Revert "tests: Use separate virtual environment for avocado"

This reverts commit e8e4298feadae7924cf7600bb3bcc5b0a8d7cbe9.

ensuregroup allows to specify both the acceptable versions of avocado,
and a locked version to be used when avocado is not installed as a system
pacakge.  This lets us install avocado in pyvenv/ using "mkvenv.py" and
reuse the distro package on Fedora and CentOS Stream (the only distros
where it's available).

ensuregroup's usage of "(>=..., <=...)" constraints when evaluating
the distro package, and "==" constraints when installing it from PyPI,
makes it possible to avoid conflicts between the known-good version and
a package plugins included in the distro.

This is because package plugins have "==" constraints on the version
that is included in the distro, and, using "pip install avocado==88.1"
on a venv that includes system packages will result in an error:

   avocado-framework-plugin-varianter-yaml-to-mux 98.0 requires avocado-framework==98.0, but you have avocado-framework 88.1 which is incompatible.
   avocado-framework-plugin-result-html 98.0 requires avocado-framework==98.0, but you have avocado-framework 88.1 which is incompatible.

But at the same time, if the venv does not include a system distribution
of avocado then we can install a known-good version and stick to LTS
releases.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1663
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

10 files changed, 37 insertions, 42 deletions

diff --git a/.gitlab-ci.d/buildtest.yml b/.gitlab-ci.d/buildtest.yml
index 77dc83a6be..aee9101507 100644
--- a/.gitlab-ci.d/buildtest.yml
+++ b/.gitlab-ci.d/buildtest.yml
@@ -103,7 +103,7 @@ crash-test-debian:
   script:
     - cd build
     - make NINJA=":" check-venv
-    - tests/venv/bin/python3 scripts/device-crash-test -q --tcg-only ./qemu-system-i386
+    - pyvenv/bin/python3 scripts/device-crash-test -q --tcg-only ./qemu-system-i386
 
 build-system-fedora:
   extends:
@@ -146,8 +146,8 @@ crash-test-fedora:
   script:
     - cd build
     - make NINJA=":" check-venv
-    - tests/venv/bin/python3 scripts/device-crash-test -q ./qemu-system-ppc
-    - tests/venv/bin/python3 scripts/device-crash-test -q ./qemu-system-riscv32
+    - pyvenv/bin/python3 scripts/device-crash-test -q ./qemu-system-ppc
+    - pyvenv/bin/python3 scripts/device-crash-test -q ./qemu-system-riscv32
 
 build-system-centos:
   extends:
diff --git a/docs/devel/acpi-bits.rst b/docs/devel/acpi-bits.rst
index 22e2580200..9677b0098f 100644
--- a/docs/devel/acpi-bits.rst
+++ b/docs/devel/acpi-bits.rst
@@ -61,19 +61,19 @@ Under ``tests/avocado/`` as the root we have:
    ::
 
      $ make check-venv (needed only the first time to create the venv)
-     $ ./tests/venv/bin/avocado run -t acpi tests/avocado
+     $ ./pyvenv/bin/avocado run -t acpi tests/avocado
 
    The above will run all acpi avocado tests including this one.
    In order to run the individual tests, perform the following:
    ::
 
-     $ ./tests/venv/bin/avocado run tests/avocado/acpi-bits.py --tap -
+     $ ./pyvenv/bin/avocado run tests/avocado/acpi-bits.py --tap -
 
    The above will produce output in tap format. You can omit "--tap -" in the
    end and it will produce output like the following:
    ::
 
-      $ ./tests/venv/bin/avocado run tests/avocado/acpi-bits.py
+      $ ./pyvenv/bin/avocado run tests/avocado/acpi-bits.py
       Fetching asset from tests/avocado/acpi-bits.py:AcpiBitsTest.test_acpi_smbios_bits
       JOB ID     : eab225724da7b64c012c65705dc2fa14ab1defef
       JOB LOG    : /home/anisinha/avocado/job-results/job-2022-10-10T17.58-eab2257/job.log
diff --git a/docs/devel/testing.rst b/docs/devel/testing.rst
index b6ad21bed1..5d1fc0aa95 100644
--- a/docs/devel/testing.rst
+++ b/docs/devel/testing.rst
@@ -894,9 +894,9 @@ You can run the avocado tests simply by executing:
 
   make check-avocado
 
-This involves the automatic creation of Python virtual environment
-within the build tree (at ``tests/venv``) which will have all the
-right dependencies, and will save tests results also within the
+This involves the automatic installation, from PyPI, of all the
+necessary avocado-framework dependencies into the QEMU venv within the
+build tree (at ``./pyvenv``). Test results are also saved within the
 build tree (at ``tests/results``).
 
 Note: the build environment must be using a Python 3 stack, and have
@@ -953,7 +953,7 @@ may be invoked by running:
 
  .. code::
 
-  tests/venv/bin/avocado run $OPTION1 $OPTION2 tests/avocado/
+  pyvenv/bin/avocado run $OPTION1 $OPTION2 tests/avocado/
 
 Note that if ``make check-avocado`` was not executed before, it is
 possible to create the Python virtual environment with the dependencies
@@ -968,20 +968,20 @@ a test file. To run tests from a single file within the build tree, use:
 
  .. code::
 
-  tests/venv/bin/avocado run tests/avocado/$TESTFILE
+  pyvenv/bin/avocado run tests/avocado/$TESTFILE
 
 To run a single test within a test file, use:
 
  .. code::
 
-  tests/venv/bin/avocado run tests/avocado/$TESTFILE:$TESTCLASS.$TESTNAME
+  pyvenv/bin/avocado run tests/avocado/$TESTFILE:$TESTCLASS.$TESTNAME
 
 Valid test names are visible in the output from any previous execution
 of Avocado or ``make check-avocado``, and can also be queried using:
 
  .. code::
 
-  tests/venv/bin/avocado list tests/avocado
+  pyvenv/bin/avocado list tests/avocado
 
 Manual Installation
 ~~~~~~~~~~~~~~~~~~~
diff --git a/python/scripts/mkvenv.py b/python/scripts/mkvenv.py
index 02bcd9a8c9..4f2349fbb6 100644
--- a/python/scripts/mkvenv.py
+++ b/python/scripts/mkvenv.py
@@ -964,14 +964,11 @@ def _parse_groups(file: str) -> Dict[str, Dict[str, Any]]:
             "Python >=3.11 does not have tomllib... what have you done!?"
         )
 
-    try:
-        # Use loads() to support both tomli v1.2.x (Ubuntu 22.04,
-        # Debian bullseye-backports) and v2.0.x
-        with open(file, "r", encoding="ascii") as depfile:
-            contents = depfile.read()
-            return tomllib.loads(contents)  # type: ignore
-    except tomllib.TOMLDecodeError as exc:
-        raise Ouch(f"parsing {file} failed: {exc}") from exc
+    # Use loads() to support both tomli v1.2.x (Ubuntu 22.04,
+    # Debian bullseye-backports) and v2.0.x
+    with open(file, "r", encoding="ascii") as depfile:
+        contents = depfile.read()
+        return tomllib.loads(contents)  # type: ignore
 
 
 def ensure_group(
diff --git a/pythondeps.toml b/pythondeps.toml
index 6be31dba30..0a35ebcf9f 100644
--- a/pythondeps.toml
+++ b/pythondeps.toml
@@ -23,3 +23,10 @@ meson = { accepted = ">=0.63.0", installed = "0.63.3", canary = "meson" }
 [docs]
 sphinx = { accepted = ">=1.6", installed = "5.3.0", canary = "sphinx-build" }
 sphinx_rtd_theme = { accepted = ">=0.5", installed = "1.1.1" }
+
+[avocado]
+# Note that qemu.git/python/ is always implicitly installed.
+# Prefer an LTS version when updating the accepted versions of
+# avocado-framework, for example right now the limit is 92.x.
+avocado-framework = { accepted = "(>=88.1, <93.0)", installed = "88.1", canary = "avocado" }
+pycdlib = { accepted = ">=1.11.0" }
diff --git a/scripts/ci/org.centos/stream/8/x86_64/test-avocado b/scripts/ci/org.centos/stream/8/x86_64/test-avocado
index e0443fc8ae..73e7a1a312 100755
--- a/scripts/ci/org.centos/stream/8/x86_64/test-avocado
+++ b/scripts/ci/org.centos/stream/8/x86_64/test-avocado
@@ -4,7 +4,7 @@
 # KVM and x86_64, or tests that are generic enough to be valid for all
 # targets. Such a test list can be generated with:
 #
-# ./tests/venv/bin/avocado list --filter-by-tags-include-empty \
+# ./pyvenv/bin/avocado list --filter-by-tags-include-empty \
 #   --filter-by-tags-include-empty-key -t accel:kvm,arch:x86_64 \
 #   tests/avocado/
 #
@@ -22,7 +22,7 @@
 #   - tests/avocado/virtio_check_params.py:VirtioMaxSegSettingsCheck.test_machine_types
 #
 make get-vm-images
-./tests/venv/bin/avocado run \
+./pyvenv/bin/avocado run \
     --job-results-dir=tests/results/ \
     tests/avocado/boot_linux.py:BootLinuxX8664.test_pc_i440fx_kvm \
     tests/avocado/boot_linux.py:BootLinuxX8664.test_pc_q35_kvm \
diff --git a/scripts/device-crash-test b/scripts/device-crash-test
index b74d887331..353aa575d7 100755
--- a/scripts/device-crash-test
+++ b/scripts/device-crash-test
@@ -43,7 +43,7 @@ except ModuleNotFoundError as exc:
     print(f"Module '{exc.name}' not found.")
     print("  Try 'make check-venv' from your build directory,")
     print("  and then one way to run this script is like so:")
-    print(f'  > $builddir/tests/venv/bin/python3 "{path}"')
+    print(f'  > $builddir/pyvenv/bin/python3 "{path}"')
     sys.exit(1)
 
 logger = logging.getLogger('device-crash-test')
diff --git a/tests/Makefile.include b/tests/Makefile.include
index 9422ddaece..985cda7a94 100644
--- a/tests/Makefile.include
+++ b/tests/Makefile.include
@@ -89,10 +89,8 @@ distclean-tcg: $(DISTCLEAN_TCG_TARGET_RULES)
 # Build up our target list from the filtered list of ninja targets
 TARGETS=$(patsubst libqemu-%.fa, %, $(filter libqemu-%.fa, $(ninja-targets)))
 
-TESTS_VENV_DIR=$(BUILD_DIR)/tests/venv
-TESTS_VENV_REQ=$(SRC_PATH)/tests/requirements.txt
+TESTS_VENV_TOKEN=$(BUILD_DIR)/pyvenv/tests.group
 TESTS_RESULTS_DIR=$(BUILD_DIR)/tests/results
-TESTS_PYTHON=$(TESTS_VENV_DIR)/bin/python3
 ifndef AVOCADO_TESTS
 	AVOCADO_TESTS=tests/avocado
 endif
@@ -108,20 +106,19 @@ else
 endif
 
 quiet-venv-pip = $(quiet-@)$(call quiet-command-run, \
-    $(TESTS_PYTHON) -m pip -q --disable-pip-version-check $1, \
+    $(PYTHON) -m pip -q --disable-pip-version-check $1, \
     "VENVPIP","$1")
 
-$(TESTS_VENV_DIR): $(TESTS_VENV_REQ)
-	$(call quiet-command, $(PYTHON) -m venv $@, VENV, $@)
+$(TESTS_VENV_TOKEN): $(SRC_PATH)/pythondeps.toml
 	$(call quiet-venv-pip,install -e "$(SRC_PATH)/python/")
-	$(call quiet-venv-pip,install -r $(TESTS_VENV_REQ))
+	$(PYTHON) python/scripts/mkvenv.py ensuregroup --online $< avocado
 	$(call quiet-command, touch $@)
 
 $(TESTS_RESULTS_DIR):
 	$(call quiet-command, mkdir -p $@, \
             MKDIR, $@)
 
-check-venv: $(TESTS_VENV_DIR)
+check-venv: $(TESTS_VENV_TOKEN)
 
 FEDORA_31_ARCHES_TARGETS=$(patsubst %-softmmu,%, $(filter %-softmmu,$(TARGETS)))
 FEDORA_31_ARCHES_CANDIDATES=$(patsubst ppc64,ppc64le,$(FEDORA_31_ARCHES_TARGETS))
@@ -131,7 +128,7 @@ FEDORA_31_DOWNLOAD=$(filter $(FEDORA_31_ARCHES),$(FEDORA_31_ARCHES_CANDIDATES))
 # download one specific Fedora 31 image
 get-vm-image-fedora-31-%: check-venv
 	$(call quiet-command, \
-             $(TESTS_PYTHON) -m avocado vmimage get \
+             $(PYTHON) -m avocado vmimage get \
              --distro=fedora --distro-version=31 --arch=$*, \
 	"AVOCADO", "Downloading avocado tests VM image for $*")
 
@@ -140,7 +137,7 @@ get-vm-images: check-venv $(patsubst %,get-vm-image-fedora-31-%, $(FEDORA_31_DOW
 
 check-avocado: check-venv $(TESTS_RESULTS_DIR) get-vm-images
 	$(call quiet-command, \
-            $(TESTS_PYTHON) -m avocado \
+            $(PYTHON) -m avocado \
             --show=$(AVOCADO_SHOW) run --job-results-dir=$(TESTS_RESULTS_DIR) \
             $(if $(AVOCADO_TAGS),, --filter-by-tags-include-empty \
 			--filter-by-tags-include-empty-key) \
@@ -163,7 +160,7 @@ check:
 check-build: run-ninja
 
 check-clean:
-	rm -rf $(TESTS_VENV_DIR) $(TESTS_RESULTS_DIR)
+	rm -rf $(TESTS_RESULTS_DIR)
 
 clean: check-clean clean-tcg
 distclean: distclean-tcg
diff --git a/tests/requirements.txt b/tests/requirements.txt
deleted file mode 100644
index 0ba561b6bd..0000000000
--- a/tests/requirements.txt
+++ /dev/null
@@ -1,6 +0,0 @@
-# Add Python module requirements, one per line, to be installed
-# in the tests/venv Python virtual environment. For more info,
-# refer to: https://pip.pypa.io/en/stable/user_guide/#id1
-# Note that qemu.git/python/ is always implicitly installed.
-avocado-framework==88.1
-pycdlib==1.11.0
diff --git a/tests/vm/Makefile.include b/tests/vm/Makefile.include
index c2a8ca1c17..f0f5d32fb0 100644
--- a/tests/vm/Makefile.include
+++ b/tests/vm/Makefile.include
@@ -5,7 +5,7 @@ ifeq ($(realpath $(SRC_PATH)),$(realpath .))
 VM_PYTHON = PYTHONPATH=$(SRC_PATH)/python /usr/bin/env python3
 VM_VENV =
 else
-VM_PYTHON = $(TESTS_PYTHON)
+VM_PYTHON = $(PYTHON)
 VM_VENV = check-venv
 endif