A system for managing operations in a virtual machine environment, comprising: at least one proxy driver object located in a first partition, wherein said at least one proxy driver object is a proxy driver for a device; at least one device driver object located in a driver stack in a second partition, wherein said at least one driver object is configured to control said device; at least one first filter object located beneath said at least one device driver object in said driver stack, wherein said at least one first filter object presents an interface to said at least one device driver object for the at least one device driver object to engage in bus-related functions including controlling said device; and at least one second filter object located above said at least one device driver object in said driver stack, wherein said at least one second filter object is configured to at least one of (a) direct first instructions from said at least one proxy driver object to said at least one device driver object and (b) intercept second instructions intended for said at least one device driver object, wherein said second instructions originate from said second partition, wherein the second filter object is configured to intercept said second instructions, and wherein upon intercepting said second instructions, said at least one second filter object compares said second instructions against at least one policy set by one of (a) said first partition and (b) a virtualizing module, wherein if said second instructions conflict with said at least one policy, said at least one second filter object replaces said second instructions with instructions consistent with said at least one policy and passes them down to said at least one device driver object or, if said at least one device driver object refuses to conform to at least one policy set by said first partition, control of said device by said at least one device driver object is revoked. at least one proxy driver object located in a first partition, wherein said at least one proxy driver object is a proxy driver for a device; at least one device driver object located in a driver stack in a second partition, wherein said at least one driver object is configured to control said device; at least one first filter object located beneath said at least one device driver object in said driver stack, wherein said at least one first filter object presents an interface to said at least one device driver object for the at least one device driver object to engage in bus-related functions including controlling said device; and at least one second filter object located above said at least one device driver object in said driver stack, wherein said at least one second filter object is configured to at least one of (a) direct first instructions from said at least one proxy driver object to said at least one device driver object and (b) intercept second instructions intended for said at least one device driver object, wherein said second instructions originate from said second partition, wherein the second filter object is configured to intercept said second instructions, and wherein upon intercepting said second instructions, said at least one second filter object compares said second instructions against at least one policy set by one of (a) said first partition and (b) a virtualizing module, wherein if said second instructions conflict with said at least one policy, said at least one second filter object replaces said second instructions with instructions consistent with said at least one policy and passes them down to said at least one device driver object or, if said at least one device driver object refuses to conform to at least one policy set by said first partition, control of said device by said at least one device driver object is revoked.