KVM PV features don't seem to be documented anywhere, in particular, the
fact that some of the features are enabled by default and some are not can
only be figured out from the code.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20211004140445.624875-1-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
