In current code, DMA remapping is enabled at very early stage, when there is no
device added.
Devices are added to VT-d context table when creating VMs.
There is potential risk that there may be device DMA transactions when DMA remapping is
enabled, but the device is not added to the VT-d context table. (Eg. this could happen in UEFI
enviroment when USB keyboard use in efi intenal shell.)
This patch defers DMA remapping enabling until vm creation.
Tracked-On: #1855
Signed-off-by: Binbin Wu <binbin.wu@intel.com>
Acked-by: Anthony Xu <anthony.xu@intel.com>