Re: [Qemu-devel] [PATCH v2 1/2] net: introduce MAC_TABLE_CHANGED event

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, May 16, 2013 at 08:24:03AM -0400, Luiz Capitulino wrote:
> On Thu, 16 May 2013 15:17:45 +0300
> "Michael S. Tsirkin" <mst@redhat.com> wrote:
> 
> > On Thu, May 16, 2013 at 07:07:24PM +0800, Amos Kong wrote:
> > > Introduce this new QMP event to notify management after guest changes
> > > mac-table configuration.
> > > 
> > > Signed-off-by: Amos Kong <akong@redhat.com>
> > > ---
> > >  QMP/qmp-events.txt        | 14 ++++++++++++++
> > >  hw/net/virtio-net.c       | 12 ++++++++++++
> > >  include/monitor/monitor.h |  1 +
> > >  monitor.c                 |  1 +
> > >  4 files changed, 28 insertions(+)
> > > 
> > > diff --git a/QMP/qmp-events.txt b/QMP/qmp-events.txt
> > > index 92fe5fb..24d62df 100644
> > > --- a/QMP/qmp-events.txt
> > > +++ b/QMP/qmp-events.txt
> > > @@ -154,6 +154,20 @@ Data:
> > >              "path": "/machine/peripheral/virtio-net-pci-0" },
> > >    "timestamp": { "seconds": 1265044230, "microseconds": 450486 } }
> > >  
> > > +MAC_TABLE_CHANGED
> > > +-----------------
> > > +
> > > +Emitted mac-table configuration is changed by the guest.
> > > +
> > > +Data:
> > > +
> > > +- "name": net client name (json-string)
> > > +
> > > +{ "event": "MAC_TABLE_CHANGED",
> > > +  "data": { "name": "vnet0" },
> > > +  "timestamp": { "seconds": 1368697518, "microseconds": 326866 }}
> > > +}
> > > +
> > >  DEVICE_TRAY_MOVED
> > >  -----------------
> > >  
> > > diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> > > index bed0822..a9b8f53 100644
> > > --- a/hw/net/virtio-net.c
> > > +++ b/hw/net/virtio-net.c
> > > @@ -21,6 +21,8 @@
> > >  #include "hw/virtio/virtio-net.h"
> > >  #include "net/vhost_net.h"
> > >  #include "hw/virtio/virtio-bus.h"
> > > +#include "qapi/qmp/qjson.h"
> > > +#include "monitor/monitor.h"
> > >  
> > >  #define VIRTIO_NET_VM_VERSION    11
> > >  
> > > @@ -395,6 +397,7 @@ static int virtio_net_handle_rx_mode(VirtIONet *n, uint8_t cmd,
> > >  {
> > >      uint8_t on;
> > >      size_t s;
> > > +    QObject *event_data;
> > >  
> > >      s = iov_to_buf(iov, iov_cnt, 0, &on, sizeof(on));
> > >      if (s != sizeof(on)) {
> > > @@ -417,6 +420,10 @@ static int virtio_net_handle_rx_mode(VirtIONet *n, uint8_t cmd,
> > >          return VIRTIO_NET_ERR;
> > >      }
> > >  
> > > +    event_data = qobject_from_jsonf("{ 'name': %s }", n->netclient_name);
> > > +    monitor_protocol_event(QEVENT_MAC_TABLE_CHANGED, event_data);
> > > +    qobject_decref(event_data);
> > > +
> > >      return VIRTIO_NET_OK;
> > >  }
> > >  
> > 
> > Sorry, pls ignore my previous mail, I see you actually
> > emit this on rx mode change as well.
> > 
> > I find the name misleading or at least it mislead me :)
> > RX_FILTER_CHANGED?
> > 
> > > @@ -425,6 +432,7 @@ static int virtio_net_handle_mac(VirtIONet *n, uint8_t cmd,
> > >  {
> > >      struct virtio_net_ctrl_mac mac_data;
> > >      size_t s;
> > > +    QObject *event_data;
> > >  
> > >      if (cmd == VIRTIO_NET_CTRL_MAC_ADDR_SET) {
> > >          if (iov_size(iov, iov_cnt) != sizeof(n->mac)) {
> > > @@ -497,6 +505,10 @@ static int virtio_net_handle_mac(VirtIONet *n, uint8_t cmd,
> > >          n->mac_table.multi_overflow = 1;
> > >      }
> > >  
> > > +    event_data = qobject_from_jsonf("{ 'name': %s }", n->netclient_name);
> > > +    monitor_protocol_event(QEVENT_MAC_TABLE_CHANGED, event_data);
> > > +    qobject_decref(event_data);
> > > +
> > >      return VIRTIO_NET_OK;
> > >  }
> > > 
> > 
> > This makes it easy for guest to flood management with
> > spurious events.
> > How about we set a flag after this, and avoid sending any more
> > events until management queries the filter status?
> 
> We have an API for that, look at monitor_protocol_event_init().

You mean monitor_protocol_event_throttle?
So what happens if guest triggers more
MAC changes per second?

> >  
> > > diff --git a/include/monitor/monitor.h b/include/monitor/monitor.h
> > > index 1a6cfcf..e88c70f 100644
> > > --- a/include/monitor/monitor.h
> > > +++ b/include/monitor/monitor.h
> > > @@ -40,6 +40,7 @@ typedef enum MonitorEvent {
> > >      QEVENT_BLOCK_JOB_ERROR,
> > >      QEVENT_BLOCK_JOB_READY,
> > >      QEVENT_DEVICE_DELETED,
> > > +    QEVENT_MAC_TABLE_CHANGED,
> > >      QEVENT_DEVICE_TRAY_MOVED,
> > >      QEVENT_SUSPEND,
> > >      QEVENT_SUSPEND_DISK,
> > > diff --git a/monitor.c b/monitor.c
> > > index 62aaebe..9e51545 100644
> > > --- a/monitor.c
> > > +++ b/monitor.c
> > > @@ -490,6 +490,7 @@ static const char *monitor_event_names[] = {
> > >      [QEVENT_BLOCK_JOB_ERROR] = "BLOCK_JOB_ERROR",
> > >      [QEVENT_BLOCK_JOB_READY] = "BLOCK_JOB_READY",
> > >      [QEVENT_DEVICE_DELETED] = "DEVICE_DELETED",
> > > +    [QEVENT_MAC_TABLE_CHANGED] = "MAC_TABLE_CHANGED",
> > >      [QEVENT_DEVICE_TRAY_MOVED] = "DEVICE_TRAY_MOVED",
> > >      [QEVENT_SUSPEND] = "SUSPEND",
> > >      [QEVENT_SUSPEND_DISK] = "SUSPEND_DISK",
> > > -- 
> > > 1.8.1.4
> >