hc
2024-10-22 8ac6c7a54ed1b98d142dce24b11c6de6a1e239a5
kernel/Documentation/admin-guide/kernel-parameters.txt
....@@ -894,10 +894,6 @@
894894
895895 debugpat [X86] Enable PAT debugging
896896
897
- decnet.addr= [HW,NET]
898
- Format: <area>[,<node>]
899
- See also Documentation/networking/decnet.rst.
900
-
901897 default_hugepagesz=
902898 [HW] The size of the default HugeTLB page. This is
903899 the size represented by the legacy /proc/ hugepages
....@@ -1487,6 +1483,26 @@
14871483 gart_fix_e820= [X86-64] disable the fix e820 for K8 GART
14881484 Format: off | on
14891485 default: on
1486
+
1487
+ gather_data_sampling=
1488
+ [X86,INTEL] Control the Gather Data Sampling (GDS)
1489
+ mitigation.
1490
+
1491
+ Gather Data Sampling is a hardware vulnerability which
1492
+ allows unprivileged speculative access to data which was
1493
+ previously stored in vector registers.
1494
+
1495
+ This issue is mitigated by default in updated microcode.
1496
+ The mitigation may have a performance impact but can be
1497
+ disabled. On systems without the microcode mitigation
1498
+ disabling AVX serves as a mitigation.
1499
+
1500
+ force: Disable AVX to mitigate systems without
1501
+ microcode mitigation. No effect if the microcode
1502
+ mitigation is present. Known to cause crashes in
1503
+ userspace with buggy AVX enumeration.
1504
+
1505
+ off: Disable GDS mitigation.
14901506
14911507 gcov_persist= [GCOV] When non-zero (default), profiling data for
14921508 kernel modules is saved and remains accessible via
....@@ -2144,24 +2160,57 @@
21442160
21452161 ivrs_ioapic [HW,X86-64]
21462162 Provide an override to the IOAPIC-ID<->DEVICE-ID
2147
- mapping provided in the IVRS ACPI table. For
2148
- example, to map IOAPIC-ID decimal 10 to
2149
- PCI device 00:14.0 write the parameter as:
2163
+ mapping provided in the IVRS ACPI table.
2164
+ By default, PCI segment is 0, and can be omitted.
2165
+
2166
+ For example, to map IOAPIC-ID decimal 10 to
2167
+ PCI segment 0x1 and PCI device 00:14.0,
2168
+ write the parameter as:
2169
+ ivrs_ioapic=10@0001:00:14.0
2170
+
2171
+ Deprecated formats:
2172
+ * To map IOAPIC-ID decimal 10 to PCI device 00:14.0
2173
+ write the parameter as:
21502174 ivrs_ioapic[10]=00:14.0
2175
+ * To map IOAPIC-ID decimal 10 to PCI segment 0x1 and
2176
+ PCI device 00:14.0 write the parameter as:
2177
+ ivrs_ioapic[10]=0001:00:14.0
21512178
21522179 ivrs_hpet [HW,X86-64]
21532180 Provide an override to the HPET-ID<->DEVICE-ID
2154
- mapping provided in the IVRS ACPI table. For
2155
- example, to map HPET-ID decimal 0 to
2156
- PCI device 00:14.0 write the parameter as:
2181
+ mapping provided in the IVRS ACPI table.
2182
+ By default, PCI segment is 0, and can be omitted.
2183
+
2184
+ For example, to map HPET-ID decimal 10 to
2185
+ PCI segment 0x1 and PCI device 00:14.0,
2186
+ write the parameter as:
2187
+ ivrs_hpet=10@0001:00:14.0
2188
+
2189
+ Deprecated formats:
2190
+ * To map HPET-ID decimal 0 to PCI device 00:14.0
2191
+ write the parameter as:
21572192 ivrs_hpet[0]=00:14.0
2193
+ * To map HPET-ID decimal 10 to PCI segment 0x1 and
2194
+ PCI device 00:14.0 write the parameter as:
2195
+ ivrs_ioapic[10]=0001:00:14.0
21582196
21592197 ivrs_acpihid [HW,X86-64]
21602198 Provide an override to the ACPI-HID:UID<->DEVICE-ID
2161
- mapping provided in the IVRS ACPI table. For
2162
- example, to map UART-HID:UID AMD0020:0 to
2163
- PCI device 00:14.5 write the parameter as:
2199
+ mapping provided in the IVRS ACPI table.
2200
+ By default, PCI segment is 0, and can be omitted.
2201
+
2202
+ For example, to map UART-HID:UID AMD0020:0 to
2203
+ PCI segment 0x1 and PCI device ID 00:14.5,
2204
+ write the parameter as:
2205
+ ivrs_acpihid=AMD0020:0@0001:00:14.5
2206
+
2207
+ Deprecated formats:
2208
+ * To map UART-HID:UID AMD0020:0 to PCI segment is 0,
2209
+ PCI device ID 00:14.5, write the parameter as:
21642210 ivrs_acpihid[00:14.5]=AMD0020:0
2211
+ * To map UART-HID:UID AMD0020:0 to PCI segment 0x1 and
2212
+ PCI device ID 00:14.5, write the parameter as:
2213
+ ivrs_acpihid[0001:00:14.5]=AMD0020:0
21652214
21662215 js= [HW,JOY] Analog joystick
21672216 See Documentation/input/joydev/joystick.rst.
....@@ -2310,6 +2359,8 @@
23102359
23112360 kvm-arm.mode=
23122361 [KVM,ARM] Select one of KVM/arm64's modes of operation.
2362
+
2363
+ none: Forcefully disable KVM.
23132364
23142365 nvhe: Standard nVHE-based mode, without support for
23152366 protected guests.
....@@ -2918,22 +2969,23 @@
29182969 Disable all optional CPU mitigations. This
29192970 improves system performance, but it may also
29202971 expose users to several CPU vulnerabilities.
2921
- Equivalent to: nopti [X86,PPC]
2972
+ Equivalent to: gather_data_sampling=off [X86]
29222973 kpti=0 [ARM64]
2923
- nospectre_v1 [X86,PPC]
2924
- nobp=0 [S390]
2925
- nospectre_v2 [X86,PPC,S390,ARM64]
2926
- spectre_v2_user=off [X86]
2927
- spec_store_bypass_disable=off [X86,PPC]
2928
- ssbd=force-off [ARM64]
2974
+ kvm.nx_huge_pages=off [X86]
29292975 l1tf=off [X86]
29302976 mds=off [X86]
2931
- tsx_async_abort=off [X86]
2932
- kvm.nx_huge_pages=off [X86]
2977
+ mmio_stale_data=off [X86]
29332978 no_entry_flush [PPC]
29342979 no_uaccess_flush [PPC]
2935
- mmio_stale_data=off [X86]
2980
+ nobp=0 [S390]
2981
+ nopti [X86,PPC]
2982
+ nospectre_v1 [X86,PPC]
2983
+ nospectre_v2 [X86,PPC,S390,ARM64]
29362984 retbleed=off [X86]
2985
+ spec_store_bypass_disable=off [X86,PPC]
2986
+ spectre_v2_user=off [X86]
2987
+ ssbd=force-off [ARM64]
2988
+ tsx_async_abort=off [X86]
29372989
29382990 Exceptions:
29392991 This does not have any effect on
....@@ -5191,6 +5243,17 @@
51915243 Not specifying this option is equivalent to
51925244 spectre_v2_user=auto.
51935245
5246
+ spec_rstack_overflow=
5247
+ [X86] Control RAS overflow mitigation on AMD Zen CPUs
5248
+
5249
+ off - Disable mitigation
5250
+ microcode - Enable microcode mitigation only
5251
+ safe-ret - Enable sw-only safe RET mitigation (default)
5252
+ ibpb - Enable mitigation by issuing IBPB on
5253
+ kernel entry
5254
+ ibpb-vmexit - Issue IBPB only on VMEXIT
5255
+ (cloud-specific mitigation)
5256
+
51945257 spec_store_bypass_disable=
51955258 [HW] Control Speculative Store Bypass (SSB) Disable mitigation
51965259 (Speculative Store Bypass vulnerability)