docs: clarify --without-default-devices

--without-default-devices is a specialized option that should only be used
when configs/devices/ is changed manually.

Explain the model towards which we should tend, with respect to failures
to start guests and to run "make check".

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2023-05-03 19:30:40 +02:00
parent 166b174188
commit 23b2a3be99

View file

@ -282,9 +282,19 @@ want to change some lines in the first group, for example like this::
CONFIG_PCI_DEVICES=y CONFIG_PCI_DEVICES=y
#CONFIG_TEST_DEVICES=n #CONFIG_TEST_DEVICES=n
and/or pick a subset of the devices in those device groups. Right now and/or pick a subset of the devices in those device groups. Without
there is no single place that lists all the optional devices for further modifications to ``configs/devices/``, a system emulator built
``CONFIG_PCI_DEVICES`` and ``CONFIG_TEST_DEVICES``. In the future, without default devices might not do much more than start an empty
machine, and even then only if ``--nodefaults`` is specified on the
command line. Starting a VM *without* ``--nodefaults`` is allowed to
fail, but should never abort. Failures in ``make check`` with
``--without-default-devices`` are considered bugs in the test code:
the tests should either use ``--nodefaults``, and should be skipped
if a necessary device is not present in the build. Such failures
should not be worked around with ``select`` directives.
Right now there is no single place that lists all the optional devices
for ``CONFIG_PCI_DEVICES`` and ``CONFIG_TEST_DEVICES``. In the future,
we expect that ``.mak`` files will be automatically generated, so that we expect that ``.mak`` files will be automatically generated, so that
they will include all these symbols and some help text on what they do. they will include all these symbols and some help text on what they do.