From: Stefano Garzarella <sgarzare@redhat.com>
To: Jorgen Hansen <jhansen@vmware.com>
Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"virtualization@lists.linux-foundation.org"
<virtualization@lists.linux-foundation.org>,
Dexuan Cui <decui@microsoft.com>,
Stefan Hajnoczi <stefanha@redhat.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"David S. Miller" <davem@davemloft.net>
Subject: Re: [PATCH net-next 3/6] vsock: add local transport support in the vsock core
Date: Thu, 21 Nov 2019 16:21:48 +0100 [thread overview]
Message-ID: <20191121152148.slv26oesn25dpjb6@steredhat> (raw)
In-Reply-To: <MWHPR05MB3376F4452F0CF38C1AFABA2EDA4E0@MWHPR05MB3376.namprd05.prod.outlook.com>
On Thu, Nov 21, 2019 at 03:04:18PM +0000, Jorgen Hansen wrote:
> > From: Stefano Garzarella [mailto:sgarzare@redhat.com]
> > Sent: Tuesday, November 19, 2019 12:01 PM
> > To: netdev@vger.kernel.org
> >
> > This patch allows to register a transport able to handle
> > local communication (loopback).
> >
> > Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
> > ---
> > 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
next prev parent reply other threads:[~2019-11-21 15:21 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-19 11:01 [PATCH net-next 0/6] vsock: add local transport support Stefano Garzarella
2019-11-19 11:01 ` [PATCH net-next 1/6] vsock/virtio_transport_common: remove unused virtio header includes Stefano Garzarella
2019-11-19 11:01 ` [PATCH net-next 2/6] vsock: add VMADDR_CID_LOCAL definition Stefano Garzarella
2019-11-21 14:49 ` Jorgen Hansen
2019-11-19 11:01 ` [PATCH net-next 3/6] vsock: add local transport support in the vsock core Stefano Garzarella
2019-11-21 15:04 ` Jorgen Hansen
2019-11-21 15:21 ` Stefano Garzarella [this message]
2019-11-21 15:53 ` Jorgen Hansen
2019-11-21 16:12 ` Stefano Garzarella
2019-11-21 16:19 ` Jorgen Hansen
2019-11-19 11:01 ` [PATCH net-next 4/6] vsock: add vsock_loopback transport Stefano Garzarella
2019-11-20 1:15 ` David Miller
2019-11-20 9:00 ` Stefano Garzarella
2019-11-21 9:34 ` Stefan Hajnoczi
2019-11-21 9:59 ` Stefano Garzarella
2019-11-21 15:25 ` Stefano Garzarella
2019-11-22 9:25 ` Stefan Hajnoczi
2019-11-22 10:02 ` Stefano Garzarella
2019-11-19 11:01 ` [PATCH net-next 5/6] vsock: use local transport when it is loaded Stefano Garzarella
2019-11-21 9:46 ` Stefan Hajnoczi
2019-11-21 10:01 ` Stefano Garzarella
2019-11-19 11:01 ` [PATCH net-next 6/6] vsock/virtio: remove loopback handling Stefano Garzarella
2019-11-21 9:46 ` [PATCH net-next 0/6] vsock: add local transport support Stefan Hajnoczi
2019-11-21 10:05 ` Stefano Garzarella
2019-11-21 14:45 ` Jorgen Hansen
2019-11-21 15:13 ` Stefano Garzarella
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