QEMU 5.1: Can we require each new device/machine to provided a test?

QEMU 5.1: Can we require each new device/machine to provided a test?

[Philippe Mathieu-Daudé]

Hello,

Following Markus thread on deprecating unmaintained (untested) code
(machines) [1] and the effort done to gather the information shared in
the replies [2], and the various acceptance tests added, is it
feasible to require for the next release that each new device/machine
is provided a test covering it?

If no, what is missing?

Thanks,

Phil.

[1] https://www.mail-archive.com/qemu-devel@nongnu.org/msg604682.html
[2] https://wiki.qemu.org/Testing/Acceptance#Machines

Re: QEMU 5.1: Can we require each new device/machine to provided a test?

[Thomas Huth]

On 07/04/2020 12.59, Philippe Mathieu-Daudé wrote:
> Hello,
> 
> Following Markus thread on deprecating unmaintained (untested) code
> (machines) [1] and the effort done to gather the information shared in
> the replies [2], and the various acceptance tests added, is it
> feasible to require for the next release that each new device/machine
> is provided a test covering it?
> 
> If no, what is missing?

If a qtest is feasible, yes, I think we should require one for new
devices. But what about machines - you normally need a test image for
this. In that case, there is still the question where testing images
could be hosted. Not every developer has a web space where they could
put their test images onto. And what about images that contain non-free
code?

 Thomas

Re: QEMU 5.1: Can we require each new device/machine to provided a test?

[Daniel P. Berrangé]

On Fri, May 15, 2020 at 12:11:17PM +0200, Thomas Huth wrote:
> On 07/04/2020 12.59, Philippe Mathieu-Daudé wrote:
> > Hello,
> > 
> > Following Markus thread on deprecating unmaintained (untested) code
> > (machines) [1] and the effort done to gather the information shared in
> > the replies [2], and the various acceptance tests added, is it
> > feasible to require for the next release that each new device/machine
> > is provided a test covering it?
> > 
> > If no, what is missing?
> 
> If a qtest is feasible, yes, I think we should require one for new
> devices. But what about machines - you normally need a test image for
> this. In that case, there is still the question where testing images
> could be hosted. Not every developer has a web space where they could
> put their test images onto. And what about images that contain non-free
> code?

Yep, it isn't feasible to make this a hard rule.

IMHO this is where a support tier classification comes into play

 - Tier 1: actively maintained, qtest coverage available. Expected
           to work reliably at all times since every commit is CI
	   tested

  - Tier 2: actively maintained, no qtest coverage. Should usually
           work but regression may creep in due to reliance on the
	   maintainer to manually test on adhoc basis

  - Tier 3: not actively maintained, unknown state but liable to
            be broken indefinitely

Tier 1 is obviously the most desirable state we would like everthing to
be at. Contributors will have to fix problems their patches cause as
they will be blocked by CI.

Tier 2 is an admission that reality gets in the way. Ideally stuff in
this tier will graduate to Tier 1 at some point. Even if it doesn't
though, it is still valid to keep it in QEMU long term. Contributors
shouldn't gratuitously break stuff in these board, but if they do,
then the maintainer is ultimately responsible for fixing it, as the
contributors don't have a test rig for it.

Tier 3 is abandonware. If a maintainer doesn't appear, users should
not expect it to continue to exist long term. Contributors are free
to send patches which break this, and are under no obligation to
fix problems in these boards. We may deprecate & delete it after a
while


Over time we'll likely add more criteria to stuff in Tier 1. This
could lead to some things dropping from Tier 1 to Tier 2. This is
OK, as it doesn't make those things worse than they already were.
We're just saying that Tier 2 isn't as thoroughly tested as we
would like it to be in an ideal world.

Regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org         -o-            https://fstop138.berrange.com :|
|: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|

Re: QEMU 5.1: Can we require each new device/machine to provided a test?

[John Snow]

On 5/15/20 6:23 AM, Daniel P. Berrangé wrote:
> On Fri, May 15, 2020 at 12:11:17PM +0200, Thomas Huth wrote:
>> On 07/04/2020 12.59, Philippe Mathieu-Daudé wrote:
>>> Hello,
>>>
>>> Following Markus thread on deprecating unmaintained (untested) code
>>> (machines) [1] and the effort done to gather the information shared in
>>> the replies [2], and the various acceptance tests added, is it
>>> feasible to require for the next release that each new device/machine
>>> is provided a test covering it?
>>>
>>> If no, what is missing?
>>
>> If a qtest is feasible, yes, I think we should require one for new
>> devices. But what about machines - you normally need a test image for
>> this. In that case, there is still the question where testing images
>> could be hosted. Not every developer has a web space where they could
>> put their test images onto. And what about images that contain non-free
>> code?
> 
> Yep, it isn't feasible to make this a hard rule.
> 
> IMHO this is where a support tier classification comes into play
> 
>  - Tier 1: actively maintained, qtest coverage available. Expected
>            to work reliably at all times since every commit is CI
> 	   tested
> 
>   - Tier 2: actively maintained, no qtest coverage. Should usually
>            work but regression may creep in due to reliance on the
> 	   maintainer to manually test on adhoc basis
> 
>   - Tier 3: not actively maintained, unknown state but liable to
>             be broken indefinitely
> 
> Tier 1 is obviously the most desirable state we would like everthing to
> be at. Contributors will have to fix problems their patches cause as
> they will be blocked by CI.
> 
> Tier 2 is an admission that reality gets in the way. Ideally stuff in
> this tier will graduate to Tier 1 at some point. Even if it doesn't
> though, it is still valid to keep it in QEMU long term. Contributors
> shouldn't gratuitously break stuff in these board, but if they do,
> then the maintainer is ultimately responsible for fixing it, as the
> contributors don't have a test rig for it.
> 
> Tier 3 is abandonware. If a maintainer doesn't appear, users should
> not expect it to continue to exist long term. Contributors are free
> to send patches which break this, and are under no obligation to
> fix problems in these boards. We may deprecate & delete it after a
> while
> 
> 
> Over time we'll likely add more criteria to stuff in Tier 1. This
> could lead to some things dropping from Tier 1 to Tier 2. This is
> OK, as it doesn't make those things worse than they already were.
> We're just saying that Tier 2 isn't as thoroughly tested as we
> would like it to be in an ideal world.
> 
> Regards,
> Daniel
> 

I really like the idea of device support tiers codified directly in the
QEMU codebase, to give upstream users some idea of which devices we
expect to work and which we ... don't, really.

Not every last device we offer is enterprise production ready, but we
don't necessarily do a good job of explaining which devices fall into
which categories, and we've got quite a few of them.

I wonder if a 2.5th tier would be useful; something like a "hobbyist"
tier for pet project SoC boards and the like -- they're not abandoned,
but we also don't expect them to work, exactly.

Mild semantic difference from Tier 3.

--js

Re: QEMU 5.1: Can we require each new device/machine to provided a test?

[Daniel P. Berrangé]

On Mon, May 18, 2020 at 03:56:36PM -0400, John Snow wrote:
> 
> 
> On 5/15/20 6:23 AM, Daniel P. Berrangé wrote:
> > On Fri, May 15, 2020 at 12:11:17PM +0200, Thomas Huth wrote:
> >> On 07/04/2020 12.59, Philippe Mathieu-Daudé wrote:
> >>> Hello,
> >>>
> >>> Following Markus thread on deprecating unmaintained (untested) code
> >>> (machines) [1] and the effort done to gather the information shared in
> >>> the replies [2], and the various acceptance tests added, is it
> >>> feasible to require for the next release that each new device/machine
> >>> is provided a test covering it?
> >>>
> >>> If no, what is missing?
> >>
> >> If a qtest is feasible, yes, I think we should require one for new
> >> devices. But what about machines - you normally need a test image for
> >> this. In that case, there is still the question where testing images
> >> could be hosted. Not every developer has a web space where they could
> >> put their test images onto. And what about images that contain non-free
> >> code?
> > 
> > Yep, it isn't feasible to make this a hard rule.
> > 
> > IMHO this is where a support tier classification comes into play
> > 
> >  - Tier 1: actively maintained, qtest coverage available. Expected
> >            to work reliably at all times since every commit is CI
> > 	   tested
> > 
> >   - Tier 2: actively maintained, no qtest coverage. Should usually
> >            work but regression may creep in due to reliance on the
> > 	   maintainer to manually test on adhoc basis
> > 
> >   - Tier 3: not actively maintained, unknown state but liable to
> >             be broken indefinitely
> > 
> > Tier 1 is obviously the most desirable state we would like everthing to
> > be at. Contributors will have to fix problems their patches cause as
> > they will be blocked by CI.
> > 
> > Tier 2 is an admission that reality gets in the way. Ideally stuff in
> > this tier will graduate to Tier 1 at some point. Even if it doesn't
> > though, it is still valid to keep it in QEMU long term. Contributors
> > shouldn't gratuitously break stuff in these board, but if they do,
> > then the maintainer is ultimately responsible for fixing it, as the
> > contributors don't have a test rig for it.
> > 
> > Tier 3 is abandonware. If a maintainer doesn't appear, users should
> > not expect it to continue to exist long term. Contributors are free
> > to send patches which break this, and are under no obligation to
> > fix problems in these boards. We may deprecate & delete it after a
> > while
> > 
> > 
> > Over time we'll likely add more criteria to stuff in Tier 1. This
> > could lead to some things dropping from Tier 1 to Tier 2. This is
> > OK, as it doesn't make those things worse than they already were.
> > We're just saying that Tier 2 isn't as thoroughly tested as we
> > would like it to be in an ideal world.
> 
> I really like the idea of device support tiers codified directly in the
> QEMU codebase, to give upstream users some idea of which devices we
> expect to work and which we ... don't, really.
> 
> Not every last device we offer is enterprise production ready, but we
> don't necessarily do a good job of explaining which devices fall into
> which categories, and we've got quite a few of them.
> 
> I wonder if a 2.5th tier would be useful; something like a "hobbyist"
> tier for pet project SoC boards and the like -- they're not abandoned,
> but we also don't expect them to work, exactly.
> 
> Mild semantic difference from Tier 3.

I guess I was thinking such hobbyist stuff would fall into tier 2  if the
hobbyist maintainer actually responds to fixing stuff, or tier 3 if they
largely aren't active on the mailing list responding to issues/questions.

We add have a 4 tier system overall and put hobbyist stuff at tier 3,
and abandonware at tier 4.

Probably shouldn't go beyond 4 tiers though, as the more criteria we add
the harder it is to clearly decide which tier something should go into.

The tier 1 vs 2 divison is clearly split based on CI which is a simple
classification to decide on.

The tier 2 vs 3 division is moderately clearly split based on whether
there is a frequently active maintainer.

We can probably squeeze in the 4th tier without too much ambiguity in
the classisfication if we think it is adding something worthwhile either
from our POV as maintainers, or for users consuming it.

Regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org         -o-            https://fstop138.berrange.com :|
|: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|

Re: QEMU 5.1: Can we require each new device/machine to provided a test?

[John Snow]

On 5/19/20 5:04 AM, Daniel P. Berrangé wrote:
> On Mon, May 18, 2020 at 03:56:36PM -0400, John Snow wrote:
>>
>>
>> On 5/15/20 6:23 AM, Daniel P. Berrangé wrote:
>>> On Fri, May 15, 2020 at 12:11:17PM +0200, Thomas Huth wrote:
>>>> On 07/04/2020 12.59, Philippe Mathieu-Daudé wrote:
>>>>> Hello,
>>>>>
>>>>> Following Markus thread on deprecating unmaintained (untested) code
>>>>> (machines) [1] and the effort done to gather the information shared in
>>>>> the replies [2], and the various acceptance tests added, is it
>>>>> feasible to require for the next release that each new device/machine
>>>>> is provided a test covering it?
>>>>>
>>>>> If no, what is missing?
>>>>
>>>> If a qtest is feasible, yes, I think we should require one for new
>>>> devices. But what about machines - you normally need a test image for
>>>> this. In that case, there is still the question where testing images
>>>> could be hosted. Not every developer has a web space where they could
>>>> put their test images onto. And what about images that contain non-free
>>>> code?
>>>
>>> Yep, it isn't feasible to make this a hard rule.
>>>
>>> IMHO this is where a support tier classification comes into play
>>>
>>>  - Tier 1: actively maintained, qtest coverage available. Expected
>>>            to work reliably at all times since every commit is CI
>>> 	   tested
>>>
>>>   - Tier 2: actively maintained, no qtest coverage. Should usually
>>>            work but regression may creep in due to reliance on the
>>> 	   maintainer to manually test on adhoc basis
>>>
>>>   - Tier 3: not actively maintained, unknown state but liable to
>>>             be broken indefinitely
>>>
>>> Tier 1 is obviously the most desirable state we would like everthing to
>>> be at. Contributors will have to fix problems their patches cause as
>>> they will be blocked by CI.
>>>
>>> Tier 2 is an admission that reality gets in the way. Ideally stuff in
>>> this tier will graduate to Tier 1 at some point. Even if it doesn't
>>> though, it is still valid to keep it in QEMU long term. Contributors
>>> shouldn't gratuitously break stuff in these board, but if they do,
>>> then the maintainer is ultimately responsible for fixing it, as the
>>> contributors don't have a test rig for it.
>>>
>>> Tier 3 is abandonware. If a maintainer doesn't appear, users should
>>> not expect it to continue to exist long term. Contributors are free
>>> to send patches which break this, and are under no obligation to
>>> fix problems in these boards. We may deprecate & delete it after a
>>> while
>>>
>>>
>>> Over time we'll likely add more criteria to stuff in Tier 1. This
>>> could lead to some things dropping from Tier 1 to Tier 2. This is
>>> OK, as it doesn't make those things worse than they already were.
>>> We're just saying that Tier 2 isn't as thoroughly tested as we
>>> would like it to be in an ideal world.
>>
>> I really like the idea of device support tiers codified directly in the
>> QEMU codebase, to give upstream users some idea of which devices we
>> expect to work and which we ... don't, really.
>>
>> Not every last device we offer is enterprise production ready, but we
>> don't necessarily do a good job of explaining which devices fall into
>> which categories, and we've got quite a few of them.
>>
>> I wonder if a 2.5th tier would be useful; something like a "hobbyist"
>> tier for pet project SoC boards and the like -- they're not abandoned,
>> but we also don't expect them to work, exactly.
>>
>> Mild semantic difference from Tier 3.
> 
> I guess I was thinking such hobbyist stuff would fall into tier 2  if the
> hobbyist maintainer actually responds to fixing stuff, or tier 3 if they
> largely aren't active on the mailing list responding to issues/questions.
> 
> We add have a 4 tier system overall and put hobbyist stuff at tier 3,
> and abandonware at tier 4.
> 
> Probably shouldn't go beyond 4 tiers though, as the more criteria we add
> the harder it is to clearly decide which tier something should go into.
> 
> The tier 1 vs 2 divison is clearly split based on CI which is a simple
> classification to decide on.
> 
> The tier 2 vs 3 division is moderately clearly split based on whether
> there is a frequently active maintainer.
> 
> We can probably squeeze in the 4th tier without too much ambiguity in
> the classisfication if we think it is adding something worthwhile either
> from our POV as maintainers, or for users consuming it.

Yes, I didn't mean to start watering it down into a 1,380 tier system
that we're never able to properly utilize.

I was thinking more along the lines of:

- Device works and is well loved
- Device works and is well loved (but we have to test manually)
- Device doesn't work, but is well loved
  (Use at your own peril, please file a bug report)
- Device doesn't work, and is unloved

Perhaps it'd be clearer to name these Tier 1A, 1B, 2, and 3; where
things can shift from 1A to 1B as their test coverage allows, but it's
not meant to indicate general status otherwise.

Mostly, I would just like some way for users to avoid accidentally
running tier 2 or 3 devices /by accident/, or the ability to compile
QEMU versions that only allow tier 1 devices to be used.

It's all arbitrary -- but I think we agree more than not! I'd love to
have a list of first-class boards and devices that we promise to test
and have working.

--js

Re: QEMU 5.1: Can we require each new device/machine to provided a test?

[Thomas Huth]

On 20/05/2020 01.06, John Snow wrote:
> 
> 
> On 5/19/20 5:04 AM, Daniel P. Berrangé wrote:
>> On Mon, May 18, 2020 at 03:56:36PM -0400, John Snow wrote:
>>>
>>>
>>> On 5/15/20 6:23 AM, Daniel P. Berrangé wrote:
>>>> On Fri, May 15, 2020 at 12:11:17PM +0200, Thomas Huth wrote:
>>>>> On 07/04/2020 12.59, Philippe Mathieu-Daudé wrote:
>>>>>> Hello,
>>>>>>
>>>>>> Following Markus thread on deprecating unmaintained (untested) code
>>>>>> (machines) [1] and the effort done to gather the information shared in
>>>>>> the replies [2], and the various acceptance tests added, is it
>>>>>> feasible to require for the next release that each new device/machine
>>>>>> is provided a test covering it?
>>>>>>
>>>>>> If no, what is missing?
>>>>>
>>>>> If a qtest is feasible, yes, I think we should require one for new
>>>>> devices. But what about machines - you normally need a test image for
>>>>> this. In that case, there is still the question where testing images
>>>>> could be hosted. Not every developer has a web space where they could
>>>>> put their test images onto. And what about images that contain non-free
>>>>> code?
>>>>
>>>> Yep, it isn't feasible to make this a hard rule.
>>>>
>>>> IMHO this is where a support tier classification comes into play
>>>>
>>>>  - Tier 1: actively maintained, qtest coverage available. Expected
>>>>            to work reliably at all times since every commit is CI
>>>> 	   tested
>>>>
>>>>   - Tier 2: actively maintained, no qtest coverage. Should usually
>>>>            work but regression may creep in due to reliance on the
>>>> 	   maintainer to manually test on adhoc basis
>>>>
>>>>   - Tier 3: not actively maintained, unknown state but liable to
>>>>             be broken indefinitely
>>>>
>>>> Tier 1 is obviously the most desirable state we would like everthing to
>>>> be at. Contributors will have to fix problems their patches cause as
>>>> they will be blocked by CI.
>>>>
>>>> Tier 2 is an admission that reality gets in the way. Ideally stuff in
>>>> this tier will graduate to Tier 1 at some point. Even if it doesn't
>>>> though, it is still valid to keep it in QEMU long term. Contributors
>>>> shouldn't gratuitously break stuff in these board, but if they do,
>>>> then the maintainer is ultimately responsible for fixing it, as the
>>>> contributors don't have a test rig for it.
>>>>
>>>> Tier 3 is abandonware. If a maintainer doesn't appear, users should
>>>> not expect it to continue to exist long term. Contributors are free
>>>> to send patches which break this, and are under no obligation to
>>>> fix problems in these boards. We may deprecate & delete it after a
>>>> while
>>>>
>>>>
>>>> Over time we'll likely add more criteria to stuff in Tier 1. This
>>>> could lead to some things dropping from Tier 1 to Tier 2. This is
>>>> OK, as it doesn't make those things worse than they already were.
>>>> We're just saying that Tier 2 isn't as thoroughly tested as we
>>>> would like it to be in an ideal world.
>>>
>>> I really like the idea of device support tiers codified directly in the
>>> QEMU codebase, to give upstream users some idea of which devices we
>>> expect to work and which we ... don't, really.
>>>
>>> Not every last device we offer is enterprise production ready, but we
>>> don't necessarily do a good job of explaining which devices fall into
>>> which categories, and we've got quite a few of them.
>>>
>>> I wonder if a 2.5th tier would be useful; something like a "hobbyist"
>>> tier for pet project SoC boards and the like -- they're not abandoned,
>>> but we also don't expect them to work, exactly.
>>>
>>> Mild semantic difference from Tier 3.
>>
>> I guess I was thinking such hobbyist stuff would fall into tier 2  if the
>> hobbyist maintainer actually responds to fixing stuff, or tier 3 if they
>> largely aren't active on the mailing list responding to issues/questions.
>>
>> We add have a 4 tier system overall and put hobbyist stuff at tier 3,
>> and abandonware at tier 4.
>>
>> Probably shouldn't go beyond 4 tiers though, as the more criteria we add
>> the harder it is to clearly decide which tier something should go into.
>>
>> The tier 1 vs 2 divison is clearly split based on CI which is a simple
>> classification to decide on.
>>
>> The tier 2 vs 3 division is moderately clearly split based on whether
>> there is a frequently active maintainer.
>>
>> We can probably squeeze in the 4th tier without too much ambiguity in
>> the classisfication if we think it is adding something worthwhile either
>> from our POV as maintainers, or for users consuming it.
> 
> Yes, I didn't mean to start watering it down into a 1,380 tier system
> that we're never able to properly utilize.
> 
> I was thinking more along the lines of:
> 
> - Device works and is well loved
> - Device works and is well loved (but we have to test manually)
> - Device doesn't work, but is well loved
>   (Use at your own peril, please file a bug report)
> - Device doesn't work, and is unloved
> 
> Perhaps it'd be clearer to name these Tier 1A, 1B, 2, and 3; where
> things can shift from 1A to 1B as their test coverage allows, but it's
> not meant to indicate general status otherwise.

All that sounds somewhat similar to the classification that we already
use in our MAINTAINERS file - Supported, Maintained, Odd-Fixes, Orphan,
Obsolete ... maybe we can avoid to introduce yet another classification
system and merge the two (e.g. by also changing the classification
system in MAINTAINERS a little bit?).

 Thomas

Re: QEMU 5.1: Can we require each new device/machine to provided a test?

[Daniel P. Berrangé]

On Wed, May 20, 2020 at 08:13:07AM +0200, Thomas Huth wrote:
> On 20/05/2020 01.06, John Snow wrote:
> > 
> > 
> > On 5/19/20 5:04 AM, Daniel P. Berrangé wrote:
> >> On Mon, May 18, 2020 at 03:56:36PM -0400, John Snow wrote:
> >>>
> >>>
> >>> On 5/15/20 6:23 AM, Daniel P. Berrangé wrote:
> >>>> On Fri, May 15, 2020 at 12:11:17PM +0200, Thomas Huth wrote:
> >>>>> On 07/04/2020 12.59, Philippe Mathieu-Daudé wrote:
> >>>>>> Hello,
> >>>>>>
> >>>>>> Following Markus thread on deprecating unmaintained (untested) code
> >>>>>> (machines) [1] and the effort done to gather the information shared in
> >>>>>> the replies [2], and the various acceptance tests added, is it
> >>>>>> feasible to require for the next release that each new device/machine
> >>>>>> is provided a test covering it?
> >>>>>>
> >>>>>> If no, what is missing?
> >>>>>
> >>>>> If a qtest is feasible, yes, I think we should require one for new
> >>>>> devices. But what about machines - you normally need a test image for
> >>>>> this. In that case, there is still the question where testing images
> >>>>> could be hosted. Not every developer has a web space where they could
> >>>>> put their test images onto. And what about images that contain non-free
> >>>>> code?
> >>>>
> >>>> Yep, it isn't feasible to make this a hard rule.
> >>>>
> >>>> IMHO this is where a support tier classification comes into play
> >>>>
> >>>>  - Tier 1: actively maintained, qtest coverage available. Expected
> >>>>            to work reliably at all times since every commit is CI
> >>>> 	   tested
> >>>>
> >>>>   - Tier 2: actively maintained, no qtest coverage. Should usually
> >>>>            work but regression may creep in due to reliance on the
> >>>> 	   maintainer to manually test on adhoc basis
> >>>>
> >>>>   - Tier 3: not actively maintained, unknown state but liable to
> >>>>             be broken indefinitely
> >>>>
> >>>> Tier 1 is obviously the most desirable state we would like everthing to
> >>>> be at. Contributors will have to fix problems their patches cause as
> >>>> they will be blocked by CI.
> >>>>
> >>>> Tier 2 is an admission that reality gets in the way. Ideally stuff in
> >>>> this tier will graduate to Tier 1 at some point. Even if it doesn't
> >>>> though, it is still valid to keep it in QEMU long term. Contributors
> >>>> shouldn't gratuitously break stuff in these board, but if they do,
> >>>> then the maintainer is ultimately responsible for fixing it, as the
> >>>> contributors don't have a test rig for it.
> >>>>
> >>>> Tier 3 is abandonware. If a maintainer doesn't appear, users should
> >>>> not expect it to continue to exist long term. Contributors are free
> >>>> to send patches which break this, and are under no obligation to
> >>>> fix problems in these boards. We may deprecate & delete it after a
> >>>> while
> >>>>
> >>>>
> >>>> Over time we'll likely add more criteria to stuff in Tier 1. This
> >>>> could lead to some things dropping from Tier 1 to Tier 2. This is
> >>>> OK, as it doesn't make those things worse than they already were.
> >>>> We're just saying that Tier 2 isn't as thoroughly tested as we
> >>>> would like it to be in an ideal world.
> >>>
> >>> I really like the idea of device support tiers codified directly in the
> >>> QEMU codebase, to give upstream users some idea of which devices we
> >>> expect to work and which we ... don't, really.
> >>>
> >>> Not every last device we offer is enterprise production ready, but we
> >>> don't necessarily do a good job of explaining which devices fall into
> >>> which categories, and we've got quite a few of them.
> >>>
> >>> I wonder if a 2.5th tier would be useful; something like a "hobbyist"
> >>> tier for pet project SoC boards and the like -- they're not abandoned,
> >>> but we also don't expect them to work, exactly.
> >>>
> >>> Mild semantic difference from Tier 3.
> >>
> >> I guess I was thinking such hobbyist stuff would fall into tier 2  if the
> >> hobbyist maintainer actually responds to fixing stuff, or tier 3 if they
> >> largely aren't active on the mailing list responding to issues/questions.
> >>
> >> We add have a 4 tier system overall and put hobbyist stuff at tier 3,
> >> and abandonware at tier 4.
> >>
> >> Probably shouldn't go beyond 4 tiers though, as the more criteria we add
> >> the harder it is to clearly decide which tier something should go into.
> >>
> >> The tier 1 vs 2 divison is clearly split based on CI which is a simple
> >> classification to decide on.
> >>
> >> The tier 2 vs 3 division is moderately clearly split based on whether
> >> there is a frequently active maintainer.
> >>
> >> We can probably squeeze in the 4th tier without too much ambiguity in
> >> the classisfication if we think it is adding something worthwhile either
> >> from our POV as maintainers, or for users consuming it.
> > 
> > Yes, I didn't mean to start watering it down into a 1,380 tier system
> > that we're never able to properly utilize.
> > 
> > I was thinking more along the lines of:
> > 
> > - Device works and is well loved
> > - Device works and is well loved (but we have to test manually)
> > - Device doesn't work, but is well loved
> >   (Use at your own peril, please file a bug report)
> > - Device doesn't work, and is unloved
> > 
> > Perhaps it'd be clearer to name these Tier 1A, 1B, 2, and 3; where
> > things can shift from 1A to 1B as their test coverage allows, but it's
> > not meant to indicate general status otherwise.
> 
> All that sounds somewhat similar to the classification that we already
> use in our MAINTAINERS file - Supported, Maintained, Odd-Fixes, Orphan,
> Obsolete ... maybe we can avoid to introduce yet another classification
> system and merge the two (e.g. by also changing the classification
> system in MAINTAINERS a little bit?).

Yes, there is a fair bit of conceptual overlap there. Main difference is
probably that we'd want to be a bit more fine grained than the MAINTAINERS
file shows, but that seems doable. 

Also somewhat related here is our security classification where we say we'll
only consider bugs security vulnerabilities if they are in components that
are targetted towards virtualization uses (ie KVM), and consider anything to
do with non-virtualization use cases to be plain bugs, not security bugs.
While as developers we can probably say which is which, for end users and
bug reporter this is not so clear. So if we're going to classify support
status for components, we should try to add a classification for security
status at the same time.

Regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org         -o-            https://fstop138.berrange.com :|
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Re: QEMU 5.1: Can we require each new device/machine to provided a test?

[John Snow]

On 5/20/20 2:13 AM, Thomas Huth wrote:
> On 20/05/2020 01.06, John Snow wrote:
>>
>>
>> On 5/19/20 5:04 AM, Daniel P. Berrangé wrote:
>>> On Mon, May 18, 2020 at 03:56:36PM -0400, John Snow wrote:
>>>>
>>>>
>>>> On 5/15/20 6:23 AM, Daniel P. Berrangé wrote:
>>>>> On Fri, May 15, 2020 at 12:11:17PM +0200, Thomas Huth wrote:
>>>>>> On 07/04/2020 12.59, Philippe Mathieu-Daudé wrote:
>>>>>>> Hello,
>>>>>>>
>>>>>>> Following Markus thread on deprecating unmaintained (untested) code
>>>>>>> (machines) [1] and the effort done to gather the information shared in
>>>>>>> the replies [2], and the various acceptance tests added, is it
>>>>>>> feasible to require for the next release that each new device/machine
>>>>>>> is provided a test covering it?
>>>>>>>
>>>>>>> If no, what is missing?
>>>>>>
>>>>>> If a qtest is feasible, yes, I think we should require one for new
>>>>>> devices. But what about machines - you normally need a test image for
>>>>>> this. In that case, there is still the question where testing images
>>>>>> could be hosted. Not every developer has a web space where they could
>>>>>> put their test images onto. And what about images that contain non-free
>>>>>> code?
>>>>>
>>>>> Yep, it isn't feasible to make this a hard rule.
>>>>>
>>>>> IMHO this is where a support tier classification comes into play
>>>>>
>>>>>  - Tier 1: actively maintained, qtest coverage available. Expected
>>>>>            to work reliably at all times since every commit is CI
>>>>> 	   tested
>>>>>
>>>>>   - Tier 2: actively maintained, no qtest coverage. Should usually
>>>>>            work but regression may creep in due to reliance on the
>>>>> 	   maintainer to manually test on adhoc basis
>>>>>
>>>>>   - Tier 3: not actively maintained, unknown state but liable to
>>>>>             be broken indefinitely
>>>>>
>>>>> Tier 1 is obviously the most desirable state we would like everthing to
>>>>> be at. Contributors will have to fix problems their patches cause as
>>>>> they will be blocked by CI.
>>>>>
>>>>> Tier 2 is an admission that reality gets in the way. Ideally stuff in
>>>>> this tier will graduate to Tier 1 at some point. Even if it doesn't
>>>>> though, it is still valid to keep it in QEMU long term. Contributors
>>>>> shouldn't gratuitously break stuff in these board, but if they do,
>>>>> then the maintainer is ultimately responsible for fixing it, as the
>>>>> contributors don't have a test rig for it.
>>>>>
>>>>> Tier 3 is abandonware. If a maintainer doesn't appear, users should
>>>>> not expect it to continue to exist long term. Contributors are free
>>>>> to send patches which break this, and are under no obligation to
>>>>> fix problems in these boards. We may deprecate & delete it after a
>>>>> while
>>>>>
>>>>>
>>>>> Over time we'll likely add more criteria to stuff in Tier 1. This
>>>>> could lead to some things dropping from Tier 1 to Tier 2. This is
>>>>> OK, as it doesn't make those things worse than they already were.
>>>>> We're just saying that Tier 2 isn't as thoroughly tested as we
>>>>> would like it to be in an ideal world.
>>>>
>>>> I really like the idea of device support tiers codified directly in the
>>>> QEMU codebase, to give upstream users some idea of which devices we
>>>> expect to work and which we ... don't, really.
>>>>
>>>> Not every last device we offer is enterprise production ready, but we
>>>> don't necessarily do a good job of explaining which devices fall into
>>>> which categories, and we've got quite a few of them.
>>>>
>>>> I wonder if a 2.5th tier would be useful; something like a "hobbyist"
>>>> tier for pet project SoC boards and the like -- they're not abandoned,
>>>> but we also don't expect them to work, exactly.
>>>>
>>>> Mild semantic difference from Tier 3.
>>>
>>> I guess I was thinking such hobbyist stuff would fall into tier 2  if the
>>> hobbyist maintainer actually responds to fixing stuff, or tier 3 if they
>>> largely aren't active on the mailing list responding to issues/questions.
>>>
>>> We add have a 4 tier system overall and put hobbyist stuff at tier 3,
>>> and abandonware at tier 4.
>>>
>>> Probably shouldn't go beyond 4 tiers though, as the more criteria we add
>>> the harder it is to clearly decide which tier something should go into.
>>>
>>> The tier 1 vs 2 divison is clearly split based on CI which is a simple
>>> classification to decide on.
>>>
>>> The tier 2 vs 3 division is moderately clearly split based on whether
>>> there is a frequently active maintainer.
>>>
>>> We can probably squeeze in the 4th tier without too much ambiguity in
>>> the classisfication if we think it is adding something worthwhile either
>>> from our POV as maintainers, or for users consuming it.
>>
>> Yes, I didn't mean to start watering it down into a 1,380 tier system
>> that we're never able to properly utilize.
>>
>> I was thinking more along the lines of:
>>
>> - Device works and is well loved
>> - Device works and is well loved (but we have to test manually)
>> - Device doesn't work, but is well loved
>>   (Use at your own peril, please file a bug report)
>> - Device doesn't work, and is unloved
>>
>> Perhaps it'd be clearer to name these Tier 1A, 1B, 2, and 3; where
>> things can shift from 1A to 1B as their test coverage allows, but it's
>> not meant to indicate general status otherwise.
> 
> All that sounds somewhat similar to the classification that we already
> use in our MAINTAINERS file - Supported, Maintained, Odd-Fixes, Orphan,
> Obsolete ... maybe we can avoid to introduce yet another classification
> system and merge the two (e.g. by also changing the classification
> system in MAINTAINERS a little bit?).
> 

Yeah, it's similar, but the granularity is per-device instead of
per-file, and it would be metadata that is introspectible.

(As part of the help files and the CLI, when you look at a list of
devices, I'd like to show which devices are in which support tiers.)

The scope of each system is meant to be just a little different --
describing source files for git management vs describing logistical
in-application API constructs.

Still, you're right -- there's a lot of overlap. I'm not sure how to
best bridge them.

Though I would like to re-engage on the idea that we should be
mechanically consuming and testing our MAINTAINERS file to ensure 100%
coverage as a CI check. IIRC there was some pushback to this idea
because we weren't sure who should own basic/generic files like
"LICENSE" or "README" and so on.

For files that SHOULD go "maintainerless", for which we would like
checkpatch.pl to simply show you "who touched it last", maybe we should
create a "Community Managed" section in MAINTAINERS that explicitly
lists these files; and get_maintainer amended to understand this section.

Maybe if we get the maintainers file getting checked regularly as a
first step it will help us bridge the gap into device metadata without
worrying about info desync.

Just brainstorming.

--js

(Slightly OT: I am working on an email that contains a quick code-tour
overview of what every file in the root of the document is, including
which are maintained and unmaintained. Might be a good jumping off point
for more MAINTAINER file discussions?)

Re: QEMU 5.1: Can we require each new device/machine to provided a test?

[Daniel P. Berrangé]

On Tue, May 19, 2020 at 07:06:40PM -0400, John Snow wrote:
> 
> 
> On 5/19/20 5:04 AM, Daniel P. Berrangé wrote:
> > On Mon, May 18, 2020 at 03:56:36PM -0400, John Snow wrote:
> >>
> >>
> >> On 5/15/20 6:23 AM, Daniel P. Berrangé wrote:
> >>> On Fri, May 15, 2020 at 12:11:17PM +0200, Thomas Huth wrote:
> >>>> On 07/04/2020 12.59, Philippe Mathieu-Daudé wrote:
> >>>>> Hello,
> >>>>>
> >>>>> Following Markus thread on deprecating unmaintained (untested) code
> >>>>> (machines) [1] and the effort done to gather the information shared in
> >>>>> the replies [2], and the various acceptance tests added, is it
> >>>>> feasible to require for the next release that each new device/machine
> >>>>> is provided a test covering it?
> >>>>>
> >>>>> If no, what is missing?
> >>>>
> >>>> If a qtest is feasible, yes, I think we should require one for new
> >>>> devices. But what about machines - you normally need a test image for
> >>>> this. In that case, there is still the question where testing images
> >>>> could be hosted. Not every developer has a web space where they could
> >>>> put their test images onto. And what about images that contain non-free
> >>>> code?
> >>>
> >>> Yep, it isn't feasible to make this a hard rule.
> >>>
> >>> IMHO this is where a support tier classification comes into play
> >>>
> >>>  - Tier 1: actively maintained, qtest coverage available. Expected
> >>>            to work reliably at all times since every commit is CI
> >>> 	   tested
> >>>
> >>>   - Tier 2: actively maintained, no qtest coverage. Should usually
> >>>            work but regression may creep in due to reliance on the
> >>> 	   maintainer to manually test on adhoc basis
> >>>
> >>>   - Tier 3: not actively maintained, unknown state but liable to
> >>>             be broken indefinitely
> >>>
> >>> Tier 1 is obviously the most desirable state we would like everthing to
> >>> be at. Contributors will have to fix problems their patches cause as
> >>> they will be blocked by CI.
> >>>
> >>> Tier 2 is an admission that reality gets in the way. Ideally stuff in
> >>> this tier will graduate to Tier 1 at some point. Even if it doesn't
> >>> though, it is still valid to keep it in QEMU long term. Contributors
> >>> shouldn't gratuitously break stuff in these board, but if they do,
> >>> then the maintainer is ultimately responsible for fixing it, as the
> >>> contributors don't have a test rig for it.
> >>>
> >>> Tier 3 is abandonware. If a maintainer doesn't appear, users should
> >>> not expect it to continue to exist long term. Contributors are free
> >>> to send patches which break this, and are under no obligation to
> >>> fix problems in these boards. We may deprecate & delete it after a
> >>> while
> >>>
> >>>
> >>> Over time we'll likely add more criteria to stuff in Tier 1. This
> >>> could lead to some things dropping from Tier 1 to Tier 2. This is
> >>> OK, as it doesn't make those things worse than they already were.
> >>> We're just saying that Tier 2 isn't as thoroughly tested as we
> >>> would like it to be in an ideal world.
> >>
> >> I really like the idea of device support tiers codified directly in the
> >> QEMU codebase, to give upstream users some idea of which devices we
> >> expect to work and which we ... don't, really.
> >>
> >> Not every last device we offer is enterprise production ready, but we
> >> don't necessarily do a good job of explaining which devices fall into
> >> which categories, and we've got quite a few of them.
> >>
> >> I wonder if a 2.5th tier would be useful; something like a "hobbyist"
> >> tier for pet project SoC boards and the like -- they're not abandoned,
> >> but we also don't expect them to work, exactly.
> >>
> >> Mild semantic difference from Tier 3.
> > 
> > I guess I was thinking such hobbyist stuff would fall into tier 2  if the
> > hobbyist maintainer actually responds to fixing stuff, or tier 3 if they
> > largely aren't active on the mailing list responding to issues/questions.
> > 
> > We add have a 4 tier system overall and put hobbyist stuff at tier 3,
> > and abandonware at tier 4.
> > 
> > Probably shouldn't go beyond 4 tiers though, as the more criteria we add
> > the harder it is to clearly decide which tier something should go into.
> > 
> > The tier 1 vs 2 divison is clearly split based on CI which is a simple
> > classification to decide on.
> > 
> > The tier 2 vs 3 division is moderately clearly split based on whether
> > there is a frequently active maintainer.
> > 
> > We can probably squeeze in the 4th tier without too much ambiguity in
> > the classisfication if we think it is adding something worthwhile either
> > from our POV as maintainers, or for users consuming it.
> 
> Yes, I didn't mean to start watering it down into a 1,380 tier system
> that we're never able to properly utilize.
> 
> I was thinking more along the lines of:
> 
> - Device works and is well loved
> - Device works and is well loved (but we have to test manually)
> - Device doesn't work, but is well loved
>   (Use at your own peril, please file a bug report)
> - Device doesn't work, and is unloved
> 
> Perhaps it'd be clearer to name these Tier 1A, 1B, 2, and 3; where
> things can shift from 1A to 1B as their test coverage allows, but it's
> not meant to indicate general status otherwise.

Yeah 1A/1B would be fairly effective.

> Mostly, I would just like some way for users to avoid accidentally
> running tier 2 or 3 devices /by accident/, or the ability to compile
> QEMU versions that only allow tier 1 devices to be used.
> 
> It's all arbitrary -- but I think we agree more than not! I'd love to
> have a list of first-class boards and devices that we promise to test
> and have working.

Yes, I think we're basically in agreement on the both the goal and
way to achieve it.

Regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org         -o-            https://fstop138.berrange.com :|
|: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|

Re: QEMU 5.1: Can we require each new device/machine to provided a test?

[Gerd Hoffmann]

On Fri, May 15, 2020 at 12:11:17PM +0200, Thomas Huth wrote:
> On 07/04/2020 12.59, Philippe Mathieu-Daudé wrote:
> > Hello,
> > 
> > Following Markus thread on deprecating unmaintained (untested) code
> > (machines) [1] and the effort done to gather the information shared in
> > the replies [2], and the various acceptance tests added, is it
> > feasible to require for the next release that each new device/machine
> > is provided a test covering it?
> > 
> > If no, what is missing?
> 
> If a qtest is feasible, yes, I think we should require one for new
> devices.

qtest is not feasible, at least not for all kinds of devices.  You can't
talk to usb devices for example, and changing that effectively requires
writing uhci/ohci/ehci/xhci drivers so one can submit usb transfers in
qtest.

The current qtests for usb devices is basically hot-plug and unplug it
and check qmp doesn't throw an error.  Better that nothing, but there is
zero functional testing and changing that is seriously non-trivial.

cheers,
  Gerd

Re: QEMU 5.1: Can we require each new device/machine to provided a test?

[Paolo Bonzini]

On 15/05/20 12:51, Gerd Hoffmann wrote:
>> If a qtest is feasible, yes, I think we should require one for new
>> devices.
> qtest is not feasible, at least not for all kinds of devices.  You can't
> talk to usb devices for example, and changing that effectively requires
> writing uhci/ohci/ehci/xhci drivers so one can submit usb transfers in
> qtest.

Yes, but that's just because no one has written a test for a USB device.
 It would be completely feasible to plug USB into qgraph, the code for
USB in SeaBIOS is 4.5 kLOC so that's more or less the ballpark of what
you'd need.  You can then stimulate keyboard or mouse devices via
chardev (-serial msmouse), or run SCSI tests for MSD and UAS.

Paolo