vfio-user: implement VFIO_USER_DMA_MAP/UNMAP
When the vfio-user container gets mapping updates, share them with the
vfio-user by sending a message; this can include the region fd, allowing
the server to directly mmap() the region as needed.
For performance, we only wait for the message responses when we're doing
with a series of updates via the listener_commit() callback.
Originally-by: John Johnson <john.g.johnson@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: John Levon <john.levon@nutanix.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/qemu-devel/20250625193012.2316242-14-john.levon@nutanix.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>
5 files changed