Re: [RFC PATCH v2 00/22] xen/arm: Add ITS support

[Julien Grall <julien.grall@linaro.org>]

On 23/03/15 16:09, Vijay Kilari wrote:
> On Mon, Mar 23, 2015 at 9:00 PM, Julien Grall <julien.grall@linaro.org> wrote:
>> On 23/03/15 15:18, Vijay Kilari wrote:
>>>> The ITS still have to manage in someway the device. There is lots of
>>>> information that doesn't need to be created at every mapd (such as the
>>>> number of MSI).
>>>
>>> First assumption is VITS driver owns converting Virtual ITS commands
>>>  to Physical ITS commands. So based on this
>>>
>>> - arch_domain contains list of all the devices attached for the domain.
>>> -  On MAPD command, device is created, physical LPI's and virtual LPIs
>>> are allocated
>>>    and added to domains list and further all other ITS commands except
>>> MAPC, INVALL and SYNC
>>>    depend on device information to convert virtual ITS commands to
>>> physical ITS commands.
>>
>> I didn't understand what you said.
> 
> I mean, all the virtual ITS commands has to be converted to
> physical ITS commands. The (most)information required to do this conversion
> is based on device_id for most of the commands (except MAPC, SYNC & INVALL)
> So vITS driver contains device management.
> However, all the devices managed using linked list attached to a domain.
> 
> Few API's are added in physical ITS driver to query
> Physical Collection ID (pCID) to Virtual Collection ID (vCID) and
> Virtual Target address(vTA)
>  to Physical Target Address(pTA) because pCID & pTA info is available
> in physical ITS driver.
> 
> Refer to : 4.9.22 Command Mapping for a Guest with a GICv3 ITS
> of PRD03-GENC-010745 20.0

A reference to this section on this commit message would have been very
useful...

> Overall the functionality was split as follows;
> 
> - Physical ITS driver manages Physical LPI allocation, Sending
> Physical commands,
>   Physical Collection ID & Target addresses
> - Virtual ITS driver manages Virtual LPI allocation, Device creation
> for respective domain,
>   Conversion of virtual ITS commands to Physical ITS commands, Virtual
> Collection ID's
>   Virtual Target address, GITS register emulation, LPI
> pending/Property table emulation.
> 
> It would be better if you go through the patch set and comment under
> relevant code
> and we can discuss.

It's nearly impossible to review this series one patch by one patch. I
have to look all the things together.

That's why I bring the discussion here.

Regards,

-- 
Julien Grall