Re: [PATCH] test: Update README.md

[Stefano Brivio <sbrivio@redhat.com>]

On Fri, 19 Sep 2025 09:43:29 +0800
Yumei Huang <yuhuang@redhat.com> wrote:

> Signed-off-by: Yumei Huang <yuhuang@redhat.com>
> ---
>  test/README.md | 31 +++++++++++++++++++++++++++++--
>  1 file changed, 29 insertions(+), 2 deletions(-)
> 
> diff --git a/test/README.md b/test/README.md
> index 91ca603..e3e9d37 100644
> --- a/test/README.md
> +++ b/test/README.md
> @@ -32,7 +32,7 @@ Example for Debian, and possibly most Debian-based distributions:
>      git go iperf3 isc-dhcp-common jq libgpgme-dev libseccomp-dev linux-cpupower
>      lm-sensors lz4 netavark netcat-openbsd psmisc qemu-efi-aarch64
>      qemu-system-arm qemu-system-misc qemu-system-ppc qemu-system-x86
> -    qemu-system-x86 sipcalc socat strace tmux uidmap valgrind
> +    sipcalc socat strace tmux uidmap valgrind
>  
>  NOTE: the tests need a qemu version >= 7.2, or one that contains commit
>  13c6be96618c ("net: stream: add unix socket"): this change introduces support
> @@ -81,7 +81,12 @@ The following additional packages are commonly needed:
>  
>  ## Regular test
>  
> -Just issue:
> +Before running the tests, you need to prepare the required assets:
> +
> +    cd test
> +    make assets
> +
> +Then issue:
>  
>      ./run
>  
> @@ -91,6 +96,28 @@ variable settings: DEBUG=1 enables debugging messages, TRACE=1 enables tracing
>  
>      PCAP=1 TRACE=1 ./run
>  
> +**Note:**
> +
> +* It's recommended to run the commands as a non-root user.
> +  Due to [Bug 967509](https://bugzilla.redhat.com/show_bug.cgi?id=967509),
> +  if you switch users with `su` or `sudo`, the directory `/run/user/ID` may
> +  not be created. In that case, `XDG_RUNTIME_DIR` will incorrectly point to
> +  `/run/user/0` instead of `/run/user/ID`, which can cause error.

Thanks for the research, I wasn't aware of that, and recently spent
quite some time figuring that out (for other reasons):

  https://issues.redhat.com/browse/RHEL-70222

in that case, XDG_RUNTIME_DIR was simply not set. Things were working
with 'machinectl shell' instead.

At the same time: running this whole stuff as root sounds rather crazy,
unless it's a throw-away VMs with absolutely nothing important on it.

That is, regardless of the issue with XDG_RUNTIME_DIR. I would maybe
make the wording stronger, something like:

* Don't run the tests as root, it's not needed!
* If you really need to, note that ...

> +  **Workaround:** Log out and log back in as the intended user to ensure the
> +  correct runtime directory is set up.

We could also suggest 'machinectl shell' if it's really needed for
whatever reason.

> +* SELinux may prevent the tests from running correctly. To avoid this,
> +  temporarily disable it by running:
> +
> +        setenforce 0

By the way, other than the DHCP client not working on Fedora in a
namespace (which we should really fix, I can look into it if you share
the messages you're getting from /var/log/audit/audit.log), did you hit
any other issue with it?

I haven't tried running tests on Fedora for a long time now.

> +* Some tests require a QEMU build that includes the following commits:
> +
> +        60f543ad917f ("virtio-net: vhost-user: Implement internal migration")
> +        3f65357313e0 ("vhost: Add stubs for the migration state transfer
> +        interface")

Given:

  $ git describe --contain 60f543ad917f 3f65357313e0
  v10.0.0-rc0~89^2~1
  v10.0.0-rc0~89^2~2

we might also save the reader from checking out a QEMU tree to check
and say something like "Some tests require a QEMU version >= 10.0.0, or
a build that includes ..."

> +
>  ## Running selected tests
>  
>  Rudimentary support to run a list of selected tests, without support for

The rest looks good to me and it's an improvement on the original
anyway so I'm fine applying as it is, as well, but those few
suggestions shouldn't take that long either.

-- 
Stefano