Re: [PATCH RFE] conf: Add extraArgs option to passt backend

On Wed, Jun 25, 2025 at 10:38 AM Pavel Hrdina <phrdina(a)redhat.com&gt; wrote: > > On Wed, Jun 25, 2025 at 09:40:16AM +0200, Enrique Llorente via Devel wrote: > > Add support for passing extra arguments to the passt binary through > > the domain XML configuration. This allows users to specify additional > > command-line arguments for passt that are not covered by existing > > structured fields. > > > > The new extraArgs attribute is added to the backend element: > > <backend type='passt' extraArgs='--debug --no-dhcp -v'/> > > > > The extraArgs string is parsed using g_shell_parse_argv() to split > > it into individual arguments before passing them to the passt command. > > > > This change includes: > > - New field in virDomainNetBackend structure > > - XML schema update to allow extraArgs attribute > > - Parsing and formatting support in domain_conf.c > > - Backend comparison function update > > - Memory cleanup for the new field > > - QEMU passt integration to use the extra arguments > > - Comprehensive tests for both user and vhostuser interfaces > > > > This is an RFE to gather feedback on the approach. I have a few questions > > for the community: > > > > 1. Is this general approach of adding extraArgs reasonable, or should we > > instead focus on adding specific structured fields for each passt option? > > No, this is not something we would add to VM XML. If there is something > missing from our XML it should be added as proper attribute and or > element. > > > 2. Should extraArgs be marked as unsupported/unstable in the documentation, > > with a clear indication that it's primarily intended for development and > > testing purposes? > > We do have similar "feature" for QEMU where you can pass any argument > you want for development/testing purposes, see [1]. > Should we implement this with a new new <passt:commandline> tag under the passt backend ?