diff options
Diffstat (limited to 'Documentation/admin-guide/kernel-parameters.txt')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 33 |
1 files changed, 27 insertions, 6 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 74ca438d2d6d..a51ab4656854 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2962,6 +2962,27 @@ (enabled). Disable by KVM if hardware lacks support for NPT. + kvm-amd.ciphertext_hiding_asids= + [KVM,AMD] Ciphertext hiding prevents disallowed accesses + to SNP private memory from reading ciphertext. Instead, + reads will see constant default values (0xff). + + If ciphertext hiding is enabled, the joint SEV-ES and + SEV-SNP ASID space is partitioned into separate SEV-ES + and SEV-SNP ASID ranges, with the SEV-SNP range being + [1..max_snp_asid] and the SEV-ES range being + (max_snp_asid..min_sev_asid), where min_sev_asid is + enumerated by CPUID.0x.8000_001F[EDX]. + + A non-zero value enables SEV-SNP ciphertext hiding and + adjusts the ASID ranges for SEV-ES and SEV-SNP guests. + KVM caps the number of SEV-SNP ASIDs at the maximum + possible value, e.g. specifying -1u will assign all + joint SEV-ES and SEV-SNP ASIDs to SEV-SNP. Note, + assigning all joint ASIDs to SEV-SNP, i.e. configuring + max_snp_asid == min_sev_asid-1, will effectively make + SEV-ES unusable. + kvm-arm.mode= [KVM,ARM,EARLY] Select one of KVM/arm64's modes of operation. @@ -3705,7 +3726,7 @@ looking for corruption. Enabling this will both detect corruption and prevent the kernel from using the memory being corrupted. - However, its intended as a diagnostic tool; if + However, it's intended as a diagnostic tool; if repeatable BIOS-originated corruption always affects the same memory, you can use memmap= to prevent the kernel from using that memory. @@ -7400,7 +7421,7 @@ (converted into nanoseconds). Fast, but depending on the architecture, may not be in sync between CPUs. - global - Event time stamps are synchronize across + global - Event time stamps are synchronized across CPUs. May be slower than the local clock, but better for some race conditions. counter - Simple counting of events (1, 2, ..) @@ -7520,12 +7541,12 @@ section. trace_trigger=[trigger-list] - [FTRACE] Add a event trigger on specific events. + [FTRACE] Add an event trigger on specific events. Set a trigger on top of a specific event, with an optional filter. - The format is is "trace_trigger=<event>.<trigger>[ if <filter>],..." - Where more than one trigger may be specified that are comma deliminated. + The format is "trace_trigger=<event>.<trigger>[ if <filter>],..." + Where more than one trigger may be specified that are comma delimited. For example: @@ -7533,7 +7554,7 @@ The above will enable the "stacktrace" trigger on the "sched_switch" event but only trigger it if the "prev_state" of the "sched_switch" - event is "2" (TASK_UNINTERUPTIBLE). + event is "2" (TASK_UNINTERRUPTIBLE). See also "Event triggers" in Documentation/trace/events.rst |