On Thu, Jan 9, 2014 at 5:16 PM, Michael S. Tsirkin <m...@redhat.com> wrote:

> On Thu, Jan 09, 2014 at 04:00:01PM +0100, Antonios Motakis wrote:
> > At runtime vhost-user netdev will detect if the vhost backend is up or
> down.
> > Upon disconnection it will set link_down accordingly and notify
> virtio-net.
>
> And then what happens?
>

The virtio-net interface goes down. On the next polling cycle the
connection will be re-attempted (see vhost_user_timer_handler).


> >
> > Signed-off-by: Antonios Motakis <a.mota...@virtualopensystems.com>
> > Signed-off-by: Nikolay Nikolaev <n.nikol...@virtualopensystems.com>
> > ---
> >  hw/net/vhost_net.c                | 16 +++++++++++
> >  hw/virtio/vhost-backend.c         | 16 +++++++++++
> >  include/hw/virtio/vhost-backend.h |  2 ++
> >  include/net/vhost_net.h           |  1 +
> >  net/vhost-user.c                  | 56
> +++++++++++++++++++++++++++++++++++++++
> >  5 files changed, 91 insertions(+)
> >
> > diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
> > index e42f4d6..56c218e 100644
> > --- a/hw/net/vhost_net.c
> > +++ b/hw/net/vhost_net.c
> > @@ -304,6 +304,17 @@ void vhost_net_virtqueue_mask(VHostNetState *net,
> VirtIODevice *dev,
> >      vhost_virtqueue_mask(&net->dev, dev, idx, mask);
> >  }
> >
> > +int vhost_net_link_status(VHostNetState *net)
> > +{
> > +    int r = 0;
> > +
> > +    if (net->dev.vhost_ops->vhost_status) {
> > +        r = net->dev.vhost_ops->vhost_status(&net->dev);
> > +    }
> > +
> > +    return r;
> > +}
> > +
> >  VHostNetState *get_vhost_net(NetClientState *nc)
> >  {
> >      VHostNetState *vhost_net = 0;
> > @@ -372,6 +383,11 @@ void vhost_net_virtqueue_mask(VHostNetState *net,
> VirtIODevice *dev,
> >  {
> >  }
> >
> > +int vhost_net_link_status(VHostNetState *net)
> > +{
> > +    return 0;
> > +}
> > +
> >  VHostNetState *get_vhost_net(NetClientState *nc)
> >  {
> >      return 0;
> > diff --git a/hw/virtio/vhost-backend.c b/hw/virtio/vhost-backend.c
> > index 50ea307..fcd274f 100644
> > --- a/hw/virtio/vhost-backend.c
> > +++ b/hw/virtio/vhost-backend.c
> > @@ -350,9 +350,23 @@ static int vhost_user_call(struct vhost_dev *dev,
> unsigned long int request,
> >          }
> >      }
> >
> > +    /* mark the backend non operational */
> > +    if (result < 0) {
> > +        error_report("%s: Connection break detected\n", __func__);
> > +        vhost_user_cleanup(dev);
> > +        return 0;
> > +    }
> > +
> >      return result;
> >  }
> >
> > +static int vhost_user_status(struct vhost_dev *dev)
> > +{
> > +    vhost_user_echo(dev);
> > +
> > +    return (dev->control >= 0);
> > +}
> > +
> >  static int vhost_user_init(struct vhost_dev *dev, const char *devpath)
> >  {
> >      int fd = -1;
> > @@ -432,6 +446,7 @@ static int vhost_user_cleanup(struct vhost_dev *dev)
> >  static const VhostOps user_ops = {
> >          .backend_type = VHOST_BACKEND_TYPE_USER,
> >          .vhost_call = vhost_user_call,
> > +        .vhost_status = vhost_user_status,
> >          .vhost_backend_init = vhost_user_init,
> >          .vhost_backend_cleanup = vhost_user_cleanup
> >  };
> > @@ -464,6 +479,7 @@ static int vhost_kernel_cleanup(struct vhost_dev
> *dev)
> >  static const VhostOps kernel_ops = {
> >          .backend_type = VHOST_BACKEND_TYPE_KERNEL,
> >          .vhost_call = vhost_kernel_call,
> > +        .vhost_status = 0,
> >          .vhost_backend_init = vhost_kernel_init,
> >          .vhost_backend_cleanup = vhost_kernel_cleanup
> >  };
> > diff --git a/include/hw/virtio/vhost-backend.h
> b/include/hw/virtio/vhost-backend.h
> > index ef87ffa..f2b4a6c 100644
> > --- a/include/hw/virtio/vhost-backend.h
> > +++ b/include/hw/virtio/vhost-backend.h
> > @@ -22,12 +22,14 @@ struct vhost_dev;
> >
> >  typedef int (*vhost_call)(struct vhost_dev *dev, unsigned long int
> request,
> >               void *arg);
> > +typedef int (*vhost_status)(struct vhost_dev *dev);
> >  typedef int (*vhost_backend_init)(struct vhost_dev *dev, const char
> *devpath);
> >  typedef int (*vhost_backend_cleanup)(struct vhost_dev *dev);
> >
> >  typedef struct VhostOps {
> >      VhostBackendType backend_type;
> >      vhost_call vhost_call;
> > +    vhost_status vhost_status;
> >      vhost_backend_init vhost_backend_init;
> >      vhost_backend_cleanup vhost_backend_cleanup;
> >  } VhostOps;
> > diff --git a/include/net/vhost_net.h b/include/net/vhost_net.h
> > index abd3d0b..6390907 100644
> > --- a/include/net/vhost_net.h
> > +++ b/include/net/vhost_net.h
> > @@ -31,5 +31,6 @@ void vhost_net_ack_features(VHostNetState *net,
> unsigned features);
> >  bool vhost_net_virtqueue_pending(VHostNetState *net, int n);
> >  void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
> >                                int idx, bool mask);
> > +int vhost_net_link_status(VHostNetState *net);
> >  VHostNetState *get_vhost_net(NetClientState *nc);
> >  #endif
> > diff --git a/net/vhost-user.c b/net/vhost-user.c
> > index 6fd5afc..56f7dd4 100644
> > --- a/net/vhost-user.c
> > +++ b/net/vhost-user.c
> > @@ -12,6 +12,7 @@
> >  #include "net/vhost_net.h"
> >  #include "net/vhost-user.h"
> >  #include "qemu/error-report.h"
> > +#include "qemu/timer.h"
> >
> >  typedef struct VhostUserState {
> >      NetClientState nc;
> > @@ -19,6 +20,9 @@ typedef struct VhostUserState {
> >      char *devpath;
> >  } VhostUserState;
> >
> > +static QEMUTimer *vhost_user_timer;
> > +#define VHOST_USER_TIMEOUT  (1*1000)
> > +
> >  VHostNetState *vhost_user_get_vhost_net(NetClientState *nc)
> >  {
> >      VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
> > @@ -31,6 +35,11 @@ static int vhost_user_running(VhostUserState *s)
> >      return (s->vhost_net) ? 1 : 0;
> >  }
> >
> > +static int vhost_user_link_status(VhostUserState *s)
> > +{
> > +    return (!s->nc.link_down) && vhost_net_link_status(s->vhost_net);
> > +}
> > +
> >  static int vhost_user_start(VhostUserState *s)
> >  {
> >      VhostNetOptions options;
> > @@ -59,6 +68,48 @@ static void vhost_user_stop(VhostUserState *s)
> >      s->vhost_net = 0;
> >  }
> >
> > +static void vhost_user_timer_handler(void *opaque)
> > +{
> > +    VhostUserState *s = opaque;
> > +    int link_down = 0;
> > +
> > +    if (vhost_user_running(s)) {
> > +        if (!vhost_user_link_status(s)) {
> > +            link_down = 1;
> > +        }
> > +    } else {
> > +        vhost_user_start(s);
> > +        if (!vhost_user_running(s)) {
> > +            link_down = 1;
> > +        }
> > +    }
> > +
> > +    if (link_down != s->nc.link_down) {
> > +
> > +        s->nc.link_down = link_down;
> > +
> > +        if (s->nc.peer) {
> > +            s->nc.peer->link_down = link_down;
> > +        }
> > +
> > +        if (s->nc.info->link_status_changed) {
> > +            s->nc.info->link_status_changed(&s->nc);
> > +        }
> > +
> > +        if (s->nc.peer && s->nc.peer->info->link_status_changed) {
> > +            s->nc.peer->info->link_status_changed(s->nc.peer);
> > +        }
> > +
> > +        if (link_down) {
> > +            vhost_user_stop(s);
> > +        }
> > +    }
> > +
> > +    /* reschedule */
> > +    timer_mod(vhost_user_timer,
> > +              qemu_clock_get_ms(QEMU_CLOCK_REALTIME) +
> VHOST_USER_TIMEOUT);
> > +}
> > +
> >  static void vhost_user_cleanup(NetClientState *nc)
> >  {
> >      VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
> > @@ -93,6 +144,11 @@ static int net_vhost_user_init(NetClientState *peer,
> const char *device,
> >
> >      r = vhost_user_start(s);
> >
> > +    vhost_user_timer = timer_new_ms(QEMU_CLOCK_REALTIME,
> > +            vhost_user_timer_handler, s);
> > +    timer_mod(vhost_user_timer,
> > +            qemu_clock_get_ms(QEMU_CLOCK_REALTIME) +
> VHOST_USER_TIMEOUT);
> > +
> >      return r;
> >  }
> >
> > --
> > 1.8.3.2
> >
>

Reply via email to