Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of staging

From	Laura Abbott <labbott@redhat.com>
Newsgroups	linux.kernel
Subject	Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of staging
Date	2017-03-13 22:30 +0100
Message-ID	<tkFHt-6Dq-33@gated-at.bofh.it> (permalink)
References	(6 earlier) <ti3wC-2gf-5@gated-at.bofh.it> <tj3bc-3I3-29@gated-at.bofh.it> <tjaFH-ma-17@gated-at.bofh.it> <tkbT4-294-21@gated-at.bofh.it> <tkvRM-7Mz-25@gated-at.bofh.it>
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On 03/13/2017 03:54 AM, Brian Starkey wrote:
> On Sun, Mar 12, 2017 at 02:34:14PM +0100, Benjamin Gaignard wrote:
>> 2017-03-09 18:38 GMT+01:00 Laura Abbott <labbott@redhat.com>:
>>> On 03/09/2017 02:00 AM, Benjamin Gaignard wrote:
>>>> 2017-03-06 17:04 GMT+01:00 Daniel Vetter <daniel@ffwll.ch>:
>>>>> On Mon, Mar 06, 2017 at 11:58:05AM +0100, Mark Brown wrote:
>>>>>> On Mon, Mar 06, 2017 at 11:40:41AM +0100, Daniel Vetter wrote:
>>>>>>
>>>>>>> No one gave a thing about android in upstream, so Greg KH just dumped it
>>>>>>> all into staging/android/. We've discussed ION a bunch of times, recorded
>>>>>>> anything we'd like to fix in staging/android/TODO, and Laura's patch
>>>>>>> series here addresses a big chunk of that.
>>>>>>
>>>>>>> This is pretty much the same approach we (gpu folks) used to de-stage the
>>>>>>> syncpt stuff.
>>>>>>
>>>>>> Well, there's also the fact that quite a few people have issues with the
>>>>>> design (like Laurent).  It seems like a lot of them have either got more
>>>>>> comfortable with it over time, or at least not managed to come up with
>>>>>> any better ideas in the meantime.
>>>>>
>>>>> See the TODO, it has everything a really big group (look at the patch for
>>>>> the full Cc: list) figured needs to be improved at LPC 2015. We don't just
>>>>> merge stuff because merging stuff is fun :-)
>>>>>
>>>>> Laurent was even in that group ...
>>>>> -Daniel
>>>>
>>>> For me those patches are going in the right direction.
>>>>
>>>> I still have few questions:
>>>> - since alignment management has been remove from ion-core, should it
>>>> be also removed from ioctl structure ?
>>>
>>> Yes, I think I'm going to go with the suggestion to fixup the ABI
>>> so we don't need the compat layer and as part of that I'm also
>>> dropping the align argument.
>>>
>>>> - can you we ride off ion_handle (at least in userland) and only
>>>> export a dma-buf descriptor ?
>>>
>>> Yes, I think this is the right direction given we're breaking
>>> everything anyway. I was debating trying to keep the two but
>>> moving to only dma bufs is probably cleaner. The only reason
>>> I could see for keeping the handles is running out of file
>>> descriptors for dma-bufs but that seems unlikely.
>>>>
>>>> In the future how can we add new heaps ?
>>>> Some platforms have very specific memory allocation
>>>> requirements (just have a look in the number of gem custom allocator in drm)
>>>> Do you plan to add heap type/mask for each ?
>>>
>>> Yes, that was my thinking.
>>
>> My concern is about the policy to adding heaps, will you accept
>> "customs" heap per
>> platforms ? per devices ? or only generic ones ?
>> If you are too strict, we will have lot of out-of-tree heaps and if
>> you accept of of them
>> it will be a nightmare to maintain....
>>
> 
> Are you concerned about actual heaps (e.g. a carveout at 0x80000000 vs
> a carveout at 0x60000000) or heap types?
> 
> For heap types, I think the policy can be strict - if it's generally
> useful then it should live in-tree in ion. Otherwise, it would be
> out-of-tree. I'd expect most "custom" heaps to be parameterisable to
> the point of being generally useful.
> 

I'm willing to be reasonably permissive in what lives in tree. A good
example would be something like a heap for the OMAP tiler which had
weird hardware requirements. The associated devices that go with the
heap should be well supported upstream though.

> For actual heap instances, I would expect them to be communicated via
> reserved-memory regions or something similar, and so the maintenance
> burden is pretty low.
> 

Yes. After the next round of review for this series I'm going to
start thinking about properties for chunk and carveout heaps if nobody
proposes something first.

> The existing query ioctl can allow heap IDs to get assigned
> dynamically at runtime, so there's no need to reserve "bit 6" for
> "CUSTOM_ACME_HEAP_1"
> 
>> Another point is how can we put secure rules (like selinux policy) on
>> heaps since all the allocations
>> go to the same device (/dev/ion) ? For example, until now, in Android
>> we have to give the same
>> access rights to all the process that use ION.
>> It will become problem when we will add secure heaps because we won't
>> be able to distinguish secure
>> processes to standard ones or set specific policy per heaps.
>> Maybe I'm wrong here but I have never see selinux policy checking an
>> ioctl field but if that
>> exist it could be a solution.
>>
> 
> I might be thinking of a different type of "secure", but...
> 
> Should the security of secure heaps be enforced by OS-level
> permissions? I don't know about other architectures, but at least on
> arm/arm64 this is enforced in hardware; it doesn't matter who has
> access to the ion heap, because only secure devices (or the CPU
> running a secure process) is physically able to access the memory
> backing the buffer.
> 
> In fact, in the use-cases I know of, the process asking for the ion
> allocation is not a secure process, and so we wouldn't *want* to
> restrict the secure heap to be allocated from only by secure
> processes.
> 
> -Brian
> 
>>>
>>>>

Thread

[RFC PATCH 00/12] Ion cleanup in preparation for moving out of staging Laura Abbott <labbott@redhat.com> - 2017-03-02 22:50 +0100
  [RFC PATCH 01/12] staging: android: ion: Remove dmap_cnt Laura Abbott <labbott@redhat.com> - 2017-03-02 22:50 +0100
  [RFC PATCH 10/12] staging: android: ion: Use CMA APIs directly Laura Abbott <labbott@redhat.com> - 2017-03-02 22:50 +0100
    Re: [RFC PATCH 10/12] staging: android: ion: Use CMA APIs directly Laurent Pinchart <laurent.pinchart@ideasonboard.com> - 2017-03-03 17:50 +0100
      Re: [RFC PATCH 10/12] staging: android: ion: Use CMA APIs directly Laura Abbott <labbott@redhat.com> - 2017-03-03 20:00 +0100
        Re: [RFC PATCH 10/12] staging: android: ion: Use CMA APIs directly Daniel Vetter <daniel@ffwll.ch> - 2017-03-06 11:50 +0100
          Re: [RFC PATCH 10/12] staging: android: ion: Use CMA APIs directly Laurent Pinchart <laurent.pinchart@ideasonboard.com> - 2017-03-06 14:50 +0100
            Re: [RFC PATCH 10/12] staging: android: ion: Use CMA APIs directly Daniel Vetter <daniel@ffwll.ch> - 2017-03-06 17:00 +0100
              Re: [RFC PATCH 10/12] staging: android: ion: Use CMA APIs directly Laura Abbott <labbott@redhat.com> - 2017-03-06 20:30 +0100
  [RFC PATCH 09/12] cma: Introduce cma_for_each_area Laura Abbott <labbott@redhat.com> - 2017-03-02 22:50 +0100
  [RFC PATCH 03/12] staging: android: ion: Duplicate sg_table Laura Abbott <labbott@redhat.com> - 2017-03-02 22:50 +0100
    Re: [RFC PATCH 03/12] staging: android: ion: Duplicate sg_table "Hillf Danton" <hillf.zj@alibaba-inc.com> - 2017-03-03 09:40 +0100
      Re: [RFC PATCH 03/12] staging: android: ion: Duplicate sg_table Laura Abbott <labbott@redhat.com> - 2017-03-03 19:50 +0100
  [RFC PATCH 11/12] staging: android: ion: Make Ion heaps selectable Laura Abbott <labbott@redhat.com> - 2017-03-02 22:50 +0100
    Re: [RFC PATCH 11/12] staging: android: ion: Make Ion heaps  selectable Daniel Vetter <daniel@ffwll.ch> - 2017-03-03 16:10 +0100
      Re: [RFC PATCH 11/12] staging: android: ion: Make Ion heaps  selectable Laura Abbott <labbott@redhat.com> - 2017-03-03 20:50 +0100
  [RFC PATCH 05/12] staging: android: ion: Remove page faulting support Laura Abbott <labbott@redhat.com> - 2017-03-02 22:50 +0100
  [RFC PATCH 02/12] staging: android: ion: Remove alignment from allocation field Laura Abbott <labbott@redhat.com> - 2017-03-02 22:50 +0100
  [RFC PATCH 04/12] staging: android: ion: Call dma_map_sg for syncing and mapping Laura Abbott <labbott@redhat.com> - 2017-03-02 22:50 +0100
    Re: [RFC PATCH 04/12] staging: android: ion: Call dma_map_sg for  syncing and mapping Dan Carpenter <dan.carpenter@oracle.com> - 2017-03-03 12:10 +0100
      Re: [RFC PATCH 04/12] staging: android: ion: Call dma_map_sg for  syncing and mapping Eric Engestrom <eric.engestrom@imgtec.com> - 2017-03-03 13:00 +0100
    Re: [RFC PATCH 04/12] staging: android: ion: Call dma_map_sg for syncing and mapping Laurent Pinchart <laurent.pinchart@ideasonboard.com> - 2017-03-03 17:40 +0100
      Re: [RFC PATCH 04/12] staging: android: ion: Call dma_map_sg for  syncing and mapping Laura Abbott <labbott@redhat.com> - 2017-03-03 19:50 +0100
  [RFC PATCH 07/12] staging: android: ion: Remove old platform support Laura Abbott <labbott@redhat.com> - 2017-03-02 22:50 +0100
    Re: [RFC PATCH 07/12] staging: android: ion: Remove old platform  support Daniel Vetter <daniel@ffwll.ch> - 2017-03-03 11:40 +0100
  [RFC PATCH 06/12] staging: android: ion: Remove crufty cache support Laura Abbott <labbott@redhat.com> - 2017-03-02 22:50 +0100
    Re: [RFC PATCH 06/12] staging: android: ion: Remove crufty cache  support Daniel Vetter <daniel@ffwll.ch> - 2017-03-03 11:00 +0100
      Re: [RFC PATCH 06/12] staging: android: ion: Remove crufty cache support Laurent Pinchart <laurent.pinchart@ideasonboard.com> - 2017-03-03 18:00 +0100
        Re: [RFC PATCH 06/12] staging: android: ion: Remove crufty cache  support Laura Abbott <labbott@redhat.com> - 2017-03-03 19:50 +0100
          Re: [RFC PATCH 06/12] staging: android: ion: Remove crufty cache  support Daniel Vetter <daniel@ffwll.ch> - 2017-03-06 11:50 +0100
            Re: [RFC PATCH 06/12] staging: android: ion: Remove crufty cache support Emil Velikov <emil.l.velikov@gmail.com> - 2017-03-06 18:40 +0100
              Re: [RFC PATCH 06/12] staging: android: ion: Remove crufty cache  support Laura Abbott <labbott@redhat.com> - 2017-03-06 20:30 +0100
  Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of  staging Daniel Vetter <daniel@ffwll.ch> - 2017-03-03 11:40 +0100
    Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of  staging Daniel Vetter <daniel@ffwll.ch> - 2017-03-03 11:40 +0100
      Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of staging Benjamin Gaignard <benjamin.gaignard@linaro.org> - 2017-03-03 15:50 +0100
    Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of staging Laurent Pinchart <laurent.pinchart@ideasonboard.com> - 2017-03-03 17:50 +0100
      Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of  staging Laura Abbott <labbott@redhat.com> - 2017-03-03 20:20 +0100
      Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of  staging Daniel Vetter <daniel@ffwll.ch> - 2017-03-06 11:50 +0100
        Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of staging Laurent Pinchart <laurent.pinchart@ideasonboard.com> - 2017-03-06 16:10 +0100
          Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of  staging Daniel Vetter <daniel@ffwll.ch> - 2017-03-06 17:40 +0100
  Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of  staging Michal Hocko <mhocko@kernel.org> - 2017-03-03 14:40 +0100
    Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of  staging Laura Abbott <labbott@redhat.com> - 2017-03-03 18:50 +0100
      Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of  staging Michal Hocko <mhocko@kernel.org> - 2017-03-06 09:10 +0100
        Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of  staging Daniel Vetter <daniel@ffwll.ch> - 2017-03-06 12:00 +0100
          Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of  staging Mark Brown <broonie@kernel.org> - 2017-03-06 12:00 +0100
            Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of  staging Daniel Vetter <daniel@ffwll.ch> - 2017-03-06 17:20 +0100
              Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of staging Benjamin Gaignard <benjamin.gaignard@linaro.org> - 2017-03-09 11:10 +0100
                Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of  staging Laura Abbott <labbott@redhat.com> - 2017-03-09 19:10 +0100
                Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of  staging Brian Starkey <brian.starkey@arm.com> - 2017-03-10 11:40 +0100
                Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of  staging Robin Murphy <robin.murphy@arm.com> - 2017-03-10 12:50 +0100
                Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of  staging Brian Starkey <brian.starkey@arm.com> - 2017-03-10 15:30 +0100
                Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of  staging Laura Abbott <labbott@redhat.com> - 2017-03-10 17:50 +0100
                Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of  staging Daniel Vetter <daniel@ffwll.ch> - 2017-03-10 13:50 +0100
                Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of staging Rob Clark <robdclark@gmail.com> - 2017-03-10 15:00 +0100
                Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of staging Benjamin Gaignard <benjamin.gaignard@linaro.org> - 2017-03-12 14:40 +0100
                Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of staging Daniel Vetter <daniel.vetter@ffwll.ch> - 2017-03-12 20:10 +0100
                Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of  staging Laura Abbott <labbott@redhat.com> - 2017-03-13 22:20 +0100
                Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of staging Rob Clark <robdclark@gmail.com> - 2017-03-13 22:30 +0100
                Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of  staging Laura Abbott <labbott@redhat.com> - 2017-03-13 23:00 +0100
                Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of staging Benjamin Gaignard <benjamin.gaignard@linaro.org> - 2017-03-14 15:50 +0100
                Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of  staging Laura Abbott <labbott@redhat.com> - 2017-03-14 20:50 +0100
                Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of  staging Nicolas Dufresne <nicolas@ndufresne.ca> - 2017-03-14 21:30 +0100
                Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of  staging Brian Starkey <brian.starkey@arm.com> - 2017-03-13 12:00 +0100
                Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of  staging Mark Brown <broonie@kernel.org> - 2017-03-13 14:30 +0100
                Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of  staging Laura Abbott <labbott@redhat.com> - 2017-03-13 22:50 +0100
                Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of  staging Laura Abbott <labbott@redhat.com> - 2017-03-13 22:30 +0100
          Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of  staging Michal Hocko <mhocko@kernel.org> - 2017-03-06 14:40 +0100
  Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of staging Laurent Pinchart <laurent.pinchart@ideasonboard.com> - 2017-03-03 17:30 +0100
    Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of  staging Laura Abbott <labbott@redhat.com> - 2017-03-03 20:20 +0100

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