Merge branch 'kvm-guest-sev-migration' into kvm-master
Add guest api and guest kernel support for SEV live migration.
Introduces a new hypercall to notify the host of changes to the page
encryption status. If the page is encrypted then it must be migrated
through the SEV firmware or a helper VM sharing the key. If page is
not encrypted then it can be migrated normally by userspace. This new
hypercall is invoked using paravirt_ops.
Conflicts: sev_active() replaced by cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT).