Merge remote-tracking branch 'remotes/philmd/tags/integration-testing-20210927' into...

Merge remote-tracking branch 'remotes/philmd/tags/integration-testing-20210927' into staging

Integration testing patches

- More Linux kernel record/replay tests (Pavel Dovgalyuk)
- Various fixes (Willian Rampazzo, Cleber Rosa)
- Split machine_ppc.py per machine (David Gibson)
- Add AVOCADO_TESTS command line environment variable (Willian Rampazzo)
- Test PowerPC PowerNV 8/9 machines (Cédric Le Goater)

# gpg: Signature made Mon 27 Sep 2021 18:24:03 BST
# gpg:                using RSA key FAABE75E12917221DCFD6BB2E3E32C2CDEADC0DE
# gpg: Good signature from "Philippe Mathieu-Daudé (F4BUG) <f4bug@amsat.org>" [full]
# Primary key fingerprint: FAAB E75E 1291 7221 DCFD  6BB2 E3E3 2C2C DEAD C0DE

* remotes/philmd/tags/integration-testing-20210927: (22 commits)
  tests/acceptance: Test powernv machines
  tests/acceptance/ppc_prep_40p.py: clean up unused import
  tests/acceptance/ppc_prep_40p.py: NetBSD 7.1.2 location update
  tests/acceptance/boot_xen.py: removed unused import
  acceptance/tests/vnc.py: use explicit syntax for enabling passwords
  Acceptance Tests: improve check-acceptance description
  qemu: Split machine_ppc.py acceptance tests
  tests/Makefile: add AVOCADO_TESTS option to make check-acceptance
  docs/devel/testing: add instruction to run a single acceptance test
  tests/Makefile: allow control over tags during check-acceptance
  avocado_qemu: fix inheritance order on LinuxTest class
  avocado_qemu: explicitly return None to avoid R1710
  avocado_qemu: tweak ssh connect method
  avocado_qemu: fix import module based on isort
  avocado_qemu: standardize super() call following PEP3135
  Acceptance Tests: add standard clean up at test tearDown()
  Acceptance tests: add myself as a reviewer for the acceptance tests
  tests/acceptance: Linux boot test for record/replay
  tests/acceptance: add replay kernel test for alpha
  tests/acceptance: add replay kernel test for nios2
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>