[Libguestfs] [V2V PATCH 0/5] Bring support for virtio-scsi back to Windows

[Richard W.M. Jones]

On Thu, Mar 02, 2023 at 08:52:33PM +0200, Andrey Drobyshev wrote:
> On 3/2/23 20:36, Richard W.M. Jones wrote:
> > I can probably do an outline of a patch if you need it, but
> > not today.
> 
> Yes, sure.  But speaking of the ways to influence the behaviour of a
> command line tool: there're also env variables, which are being used by
> v2v as well (for instance, for setting the tools ISO location).  So what
> if we introduce an env variable here instead?  I presume it would be
> much easier to implement.  Smth like:

The environment variable is a bit of a mistake too.  It'd be better to
specify that through the command line; and in fact that's what I went
with for the new virt-customize --inject-virtio-win option:

       --inject-virtio-win METHOD
           Inject virtio-win drivers into a Windows guest.  These drivers add
           virtio accelerated drivers suitable when running on top of a
           hypervisor that supports virtio (such as qemu/KVM).  The operation
           also adjusts the Windows Registry so that the drivers are installed
           when the guest boots.

           The parameter can be one of:

           ISO The path to the ISO image containing the virtio-win drivers
               (eg. /usr/share/virtio-win/virtio-win.iso).
   [etc]

> > diff --git a/mlcustomize/inject_virtio_win.ml b/mlcustomize/inject_virtio_win.ml
> > index 62f7710..562f055 100644
> > --- a/mlcustomize/inject_virtio_win.ml
> > +++ b/mlcustomize/inject_virtio_win.ml
> > @@ -177,6 +177,11 @@ let rec inject_virtio_win_drivers ({ g } as t) reg =
> >      (* Can we install the block driver? *)
> >      let block : block_type =
> >        let filenames = ["virtio_blk"; "vrtioblk"; "viostor"] in
> > +      let viostor_drv_env = Sys.getenv_opt "VIOSTOR_DRIVER" in
> > +      let filenames =
> > +        match viostor_drv_env with
> > +        | None -> filenames
> > +        | Some str -> str :: filenames in
> >        let viostor_driver = try (
> >          Some (
> >            List.find (
> 
> As you can see here the default doesn't change if the variable isn't
> provided at all (or it is, but is set to a non-existing driver).
> What do you think of such a solution?

I prefer the command line option even though it's a little bit more
work.  Offer above still stands if you can't work out the complexities
of OCaml command line parsing.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
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