From: Benjamin Gaignard <benjamin.gaignard@collabora.com>
To: "Joakim Bech" <joakim.bech@linaro.org>,
"Yong Wu (吴勇)" <Yong.Wu@mediatek.com>
Cc: "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
"conor+dt@kernel.org" <conor+dt@kernel.org>,
"Kuohong Wang (王國鴻)" <kuohong.wang@mediatek.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"dri-devel@lists.freedesktop.org"
<dri-devel@lists.freedesktop.org>,
"christian.koenig@amd.com" <christian.koenig@amd.com>,
"linaro-mm-sig@lists.linaro.org" <linaro-mm-sig@lists.linaro.org>,
"robh+dt@kernel.org" <robh+dt@kernel.org>,
"linux-mediatek@lists.infradead.org"
<linux-mediatek@lists.infradead.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"krzysztof.kozlowski+dt@linaro.org"
<krzysztof.kozlowski+dt@linaro.org>,
"matthias.bgg@gmail.com" <matthias.bgg@gmail.com>,
"jstultz@google.com" <jstultz@google.com>,
"tjmercier@google.com" <tjmercier@google.com>,
"linux-media@vger.kernel.org" <linux-media@vger.kernel.org>,
"sumit.semwal@linaro.org" <sumit.semwal@linaro.org>,
"Jianjiao Zeng (曾健姣)" <Jianjiao.Zeng@mediatek.com>,
"angelogioacchino.delregno@collabora.com"
<angelogioacchino.delregno@collabora.com>
Subject: Re: [PATCH 5/9] dma-buf: heaps: mtk_sec_heap: Initialise tee session
Date: Wed, 27 Sep 2023 17:17:58 +0200 [thread overview]
Message-ID: <3aaafe47-3733-a4d5-038d-a7e439309282@collabora.com> (raw)
In-Reply-To: <20230927134614.kp27moxdw72jiu4y@pop-os.localdomain>
Le 27/09/2023 à 15:46, Joakim Bech a écrit :
> On Mon, Sep 25, 2023 at 12:49:50PM +0000, Yong Wu (吴勇) wrote:
>> On Tue, 2023-09-12 at 11:32 +0200, AngeloGioacchino Del Regno wrote:
>>> Il 12/09/23 08:17, Yong Wu (吴勇) ha scritto:
>>>> On Mon, 2023-09-11 at 11:29 +0200, AngeloGioacchino Del Regno
>>>> wrote:
>>>>> Il 11/09/23 04:30, Yong Wu ha scritto:
>>>>>> The TEE probe later than dma-buf heap, and PROBE_DEDER doesn't
>>>>>> work
>>>>>> here since this is not a platform driver, therefore initialise
>>>>>> the
>>>>>> TEE
>>>>>> context/session while we allocate the first secure buffer.
>>>>>>
>>>>>> Signed-off-by: Yong Wu <yong.wu@mediatek.com>
>>>>>> ---
>>>>>> drivers/dma-buf/heaps/mtk_secure_heap.c | 61
>>>>>> +++++++++++++++++++++++++
>>>>>> 1 file changed, 61 insertions(+)
>>>>>>
>>>>>> diff --git a/drivers/dma-buf/heaps/mtk_secure_heap.c
>>>>>> b/drivers/dma-
>>>>>> buf/heaps/mtk_secure_heap.c
>>>>>> index bbf1c8dce23e..e3da33a3d083 100644
>>>>>> --- a/drivers/dma-buf/heaps/mtk_secure_heap.c
>>>>>> +++ b/drivers/dma-buf/heaps/mtk_secure_heap.c
>>>>>> @@ -10,6 +10,12 @@
>>>>>> #include <linux/err.h>
>>>>>> #include <linux/module.h>
>>>>>> #include <linux/slab.h>
>>>>>> +#include <linux/tee_drv.h>
>>>>>> +#include <linux/uuid.h>
>>>>>> +
>>>>>> +#define TZ_TA_MEM_UUID "4477588a-8476-11e2-ad15-
>>>>>> e41f1390d676"
>>>>>> +
>>>>> Is this UUID the same for all SoCs and all TZ versions?
>>>> Yes. It is the same for all SoCs and all TZ versions currently.
>>>>
>>> That's good news!
>>>
>>> Is this UUID used in any userspace component? (example: Android
>>> HALs?)
>> No. Userspace never use it. If userspace would like to allocate this
>> secure buffer, it can achieve through the existing dmabuf IOCTL via
>> /dev/dma_heap/mtk_svp node.
>>
> In general I think as mentioned elsewhere in comments, that there isn't
> that much here that seems to be unique for MediaTek in this patch
> series, so I think it worth to see whether this whole patch set can be
> made more generic. Having said that, the UUID is always unique for a
> certain Trusted Application. So, it's not entirely true saying that the
> UUID is the same for all SoCs and all TrustZone versions. It might be
> true for a family of MediaTek devices and the TEE in use, but not
> generically.
>
> So, if we need to differentiate between different TA implementations,
> then we need different UUIDs. If it would be possible to make this patch
> set generic, then it sounds like a single UUID would be sufficient, but
> that would imply that all TA's supporting such a generic UUID would be
> implemented the same from an API point of view. Which also means that
> for example Trusted Application function ID's needs to be the same etc.
> Not impossible to achieve, but still not easy (different TEE follows
> different specifications) and it's not typically something we've done in
> the past.
>
> Unfortunately there is no standardized database of TA's describing what
> they implement and support.
>
> As an alternative, we could implement a query call in the TEE answering,
> "What UUID does your TA have that implements secure unmapped heap?".
> I.e., something that reminds of a lookup table. Then we wouldn't have to
> carry this in UAPI, DT or anywhere else.
Joakim does a TA could offer a generic API and hide the hardware specific
details (like kernel uAPI does for drivers) ?
Aside that question I wonder what are the needs to perform a 'secure' playback.
I have in mind 2 requirements:
- secure memory regions, which means configure the hardware to ensure that only
dedicated hardware blocks and read or write into it.
- set hardware blocks in secure modes so they access to secure memory.
Do you see something else ?
Regards,
Benjamin
>
next prev parent reply other threads:[~2023-09-27 15:18 UTC|newest]
Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-11 2:30 [PATCH 0/9] dma-buf: heaps: Add MediaTek secure heap Yong Wu
2023-09-11 2:30 ` [PATCH 1/9] dma-buf: heaps: Deduplicate docs and adopt common format Yong Wu
2023-09-11 9:36 ` Christian König
2023-09-11 23:51 ` T.J. Mercier
2023-09-11 2:30 ` [PATCH 2/9] dma-heap: Add proper kref handling on dma-buf heaps Yong Wu
2023-09-11 9:48 ` Christian König
2023-09-22 18:19 ` T.J. Mercier
2023-09-11 2:30 ` [PATCH 3/9] dma-heap: Provide accessors so that in-kernel drivers can allocate dmabufs from specific heaps Yong Wu
2023-09-11 10:13 ` Christian König
2023-09-11 18:29 ` John Stultz
2023-09-12 7:06 ` Christian König
2023-09-12 8:52 ` Yong Wu (吴勇)
2023-09-12 14:46 ` Christian König
2023-09-12 14:58 ` Nicolas Dufresne
2023-09-13 8:30 ` Christian König
2023-09-12 14:50 ` Nicolas Dufresne
2023-09-11 16:12 ` Nicolas Dufresne
2023-09-12 8:47 ` Yong Wu (吴勇)
2023-09-12 15:05 ` Nicolas Dufresne
2023-09-18 10:46 ` Yong Wu (吴勇)
2023-09-11 2:30 ` [PATCH 4/9] dma-buf: heaps: Initialise MediaTek secure heap Yong Wu
2023-09-11 8:05 ` kernel test robot
2023-09-27 14:42 ` Joakim Bech
2023-09-28 8:03 ` Yong Wu (吴勇)
2023-10-19 4:45 ` Vijayanand Jitta
2023-10-20 9:59 ` Yong Wu (吴勇)
2023-10-26 4:48 ` Vijayanand Jitta
2023-10-27 7:47 ` Yong Wu (吴勇)
2023-10-30 8:06 ` Vijayanand Jitta
2023-09-11 2:30 ` [PATCH 5/9] dma-buf: heaps: mtk_sec_heap: Initialise tee session Yong Wu
2023-09-11 9:29 ` AngeloGioacchino Del Regno
2023-09-11 10:15 ` Christian König
2023-09-12 6:17 ` Yong Wu (吴勇)
2023-09-12 9:32 ` AngeloGioacchino Del Regno
2023-09-25 12:49 ` Yong Wu (吴勇)
2023-09-27 13:46 ` Joakim Bech
2023-09-27 15:17 ` Benjamin Gaignard [this message]
2023-09-27 18:56 ` Jeffrey Kardatzke
2023-09-28 8:30 ` Benjamin Gaignard
2023-09-28 17:48 ` Jeffrey Kardatzke
2023-09-29 6:54 ` Benjamin Gaignard
2023-10-13 19:09 ` Jeffrey Kardatzke
2023-10-13 19:10 ` Jeffrey Kardatzke
2023-09-27 18:54 ` Jeffrey Kardatzke
2023-09-13 13:35 ` kernel test robot
2023-09-11 2:30 ` [PATCH 6/9] dma-buf: heaps: mtk_sec_heap: Add tee service call for buffer allocating/freeing Yong Wu
2023-09-14 10:18 ` kernel test robot
2023-09-27 14:37 ` Joakim Bech
2023-09-28 5:24 ` Yong Wu (吴勇)
2023-10-19 4:45 ` Vijayanand Jitta
2023-10-20 10:01 ` Yong Wu (吴勇)
2023-09-11 2:30 ` [PATCH 7/9] dma-buf: heaps: mtk_sec_heap: Add dma_ops Yong Wu
2023-09-11 2:30 ` [PATCH 8/9] dt-bindings: reserved-memory: MediaTek: Add reserved memory for SVP Yong Wu
2023-09-11 15:44 ` Rob Herring
2023-09-12 6:16 ` Yong Wu (吴勇)
2023-09-12 8:28 ` Krzysztof Kozlowski
2023-09-12 10:13 ` Robin Murphy
2023-09-12 15:53 ` Rob Herring
2023-09-12 16:05 ` Robin Murphy
2023-09-18 10:47 ` Yong Wu (吴勇)
2023-09-19 22:15 ` Jeffrey Kardatzke
2023-10-12 6:54 ` Yong Wu (吴勇)
2023-10-12 7:07 ` Krzysztof Kozlowski
2023-10-12 11:15 ` Yong Wu (吴勇)
2023-10-19 4:46 ` Vijayanand Jitta
2023-10-20 9:50 ` Yong Wu (吴勇)
2023-11-01 5:50 ` Jaskaran Singh
2023-11-06 5:56 ` Yong Wu (吴勇)
2023-11-20 8:20 ` Jaskaran Singh
2023-09-11 2:30 ` [PATCH 9/9] dma_buf: heaps: mtk_sec_heap: Add a new CMA heap Yong Wu
2023-09-11 9:33 ` AngeloGioacchino Del Regno
2023-10-19 4:44 ` [PATCH 0/9] dma-buf: heaps: Add MediaTek secure heap Vijayanand Jitta
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