[Spice-devel] [Xen-devel] Is: QXL in Xen (busted) Was :Re: Xen 4.5-rc1 update (RC1 is out 2014-Oct-24th)

[Fabio Fantoni]

Il 03/11/2014 17:03, Konrad Rzeszutek Wilk ha scritto:
> On Mon, Nov 03, 2014 at 12:05:44PM +0100, Fabio Fantoni wrote:
>> Il 31/10/2014 15:33, Konrad Rzeszutek Wilk ha scritto:
>>>> I always posted all versions of the patch in xen-devel, the latest was long
>>>> time ago.
>>> Sometimes you need to poke the maintainers. They (at least
>>> I do) have mailboxes so packed that sometimes emails end up
>>> going missing. But I think their arguments is going to be:
>>> lets figure out what is broken before putting this in the source.
>>>
>>> .. snip..
>>>>> Does SPICE always have to be enabled to use QXL?
>>>>>
>>> .. snip ..
>>>> Xen with spice full working on both windows and linux (including
>>>> save/restore) used for both vkvm and thin client I think would be perfect.
>>> Right. But there is some work needed in that area (figure out what
>>> is happening on Linux).
>>>
>>> ..snip..
>>>>> OK, looking at how the driver is setup - it seems that there is an QXL
>>>>> KMS driver. If you boot without Xorg running but just with in the console
>>>>> can
>>>>> you use 'fbset' or any other framebuffer tools (linux-fb-tools)?
>>>>> That is I am curious to see whether the 'FB' is working properly first
>>>>> before figuring out whether Xorg is working.
>>>>>
>>>> Some tests ago I tried without xorg to see if kernel parts is ok (advice of
>>>> other developer) and seems was ok.
>>> What did you test? There is an 'drm-test' tool that was floating around?
>>> (http://cgit.freedesktop.org/mesa/drm/)
>>>
>>> It allows you to run most (if not all) of the Xorg functionality - but
>>> using an tool from user-space - and with much more exposure of what
>>> went wrong.
>>>
>>> Could you try the following (without having Xorg in either guest):
>>>   1). Boot up your KVM guest, install said tool - run it. Record what
>>>      works and what does not.
>>>
>>>   2). Boot up your Xen guest, and do the same thing.
>>>
>>> That should narrow down which of the hundreds' of DRM ioctls is failing
>>> when using spice under Xen. And that ought to help narrow down this further.
>>>
>>> I can help you a bit by sending you some debug patches, thought I do
>>> have to warn you that I am under a lot of time-pressure so my response
>>> is not as fast as I would want it to be.
>>>
>> I tested only without xorg, just console with drm without particular tests.
>>
>> I can't find the drm-test tool you mentioned, is it available in debian
>> and/or fedora repositories an what is it called?
>> I also did a quick google search and found only something about wayland and
>> not about X.org.
> I mentioned the URL in the email, but here it is again:
>
> http://cgit.freedesktop.org/mesa/drm/
>
> You will need to compile it, etc.

Thanks for your reply, sorry for my late reply, I was busy.
I prepared 2 Trusty (ubuntu 14.04) vm minimal for the tests (one on kvm 
and one on xen).
Started and both arrive to console login successfull and they have qxl 
kernel module active:

lsmod
...
qxl
drm_kms_helper qxl
drm qxl,ttm,drm_kms_helper
...

I downloaded compile and installed mesa/drm from git master brach
./configure
make
sudo make install

After I tried to execute the tests binary I found under test but all fails:
sudo ./modetest
...
no device found.

sudo ./vbltest
...
failed to load any modules, aborting.

sudo ./kmstest
main: Could not open device (Operation not permitted)

Same result on both xen and kvm.
Seems that there is any module in mesa/drm about qxl even if kernel 
modules is present and active and qxl xorg driver use it FWIK.

I did another fast search on google without found how to test qxl drm to 
find the difference between xen and kvm.
Someone can tell me what I must do to take useful data about xen and kvm 
difference for qxl problem?

I added also spice-devel to cc.

Thanks for any reply and sorry for my bad english.