mbox series

[0/4] Fix XPU violation during modem metadata authentication

Message ID 20221213140724.8612-1-quic_sibis@quicinc.com
Headers
Series Fix XPU violation during modem metadata authentication |

Message

Sibi Sankar Dec. 13, 2022, 2:07 p.m. UTC 
  The memory region allocated using dma_alloc_attr with no kernel mapping
attribute set would still be a part of the linear kernel map. Any access
to this region by the application processor after assigning it to the
remote Q6 will result in a XPU violation. Fix this by replacing the
dynamically allocated memory region with a no-map carveout and unmap the
modem metadata memory region before passing control to the remote Q6.
The addition of the carveout and memunmap is required only on SoCs that
mandate memory protection before transferring control to Q6, hence the
driver falls back to dynamic memory allocation in the absence of the
modem metadata carveout.

Relevant discussions on the mailing list:
https://lore.kernel.org/lkml/20221114110329.68413-1-manivannan.sadhasivam@linaro.org/

Depends on:
https://patchwork.kernel.org/project/linux-arm-msm/cover/20221124184333.133911-1-krzysztof.kozlowski@linaro.org/

Reported-by: Amit Pundir <amit.pundir@linaro.org>
https://people.linaro.org/~amit.pundir/linaro-sid-developer-dragonboard-845c-569/6.1-rc4_defconfig
Reproduced with ^^ defconfig SDM845 SoCs

Sibi Sankar (4):
  arm64: dts: qcom: Introduce a carveout for modem metadata
  dt-bindings: remoteproc: qcom: sc7180: Update memory-region
    requirements
  dt-bindings: remoteproc: qcom: q6v5: Update memory region requirements
  remoteproc: qcom_q6v5_mss: Use a carveout to authenticate modem
    headers

 .../bindings/remoteproc/qcom,q6v5.txt         | 29 ++++++-
 .../remoteproc/qcom,sc7180-mss-pil.yaml       |  3 +-
 .../remoteproc/qcom,sc7280-mss-pil.yaml       |  3 +-
 .../boot/dts/qcom/msm8996-xiaomi-common.dtsi  |  6 ++
 arch/arm64/boot/dts/qcom/msm8996.dtsi         |  9 ++
 arch/arm64/boot/dts/qcom/msm8998.dtsi         |  9 ++
 arch/arm64/boot/dts/qcom/sc7180-idp.dts       |  7 +-
 arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi  |  7 +-
 .../dts/qcom/sc7280-herobrine-lte-sku.dtsi    |  7 +-
 arch/arm64/boot/dts/qcom/sdm845.dtsi          |  9 ++
 drivers/remoteproc/qcom_q6v5_mss.c            | 85 +++++++++++++------
 11 files changed, 142 insertions(+), 32 deletions(-)

Comments

Amit Pundir Dec. 27, 2022, 12:18 p.m. UTC | #1 
On Tue, 13 Dec 2022 at 19:37, Sibi Sankar <quic_sibis@quicinc.com> wrote:
>
> The memory region allocated using dma_alloc_attr with no kernel mapping
> attribute set would still be a part of the linear kernel map. Any access
> to this region by the application processor after assigning it to the
> remote Q6 will result in a XPU violation. Fix this by replacing the
> dynamically allocated memory region with a no-map carveout and unmap the
> modem metadata memory region before passing control to the remote Q6.
> The addition of the carveout and memunmap is required only on SoCs that
> mandate memory protection before transferring control to Q6, hence the
> driver falls back to dynamic memory allocation in the absence of the
> modem metadata carveout.
>
> Relevant discussions on the mailing list:
> https://lore.kernel.org/lkml/20221114110329.68413-1-manivannan.sadhasivam@linaro.org/
>
> Depends on:
> https://patchwork.kernel.org/project/linux-arm-msm/cover/20221124184333.133911-1-krzysztof.kozlowski@linaro.org/
>
> Reported-by: Amit Pundir <amit.pundir@linaro.org>

Smoke tested this series on db845c (SDM845) running v6.2-rc1, with the
upstream workaround (b7d9aae40484 Revert "arm64: dma: Drop cache
invalidation from arch_dma_prep_coherent()") reverted and I can no
longer reproduce the above crash in my limited (10+) test runs so far.
So for the entire series:

Tested-by: Amit Pundir <amit.pundir@linaro.org>

Regards,
Amit Pundir

> https://people.linaro.org/~amit.pundir/linaro-sid-developer-dragonboard-845c-569/6.1-rc4_defconfig
> Reproduced with ^^ defconfig SDM845 SoCs
>
> Sibi Sankar (4):
>   arm64: dts: qcom: Introduce a carveout for modem metadata
>   dt-bindings: remoteproc: qcom: sc7180: Update memory-region
>     requirements
>   dt-bindings: remoteproc: qcom: q6v5: Update memory region requirements
>   remoteproc: qcom_q6v5_mss: Use a carveout to authenticate modem
>     headers
>
>  .../bindings/remoteproc/qcom,q6v5.txt         | 29 ++++++-
>  .../remoteproc/qcom,sc7180-mss-pil.yaml       |  3 +-
>  .../remoteproc/qcom,sc7280-mss-pil.yaml       |  3 +-
>  .../boot/dts/qcom/msm8996-xiaomi-common.dtsi  |  6 ++
>  arch/arm64/boot/dts/qcom/msm8996.dtsi         |  9 ++
>  arch/arm64/boot/dts/qcom/msm8998.dtsi         |  9 ++
>  arch/arm64/boot/dts/qcom/sc7180-idp.dts       |  7 +-
>  arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi  |  7 +-
>  .../dts/qcom/sc7280-herobrine-lte-sku.dtsi    |  7 +-
>  arch/arm64/boot/dts/qcom/sdm845.dtsi          |  9 ++
>  drivers/remoteproc/qcom_q6v5_mss.c            | 85 +++++++++++++------
>  11 files changed, 142 insertions(+), 32 deletions(-)
>
> --
> 2.17.1
>