This series aim to kill a recent class of bug, the infamous
"DMA reentrancy" issues found by Alexander while fuzzing.
Introduce the 'memory' field in MemTxAttrs, allowing to restrict
a controller to memories (and not devices).
If a transaction permission is not allowed (for example access
to device), we return the specific MEMTX_BUS_ERROR.
Permissions are checked in after the flatview is resolved, and
before the access is done, in a new function: flatview_access_allowed().
Since v2 [1]:
- Addressed review comments:
- reword arm_gicv3 description (pm215)
- merged patches 3/4/5 (peterx & dhildenb)
- simplify flatview_access_allowed() logic (stefanha)
- drop MEMTXPERM enum and reword following AMBA terminology (edgar)
Since v1 ("hw: Forbid DMA write accesses to MMIO regions") [2]:
- rewrite based on Peter / Stefan feedbacks
Based on "hw: Let the DMA API take a MemTxAttrs argument" [3].
Based-on: <20210702092439.989969-1-phi...@redhat.com>
[1] https://www.mail-archive.com/qemu-devel@nongnu.org/msg831168.html
[2] https://www.mail-archive.com/qemu-block@nongnu.org/msg72924.html
[3] https://www.mail-archive.com/qemu-devel@nongnu.org/msg820359.html
Philippe Mathieu-Daudé (3):
hw/intc/arm_gicv3: Check for !MEMTX_OK instead of MEMTX_ERROR
softmmu/physmem: Simplify flatview_write and
address_space_access_valid
softmmu/physmem: Introduce MemTxAttrs::memory field and
MEMTX_BUS_ERROR
include/exec/memattrs.h | 9 +++++++
hw/intc/arm_gicv3_redist.c | 4 +--
softmmu/physmem.c | 54 +++++++++++++++++++++++++++++++-------
3 files changed, 55 insertions(+), 12 deletions(-)
--
2.33.1
