vfio: add vfio_device_get_region_fd()

This keeps the existence of ->region_fds private to hw/vfio/device.c.

Signed-off-by: John Levon <john.levon@nutanix.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Link: https://lore.kernel.org/qemu-devel/20250616101337.3190027-1-john.levon@nutanix.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>
3 files changed