I hate to interfere with the merging of working code for non-technical reasons....
This is a plugin interface. As I wrote in reply to v4, I'd like to see a pragmatic argument why abuse of the plugin interface to circumvent the GPL is not practical. This might include "not a stable interface", "you have to link with a truckload of gpl code", "the set of things you can do is deliberately extremely limited". Perhaps such an argument is made somewhere in these 73 patches already. I admit to not having read them all :) In the TCG plugin design document perhaps? Assuming it exists... I proposed discussing the project's requirements for external interfaces on GPL circumvention deterrence at the QEMU Summit next week. If merging this could be delayed until the licensing ramifications have become a bit more clear, I'd be obliged.