Supersedes: <20250828-san-v9-0-c0dff4b8a...@rsg.ci.i.u-tokyo.ac.jp>
("[PATCH v9 0/2] Fix check-qtest-ppc64 sanitizer errors")
Based-on: <20250906-use-v1-0-c51caafd1...@rsg.ci.i.u-tokyo.ac.jp>
("[PATCH 00/22] Fix memory region leaks and use-after-finalization")
MemoryRegions used to "piggyback" on their owners instead of using their
reference counters due to the circular dependencies between them, which
caused memory leak.
I tried to fix it with "[PATCH v9 0/2] Fix check-qtest-ppc64 sanitizer
errors" but it resulted in a lengthy discussion; ultimately it is
attributed to the fact that "piggybacking" is hard to understand and
forces us design trade-offs. It was also insufficient because it only
deals with the container/subregion pattern and did not deal with
AddressSpace and DMA. Fixing all possible memory leaks require checking
the referrer at many places where memory_region_ref() is called.
With this series, I remove the "piggyback" hack altogather.
The key insight here is that the unparented devices have the finalizable
MemoryRegions and they do not need them. I code the fact by calling
object_unparent() in device_unparent(). This eliminates the entire class
of memory leaks caused by references from owners to their MemoryRegions.
Signed-off-by: Akihiko Odaki <od...@rsg.ci.i.u-tokyo.ac.jp>
---
Changes in v2:
- Expanded the message of patch
"vfio/pci: Do not unparent in instance_finalize()".
- Changed to exploit the unparenting timing instead of the unrealization
timing.
- Link to v1:
https://lore.kernel.org/qemu-devel/20250901-mr-v1-0-dd7cb6b14...@rsg.ci.i.u-tokyo.ac.jp
---
Akihiko Odaki (3):
qom: Do not finalize twice
virtio-gpu-virgl: Add virtio-gpu-virgl-hostmem-region type
memory: Stop piggybacking on memory region owners
docs/devel/memory.rst | 41 +++++++++++++++++-----------------
include/qom/object.h | 1 +
include/system/memory.h | 51 +++++++++++++++++++++----------------------
hw/core/qdev.c | 16 ++++++++++++++
hw/display/virtio-gpu-virgl.c | 50 ++++++++++++++++++++++++++++++------------
qom/object.c | 5 +++++
system/memory.c | 33 ++++++++++++++++++++--------
7 files changed, 127 insertions(+), 70 deletions(-)
---
base-commit: e101d33792530093fa0b0a6e5f43e4d8cfe4581e
change-id: 20250831-mr-d0dc495bad11
prerequisite-message-id: <20250906-use-v1-0-c51caafd1...@rsg.ci.i.u-tokyo.ac.jp>
prerequisite-patch-id: d464fda86a3c79ff8e6d7a2e623d979b2a47019b
prerequisite-patch-id: 17b153237f69c898b9c5b93aad0d5116d0bfe49f
prerequisite-patch-id: a323f67e01c672ab2958a237ea54b77f1443e2d1
prerequisite-patch-id: 019969fe248bd57ddcda1ff5fc960b214ccffefe
prerequisite-patch-id: 74ded25b212b75b2f7d1859fedc601cf33d59107
prerequisite-patch-id: 43f841a1924749e2a5a3b74b35e54f89afb7e3c5
prerequisite-patch-id: 44300da5065efee0390be5d450225868e01cecfc
prerequisite-patch-id: 4af306d6f3d0a4585015c5907ca1e1dcfced77d3
prerequisite-patch-id: fff78c7af9b0a56190a1b4afbb122c460a6b0e7d
prerequisite-patch-id: 3d38803ce09ba9c93f2a876f54309e673b396ab1
prerequisite-patch-id: 822094864ad7a6a702fee098e4835621bd8092fe
prerequisite-patch-id: 5757efd81557b060257b5db6dec6fd189076ee77
prerequisite-patch-id: bd912830a326f13186bf38e916655ec980e11af8
prerequisite-patch-id: fe6b92112288829e60f10c305742a544f45e8984
prerequisite-patch-id: ac4ff0c11dcc1fc5d08b4fc480c14721fde574ad
prerequisite-patch-id: ff398fa97b5f2feee85372fdf108d82d8d5526b0
prerequisite-patch-id: 7ac446ae76e05dd267a63889ff775ac609712c31
prerequisite-patch-id: b49a74cd5f31348c3dc13dcfd1dad629e6b30387
prerequisite-patch-id: 8f61fe1b81cf3ec906ebbf61776573edd96c1e8c
prerequisite-patch-id: 01fb8ccbe7326021a94a8d7531189568d2e311a7
prerequisite-patch-id: 974b0fc6d7c8d6d56b8f44597260647e1a53cf38
prerequisite-patch-id: 55c4711a2a4e6b02b8b512e0283f8feaf7d3bfa3
Best regards,
--
Akihiko Odaki <od...@rsg.ci.i.u-tokyo.ac.jp>
