[PATCH v2 00/10] Improve reliability of VM tests

[John Snow]

This patch series attempts to improve the reliability of several of the
VM test targets. In particular, both CentOS 8 tests are non-functional
because CentOS 8 was EOL at the beginning of this calendar year, with
repositories and mirrors going offline.

Notably, I also remove the ubuntu.i386 test because we no longer support
Ubuntu 18.04 nor do we have explicit need of an i386 build test.

After this series, I am able to successfully run every VM target on an
x86_64 host, except:

- ubuntu.aarch64: Hangs often during testing, see below.
- centos.aarch64: Hangs often during testing, see below.
- haiku.x86_64: Build failures not addressed by this series, see
  https://lists.gnu.org/archive/html/qemu-devel/2022-06/msg02103.html

The unit tests that I see fail most often are:

- qom-test: ENOMEM with default config and many cores
- test-hmp: ENOMEM with default config and many cores
- virtio-net-failover: Seems to like to hang on openbsd
- migration-test: Tends to hang under aarch64 tcg

Increasing the default memory (patch 10) has seemingly helped both
reliability *and* reduced race conditions quite a bit, both on my
12-thread intel laptop and on my 32-thread AMD 5950x desktop.

Due to how long it takes to run these tests, though, I can't claim
perfect reliability. The flakiness of virtio-net-failover and
migration-test is something that probably still needs to be addressed,
but it's outside of my expertise and time budget at present to pursue
it.

Future work (next version? next series?);

- Try to get centos.aarch64 working reliably under TCG
- Upgrade ubuntu.aarch64 to 20.04 after fixing centos.aarch64
- Fix the Haiku build test, if possible.
- Ensure I can reliably run and pass "make vm-build-all".
  (Remove VMs from this recipe if necessary.)

John Snow (10):
  tests/qemu-iotests: hotfix for 307, 223 output
  tests/qemu-iotests: skip 108 when FUSE is not loaded
  qga: treat get-guest-fsinfo as "best effort"
  tests/vm: use 'cp' instead of 'ln' for temporary vm images
  tests/vm: switch CentOS 8 to CentOS 8 Stream
  tests/vm: switch centos.aarch64 to CentOS 8 Stream
  tests/vm: update sha256sum for ubuntu.aarch64
  tests/vm: remove ubuntu.i386 VM test
  tests/vm: remove duplicate 'centos' VM test
  tests/vm: add 512MB extra memory per core

 qga/commands-posix.c       |   8 +-
 tests/qemu-iotests/108     |   5 ++
 tests/qemu-iotests/223.out |   4 +-
 tests/qemu-iotests/307.out |   4 +-
 tests/vm/Makefile.include  |   5 +-
 tests/vm/basevm.py         |   6 ++
 tests/vm/centos            |   8 +-
 tests/vm/centos.aarch64    | 174 +++++--------------------------------
 tests/vm/ubuntu.aarch64    |   8 +-
 tests/vm/ubuntu.i386       |  40 ---------
 10 files changed, 58 insertions(+), 204 deletions(-)
 delete mode 100755 tests/vm/ubuntu.i386

-- 
2.34.3