Re: [PATCH v2 0/7] Implement forced unplug and forced activation

["Tu Dinh" <ngoc-tu.dinh@xxxxxxxxxx>]

On 01/08/2025 10:52, Owen Smith wrote:
> It may be possible to change the PDO's DeviceID to not include the full
> XenBus DeviceID, only the VENDOR_PREFIX_STR (to avoid
> compatibility issues between different vendor driver sets) and the
> device type.
> e.g. DeviceID = "XENBUS\VEN_XP&DEV_VBD"
> Keep the CompatibleIDs including the XenBus DeviceID would allow vendors
> to limit Windows Update distribution to their VENDOR_PREFIX_STR +
> VENDOR_DEVICE_ID. The INF files would require an exact match against a
> CompatibleID, which would also include the REV part, preventing child
> devices installing on parent devices that dont expose the correct
> interface versions.
>
> Then this change and a combination of ForceActivate and ForceUnplug
> should cover most edge cases.
>
> Owen
>
Thanks Owen. It's a good solution for the Xenbus PDO issue. Although now
that I reviewed the documentation I think we might need some changes to
the feature scores of Xenvbd.inf to make sure that Windows Update
drivers will bind preferentially over non-Windows Update ones.

I also have a concern with the platform device binding, as this will
also need to be under one device/compatible ID for Windows to pick up
the Xenbus driver on boot once the device ID changes. Namely, binding
xenbus.inf to PCI\VEN_5853 will lead to a worse ranking than the
previous drivers that bound to PCI\VEN_5853&DEV_000x /
PCI\VEN_5853&DEV_Cyyy&SUBSYS_Cyyy5853&REV_01, and so we might need to
set the feature score to compensate.

I noticed that there are some devices under PCI\VEN_5853 that are not
platform or vendor devices (5853:c110 and 5853:c147). Are they currently
being used? Increasing the feature score will cause Xenbus.inf to bind
instead of these drivers and break these devices.

I'll try to suss out the INF changes needed to see how driver selection
would be impacted by the series.


Ngoc Tu Dinh | Vates XCP-ng Developer

XCP-ng & Xen Orchestra - Vates solutions

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