CA-116819: xenlight: don't attach storage during VM_restore

When migration a VM, its VBDs need to be attached after VM_restore, during the
VM_restore_devices operation.  This is the case in classic xenopsd, and must
also be the case in the xenlight version, because the sender host in a
migration detaches itself from the storage only after sending the memory image
across.

Signed-off-by: Rob Hoes <rob.hoes@citrix.com>
Don't reopen already open module

Signed-off-by: Si Beaumont <simon.beaumont@citrix.com>
CA-116814: Correctly calculate shahow_memkb

There was a typo in the divisor and also the units were not converted from MB
to kB.

These values are used for machines without HAP.

Signed-off-by: Si Beaumont <simon.beaumont@citrix.com>
Merge pull request #22 from robhoes/ca116819

CA-116819: xenlight: don't attach storage during VM_restore
Merge pull request #23 from simonjbeaumont/cp-6238

Fix computation of shadow_memkb for HVM domains without HAP
CA-117402: fix cd-eject for HVM guests

Signed-off-by: Rob Hoes <rob.hoes@citrix.com>
Merge pull request #24 from robhoes/cd-eject

CA-117402: fix cd-eject for HVM guests
xenlight: use PHY backend when adding an empty CD-ROM and not using qdisk

Signed-off-by: Rob Hoes <rob.hoes@citrix.com>
xenlight: add block-xl script

Signed-off-by: Rob Hoes <rob.hoes@citrix.com>