Re: [dpdk-dev] building LIBRTE_PMD_XENVIRT in 32bit triggers some errors

["Martinx - ジェームズ" <thiagocmartinsc@gmail.com>]

On 10 December 2015 at 02:45, Xie, Huawei <huawei.xie@intel.com> wrote:
> On 12/10/2015 6:49 AM, Martinx - ジェームズ wrote:
>> On 9 December 2015 at 18:05, Thomas Monjalon <thomas.monjalon@6wind.com> wrote:
>>> 2015-12-09 15:54, Martinx - ジェームズ:
>>>>  Sorry to insist on this subject but, the time for releasing DPDK 2.2
>>>> is near and DPDK build with Xen 32-bit is broken.
>>>>
>>>>  If DPDK doesn't fix this, there will be no way to enable XenVirt
>>>> support for next Ubuntu LTS 16.04, which is a shame...
>>>>
>>>>  I'm planning to use DPDK on Xen domUs (PVM, HVM, XenServer and on
>>>> Amazon EC2) powered exclusively by a supported version of Ubuntu but,
>>>> it is broken now...
>>>>
>>>>  So, please, can someone take a look into this?    :-P
>>>>
>>>>  Thanks in advance!
>>> Sorry, this area has no maintainer:
>>>         http://dpdk.org/browse/dpdk/tree/MAINTAINERS#n169
>>>
>>> In such case, it may be logic to remove the dead code.
>>> If someone wants to make it alive, he's welcome!
>> Hi Thomas,
>>
>>  Listen, if DPDK on Xen has no maintainer, where can I find the
>> current state of DPDK on Xen?
>>
>>  I mean, I'm planning to use DPDK with Xen on the following environments:
>>
>>  * Amazon EC2 - HVM Enhanced Networking - *priority*
>>  * XenServer
>>  * Open Source Xen on Debian / Ubuntu (both PVM / HVM)
>>
>>  But, if Xen support on DPDK has no maintainer, how to you guys are
>> running DPDK on top of Xen (like for example, within Amazon EC2)?
>>
>>  If I google for "DPDK Xen", I can find lots of good information but,
>> I can't find recommended setup / drivers...
>>
>>  Do you have any recommendation?
> Thiago:
> This xen PMD is based on grant table mechanism and virtio interface.
> Worth to note is it needs customized backend, which now resides in
> examples/vhost_xen.
> Another approach is netfront based PMD, which has kernel netback backend
> in place, but i guess it couldn't achieve best performance as we need
> map each grant page in backend. Stephen submitted the patch for netfront
> PMD http://dpdk.org/dev/patchwork/patch/3330/. Thomas, do you know its
> status?
> Anyway i will try to create the XEN environment, and check the issues.
>
>>
>>  Thank you!
>>
>> Best,
>> Thiago
>>
>

Hello Xie,

Thank you for your help, I really appreciated it!

Basically, what I would like to understand is:


- What is the BEST way of running DPDK inside a Xen domU guest?


I'm seeing that there are too many options and not enough
documentation about each, for example...

* Does DPDK XENVIRT option, depends on XENDOM0 option? However, you
said that it isn't fast / can't achieve best performance...

* Apparently, Xen supports VirtIO (if I'm not wrong), but, I honestly
don't know for sure, where/when it is available (XenServer? Amazon
high-perf Net Instance? HVM? PVM?)

* If Xen supports VirtIO (especially on Amazon / XenServer), isn't
this the BEST way of running DPDK Apps on top of this kind of
hypervisor (i.e., by not using XENVIRT at all)?

Thanks again!
Thiago