Merge 6.5-rc6 into usb-next

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

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 29fbb38..50fc936 100644 (file)
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1623,6 +1623,26 @@
                        Format: off | on
                        default: on
 
+       gather_data_sampling=
+                       [X86,INTEL] Control the Gather Data Sampling (GDS)
+                       mitigation.
+
+                       Gather Data Sampling is a hardware vulnerability which
+                       allows unprivileged speculative access to data which was
+                       previously stored in vector registers.
+
+                       This issue is mitigated by default in updated microcode.
+                       The mitigation may have a performance impact but can be
+                       disabled. On systems without the microcode mitigation
+                       disabling AVX serves as a mitigation.
+
+                       force:  Disable AVX to mitigate systems without
+                               microcode mitigation. No effect if the microcode
+                               mitigation is present. Known to cause crashes in
+                               userspace with buggy AVX enumeration.
+
+                       off:    Disable GDS mitigation.
+
        gcov_persist=   [GCOV] When non-zero (default), profiling data for
                        kernel modules is saved and remains accessible via
                        debugfs, even when the module is unloaded/reloaded.
@@ -3273,24 +3293,25 @@
                                Disable all optional CPU mitigations.  This
                                improves system performance, but it may also
                                expose users to several CPU vulnerabilities.
-                               Equivalent to: nopti [X86,PPC]
-                                              if nokaslr then kpti=0 [ARM64]
-                                              nospectre_v1 [X86,PPC]
-                                              nobp=0 [S390]
-                                              nospectre_v2 [X86,PPC,S390,ARM64]
-                                              spectre_v2_user=off [X86]
-                                              spec_store_bypass_disable=off [X86,PPC]
-                                              ssbd=force-off [ARM64]
-                                              nospectre_bhb [ARM64]
+                               Equivalent to: if nokaslr then kpti=0 [ARM64]
+                                              gather_data_sampling=off [X86]
+                                              kvm.nx_huge_pages=off [X86]
                                               l1tf=off [X86]
                                               mds=off [X86]
-                                              tsx_async_abort=off [X86]
-                                              kvm.nx_huge_pages=off [X86]
-                                              srbds=off [X86,INTEL]
+                                              mmio_stale_data=off [X86]
                                               no_entry_flush [PPC]
                                               no_uaccess_flush [PPC]
-                                              mmio_stale_data=off [X86]
+                                              nobp=0 [S390]
+                                              nopti [X86,PPC]
+                                              nospectre_bhb [ARM64]
+                                              nospectre_v1 [X86,PPC]
+                                              nospectre_v2 [X86,PPC,S390,ARM64]
                                               retbleed=off [X86]
+                                              spec_store_bypass_disable=off [X86,PPC]
+                                              spectre_v2_user=off [X86]
+                                              srbds=off [X86,INTEL]
+                                              ssbd=force-off [ARM64]
+                                              tsx_async_abort=off [X86]
 
                                Exceptions:
                                               This does not have any effect on
@@ -5875,6 +5896,17 @@
                        Not specifying this option is equivalent to
                        spectre_v2_user=auto.
 
+       spec_rstack_overflow=
+                       [X86] Control RAS overflow mitigation on AMD Zen CPUs
+
+                       off             - Disable mitigation
+                       microcode       - Enable microcode mitigation only
+                       safe-ret        - Enable sw-only safe RET mitigation (default)
+                       ibpb            - Enable mitigation by issuing IBPB on
+                                         kernel entry
+                       ibpb-vmexit     - Issue IBPB only on VMEXIT
+                                         (cloud-specific mitigation)
+
        spec_store_bypass_disable=
                        [HW] Control Speculative Store Bypass (SSB) Disable mitigation
                        (Speculative Store Bypass vulnerability)