[ofw] Expose a vendor defined device in ibbus?

[Hal Rosenstock]

On Wed, Dec 17, 2008 at 1:35 PM, Fab Tillier
<ftillier at windows.microsoft.com> wrote:
>> On Wed, Dec 17, 2008 at 4:11 AM, Leonid Keller <leonid at mellanox.co.il>
>> wrote:
>>>> How does IOU device get notification and thus create PDO?
>>> IBAL requests SA whether there are IOU devices registered.
>>
>> Which SA requests are used for this or do you mean device manager ?
>
> The IOC PnP manager in IBAL does a bulk query for all node records and another for all path records.  From there it does a join of the two to create a list of nodes and the paths to them, by port GUID.  It then collapses this list to represent IOUs by node GUID (to handle multi-port IOUs as a single entity).  Then it issues an IO_UNIT_INFO query to each potential IOU, and prunes from the list those that have max_controllers == 0.  For every IOU that has a non-zero max_controllers value, it queries the IOU for IOC profiles, and builds a list of IOCs from the response.  Then for each IOC it queries service entries.
>
> Once this is done, it merges the newly built tree of IOU/IOC/Paths with the existing one and reports changes to registered clients (IOU add/remove, IOC add/remove, IOC add/remove path

Thanks.

> Now if the SA had a query that a client could issue to return all nodes that have device management enabled that would help reduce the query load.

There is a "newer" SA query which can get all the ports with
IsDeviceManagementSupported. You can tell if the SA supports this
based on IsPortInfoCapMaskMatchSupported is set in SA's
ClassPortInfo.CapabilityMask.

That would help scalability on SA's which support this optional
feature. BTW, OpenSM supports this but likely the current Windows
version doesn't.

-- Hal

> -Fab
>