This adds boot Linux tests for x86_64, aarch64, ppc64, s390x
targets which, unlike others, tell QEMU to use KVM. Likewise
it was added cases for tcg.

The patch 01 introduce an infraestructure on avocado_qemu framework
so that:
a) simply tagging the test with `accel:kvm` (or `accel:tcg`) will
   automatically set the corresponding '--accel' on the launched
   QEMU;
a) test is canceled if the accelerator is not enabled in QEMU
   binary and not present in the host.

Changes v1 -> v2:
- old patch 01 was removed becase the same feature is merged on
  commit 74b56bb55395.
- old patch 02 became 01 on v2, and with a major re-implementation. The
  bits that added the accel module is merged on commit 8b272e00186.
- old patch 03 was removed. Based on comments of ehabkost and crosa,
  instead the boot_linux_console test suite got new cases which uses
  the 'accel' tag to specify the use of kvm or tcg.
- Added patch 03 which refactor the handler of 'machine' tag that
  was introduced on commit ba21bde930f.

v1: [PATCH 0/3] Acceptance tests: boot Linux with KVM test
- https://www.mail-archive.com/qemu-devel@nongnu.org/msg627498.html

Tree:
- Git: https://github.com/wainersm/qemu
- Branch: acceptance_kvm_test-v2

CI:
- Travis (FAIL): https://travis-ci.org/wainersm/qemu/builds/626703965
  Not related with those change. Acceptance tests on Travis ran just
fine.

Wainer dos Santos Moschetta (3):
  tests/acceptance: avocado_qemu: Introduce the 'accel' test parameter
  tests/acceptance: boot_linux_console: Add boot Linux with kvm tests
  tests/acceptance: avocado_qemu: Refactor the handler of 'machine'
    parameter

 docs/devel/testing.rst                    | 16 +++++
 tests/acceptance/avocado_qemu/__init__.py | 27 ++++++-
 tests/acceptance/boot_linux_console.py    | 88 +++++++++++++++++------
 3 files changed, 109 insertions(+), 22 deletions(-)

-- 
2.23.0