[libvirt PATCH v6 00/30] Add support for persistent mediated devices

[Erik Skultety]

On Fri, Mar 26, 2021 at 11:47:56AM -0500, Jonathon Jongsma wrote:
> This patch series follows the previously-merged series which added support for
> transient mediated devices. This series expands mdev support to include
> persistent device definitions. Again, it relies on mdevctl as the backend.
> 
> It follows the common libvirt pattern of APIs by adding the following new APIs
> for node devices:
>     - virNodeDeviceDefineXML() - defines a persistent device
>     - virNodeDeviceUndefine() - undefines a persistent device
>     - virNodeDeviceCreate() - starts a previously-defined device
> 
> It also adds virsh commands mapping to these new APIs: nodedev-define,
> nodedev-undefine, and nodedev-start.
> 
> Since we rely on mdevctl for the definition of mediated devices, we need a way
> to stay up-to-date with devices that are defined by mdevctl (outside of
> libvirt).  The method for staying up-to-date is currently a little bit crude
> due to the fact that mdevctl does not emit any events when new devices are
> added or removed. As a workaround, we create a file monitor for the mdevctl
> config directory and re-query mdevctl when we detect changes within that
> directory. In the future, mdevctl may introduce a more elegant solution.
> 
> Changes in v6:
>  - rebase to git master again
>  - remove typedefs for various *Ptr types, since they're now discouraged in
>    libvirt.

Okay, so I think I ACKed all of the patches now (if not, let me know which one
I missed). I tested the patches, found 3 leaks, one of them I mentioned here, 2
were related to the code but not a direct result of this series I believe, so
I'll tackle them some other time as a follow up.
Overall, I think we're good to push this starting with the 7.3.0 cycle.

Now, in v4 I promised to share my adjustments I made on top of your code. Some
of them you already handled yourself in v6, so I rebased and performed a bunch
of changes, so here they are:
https://gitlab.com/eskultety/libvirt/-/commits/mdev-adjustments

Note, that I only split them into multiple patches so that they're easier to
read, but I'm very well aware that probably none of them cannot be compiled
on its own (I didn't bother to be that thorough), it's just to give you an idea
what I've failed to express with words until we came to this v6. Please let me
know your opinion on the changes so that:
    a) I can send it as a *proper* follow up series
    b) you can incorporate some of the changes into your series

I don't care either way.

Regards and thanks for being patient with the review process :),
Erik