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| author | Michael Roth <michael.roth@amd.com> | 2024-05-01 10:10:48 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2024-05-07 20:28:05 +0300 |
| commit | 4af663c2f64a8d252e690c60cf8b8abf22dc2951 (patch) | |
| tree | 3e5d4cb911e47f8303126647a753b9b8b57fdc11 /Documentation/virt | |
| parent | 8d1a36e42be6b0864c2c30f94536663b6f08fb48 (diff) | |
| download | linux-4af663c2f64a8d252e690c60cf8b8abf22dc2951.tar.xz | |
KVM: SEV: Allow per-guest configuration of GHCB protocol version
The GHCB protocol version may be different from one guest to the next.
Add a field to track it for each KVM instance and extend KVM_SEV_INIT2
to allow it to be configured by userspace.
Now that all SEV-ES support for GHCB protocol version 2 is in place, go
ahead and default to it when creating SEV-ES guests through the new
KVM_SEV_INIT2 interface. Keep the older KVM_SEV_ES_INIT interface
restricted to GHCB protocol version 1.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Michael Roth <michael.roth@amd.com>
Message-ID: <20240501071048.2208265-5-michael.roth@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'Documentation/virt')
| -rw-r--r-- | Documentation/virt/kvm/x86/amd-memory-encryption.rst | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/Documentation/virt/kvm/x86/amd-memory-encryption.rst b/Documentation/virt/kvm/x86/amd-memory-encryption.rst index 3381556d596d..9677a0714a39 100644 --- a/Documentation/virt/kvm/x86/amd-memory-encryption.rst +++ b/Documentation/virt/kvm/x86/amd-memory-encryption.rst @@ -95,13 +95,19 @@ Returns: 0 on success, -negative on error struct kvm_sev_init { __u64 vmsa_features; /* initial value of features field in VMSA */ __u32 flags; /* must be 0 */ - __u32 pad[9]; + __u16 ghcb_version; /* maximum guest GHCB version allowed */ + __u16 pad1; + __u32 pad2[8]; }; It is an error if the hypervisor does not support any of the bits that are set in ``flags`` or ``vmsa_features``. ``vmsa_features`` must be 0 for SEV virtual machines, as they do not have a VMSA. +``ghcb_version`` must be 0 for SEV virtual machines, as they do not issue GHCB +requests. If ``ghcb_version`` is 0 for any other guest type, then the maximum +allowed guest GHCB protocol will default to version 2. + This command replaces the deprecated KVM_SEV_INIT and KVM_SEV_ES_INIT commands. The commands did not have any parameters (the ```data``` field was unused) and only work for the KVM_X86_DEFAULT_VM machine type (0). @@ -112,7 +118,8 @@ They behave as if: KVM_SEV_ES_INIT * the ``flags`` and ``vmsa_features`` fields of ``struct kvm_sev_init`` are - set to zero + set to zero, and ``ghcb_version`` is set to 0 for KVM_SEV_INIT and 1 for + KVM_SEV_ES_INIT. If the ``KVM_X86_SEV_VMSA_FEATURES`` attribute does not exist, the hypervisor only supports KVM_SEV_INIT and KVM_SEV_ES_INIT. In that case, note that KVM_SEV_ES_INIT |