AHCI has code to fill in the D2H FIS trigger the IRQ all over the place.
Centralize this in a single cmd_done callback by generalizing the existing
async_cmd_done callback.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJohn Snow <jsnow@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>