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author | Paolo Bonzini <pbonzini@redhat.com> | 2024-03-18 19:11:41 +0300 |
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committer | Paolo Bonzini <pbonzini@redhat.com> | 2024-03-19 02:03:53 +0300 |
commit | c20722c412f1cc1879e994fe169278bd0f322ad9 (patch) | |
tree | 1a3e0641f24164d6cb22c40823c75a274c9df497 /Documentation/virt/kvm/x86 | |
parent | 19cebbab995b2c99e927d6c5f3f24ded0740efd5 (diff) | |
download | linux-c20722c412f1cc1879e994fe169278bd0f322ad9.tar.xz |
Documentation: kvm/sev: clarify usage of KVM_MEMORY_ENCRYPT_OP
Explain that it operates on the VM file descriptor, and also clarify how
detection of SEV operates on old kernels predating commit 2da1ed62d55c
("KVM: SVM: document KVM_MEM_ENCRYPT_OP, let userspace detect if SEV
is available").
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'Documentation/virt/kvm/x86')
-rw-r--r-- | Documentation/virt/kvm/x86/amd-memory-encryption.rst | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/Documentation/virt/kvm/x86/amd-memory-encryption.rst b/Documentation/virt/kvm/x86/amd-memory-encryption.rst index 4f2eb441c718..84335d119ff1 100644 --- a/Documentation/virt/kvm/x86/amd-memory-encryption.rst +++ b/Documentation/virt/kvm/x86/amd-memory-encryption.rst @@ -49,12 +49,13 @@ defined in the CPUID 0x8000001f[ecx] field. The KVM_MEMORY_ENCRYPT_OP ioctl =============================== -The main ioctl to access SEV is KVM_MEMORY_ENCRYPT_OP. If the argument -to KVM_MEMORY_ENCRYPT_OP is NULL, the ioctl returns 0 if SEV is enabled -and ``ENOTTY`` if it is disabled (on some older versions of Linux, -the ioctl runs normally even with a NULL argument, and therefore will -likely return ``EFAULT``). If non-NULL, the argument to KVM_MEMORY_ENCRYPT_OP -must be a struct kvm_sev_cmd:: +The main ioctl to access SEV is KVM_MEMORY_ENCRYPT_OP, which operates on +the VM file descriptor. If the argument to KVM_MEMORY_ENCRYPT_OP is NULL, +the ioctl returns 0 if SEV is enabled and ``ENOTTY`` if it is disabled +(on some older versions of Linux, the ioctl tries to run normally even +with a NULL argument, and therefore will likely return ``EFAULT`` instead +of zero if SEV is enabled). If non-NULL, the argument to +KVM_MEMORY_ENCRYPT_OP must be a struct kvm_sev_cmd:: struct kvm_sev_cmd { __u32 id; |