At KVM Forum Jeff Cody, John Snow, Denis Lunev, Markus Armbruster, Max Reitz, and I discussed the next steps for planned the op blockers enhancement work.
The idea is to make op blockers more powerful and usable outside the block layer. The following action items were agreed upon to start this work: 1. Jeff to post op blockers design on wiki Features/OpBlockers page 2. Jeff to include test interface (QMP command?) for error injection, allowing tests to exercise code paths where op blockers prohibit execution. 3. Alberto Garcia, John Snow, and Kevin Wolf reviewers/maintainer for op blockers work. In this session two unrelated issues were also raised. We did not discuss them in depth: 1. Denis is concerned that destination QEMU opens image file in read/write mode during live migration. Read-only would be safer. 2. Denis is concerned that caching image file size may lead to incorrect image sizes during migration. Stefan