On Wed, Oct 28, 2026 at 08:33:30PM +0100, Tim Pambor wrote:
On Wed, Oct 28, 2026 at 7:44 PM Stefan Hajnoczi <[email protected]> wrote:
On Wed, Oct 28, 2026 at 02:23:55PM +0100, Stefano Garzarella wrote:
> On Wed, Oct 28, 2026 at 08:33:46AM -0400, Stefan Hajnoczi wrote:
> > On Wed, Oct 28, 2026 at 09:32:05AM +0100, Stefano Garzarella wrote:
> > > On Tue, Oct 27, 2026 at 03:24:45PM -0400, Stefan Hajnoczi wrote:
> > > > On Thu, Oct 22, 2026 at 03:47:26PM +0200, Tim Pambor wrote:
> > > > > diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
> > > > > index 6e05c995f1..788913953d 100644
> > > > > --- a/hw/net/vhost_net.c
> > > > > +++ b/hw/net/vhost_net.c
> > > > > @@ -33,7 +33,13 @@
> > > > > #include "standard-headers/linux/virtio_ring.h"
> > > > > #include "hw/virtio/vhost.h"
> > > > > #include "hw/virtio/virtio-bus.h"
> > > > > +#if defined(__linux__)
> > > > > #include "linux-headers/linux/vhost.h"
> > > > > +#endif
> > > > > +
> > > > > +#ifndef VHOST_FILE_UNBIND
> > > > > +#define VHOST_FILE_UNBIND -1
> > > > > +#endif
> > > >
> > > > This constant is for hw/virtio/vhost.c's vhost_net_set_backend() API. It
> > > > should be defined along with that API. Define it alongside
> > > > vhost_net_set_backend() in hw/virtio/vhost.h and call it
> > > > VHOST_NET_FILE_UNBIND?
> > > >
> > >
> > > That constant is defined by a Linux header (see
> > > linux-headers/linux/vhost.h). Are you suggesting to add another constant
> > > that is defined with VHOST_FILE_UNBIND on Linux and -1 on other platforms?
> >
> > Looking again, we should probably just use -1 instead of a constant
>
> Yep, this would be fine too.
> I don't remember why I did in this way, maybe to keep the diff smaller
> enough, but I don't have a strong opinion, we can avoid this ifndef and use
> -1 everywhere if you prefer that.
IMO VHOST_FILE_UNBIND doesn't belong in vhost_net.c, so it would be nice
to avoid the #ifndef.
So, for v2, is it ok if I replace the one usage of VHOST_FILE_UNBIND in
vhost_net.c with -1 and remove the #ifndef?
Yep.
> > since include/standard-headers/linux/vhost_types.h doesn't even define a
> > constant:
> >
> > struct vhost_vring_file {
> > unsigned int index;
> > int fd; /* Pass -1 to unbind from file. */
> >
> > };
> >
> > It's strange that VHOST_FILE_UNBIND was defined in <linux/vhost.h>
> > instead of <linux/vhost_types.h> where struct vhost_vring_file is
> > defined.
>
> Oh, VHOST_FILE_UNBIND was introduced after struct vhost_vring_file, with
> commit 776f395004d8 ("vhost_vdpa: Support config interrupt in vdpa").
>
> But I agree that should be moved to vhost_types.h. BTW <linux/vhost.h>
> already includes <linux/vhost_types.h>, so maybe we can fix it without too
> much trouble.
Yes, that change seems safe and will improve things in the long term.
Or should I send a patch to linux adding VHOST_FILE_UNBIND to vhost_types.h
and then drop it from vhost.h and remove the #ifndef?
This is orthogonal, the issue this patch was fixing was to build on
no-Linux systems, so changing Linux headers will not help.
This is more a cleanup, if you can send also that patch to Linux (which
is unrelated to this work) would be nice, otherwise let me know and I
can do that.
Note: files under linux-headers/ are imported from Linux, can't be
changed here.
Thanks,
Stefano
