Assuming you've migrated all your vmnics to the DVS and have none connecting to a vSwitch in your case, the easiest way would be to get onto the console, KVM, or iLO of the box, create a standard vSwitch with a temporary service console, migrate one adapter from the DVS to the vSwitch then correct your 1000v config.
1. From the command line you'll need to find the DVPort ID, the DVS Switch name and the adapter (vmnic) you wish to migrate.
You can get this info by issuing:
esxcfg-vswitch -l | more
(This will list all the items above, take note of them).
2. Then issue:
esxcfg-vswitch -Q <vmnic#> -V <DVPort ID#> <DVS Switch Name>
(This will remove an adapter attached to the 1000v).
3. Next step is to create your temp vSwitch and Service Console and assign that vmnic to the vSwitch. You should be familiar with this procedure.
The first time you add a vSphere host to the DVS it will push the DVS configuration out over the Management VLAN (service console/VMKernel port) and then connect back to the 1000v using the Control VLAN. Since the Control VLAN is required for all communication between the VSM and VEM hosts, this VLAN needs to always be in a forwarding state (aka defined as a system VLAN).As I'vesaid before other VLANs that should be included as a System VLAN are those for IP Storage and Host Management)
Robert