To change the cd-rom medium, libxl will:
- QMP eject the medium from QEMU
- block-detach the old PV disk
- block-attach the new PV disk
- QMP change the medium to the new PV disk by fdset-id
The QMP code is reused, and remove and attach are implemented here.
The stubdom must internally handle adding /dev/xvdc to the appropriate
fdset. libxl in dom0 doesn't see the result of adding to the fdset as
that is internal to the stubdom, but the fdset's opaque fields will be
set to stub-devid:$devid, so libxl can identify it. $devid is common
between the stubdom and libxl, so it can be identified on both side.
The stubdom will name the device xvdY regardless of the guest name hdY,
sdY, or xvdY, but the stubdom will be assigned the same devid
facilitating lookup. Because the stubdom add-fd call is asynchronous,
libxl needs to poll query-fdsets to identify when add-fd has completed.
For cd-eject, we still need to attach the empty vbd. This is necessary
since xenstore is used to determine that hdc exists. Otherwise after
eject, hdc would be gone and the cd-insert would fail to find the drive
to insert new media.
Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Signed-off-by: Jason Andryuk <jason.andryuk@amd.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
Jason Andryuk
a18b50614d