Re: [libvirt] [PATCH 07/17] conf: HostdevDef parse/format helper functions

In an upcoming patch, virDomainNetDef will acquire a virDomainHostdevDef, and the <interface> XML will take on some of the elements of a <hostdev>. To avoid duplicating the code for parsing and formatting the <source> element (which will be nearly identical in these two cases), this patch factors those parts out of the HostdevDef's parse and format functions, and puts them into separate helper functions that are now called by the HostdevDef parser/formatter, and will soon be called by the NetDef parser/formatter. One change in behavior - previously virDomainHostdevDefParseXML() had diverged from current common coding practice by logging an error and failing if it found any subelements of <hostdev> other than those it understood (standard libvirt practice is to ignore/discard unknown elements and attributes during parse). The new helper function ignores unknown elements, and thus so does the new virDomainHostdevDefParseXML. --- V2: Unchanged from V1.