Probably not (but who knows, you could probably use this as part of a fuzzer). Instruction emulation is a superset of instruction decoding. You need to decode and then emulate the behavior.
Aside: Instruction emulation is pretty finicky and bug prone. I'm not too familiar with Xen, but KVM has had at least 10 instruction emulation CVEs. There were talks at both KVM Forum and Xen Summit last summer mentioning the sketchiness of instruction emulation.
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-9932
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-9383