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

[Vijay Kilari <vijay.kilari@xxxxxxxxx>]

On Tue, Apr 1, 2014 at 6:21 PM, Julien Grall <julien.grall@xxxxxxxxxx> wrote:
> On 04/01/2014 01:32 PM, Vijay Kilari wrote:
>> On Tue, Apr 1, 2014 at 4:30 PM, Julien Grall <julien.grall@xxxxxxxxxx> 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@xxxxxxxxxx> 
>>>> wrote:
>>>>> On 03/27/2014 05:40 AM, Vijay Kilari wrote:
>>>>>> On Wed, Mar 26, 2014 at 8:17 PM, Julien Grall <julien.grall@xxxxxxxxxx> 
>>>>>> 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@xxxxxxxxxx> wrote:
>>>>>>>>> On 03/21/2014 05:17 PM, Ian Campbell wrote:
>>>>>>>>>> On Wed, 2014-03-19 at 19:47 +0530, vijay.kilari@xxxxxxxxx wrote:
>>>>>>>>>>> From: Vijaya Kumar K <Vijaya.Kumar@xxxxxxxxxxxxxxxxxx>
>>>>>>>>>>>
>>>>>>>>>>> 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 patch that we know it will be superseded in a couple of months.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?

Yes, I plan to make this list fixed with 16 entries and managing
similar to x86/hvm/intercept.c "hvm_domain.io_handler".
>
> --
> Julien Grall

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel