Description of problem: The register states of CSV2 guest are protected by encrypted VMSA. When live migrate a CSV2 guest, we need invoke SEND_UPDATE_VMSA to prepare for transfer VMSA at the source side, and invoke RECEIVE_UPDATE_VMSA to restore VMSA at the receipt side. GHCB registers are important component to support communication between KVM and CSV2 guest. The GHCB register supports two modes: 1. msr negotiation, or 2. shared memory page. When migrate a CSV2 guest, the GHCB register states also should be migrated. The VCPU mode is crucial for the operation of a VM, KVM will track VCPU mode in auxiliary register values (see struct kvm_vcpu_arch) and determine the guest context. In order to support CSV2 guest run under correct VCPU mode, the auxiliary register values should be migrated when migrating CSV2 guest. Version-Release number of selected component (if applicable): How reproducible: Steps to Reproduce: 1. 2. 3. Actual results: Expected results: Additional info: