Re: Issue with ARM: Network doesn't work in the guest

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

On 11/11/2013 01:13 PM, Stefano Stabellini wrote:
> On Thu, 7 Nov 2013, Julien Grall wrote:
>> On 11/06/2013 10:12 AM, Stefano Stabellini wrote:
>>> On Wed, 30 Oct 2013, mail fetch wrote:
>>>> 2013/10/29, mail fetch <fetchmail.0104@gmail.com>:
>>>>> Hi all,
>>>>>
>>>>> I just saw a know bug from wiki that network doesn't work in guest in
>>>>> arndale board :
>>>>>
>>>>> Network doesn't work in the guest
>>>>>
>>>>> Contact: julien.grall@citrix.com
>>>>> Status: In progress
>>>>> Description: Network doesn't work in the guest when an ehternet cable is
>>>>> plugged
>>>>> References: http://pastebin.com/gEP3HdCg
>>>>>
>>>>> What's the latest status?
>>>>>
>>>>> best regards
>>>>> Mail
>>>>>
>>>>
>>>> Any comments?
>>>
>>> Sorry for the late reply. Usually we respond pretty quickly but you
>>> caught us between Xen Developer Summit and Linaro Connect: most Xen
>>> hackers were traveling. In fact Julien Grall is still AFK and he
>>> is the one that knows the answer.
>>>
>>> I think that the 1:1 workaround in dom0 (that is having pseudo-physical
>>> addresses == physical addresses for dom0) should fix it. Give a look at
>>
>> Actually it's not enough. The problem is because when the balloon driver will
>> release a page, Xen will populate with a new allocated page. So it will break
>> the 1:1 Workaround.
>> The commit eee34edcd1daecb70560dfe23009af2e65f7d26d on my tree in xenbits
>> (git://xenbits.xen.org/people/julieng/xen-unstable.git) aims to fix this
>> issue.
>> I will try to remember to update the wiki page monday when I will come back to
>> the office.
>>
>> Stefano: A couple of weeks ago, you told me you plan to rework this commit for
>> the swiotlb, is it still relevant?
>
> After looking at this a bit more, I think that your workaround is
> reasonable and less fragile than my original idea based on modifying the
> Linux balloon driver. I think that it just needs to be cleaned a bit,
> see appended comments.

Thanks. I will rework the patch and send it soon.

-- 
Julien Grall