Re: [kvm-unit-tests RFC PATCH 3/5] run_tests.sh: Add kvmtool support

Andrew Jones
2021-09-09T13:00:31Z

On Thu, Sep 09, 2021 at 12:33:11PM +0100, Alexandru Elisei wrote:
> Hi Drew,
>
> On 9/8/21 4:49 PM, Andrew Jones wrote:
> > On Wed, Sep 08, 2021 at 04:46:19PM +0100, Alexandru Elisei wrote:
> >> Hi Drew,
> >>
> >> On 9/8/21 4:09 PM, Andrew Jones wrote:
> >>> On Wed, Sep 08, 2021 at 03:33:19PM +0100, Alexandru Elisei wrote:
> >>> ...
> >>>>>> +fixup_kvmtool_opts()
> >>>>>> +{
> >>>>>> + local opts=$1
> >>>>>> + local groups=$2
> >>>>>> + local gic
> >>>>>> + local gic_version
> >>>>>> +
> >>>>>> + if find_word "pmu" $groups; then
> >>>>>> + opts+=" --pmu"
> >>>>>> + fi
> >>>>>> +
> >>>>>> + if find_word "its" $groups; then
> >>>>>> + gic_version=3
> >>>>>> + gic="gicv3-its"
> >>>>>> + elif [[ "$opts" =~ -machine\ *gic-version=(2|3) ]]; then
> >>>>>> + gic_version="${BASH_REMATCH[1]}"
> >>>>>> + gic="gicv$gic_version"
> >>>>>> + fi
> >>>>>> +
> >>>>>> + if [ -n "$gic" ]; then
> >>>>>> + opts=${opts/-machine gic-version=$gic_version/}
> >>>>>> + opts+=" --irqchip=$gic"
> >>>>>> + fi
> >>>>>> +
> >>>>>> + opts=${opts/-append/--params}
> >>>>>> +
> >>>>>> + echo "$opts"
> >>>>>> +}
> >>>>> Hmm, I don't think we want to write a QEMU parameter translator for
> >>>>> all other VMMs, and all other VMM architectures, that we want to
> >>>>> support. I think we should add new "extra_params" variables to the
> >>>>> unittest configuration instead, e.g. "kvmtool_params", where the
> >>>>> extra parameters can be listed correctly and explicitly. While at
> >>>>> it, I would create an alias for "extra_params", which would be
> >>>>> "qemu_params" allowing unittests that support more than one VMM
> >>>>> to clearly show what's what.
> >>>> I agree, this is a much better idea than a parameter translator. Using a dedicated
> >>>> variable in unittests.cfg will make it easier for new tests to get support for all
> >>>> VMMs (for example, writing a list of parameters in unittests.cfg should be easier
> >>>> than digging through the scripts to figure exactly how and where to add a
> >>>> translation for a new parameter), and it allow us to express parameters for other
> >>>> VMMs which don't have a direct correspondent in qemu.
> >>>>
> >>>> By creating an alias, do you mean replacing extra_params with qemu_params in
> >>>> arm/unittests.cfg? Or something else?
> >>> Probably something like this
> >>>
> >>> diff --git a/scripts/common.bash b/scripts/common.bash
> >>> index 7b983f7d6dd6..e5119ff216e5 100644
> >>> --- a/scripts/common.bash
> >>> +++ b/scripts/common.bash
> >>> @@ -37,7 +37,12 @@ function for_each_unittest()
> >>> elif [[ $line =~ ^smp\ *=\ *(.*)$ ]]; then
> >>> smp=${BASH_REMATCH[1]}
> >>> elif [[ $line =~ ^extra_params\ *=\ *(.*)$ ]]; then
> >>> - opts=${BASH_REMATCH[1]}
> >>> + elif [[ $line =~ ^extra_params\ *=\ *(.*)$ ]]; then
> >>> + qemu_opts=${BASH_REMATCH[1]}
> >>> + elif [[ $line =~ ^qemu_params\ *=\ *(.*)$ ]]; then
> >>> + qemu_opts=${BASH_REMATCH[1]}
> >>> + elif [[ $line =~ ^kvmtool_params\ *=\ *(.*)$ ]]; then
> >>> + kvmtool_opts=${BASH_REMATCH[1]}
> >>> elif [[ $line =~ ^groups\ *=\ *(.*)$ ]]; then
> >>> groups=${BASH_REMATCH[1]}
> >>> elif [[ $line =~ ^arch\ *=\ *(.*)$ ]]; then
> >>>
> >>> and all other changes needed to support the s/opts/qemu_opts/ change
> >>> should work. Also, an addition to the unittests.cfg documentation.
> >> Got it, replace extra_opts with qemu_opts in the scripts.
> >>
> >> Yes, the documentation for unittests.cfg (at the top of the file) should
> >> definitely be updated to document the new configuration option, kvmtool_params.
> >>
> >>> The above diff doesn't consider that a unittests.cfg file could have
> >>> both an 'extra_params' and a 'qemu_params' field, but I'm not sure
> >>> we care about that. Users should read the documentation and we
> >>> should review changes to the committed unittests.cfg files to avoid
> >>> that.
> >> What do you feel about renaming extra_params -> qemu_params in unittests.cfg?
> > Yes, that's what I would expect the patch to do.
> >
> >> I'm
> >> thinking it would make the usage clearer, improve consistency (we would have
> >> qemu_params and kvmtool_params, instead of extra_params and kvmtool_params), and
> >> remove any confusions regarding when they are used (I can see someone thinking
> >> that extra_params are used all the time, and are appended to kvmtool_params when
> >> --target=kvmtool). On the other hand, this could be problematic for people using
> >> out-of-tree scripts that parse the unittest.cfg file for whatever reason (are
> >> there people that do that?).
> > I'm not as worried about that as about people using out-of-tree
> > unittests.cfg files that will break when the 'extra_params' field
> > disappears. That's why I suggested to make 'extra_params' an alias.
>
> I'm sorry, but I'm still having trouble parsing what alias means in this context.
> Do you mean keep extra_params for current tests, encourage qemu_params for new
> tests, document that they mean the same thing and going forward qemu_params should
> be used?

Exactly, which just amounts to keeping the parsing line

elif [[ $line =~ ^extra_params\ *=\ *(.*)$ ]]; then
qemu_opts=${BASH_REMATCH[1]}

and some documentation changes.

Thanks,
drew

>
> Thanks,
>
> Alex
>
> >
> > Thanks,
> > drew
> >
> >> Thanks,
> >>
> >> Alex
> >>
> >>> Thanks,
> >>> drew
> >>>
>