Re: [RFC PATCH v1 02/10] xen/arm: register mmio handler at runtime

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

On 04/01/2014 01:32 PM, Vijay Kilari wrote:
> On Tue, Apr 1, 2014 at 4:30 PM, Julien Grall <julien.grall@linaro.org> wrote:
>> On 04/01/2014 10:34 AM, Vijay Kilari wrote:
>>> Hi Julien,
>>
>> Hello Vijay,
>>
>>> On Thu, Mar 27, 2014 at 8:32 PM, Julien Grall <julien.grall@linaro.org> wrote:
>>>> On 03/27/2014 05:40 AM, Vijay Kilari wrote:
>>>>> On Wed, Mar 26, 2014 at 8:17 PM, Julien Grall <julien.grall@linaro.org> wrote:
>>>>>> On 03/26/2014 12:29 PM, Vijay Kilari wrote:
>>>>>>> Hi Julien,
>>>>>>>
>>>>>>>
>>>>>>> On Fri, Mar 21, 2014 at 10:53 PM, Julien Grall <julien.grall@linaro.org> wrote:
>>>>>>>> On 03/21/2014 05:17 PM, Ian Campbell wrote:
>>>>>>>>> On Wed, 2014-03-19 at 19:47 +0530, vijay.kilari@gmail.com wrote:
>>>>>>>>>> From: Vijaya Kumar K <Vijaya.Kumar@caviumnetworks.com>
>>>>>>>>>>
>>>>>>>>>> mmio handlers are registers at compile time
>>>>>>>>>> for drivers like vuart and vgic.
>>>>>>>>>> Make mmio handler registered at runtime by
>>>>>>>>>> creating linked list of mmio handlers
>>>>>>>>>
>>>>>>>>> I'm not convinced of the need for this, certainly the vgic side can just
>>>>>>>>> demux into v2 or v3 as necessary.
>>>>>>>>
>>>>>>>> Demux the code just add an indirection. We could have a list of mmio
>>>>>>>> handler per domain and rely on it to call the right handler. A bit like x86.
>>>>>>>>
>>>>>>>  Until Andrii adds IOMMU  handling should keep this patch? and adopt
>>>>>>> to it later?
>>>>>>
>>>>>> I'm not sure to understand. IHMO, it doesn't sound right to upstream a
>>>>>> patch that we know it will be superseded in a couple of months. Why
>>>>>> can't you rework your patch to have it in good shape now?
>>>>>>
>>>>>  I assume that Andii's patch will be required to make mmio handlers
>>>>> per domain. If not let me know references in x86 that I can make it
>>>>> per domain specific mmio handlers.
>>>>
>>>> I have already pointed out to the x86 code few mails before.
>>>>
>>>> You can look at xen/arch/x86/intercept.c.
>>>
>>>    From the x86/hvm/intercept.c file, the mmio handling of x86 is
>>> similar to existing arm mmio handling in arm/io.c file, where the
>>> handlers are registered statically.
>>
>> Not really, x86 use an hybrid approach:
>>     - static handler for IO region that are handled by every guest (hpet
>> ...)
>>      - dynamic handler registered by register_io_handler
>>
> I think, I can still keep dynamic handler registration.

Per domain?

-- 
Julien Grall