Re: [PATCH v2 1/1] vhost: tolerate file descriptor in REM_MEM_REG msg

On Fri, 31 Jul 2026 08:19:07 +0000
"Bathija, Pravin" <[email protected]> wrote:

> > > While the immediate motivation was libblkio, the spec's compatibility
> > > clause was written for exactly this situation =E2=80=94 any front-end=
 could
> > > make the same mistake. QEMU's libvhost-user reference implementation =
=20
> > already tolerates it (see vu_rem_mem_reg).
> >
> > Which does not change that I dislike such compat. =20
>=20
> I couldn't agree with you more.  The libblkio fix is ready and will stop =
sending the fd.
> In an ideal world we'd fix libblkio and move on,  but there are already s=
everal released versions
> of libblkio in the wild that exhibit this behavior.  Users pairing those =
with a current DPDK will hit
> a broken connection with no obvious workaround.

IMHO security safety trumps the specification in this case.
Although it might help to document this somewhere and add a better message.