[libvirt] [PATCH 2/2] tests: Document procedure to build QEMU for *.replies generation

[Cole Robinson]

On 1/23/19 3:59 PM, John Ferlan wrote:
> Add some comments to describe how to set up the QEMU environment
> prior to running the qemucapsprobe in order to allow for the
> creation of consistent results.
> 
> Signed-off-by: John Ferlan <jferlan at redhat.com>
> ---
>  tests/qemucapabilitiestest.c | 34 ++++++++++++++++++++++++++++++++--
>  1 file changed, 32 insertions(+), 2 deletions(-)
> 
> diff --git a/tests/qemucapabilitiestest.c b/tests/qemucapabilitiestest.c
> index 00137bb415..2b6291e99e 100644
> --- a/tests/qemucapabilitiestest.c
> +++ b/tests/qemucapabilitiestest.c
> @@ -200,11 +200,41 @@ mymain(void)
>      DO_TEST("riscv64", "caps_3.0.0");
>  
>      /*
> +     * Create a QEMU build environment using a checked out version
> +     * of the release tag, such as:
> +     *
> +     *    git checkout -b v3.0.0 v3.0.0
> +     *
> +     * Be sure the build dependencies are up to date, such as via yum:
> +     *
> +     *    yum builddep qemu
> +     *
> +     * Configure the environment, such as for x86_64:
> +     *
> +     *   ./configure --target-list=x86_64-softmmu \
> +     *      --disable-xen --disable-strip --disable-fdt \
> +     *      --disable-werror --enable-debug \
> +     *      --enable-system --enable-user --enable-linux-user \
> +     *      --with-pkgversion=v3.0.0
> +     *

AFAICT --enable-system/--enable-user/--enable-linux-user are all
redundant if a manual --target-list is specified. I don't know why
--disable-fdt matters, nor --enable-debug or --disable-strip. I figure
less options the better, defaults should be fine

> +     * Build the QEMU emulator binary.
> +     *
> +     * Then from a clean libvirt build:
> +     *
>       * Run "tests/qemucapsprobe /path/to/qemu/binary >foo.replies"
> -     * to generate updated or new *.replies data files.
> +     * to generate updated or new *.replies data files, such as:
> +     *
> +     *    tests/qemucapsprobe /path/to/qemu/binary > \
> +     *          tests/qemucapabilitiesdata/caps_3.0.0.x86_64.replies
>       *
> -     * If you manually edit replies files you can run
> +     * If you needed to manually edit replies files you can run
>       * "tests/qemucapsfixreplies foo.replies" to fix the replies ids.
> +     *
> +     * Run "VIR_TEST_REGENERATE_OUTPUT=1 tests/qemucapabilitiestest" to
> +     * update the corresponding tests/qemucapabilitiesdata/caps_*.xml file.
> +     *
> +     * May also need to run "VIR_TEST_REGENERATE_OUTPUT=1 tests/domaincapstest"
> +     * depending on what changed.
>       */
>  

If we are getting this detailed, maybe also mention extending
qemucaps2xmltest.c and qemucapabilitiestest.c for newly added
capabilities files. Up to you

Reviewed-by: Cole Robinson <crobinso at redhat.com>

- Cole