Currently, the previous configurations about guest_flags set by DM will
not be cleared when shutdown the vm. Then it might bring issue for the
next dm-launched vm.
For example, if we create one vm with LAPIC_PASSTHROUGH flag and shutdown it.
Then the next dm-launched vm will has the LAPIC_PASSTHROUGH flag set no matter
whether we set it in DM.
This patch clears all the DM set flags when shtudown vm.
Tracked-On: #2991
Signed-off-by: Kaige Fu <kaige.fu@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
565f3c723a