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-rw-r--r--Documentation/admin-guide/kernel-parameters.txt39
1 files changed, 39 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 3edc5ce0e2a3..6c42061ca20e 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -608,6 +608,24 @@
ccw_timeout_log [S390]
See Documentation/arch/s390/common_io.rst for details.
+ cfi= [X86-64] Set Control Flow Integrity checking features
+ when CONFIG_FINEIBT is enabled.
+ Format: feature[,feature...]
+ Default: auto
+
+ auto: Use FineIBT if IBT available, otherwise kCFI.
+ Under FineIBT, enable "paranoid" mode when
+ FRED is not available.
+ off: Turn off CFI checking.
+ kcfi: Use kCFI (disable FineIBT).
+ fineibt: Use FineIBT (even if IBT not available).
+ norand: Do not re-randomize CFI hashes.
+ paranoid: Add caller hash checking under FineIBT.
+ bhi: Enable register poisoning to stop speculation
+ across FineIBT. (Disabled by default.)
+ warn: Do not enforce CFI checking: warn only.
+ debug: Report CFI initialization details.
+
cgroup_disable= [KNL] Disable a particular controller or optional feature
Format: {name of the controller(s) or feature(s) to disable}
The effects of cgroup_disable=foo are:
@@ -2962,6 +2980,27 @@
(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.