[libvirt] [PATCHv4 0/8] bulk stats: QEMU implementation

[Francesco Romani]

This patchset enhances the QEMU support
for the new bulk stats API to include
equivalents of these APIs:

virDomainBlockInfo
virDomainGetInfo - for balloon stats
virDomainGetCPUStats
virDomainBlockStatsFlags
virDomainInterfaceStats
virDomainGetVcpusFlags
virDomainGetVcpus

This subset of API is the one oVirt relies on.
Scale/stress test on an oVirt test environment is in progress.

The patchset is organized as follows:
- the first patch enhances the internal stats gathering API
  to accomodate the needs of the groups which extract information
  using QEMU monitor jobs.
- the next five patches implement the bulk stats groups, extracting
  helpers where do refactoring to extract internal helpers every time
  it is feasible and convenient.
- the seventh patch enhances the virsh domstats command with options
  to use the new bulk stats.
- the last patch enhances the block stats group adding the wr_highest_offset
  information, needed by oVirt for thin provisioned disks.

ChangeLog

v4: fixes and cleanups
- addressed reviewers comments (Peter, Wang Rui).
- pushed domain check into group stats functions. This follows
  the strategy to gather and report as much data as possible,
  silently skipping errors along the way.
- moved the block allocation patch to the end of the series.

v3: more polishing and fixes after first review
- addressed Eric's comments.
- squashed patches which extracts helpers with patches which
  use them.
- changed gathering strategy: now code tries to reap as much
  information as possible instead to give up and bail out with
  error. Only critical errors cause the bulk stats to fail.
- moved away from the transfer semantics. I find it error-prone
  and not flexible enough, I'd like to avoid as much as possible.
- rearranged helpers to have one single QEMU query job with
  many monitor jobs nested inside.
- fixed docs.
- implemented missing virsh domstats bits.

in v2: polishing and optimizations.
- incorporated feedback from Li Wei (thanks).
- added documentation.
- optimized block group to gather all the information with just
  one call to QEMU monitor.
- stripped to bare bones merged the 'block info' group into the
  'block' group - oVirt actually needs just one stat from there.
- reorganized the keys to be more consistent and shorter.


Francesco Romani (8):
  qemu: bulk stats: extend internal collection API
  qemu: bulk stats: implement CPU stats group
  qemu: bulk stats: implement balloon group
  qemu: bulk stats: implement VCPU group
  qemu: bulk stats: implement interface group
  qemu: bulk stats: implement block group
  virsh: add options to query bulk stats group
  qemu: bulk stats: add block allocation information

 include/libvirt/libvirt.h.in |   5 +
 src/libvirt.c                |  61 +++++
 src/qemu/qemu_driver.c       | 575 +++++++++++++++++++++++++++++++++++++------
 src/qemu/qemu_monitor.c      |  26 ++
 src/qemu/qemu_monitor.h      |  21 ++
 src/qemu/qemu_monitor_json.c | 227 ++++++++++++-----
 src/qemu/qemu_monitor_json.h |   4 +
 tools/virsh-domain-monitor.c |  35 +++
 tools/virsh.pod              |   4 +-
 9 files changed, 822 insertions(+), 136 deletions(-)

-- 
1.9.3