Is it possible to host/colocate your own rack servers/equipment in Google's/Amazon's/Microsoft's data centers?
Google has an option for hosted private HSM but explicitly notes that this is not a general server housing solution
This offering is limited to FIPS 140-2 Level 3 (or better) certified HSMs, and is not a generalized hosting or colocation service.
Another option is to house your servers near (topographically) the cloud regions or with the cloud's partner and connect with Direct Connect or Interconnect.
But is it possible to hand your server/appliance off to Google/Amazon/Micrososft and have them host it with only logical control left for the client?