xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

xen-netback: add support for multicast control

Browse Source 
Xen's PV network protocol includes messages to add/remove ethernet
multicast addresses to/from a filter list in the backend. This allows
the frontend to request the backend only forward multicast packets
which are of interest thus preventing unnecessary noise on the shared
ring.

The canonical netif header in git://xenbits.xen.org/xen.git specifies
the message format (two more XEN_NETIF_EXTRA_TYPEs) so the minimal
necessary changes have been pulled into include/xen/interface/io/netif.h.

To prevent the frontend from extending the multicast filter list
arbitrarily a limit (XEN_NETBK_MCAST_MAX) has been set to 64 entries.
This limit is not specified by the protocol and so may change in future.
If the limit is reached then the next XEN_NETIF_EXTRA_TYPE_MCAST_ADD
sent by the frontend will be failed with NETIF_RSP_ERROR.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Paul Durrant
2015-09-02 17:58:36 +01:00
committed by David S. Miller
parent 4db78d31de
commit 210c34dcd8
5 changed files with 144 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

13
drivers/net/xen-netback/xenbus.c
View File

@@ -327,6 +327,14 @@ static int netback_probe(struct xenbus_device *dev,
goto abort_transaction;
}
/* We support multicast-control. */
err = xenbus_printf(xbt, dev->nodename,
"feature-multicast-control", "%d", 1);
if (err) {
message = "writing feature-multicast-control";
goto abort_transaction;
}
err = xenbus_transaction_end(xbt, 0);
} while (err == -EAGAIN);
@@ -1016,6 +1024,11 @@ static int read_xenbus_vif_flags(struct backend_info *be)
val = 0;
vif->ipv6_csum = !!val;
if (xenbus_scanf(XBT_NIL, dev->otherend, "request-multicast-control",
"%d", &val) < 0)
val = 0;
vif->multicast_control = !!val;
return 0;
}