[Qualcomm feedback] Chapter 5.1. Clarify TSM access to memory regions

[rsahita]

Reference: link

A TVM and/or TSM
needs to access both types of memory:
◦ Confidential memory - used for TVM code, data
◦ Non-confidential memory - used for communication between TVM and the non-TCB host
software and/or non-TCB IO devices.

The examples below only show why TVMs needs access to both. Why do TSMs? Is that for case (1), where TSM is nesting the TVM at the same privilege level?

[rsahita]

right. added a clarification

A TVM and/or TSM needs to access both types of memory:

• Confidential memory - used for TVM/TSM code and security-sensitive data;
  including state such as 1st-stage, G-stage page tables.
• Non-confidential memory - used only for shared data, e.g. communication
  between the TVM/TSM and the non-TCB host software and/or non-TCB IO devices.

[rsahita]

Closing as addressed in PR #70
cc @ozkoyuncu