On Thu, Nov 21, 2019 at 03:04:18PM +0000, Jorgen Hansen wrote: > > From: Stefano Garzarella [mailto:sgarzare@xxxxxxxxxx] > > Sent: Tuesday, November 19, 2019 12:01 PM > > To: netdev@xxxxxxxxxxxxxxx > > > > This patch allows to register a transport able to handle > > local communication (loopback). > > > > Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx> > > --- > > include/net/af_vsock.h | 2 ++ > > net/vmw_vsock/af_vsock.c | 17 ++++++++++++++++- > > 2 files changed, 18 insertions(+), 1 deletion(-) > > > > diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h > > index 4206dc6d813f..b1c717286993 100644 > > --- a/include/net/af_vsock.h > > +++ b/include/net/af_vsock.h > > @@ -98,6 +98,8 @@ struct vsock_transport_send_notify_data { > > #define VSOCK_TRANSPORT_F_G2H 0x00000002 > > /* Transport provides DGRAM communication */ > > #define VSOCK_TRANSPORT_F_DGRAM 0x00000004 > > +/* Transport provides local (loopback) communication */ > > +#define VSOCK_TRANSPORT_F_LOCAL 0x00000008 > > > > struct vsock_transport { > > struct module *module; > > diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c > > index cc8659838bf2..c9e5bad59dc1 100644 > > --- a/net/vmw_vsock/af_vsock.c > > +++ b/net/vmw_vsock/af_vsock.c > > @@ -136,6 +136,8 @@ static const struct vsock_transport *transport_h2g; > > static const struct vsock_transport *transport_g2h; > > /* Transport used for DGRAM communication */ > > static const struct vsock_transport *transport_dgram; > > +/* Transport used for local communication */ > > +static const struct vsock_transport *transport_local; > > static DEFINE_MUTEX(vsock_register_mutex); > > > > /**** UTILS ****/ > > @@ -2130,7 +2132,7 @@ EXPORT_SYMBOL_GPL(vsock_core_get_transport); > > > > int vsock_core_register(const struct vsock_transport *t, int features) > > { > > - const struct vsock_transport *t_h2g, *t_g2h, *t_dgram; > > + const struct vsock_transport *t_h2g, *t_g2h, *t_dgram, *t_local; > > int err = mutex_lock_interruptible(&vsock_register_mutex); > > > > if (err) > > @@ -2139,6 +2141,7 @@ int vsock_core_register(const struct > > vsock_transport *t, int features) > > t_h2g = transport_h2g; > > t_g2h = transport_g2h; > > t_dgram = transport_dgram; > > + t_local = transport_local; > > > > if (features & VSOCK_TRANSPORT_F_H2G) { > > if (t_h2g) { > > @@ -2164,9 +2167,18 @@ int vsock_core_register(const struct > > vsock_transport *t, int features) > > t_dgram = t; > > } > > > > + if (features & VSOCK_TRANSPORT_F_LOCAL) { > > + if (t_local) { > > + err = -EBUSY; > > + goto err_busy; > > + } > > + t_local = t; > > + } > > + > > transport_h2g = t_h2g; > > transport_g2h = t_g2h; > > transport_dgram = t_dgram; > > + transport_local = t_local; > > > > err_busy: > > mutex_unlock(&vsock_register_mutex); > > @@ -2187,6 +2199,9 @@ void vsock_core_unregister(const struct > > vsock_transport *t) > > if (transport_dgram == t) > > transport_dgram = NULL; > > > > + if (transport_local == t) > > + transport_local = NULL; > > + > > mutex_unlock(&vsock_register_mutex); > > } > > EXPORT_SYMBOL_GPL(vsock_core_unregister); > > -- > > 2.21.0 > > Having loopback support as a separate transport fits nicely, but do we need to support > different variants of loopback? It could just be built in. I agree with you, indeed initially I developed it as built in, but DEPMOD found a cyclic dependency because vsock_transport use virtio_transport_common that use vsock, so if I include vsock_transport in the vsock module, DEPMOD is not happy. I don't know how to break this cyclic dependency, do you have any ideas? Thanks, Stefano
