commit 97f524907595d5c4cbe78efa1ea912f66471d40f
author Pierre-Clément Tosi <ptosi@google.com> Tue Apr 04 15:52:17 2023 +0100
committer Pierre-Clément Tosi <ptosi@google.com> Thu Apr 27 11:07:14 2023 +0000
tree 7af02a752a54773a452c571f065e35148039f494
parent c25d68ebeeb586ab5eb26af5c0a69d8511904f8f

pvmfw: Zero all scratch memory before guest runs

Zero any memory that could still hold secrets before executing the guest
OS, to reduce as much as possible the risk of leaking them.

Note that this only covers memory that can't be zeroed from high-level
compiled code (i.e. the .bss and .data sections and stack regions) and
doesn't zero the received configuration data, which contains the
BccHandover holding the secret CDIs as that is (and must still be)
zeroed from Rust.

Furthermore, no other region is flushed so data such as the DT or BCC
that must be made available to the guest OS (even if it doesn't
immediately re-enable the MMU) should still be flushed from Rust.

Remove unnecessary ISB in jump_to_payload().

Bug: 270684188
Test: atest MicrodroidHostTests
Change-Id: I8e923a468d1826c00ce1d0b07e1a91f5d2909f99