[libvirt] chardev aliases [was: [RFC PATCHv2 5/5] WIP: smartcard: turn on qemu support]

> The 'id' setting for the chardev should really have a prefix > on it, because we won't want it to be the same as the 'id' > setting used for the -device option. This is in fact a pre-existing flaw in our chardev handling which we need to fix. The 'qemuBuildChrChardevStr' API & its callers are buggy. They takes the assigned alias from the XML and use it directly for the chardev. So we end up with -chardev pty,id=$alias -device isa-serial,chardev=$alias The serial/parallel/channels -device args are all missing any 'id' property entirely which is bad, because it means we won't be able to support hotplug. What we should be generating is -chardev pty,id=cdev$alias -device isa-serial,id=$alias,chardev=cdev$alias So that both parts have a unique identifier assigned, and the alias from the XML is associated with the '-device' arg, and the -chardev is a derivative.