KNL] Enable or disable pressure stall information
+			tracking.
+			Format: <bool>
+
 	psmouse.proto=	[HW,MOUSE] Highest PS2 mouse protocol extension to
 			probe for; one of (bare|imps|exps|lifebook|any).
 	psmouse.rate=	[HW,MOUSE] Set desired mouse report rate, in reports
@@ -4194,9 +4199,13 @@
 
 	spectre_v2=	[X86] Control mitigation of Spectre variant 2
 			(indirect branch speculation) vulnerability.
+			The default operation protects the kernel from
+			user space attacks.
 
-			on   - unconditionally enable
-			off  - unconditionally disable
+			on   - unconditionally enable, implies
+			       spectre_v2_user=on
+			off  - unconditionally disable, implies
+			       spectre_v2_user=off
 			auto - kernel detects whether your CPU model is
 			       vulnerable
 
@@ -4206,6 +4215,12 @@
 			CONFIG_RETPOLINE configuration option, and the
 			compiler with which the kernel was built.
 
+			Selecting 'on' will also enable the mitigation
+			against user space to user space task attacks.
+
+			Selecting 'off' will disable both the kernel and
+			the user space protections.
+
 			Specific mitigations can also be selected manually:
 
 			retpoline	  - replace indirect branches
@@ -4215,6 +4230,48 @@
 			Not specifying this option is equivalent to
 			spectre_v2=auto.
 
+	spectre_v2_user=
+			[X86] Control mitigation of Spectre variant 2
+		        (indirect branch speculation) vulnerability between
+		        user space tasks
+
+			on	- Unconditionally enable mitigations. Is
+				  enforced by spectre_v2=on
+
+			off     - Unconditionally disable mitigations. Is
+				  enforced by spectre_v2=off
+
+			prctl   - Indirect branch speculation is enabled,
+				  but mitigation can be enabled via prctl
+				  per thread.  The mitigation control state
+				  is inherited on fork.
+
+			prctl,ibpb
+				- Like "prctl" above, but only STIBP is
+				  controlled per thread. IBPB is issued
+				  always when switching between different user
+				  space processes.
+
+			seccomp
+				- Same as "prctl" above, but all seccomp
+				  threads will enable the mitigation unless
+				  they explicitly opt out.
+
+			seccomp,ibpb
+				- Like "seccomp" above, but only STIBP is
+				  controlled per thread. IBPB is issued
+				  always when switching between different
+				  user space processes.
+
+			auto    - Kernel selects the mitigation depending on
+				  the available CPU features and vulnerability.
+
+			Default mitigation:
+			If CONFIG_SECCOMP=y then "seccomp", otherwise "prctl"
+
+			Not specifying this option is equivalent to
+			spectre_v2_user=auto.
+
 	spec_store_bypass_disable=
 			[HW] Control Speculative Store Bypass (SSB) Disable mitigation
 			(Speculative Store Bypass vulnerability)
@@ -4713,6 +4770,8 @@
 					prevent spurious wakeup);
 				n = USB_QUIRK_DELAY_CTRL_MSG (Device needs a
 					pause after every control message);
+				o = USB_QUIRK_HUB_SLOW_RESET (Hub needs extra
+					delay after resetting its port);
 			Example: quirks=0781:5580:bk,0a5c:5834:gij
 
 	usbhid.mousepoll=