[libvirt] [RFC] Overriding graphics relocation URI

[Jiri Denemark]

Hi all.

Graphics relocation URI is currently transmitted within migration cookie
in the form of graphics type, address, port, tlsPort, and certificate
subject. The cookie is generated by target libvirtd and consumed by
source libvirtd which than forwards this data through QEMU to the
graphics client.

In case the target libvirtd is not able to provide the data in a way
usable by the client (e.g., because it needs to use different address),
we need to provide a way to override the graphics URI. We already
support similar thing for migration URI.

So the question is how we can support $SUBJ? The only way I came up with
is to introduce another set of migration APIs (such as
virDomainMigrateToURI3, ...) with an additional graphics URI parameter.
The URI would be formed as

    type "://" address ":" port "?tlsPort="  tlsPort "&subject=" cert

with various parts being optional. That would allow us to override any
part of the graphics cookie we need.

However, I don't like the addition of another set of migration APIs and
I'd be glad to hear better ideas :-)

Jirka