QEMU is gaining introspectable statistics which can be queried via the
"query-stats" QMP command. This patchset aims to add an API for the
same.
The returned JSON for "query-stats" is an array of objects containing
their own respective array of statistics.
Patch 1 adds the API for "query-stats" and a function to deserialize the
returned objects into respective hashtables.
Patch 2 adds the "query-stats" to QEMU capabilities.
Patch 3 uses the API to query the halt poll success time and the halt
poll failure time.
v3 -> v4
========
Some changes based on past reviews by Mr. Martin and me
[1/3]:
-
- clean up qemuMonitorQueryStatsProviderNew.
- make relevant checks/changes to support the change above.
- do NOT return the GPtrArray, instead just return the json object.
(this helps retain the non-stat info returned which will be
useful in the future patches).
- add a function which deserializes value associated with the "stats"
key in the JSON object (one of the objects returned in the JSON
array above) into a GHashTable.
[2/3]:
- add a flag to for the capability in tests.
[3/3]:
- use a helper function to make things cleaner.
v2 -> v3
========
Sorry for the late patchset, I was under the impression I had sent it on
Monday but apparently, I did not.
[1/3]:
- use a single enum for all the statistics.
- use QEMU_MONITOR_QUERY_STATS_NAME_LAST as the sentinel value for the
provider constructor.
- relevant changes to enum values.
[2/3]:
- fix comment spacing
[3/3]
- better checks
v1 -> v2
========
I have been tinkering with the v1 patchset and have rewrote the v2
patches a couple of times. I believe the current patchset is still not
perfect and would appreciate some reviews.
I have another patch or two written but they do not make any significant
changes to the current patchset.
[1/3]:
- use virBitmap instead of an array of strings for statistics.
- add enums for the stat names and add
qemuMonitorQueryStatsNameTypeToString to switch between the
"ToString" functions based on the target type.
- change qemuMonitorQueryStatsProviderNew to a variadic function that
takes stat enum values with the sentinel value being -1.
[2/3]:
- No changes
[3/3]:
- Add relevant monitor related checks to check if the domain is
active.
- Acquire and release qemuMonitorObj lock before and after calling
qemuMonitorQueryStats respectively.
- Add the check for privileged access.
Relevant QEMU patches can be found here:
https://lore.kernel.org/all/20220530150714.756954-1-pbonzini@xxxxxxxxxx/
This patchset is part of the 2022 GSOC contributor project.
Amneesh Singh (3):
qemu_monitor: add qemuMonitorQueryStats
qemu_capabilities: add "query-stats" QMP command to the QEMU
capabilities
qemu_driver: use qemuMonitorQueryStats to extract halt poll time
src/qemu/qemu_capabilities.c | 4 +
src/qemu/qemu_capabilities.h | 3 +
src/qemu/qemu_driver.c | 81 +++++++++++-
src/qemu/qemu_monitor.c | 117 ++++++++++++++++++
src/qemu/qemu_monitor.h | 48 +++++++
src/qemu/qemu_monitor_json.c | 91 ++++++++++++++
src/qemu/qemu_monitor_json.h | 6 +
.../caps_7.1.0.x86_64.xml | 1 +
8 files changed, 345 insertions(+), 6 deletions(-)
--
2.37.1
