[Qemu-devel] KVM call minutes for June 15

[Chris Wright <chrisw@redhat.com>]

Page cache controls
- cache is 60% duplicated between host and guest (when not using cache=none)
- Balbir posted 2 patches to eliminate this
- boot parameter for preferred reclaim
  - not always have balloon driver
  - need a boot parameter
  - perhaps add a balloon cmd to give a hint before a more forceful request
    - hard/soft quota
      - exceed hard, swap
      - exceed soft...no real penalty
  - another consideration, block device hint (has large cache in host, don't
    agressively cache in guest)
    - lru weighted by disk speed might make sense on bare metal
- balloon driver filter
  - balloon unmapped page cache pages first
- guest has no incentive to cooperate (give up memory and possibly performance)
  
Migration Subsections
- looks good...
- doesn't replace need to increment version numbers
- needs some documentation to make sure subtlties are clear
- size for each section would be useful (breaks protocol)
  - while size is possibly useful, breaks protocol
  - anthony wants a self-descriptive protocol if we break (like ASN.1)
  - but all moot until everything is converted to vmstate
  - need to consider specifying a new protocol

KVM/qemu patches
- patch rate is high, documentation is low, review is low
- patches need to include better descriptions and documentation
  - will slow down patch writers
  - will make it easier for patch reviewers

QMP
- spec review 
- migration events
  - introduce migration connected event
  - migration completed/done event (more contentious)
    - no data, just indication that it's done
    - run query migrate to get status
    - 0.14 proper async
- (-rc is coming next Monday)
- important to start simple, fix as go...
- no good indication of completion in general across monitor
  - includes feedback from guest (pci remove device, shutdown, balloon, etc...)
- async is the consistent issue
- libvirt should not use QMP in 0.13
- need to declare QMP Unstable 0.13  (still need spec review)