Description of problem:
The static checker is merged usptream; backport it for 7.1.
This will be useful to get vmstate json output and check for migration compatibility between various versions of qemu.
qemu-kvm -dump-vmstate -M <machine type> -dump-vmstate <filename>
Later, from the qemu sources,
./scripts/vmstate-static-checker.py -s src.json -d dest.json
will output any migration-breaking changes introduced in dest.json as compared with src.json.
More info on invocation from upstream commit messages:
migration: dump vmstate info as a json file for static analysis
This commit adds a new command, '-dump-vmstate', that takes a filename
as an argument. When executed, QEMU will dump the vmstate information
for the machine type it's invoked with to the file, and quit.
The JSON-format output can then be used to compare the vmstate info for
different QEMU versions, specifically to test whether live migration
would break due to changes in the vmstate data.
A Python script that compares the output of such JSON dumps is included
in the following commit.
and the script:
vmstate-static-checker: script to validate vmstate changes
This script compares the vmstate dumps in JSON format as output by QEMU
with the -dump-vmstate option.
It flags various errors, like version mismatch, sections going away,
size mismatches, etc.
This script is tolerant of a few changes that do not change the on-wire
format, like embedding a few fields within substructs.
The script takes -s/--src and -d/--dest parameters, to which filenames
are given as arguments.
(in a qemu 2.0 tree):
./x86_64-softmmu/qemu-system-x86_64 -dump-vmstate qemu-2.0.json
(in a qemu 2.2 tree:)
./x86_64-softmmu/qemu-system-x86_64 -dump-vmstate -M pc-i440fx-2.0 \
./scripts/vmstate-static-checker.py -s qemu-2.0.json -d qemu-2.2-m2.0.json
The script also takes a --reverse parameter to switch the src and dest
jsons. This is just a shorthand for reversing the src and dest.
The --help parameter shows usage information.
Fix included in qemu-kvm-1.5.3-67.el7
Verified on qemu-kvm-rhev-2.1.2-3.el7.x86_64:
# /usr/libexec/qemu-kvm -M pc-q35-rhel7.1.0 -dump-vmstate pc-q35-rhel7.1.0
# cat pc-q35-rhel7.1.0 | head -n 20
Verified on qemu-kvm-1.5.3-75.el7.x86_64:
# /usr/libexec/qemu-kvm -M pc-q35-rhel7.0.0 -dump-vmstate pc-q35-rhel7.0.0
# cat pc-q35-rhel7.0.0 | head -n 20
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.