diff options
Diffstat (limited to 'Documentation/admin-guide/kernel-parameters.txt')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 77 |
1 files changed, 68 insertions, 9 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 2522b11e593f..9ea3ae8b3893 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2266,23 +2266,39 @@ ivrs_ioapic [HW,X86-64] Provide an override to the IOAPIC-ID<->DEVICE-ID - mapping provided in the IVRS ACPI table. For - example, to map IOAPIC-ID decimal 10 to - PCI device 00:14.0 write the parameter as: + mapping provided in the IVRS ACPI table. + By default, PCI segment is 0, and can be omitted. + For example: + * To map IOAPIC-ID decimal 10 to PCI device 00:14.0 + write the parameter as: ivrs_ioapic[10]=00:14.0 + * To map IOAPIC-ID decimal 10 to PCI segment 0x1 and + PCI device 00:14.0 write the parameter as: + ivrs_ioapic[10]=0001:00:14.0 ivrs_hpet [HW,X86-64] Provide an override to the HPET-ID<->DEVICE-ID - mapping provided in the IVRS ACPI table. For - example, to map HPET-ID decimal 0 to - PCI device 00:14.0 write the parameter as: + mapping provided in the IVRS ACPI table. + By default, PCI segment is 0, and can be omitted. + For example: + * To map HPET-ID decimal 0 to PCI device 00:14.0 + write the parameter as: ivrs_hpet[0]=00:14.0 + * To map HPET-ID decimal 10 to PCI segment 0x1 and + PCI device 00:14.0 write the parameter as: + ivrs_ioapic[10]=0001:00:14.0 ivrs_acpihid [HW,X86-64] Provide an override to the ACPI-HID:UID<->DEVICE-ID - mapping provided in the IVRS ACPI table. For - example, to map UART-HID:UID AMD0020:0 to - PCI device 00:14.5 write the parameter as: + mapping provided in the IVRS ACPI table. + + For example, to map UART-HID:UID AMD0020:0 to + PCI segment 0x1 and PCI device ID 00:14.5, + write the parameter as: + ivrs_acpihid[0001:00:14.5]=AMD0020:0 + + By default, PCI segment is 0, and can be omitted. + For example, PCI device 00:14.5 write the parameter as: ivrs_acpihid[00:14.5]=AMD0020:0 js= [HW,JOY] Analog joystick @@ -5197,6 +5213,30 @@ retain_initrd [RAM] Keep initrd memory after extraction + retbleed= [X86] Control mitigation of RETBleed (Arbitrary + Speculative Code Execution with Return Instructions) + vulnerability. + + off - no mitigation + auto - automatically select a migitation + auto,nosmt - automatically select a mitigation, + disabling SMT if necessary for + the full mitigation (only on Zen1 + and older without STIBP). + ibpb - mitigate short speculation windows on + basic block boundaries too. Safe, highest + perf impact. + unret - force enable untrained return thunks, + only effective on AMD f15h-f17h + based systems. + unret,nosmt - like unret, will disable SMT when STIBP + is not available. + + Selecting 'auto' will choose a mitigation method at run + time according to the CPU. + + Not specifying this option is equivalent to retbleed=auto. + rfkill.default_state= 0 "airplane mode". All wifi, bluetooth, wimax, gps, fm, etc. communication is blocked by default. @@ -5568,6 +5608,7 @@ eibrs - enhanced IBRS eibrs,retpoline - enhanced IBRS + Retpolines eibrs,lfence - enhanced IBRS + LFENCE + ibrs - use IBRS to protect kernel Not specifying this option is equivalent to spectre_v2=auto. @@ -5771,6 +5812,24 @@ expediting. Set to zero to disable automatic expediting. + srcutree.srcu_max_nodelay [KNL] + Specifies the number of no-delay instances + per jiffy for which the SRCU grace period + worker thread will be rescheduled with zero + delay. Beyond this limit, worker thread will + be rescheduled with a sleep delay of one jiffy. + + srcutree.srcu_max_nodelay_phase [KNL] + Specifies the per-grace-period phase, number of + non-sleeping polls of readers. Beyond this limit, + grace period worker thread will be rescheduled + with a sleep delay of one jiffy, between each + rescan of the readers, for a grace period phase. + + srcutree.srcu_retry_check_delay [KNL] + Specifies number of microseconds of non-sleeping + delay between each non-sleeping poll of readers. + srcutree.small_contention_lim [KNL] Specifies the number of update-side contention events per jiffy will be tolerated before |