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Diffstat (limited to 'Documentation/admin-guide')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 3edc5ce0e2a3..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. |