3:35 p.m.
On 8/13/20 11:33 AM, Cornelia Huck wrote:
On Fri, 7 Aug 2020 13:59:42 +0200
Cornelia Huck <cohuck(a)redhat.com> wrote:
> On Wed, 05 Aug 2020 12:35:01 +0100
> Sean Mooney <smooney(a)redhat.com> wrote:
>
>> 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.
>
> So, what would be the most helpful format? A 'software_version' field
> that follows the conventions outlined above, and other (possibly
> optional) fields that have to match?
Just to get a different perspective, I've been trying to come up with
what would be useful for a very different kind of device, namely
vfio-ccw. (Adding Eric to cc: for that.)
software_version makes sense for everybody, so it should be a standard
attribute.
For the vfio-ccw type, we have only one vendor driver (vfio-ccw_IO).
Given a subchannel A, we want to make sure that subchannel B has a
reasonable chance of being compatible. I guess that means:
- same subchannel type (I/O)
- same chpid type (e.g. all FICON; I assume there are no 'mixed' setups
-- Eric?)
Correct.
- same number of chpids? Maybe we can live without that and just
inject
some machine checks, I don't know. Same chpid numbers is something we
cannot guarantee, especially if we want to migrate cross-CEC (to
another machine.)
I think we'd live without it, because I wouldn't expect it to be
consistent between systems.
Other possibly interesting information is not available at the
subchannel level (vfio-ccw is a subchannel driver.)
I presume you're alluding to the DASD uid (dasdinfo -x) here?
>
> So, looking at a concrete subchannel on one of my machines, it would
> look something like the following:
>
> <common>
> software_version=1.0.0
> type=vfio-ccw <-- would be vfio-pci on the example above
> <vfio-ccw specific>
> subchannel_type=0
> <vfio-ccw_IO specific>
> chpid_type=0x1a
> chpid_mask=0xf0 <-- not sure if needed/wanted
>
> Does that make sense?
>