KVM: SEV-ES: Prevent MSR access post VMSA encryption

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KVM currently allows userspace to read/write MSRs even after the VMSA is
encrypted. This can cause unintentional issues if MSR access has side-
effects. For ex, while migrating a guest, userspace could attempt to
migrate MSR_IA32_DEBUGCTLMSR and end up unintentionally disabling LBRV on
the target. Fix this by preventing access to those MSRs which are context
switched via the VMSA, once the VMSA is encrypted.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Nikunj A Dadhania <nikunj@amd.com>
Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
Message-ID: <20240531044644.768-2-ravi.bangoria@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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Nikunj A Dadhania 2024-05-31 04:46:42 +00:00 • committed by Paolo Bonzini

parent b4bd556467

commit 27bd5fdc24

1 changed files with 18 additions and 0 deletions

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arch/x86/kvm/svm/svm.c

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