Re: [PATCH] acpi/tests/bios-tables-test: add an environment variable for iasl location

["Alex Bennée" <alex.bennee@linaro.org>]

"Michael S. Tsirkin" <mst@redhat.com> writes:

> On Wed, May 17, 2023 at 04:16:47PM +0100, Alex Bennée wrote:
>> 
>> Ani Sinha <anisinha@redhat.com> writes:
>> 
>> >> On 17-May-2023, at 8:06 PM, Michael S. Tsirkin <mst@redhat.com> wrote:
>> >> 
>> >> On Wed, May 17, 2023 at 07:57:53PM +0530, Ani Sinha wrote:
>> >>> 
>> >>> 
>> >>>> On 17-May-2023, at 7:47 PM, Michael S. Tsirkin <mst@redhat.com> wrote:
>> >>>> 
>> >>>> On Wed, May 17, 2023 at 05:37:51PM +0530, Ani Sinha wrote:
>> >>>>> Currently the meson based QEMU build process locates the iasl binary from the
>> >>>>> current PATH and other locations [1] and uses that to set CONFIG_IASL which is
>> >>>>> then used by the test.
>> >>>>> 
>> >>>>> This has two disadvantages:
>> >>>>> - If iasl was not previously installed in the PATH, one has to install iasl
>> >>>>>  and rebuild QEMU in order to pick up the iasl location. One cannot simply
>> >>>>>  use the existing bios-tables-test binary because CONFIG_IASL is only set
>> >>>>>  during the QEMU build time by meson and then bios-tables-test has to be
>> >>>>>  rebuilt with CONFIG_IASL set in order to use iasl.
>> 
>> Usually we work the other way by checking at configure time and skipping
>> the feature if the prerequisites are not in place. We do this with gdb:
>> 
>>   ../../configure --gdb=/home/alex/src/tools/binutils-gdb.git/builds/all/install/bin/gdb
>> 
>> which checks gdb is at least new enough to support the features we need:
>> 
>>   if test -n "$gdb_bin"; then
>>       gdb_version=$($gdb_bin --version | head -n 1)
>>       if version_ge ${gdb_version##* } 9.1; then
>>           echo "HAVE_GDB_BIN=$gdb_bin" >> $config_host_mak
>>           gdb_arches=$("$source_path/scripts/probe-gdb-support.py" $gdb_bin)
>>       else
>>           gdb_bin=""
>>       fi
>>   fi
>> 
>> >>>>> - Sometimes, the stock iasl that comes with distributions is simply not good
>> >>>>>  enough because it does not support the latest ACPI changes - newly
>> >>>>>  introduced tables or new table attributes etc. In order to test ACPI code
>> >>>>>  in QEMU, one has to clone the latest acpica upstream repository and
>> >>>>>  rebuild iasl in order to get support for it. In those cases, one may want
>> >>>>>  the test to use the iasl binary from a non-standard location.
>> 
>> I think configure should be checking if iasl is new enough and reporting
>> to the user at configure time they need to do something different. We
>> don't want to attempt to run tests that will fail unless the user has
>> added the right magic to their environment.
>
> iasl is a disassembler we trigger for user convenience in case tests
> fail. It will never cause tests to fail.

Fair enough. But I still think the place to report it is in configure.
Maybe something like:

    iasl                         : /usr/bin/iasl (version 20200925, might not handle all ACPI)           

in the Host Binaries section. Re-configuring shouldn't cause too much of
the build to be regenerated although we could certainly do better in
this regard.

-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro