[ovirt-devel] Re: device compatibility interface for live migration with assigned devices

On Wed, 2020-08-05 at 12:53 +0200, Jiri Pirko wrote: > Wed, Aug 05, 2020 at 11:33:38AM CEST, yan.y.zhao(a)intel.com wrote:

> > software_version: device driver's version. > > in <major>.<minor>[.bugfix] scheme, where there is no > > compatibility across major versions, minor versions have > > forward compatibility (ex. 1-> 2 is ok, 2 -> 1 is not) and > > bugfix version number indicates some degree of internal > > improvement that is not visible to the user in terms of > > features or compatibility, > > > > vendor specific attributes: each vendor may define different attributes > > device id : device id of a physical devices or mdev's parent pci device. > > it could be equal to pci id for pci devices > > aggregator: used together with mdev_type. e.g. aggregator=2 together > > with i915-GVTg_V5_4 means 2*1/4=1/2 of a gen9 Intel > > graphics device. > > remote_url: for a local NVMe VF, it may be configured with a remote > > url of a remote storage and all data is stored in the > > remote side specified by the remote url. > > ... just a minor not that i find ^ much more simmple to understand then the current proposal with self and compatiable. if i have well defiend attibute that i can parse and understand that allow me to calulate the what is and is not compatible that is likely going to more useful as you wont have to keep maintianing a list of other compatible devices every time a new sku is released. in anycase thank for actully shareing ^ as it make it simpler to reson about what you have previously proposed.

> Thanks for the explanation, I'm still fuzzy about the details. > Anyway, I suggest you to check "devlink dev info" command we have > implemented for multiple drivers. is devlink exposed as a filesytem we can read with just open? openstack will likely try to leverage libvirt to get this info but when we cant its much simpler to read sysfs then it is to take a a depenency on a commandline too and have to fork shell to execute it and parse the cli output. pyroute2 which we use in some openstack poject has basic python binding for devlink but im not sure how complete it is as i think its relitivly new addtion. if we need to take a dependcy we will but that would be a drawback fo devlink not that that is a large one just something to keep in mind.