Re: [PATCH v3 00/11] Add mediate-drm secure flow for SVP

From: "CK Hu (胡俊光)" <ck.hu@mediatek.com>
To: "matthias.bgg@gmail.com" <matthias.bgg@gmail.com>,
	"Jason-JH Lin (林睿祥)" <Jason-JH.Lin@mediatek.com>,
	"chunkuang.hu@kernel.org" <chunkuang.hu@kernel.org>,
	"conor+dt@kernel.org" <conor+dt@kernel.org>,
	"robh+dt@kernel.org" <robh+dt@kernel.org>,
	"krzysztof.kozlowski+dt@linaro.org"
	<krzysztof.kozlowski+dt@linaro.org>,
	"angelogioacchino.delregno@collabora.com"
	<angelogioacchino.delregno@collabora.com>
Cc: "jkardatzke@google.com" <jkardatzke@google.com>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	Project_Global_Chrome_Upstream_Group
	<Project_Global_Chrome_Upstream_Group@mediatek.com>,
	"jason-jh.lin@mediatek.corp-partner.google.com"
	<jason-jh.lin@mediatek.corp-partner.google.com>,
	"Singo Chang (張興國)" <Singo.Chang@mediatek.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"dri-devel@lists.freedesktop.org"
	<dri-devel@lists.freedesktop.org>,
	"linaro-mm-sig@lists.linaro.org" <linaro-mm-sig@lists.linaro.org>,
	"Jason-ch Chen (陳建豪)" <Jason-ch.Chen@mediatek.com>,
	"Nancy Lin (林欣螢)" <Nancy.Lin@mediatek.com>,
	"linux-mediatek@lists.infradead.org"
	<linux-mediatek@lists.infradead.org>,
	"Shawn Sung (宋孝謙)" <Shawn.Sung@mediatek.com>,
	"Johnson Wang (王聖鑫)" <Johnson.Wang@mediatek.com>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>,
	"linux-media@vger.kernel.org" <linux-media@vger.kernel.org>
Subject: Re: [PATCH v3 00/11] Add mediate-drm secure flow for SVP
Date: Thu, 28 Dec 2023 06:27:06 +0000	[thread overview]
Message-ID: <4fd704b3438e524362fada762b380bd18949cd0a.camel@mediatek.com> (raw)
In-Reply-To: <20231223182932.27683-1-jason-jh.lin@mediatek.com>

[-- Attachment #1: Type: text/html, Size: 13328 bytes --]

[-- Attachment #2: Type: text/plain, Size: 7683 bytes --]

Hi, Jason:

On Sun, 2023-12-24 at 02:29 +0800, Jason-JH.Lin wrote:
> From: Jason-jh Lin <jason-jh.lin@mediatek.corp-partner.google.com>
> 
> Memory Definitions:
> secure memory - Memory allocated in the TEE (Trusted Execution
> Environment) which is inaccessible in the REE (Rich Execution
> Environment, i.e. linux kernel/userspace).
> secure handle - Integer value which acts as reference to 'secure
> memory'. Used in communication between TEE and REE to reference
> 'secure memory'.
> secure buffer - 'secure memory' that is used to store decrypted,
> compressed video or for other general purposes in the TEE.
> secure surface - 'secure memory' that is used to store graphic
> buffers.
> 
> Memory Usage in SVP:
> The overall flow of SVP starts with encrypted video coming in from an
> outside source into the REE. The REE will then allocate a 'secure
> buffer' and send the corresponding 'secure handle' along with the
> encrypted, compressed video data to the TEE. The TEE will then
> decrypt
> the video and store the result in the 'secure buffer'. The REE will
> then allocate a 'secure surface'. The REE will pass the 'secure
> handles' for both the 'secure buffer' and 'secure surface' into the
> TEE for video decoding. The video decoder HW will then decode the
> contents of the 'secure buffer' and place the result in the 'secure
> surface'. The REE will then attach the 'secure surface' to the
> overlay
> plane for rendering of the video.
> 
> Everything relating to ensuring security of the actual contents of
> the
> 'secure buffer' and 'secure surface' is out of scope for the REE and
> is the responsibility of the TEE.
> 
> DRM driver handles allocation of gem objects that are backed by a
> 'secure
> surface' and for displaying a 'secure surface' on the overlay plane.
> This introduces a new flag for object creation called
> DRM_MTK_GEM_CREATE_ENCRYPTED which indicates it should be a 'secure
> surface'. All changes here are in MediaTek specific code.

I would like to decouple secure display and secure decode. One reason
is that I would like secure display could be tested itself without
secure decode. Another reason is that if someone has draw an image and
want to display securely, this is not related to decode.

To achieve this, mediatek drm driver should provide render function on
secure surface. The most simple function is to bitblt a normal surface
onto secure surface. User could allocate both normal surface and secure
surface, draw on normal surface and bitblt normal surface onto secure
surface. We could have limitation that normal surface and secure
surface have the same width, height, pitch, pixel format, and the
bitblt is the full image bitblt. So mediatek drm driver just need a TEE
function that do memory copy from normal surface to secure surface.

This is not a must-be function, but it has some benefit for secure
display.

Regards,
CK

> ---
> TODO:
> 1) Remove get sec larb port interface in ddp_comp, ovl and
> ovl_adaptor.
> 2) Verify instruction for enabling/disabling dapc and larb port in
> TEE
>    drop the sec_engine flags in normal world and.
> 3) Move DISP_REG_OVL_SECURE setting to secure world for
> mtk_disp_ovl.c.
> 4) Change the parameter register address in mtk_ddp_sec_write()
>    from "u32 addr" to "struct cmdq_client_reg *cmdq_reg".
> 5) Implement setting mmsys routing table in the secure world series.
> ---
> Based on 5 series and 1 patch:
> [1] v3 dma-buf: heaps: Add MediaTek secure heap
> - 
> https://urldefense.com/v3/__https://patchwork.kernel.org/project/linux-mediatek/list/?series=809023__;!!CTRNKA9wMg0ARbw!lYGWfjjIBlxJvwBXWyxHTyc2vew5YagqT_qJZrYONTH20h95qxC3PH9V91vjplYU3S0ayseyHpxRQFSqATHgDnU$
>  
> [2] v3 add driver to support secure video decoder
> - 
> https://urldefense.com/v3/__https://patchwork.kernel.org/project/linux-mediatek/list/?series=807308__;!!CTRNKA9wMg0ARbw!lYGWfjjIBlxJvwBXWyxHTyc2vew5YagqT_qJZrYONTH20h95qxC3PH9V91vjplYU3S0ayseyHpxRQFSq9TXMSIQ$
>  
> [3] v4 soc: mediatek: Add register definitions for GCE
> - 
> https://urldefense.com/v3/__https://patchwork.kernel.org/project/linux-mediatek/patch/20231212121957.19231-2-shawn.sung@mediatek.com/__;!!CTRNKA9wMg0ARbw!lYGWfjjIBlxJvwBXWyxHTyc2vew5YagqT_qJZrYONTH20h95qxC3PH9V91vjplYU3S0ayseyHpxRQFSqkO4_0ac$
>  
> [4] v2 Add CMDQ driver support for mt8188
> - 
> https://urldefense.com/v3/__https://patchwork.kernel.org/project/linux-mediatek/list/?series=810302__;!!CTRNKA9wMg0ARbw!lYGWfjjIBlxJvwBXWyxHTyc2vew5YagqT_qJZrYONTH20h95qxC3PH9V91vjplYU3S0ayseyHpxRQFSqcXdKnXU$
>  
> [5] Add mediatek,gce-events definition to mediatek,gce-mailbox
> bindings
> - 
> https://urldefense.com/v3/__https://patchwork.kernel.org/project/linux-mediatek/list/?series=810938__;!!CTRNKA9wMg0ARbw!lYGWfjjIBlxJvwBXWyxHTyc2vew5YagqT_qJZrYONTH20h95qxC3PH9V91vjplYU3S0ayseyHpxRQFSqqGM08aE$
>  
> [6] v3 Add CMDQ secure driver for SVP
> - 
> https://urldefense.com/v3/__https://patchwork.kernel.org/project/linux-mediatek/list/?series=812379__;!!CTRNKA9wMg0ARbw!lYGWfjjIBlxJvwBXWyxHTyc2vew5YagqT_qJZrYONTH20h95qxC3PH9V91vjplYU3S0ayseyHpxRQFSq_YXTH9A$
>  
> ---
> Change in v3:
> 1. fix kerneldoc problems
> 2. fix typo in title and commit message
> 3. adjust naming for secure variable
> 4. add the missing part for is_suecure plane implementation
> 5. use BIT_ULL macro to replace bit shifting
> 6. move modification of ovl_adaptor part to the correct patch
> 7. add TODO list in commit message
> 8. add commit message for using share memory to store execute count
> 
> Change in v2:
> 
> 1. remove the DRIVER_RDNDER flag for mtk_drm_ioctl
> 2. move cmdq_insert_backup_cookie into client driver
> 3. move secure gce node define from mt8195-cherry.dtsi to mt8195.dtsi
> ---
> CK Hu (1):
>   drm/mediatek: Add interface to allocate MediaTek GEM buffer.
> 
> Jason-JH.Lin (10):
>   drm/mediatek/uapi: Add DRM_MTK_GEM_CREATE_ENCRYPTED flag
>   drm/mediatek: Add secure buffer control flow to mtk_drm_gem
>   drm/mediatek: Add secure identify flag and funcution to
> mtk_drm_plane
>   drm/mediatek: Add mtk_ddp_sec_write to config secure buffer info
>   drm/mediatek: Add get_sec_port interface to mtk_ddp_comp
>   drm/mediatek: Add secure layer config support for ovl
>   drm/mediatek: Add secure layer config support for ovl_adaptor
>   drm/mediatek: Add secure flow support to mediatek-drm
>   drm/mediatek: Add cmdq_insert_backup_cookie before secure pkt
> finalize
>   arm64: dts: mt8195: Add secure mbox settings for vdosys
> 
>  arch/arm64/boot/dts/mediatek/mt8195.dtsi      |   6 +-
>  drivers/gpu/drm/mediatek/mtk_disp_drv.h       |   3 +
>  drivers/gpu/drm/mediatek/mtk_disp_ovl.c       |  31 +-
>  .../gpu/drm/mediatek/mtk_disp_ovl_adaptor.c   |  15 +
>  drivers/gpu/drm/mediatek/mtk_drm_crtc.c       | 274
> +++++++++++++++++-
>  drivers/gpu/drm/mediatek/mtk_drm_crtc.h       |   1 +
>  drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c   |  30 ++
>  drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h   |  14 +
>  drivers/gpu/drm/mediatek/mtk_drm_drv.c        |  13 +
>  drivers/gpu/drm/mediatek/mtk_drm_gem.c        | 122 ++++++++
>  drivers/gpu/drm/mediatek/mtk_drm_gem.h        |  16 +
>  drivers/gpu/drm/mediatek/mtk_drm_plane.c      |  26 ++
>  drivers/gpu/drm/mediatek/mtk_drm_plane.h      |   2 +
>  drivers/gpu/drm/mediatek/mtk_mdp_rdma.c       |  11 +-
>  drivers/gpu/drm/mediatek/mtk_mdp_rdma.h       |   2 +
>  include/uapi/drm/mediatek_drm.h               |  59 ++++
>  16 files changed, 607 insertions(+), 18 deletions(-)
>  create mode 100644 include/uapi/drm/mediatek_drm.h
> 