[ovs-dev] AB bonding: Add "primary" interface concept
diff mbox series

Message ID 20200323200223.13599-1-jsquyres@cisco.com
State New
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Series
  • [ovs-dev] AB bonding: Add "primary" interface concept
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Commit Message

Jeff Squyres \(jsquyres\) via dev March 23, 2020, 8:02 p.m. UTC
A "primary" slave interface will always become active if it is
enabled.  The "primary" concept exists in Linux kernel network
interface bonding, but did not previously exist in OVS bonding.

Only one "primary" slave inteface is supported per bond, and
is only supported for active/backup bonding.

The primary slave interface is designated via
"other_config:bond-primary" when creating a bond.

Signed-off-by: Jeff Squyres <jsquyres@cisco.com>
---
 ofproto/bond.c        | 58 +++++++++++++++++++++++++++++++-
 ofproto/bond.h        |  1 +
 tests/lacp.at         |  1 +
 tests/ofproto-dpif.at | 78 ++++++++++++++++++++++++++++++++++++++++++-
 vswitchd/bridge.c     |  5 +++
 vswitchd/vswitch.xml  |  8 +++++
 6 files changed, 149 insertions(+), 2 deletions(-)

Comments

Jeff Squyres \(jsquyres\) via dev March 29, 2020, 6:46 p.m. UTC | #1
I haven't seen any comments on this patch yet; just wanted to make sure it didn't get overlooked.

Thanks!



> On Mar 23, 2020, at 4:02 PM, Jeff Squyres <jsquyres@cisco.com> wrote:
> 
> A "primary" slave interface will always become active if it is
> enabled.  The "primary" concept exists in Linux kernel network
> interface bonding, but did not previously exist in OVS bonding.
> 
> Only one "primary" slave inteface is supported per bond, and
> is only supported for active/backup bonding.
> 
> The primary slave interface is designated via
> "other_config:bond-primary" when creating a bond.
> 
> Signed-off-by: Jeff Squyres <jsquyres@cisco.com>
> ---
> ofproto/bond.c        | 58 +++++++++++++++++++++++++++++++-
> ofproto/bond.h        |  1 +
> tests/lacp.at         |  1 +
> tests/ofproto-dpif.at | 78 ++++++++++++++++++++++++++++++++++++++++++-
> vswitchd/bridge.c     |  5 +++
> vswitchd/vswitch.xml  |  8 +++++
> 6 files changed, 149 insertions(+), 2 deletions(-)
> 
> diff --git a/ofproto/bond.c b/ofproto/bond.c
> index 405202fb6..2437246ca 100644
> --- a/ofproto/bond.c
> +++ b/ofproto/bond.c
> @@ -93,6 +93,7 @@ struct bond_slave {
>     /* Link status. */
>     bool enabled;               /* May be chosen for flows? */
>     bool may_enable;            /* Client considers this slave bondable. */
> +    bool is_primary;            /* This slave is preferred over others. */
>     long long delay_expires;    /* Time after which 'enabled' may change. */
> 
>     /* Rebalancing info.  Used only by bond_rebalance(). */
> @@ -126,6 +127,7 @@ struct bond {
>     enum lacp_status lacp_status; /* Status of LACP negotiations. */
>     bool bond_revalidate;       /* True if flows need revalidation. */
>     uint32_t basis;             /* Basis for flow hash function. */
> +    char *primary;              /* Name of the primary slave interface. */
> 
>     /* SLB specific bonding info. */
>     struct bond_entry *hash;     /* An array of BOND_BUCKETS elements. */
> @@ -241,6 +243,7 @@ bond_create(const struct bond_settings *s, struct ofproto_dpif *ofproto)
> 
>     bond->active_slave_mac = eth_addr_zero;
>     bond->active_slave_changed = false;
> +    bond->primary = NULL;
> 
>     bond_reconfigure(bond, s);
>     return bond;
> @@ -290,6 +293,7 @@ bond_unref(struct bond *bond)
>     update_recirc_rules__(bond);
> 
>     hmap_destroy(&bond->pr_rule_ops);
> +    free(bond->primary);
>     free(bond->name);
>     free(bond);
> }
> @@ -459,6 +463,31 @@ bond_reconfigure(struct bond *bond, const struct bond_settings *s)
>         bond->bond_revalidate = false;
>     }
> 
> +    /*
> +     * If a primary interface is set on the new settings:
> +     * 1. If the bond has no primary previously set, save it and
> +     * revalidate.
> +     * 2. If the bond has a different primary previously set, save the
> +     * new one and revalidate.
> +     * 3. If the bond has the same primary previously set, do nothing.
> +     */
> +    if (s->primary) {
> +        bool changed = false;
> +        if (bond->primary) {
> +            if (strcmp(bond->primary, s->primary) != 0) {
> +                free(bond->primary);
> +                changed = true;
> +            }
> +        } else {
> +            changed = true;
> +        }
> +
> +        if (changed) {
> +            bond->primary = xstrdup(s->primary);
> +            revalidate = true;
> +        }
> +    }
> +
>     if (bond->balance != BM_AB) {
>         if (!bond->recirc_id) {
>             bond->recirc_id = recirc_alloc_id(bond->ofproto);
> @@ -549,6 +578,12 @@ bond_slave_register(struct bond *bond, void *slave_,
>         slave->name = xstrdup(netdev_get_name(netdev));
>         bond->bond_revalidate = true;
> 
> +        if (bond->primary && strcmp(bond->primary, slave->name) == 0) {
> +            slave->is_primary = true;
> +        } else {
> +            slave->is_primary = false;
> +        }
> +
>         slave->enabled = false;
>         bond_enable_slave(slave, netdev_get_carrier(netdev));
>     }
> @@ -644,6 +679,7 @@ bond_run(struct bond *bond, enum lacp_status lacp_status)
> {
>     struct bond_slave *slave;
>     bool revalidate;
> +    struct bond_slave *primary;
> 
>     ovs_rwlock_wrlock(&rwlock);
>     if (bond->lacp_status != lacp_status) {
> @@ -659,11 +695,19 @@ bond_run(struct bond *bond, enum lacp_status lacp_status)
>     }
> 
>     /* Enable slaves based on link status and LACP feedback. */
> +    primary = NULL;
>     HMAP_FOR_EACH (slave, hmap_node, &bond->slaves) {
>         bond_link_status_update(slave);
>         slave->change_seq = seq_read(connectivity_seq_get());
> +
> +        /* Discover if there is an active slave marked "primary". */
> +        if (bond->balance == BM_AB && slave->is_primary && slave->enabled) {
> +            primary = slave;
> +        }
>     }
> -    if (!bond->active_slave || !bond->active_slave->enabled) {
> +
> +    if (!bond->active_slave || !bond->active_slave->enabled ||
> +        (primary && bond->active_slave != primary)) {
>         bond_choose_active_slave(bond);
>     }
> 
> @@ -1393,6 +1437,11 @@ bond_print_details(struct ds *ds, const struct bond *bond)
>     ds_put_format(ds, "lacp_fallback_ab: %s\n",
>                   bond->lacp_fallback_ab ? "true" : "false");
> 
> +    if (bond->balance == BM_AB) {
> +        ds_put_format(ds, "primary: %s\n",
> +                      bond->primary ? bond->primary : "<none>");
> +    }
> +
>     ds_put_cstr(ds, "active slave mac: ");
>     ds_put_format(ds, ETH_ADDR_FMT, ETH_ADDR_ARGS(bond->active_slave_mac));
>     slave = bond_find_slave_by_mac(bond, bond->active_slave_mac);
> @@ -1862,6 +1911,13 @@ bond_choose_slave(const struct bond *bond)
> {
>     struct bond_slave *slave, *best;
> 
> +    /* If there's a primary and it's active, return that. */
> +    HMAP_FOR_EACH (slave, hmap_node, &bond->slaves) {
> +        if (slave->is_primary && slave->enabled) {
> +            return slave;
> +        }
> +    }
> +
>     /* Find the last active slave. */
>     slave = bond_find_slave_by_mac(bond, bond->active_slave_mac);
>     if (slave && slave->enabled) {
> diff --git a/ofproto/bond.h b/ofproto/bond.h
> index e7c3d9bc3..3a923dcfa 100644
> --- a/ofproto/bond.h
> +++ b/ofproto/bond.h
> @@ -45,6 +45,7 @@ struct bond_settings {
> 
>     /* Balancing configuration. */
>     enum bond_mode balance;
> +    const char *primary;        /* For AB balance, primary interface name. */
>     int rebalance_interval;     /* Milliseconds between rebalances.
>                                    Zero to disable rebalancing. */
> 
> diff --git a/tests/lacp.at b/tests/lacp.at
> index 7b460d7be..696ffc6d4 100644
> --- a/tests/lacp.at
> +++ b/tests/lacp.at
> @@ -125,6 +125,7 @@ updelay: 0 ms
> downdelay: 0 ms
> lacp_status: negotiated
> lacp_fallback_ab: false
> +primary: <none>
> active slave mac: 00:00:00:00:00:00(none)
> 
> slave p1: disabled
> diff --git a/tests/ofproto-dpif.at b/tests/ofproto-dpif.at
> index d444cf084..de499bd9a 100644
> --- a/tests/ofproto-dpif.at
> +++ b/tests/ofproto-dpif.at
> @@ -29,7 +29,82 @@ AT_CHECK([ovs-appctl revalidator/wait])
> OVS_VSWITCHD_STOP
> AT_CLEANUP
> 
> -AT_SETUP([ofproto-dpif - active-backup bonding])
> +AT_SETUP([ofproto-dpif - active-backup bonding (with primary)])
> +
> +# Create br0 with interfaces p1, p2 and p7, creating bond0 with p1 and
> +#    p2 (p1 as primary) and br1 with interfaces p3, p4 and p8.
> +# toggle p1,p2 of bond0 up and down to test bonding in active-backup mode.
> +# With p1 down and p2 up/active, bring p1 back up.  Since p1 is the primary,
> +# it should become active.
> +OVS_VSWITCHD_START(
> +  [add-bond br0 bond0 p1 p2 bond_mode=active-backup \
> +                other_config:bond-primary=p1 -- \
> +   set interface p1 type=dummy options:pstream=punix:$OVS_RUNDIR/p1.sock ofport_request=1 -- \
> +   set interface p2 type=dummy options:pstream=punix:$OVS_RUNDIR/p2.sock ofport_request=2 -- \
> +   add-port br0 p7 -- set interface p7 ofport_request=7 type=dummy -- \
> +   add-br br1 -- \
> +   set bridge br1 other-config:hwaddr=aa:66:aa:66:00:00 -- \
> +   set bridge br1 datapath-type=dummy other-config:datapath-id=1234 \
> +                  fail-mode=secure -- \
> +   add-port br1 p3 -- set interface p3 type=dummy options:stream=unix:$OVS_RUNDIR/p1.sock ofport_request=3 -- \
> +   add-port br1 p4 -- set interface p4 type=dummy options:stream=unix:$OVS_RUNDIR/p2.sock ofport_request=4 -- \
> +   add-port br1 p8 -- set interface p8 ofport_request=8 type=dummy --])
> +WAIT_FOR_DUMMY_PORTS([p3], [p4])
> +AT_CHECK([test -n "`ovs-appctl bond/show | grep 'primary: p1'`"])
> +AT_CHECK([ovs-appctl vlog/set dpif:dbg dpif_netdev:dbg])
> +
> +AT_CHECK([ovs-ofctl add-flow br0 action=normal])
> +AT_CHECK([ovs-ofctl add-flow br1 action=normal])
> +ovs-appctl netdev-dummy/set-admin-state up
> +ovs-appctl time/warp 100
> +ovs-appctl netdev-dummy/set-admin-state p2 down
> +ovs-appctl time/stop
> +ovs-appctl time/warp 100
> +AT_CHECK([ovs-appctl netdev-dummy/receive p7 'in_port(7),eth(src=50:54:00:00:00:09,dst=50:54:00:00:00:0a),eth_type(0x0800),ipv4(src=10.0.0.2,dst=10.0.0.1,proto=1,tos=0,ttl=64,frag=no),icmp(type=8,code=0)'])
> +AT_CHECK([ovs-appctl netdev-dummy/receive p7 'in_port(7),eth(src=50:54:00:00:00:0b,dst=50:54:00:00:00:0c),eth_type(0x0800),ipv4(src=10.0.0.3,dst=10.0.0.4,proto=1,tos=0,ttl=64,frag=no),icmp(type=8,code=0)'])
> +ovs-appctl time/warp 100
> +ovs-appctl netdev-dummy/set-admin-state p2 up
> +ovs-appctl netdev-dummy/set-admin-state p1 down
> +wovs-appctl time/warp 100
> +AT_CHECK([ovs-appctl netdev-dummy/receive p7 'in_port(7),eth(src=50:54:00:00:00:09,dst=50:54:00:00:00:0d),eth_type(0x0800),ipv4(src=10.0.0.5,dst=10.0.0.1,proto=1,tos=0,ttl=64,frag=no),icmp(type=8,code=0)'])
> +AT_CHECK([ovs-appctl netdev-dummy/receive p7 'in_port(7),eth(src=50:54:00:00:00:09,dst=50:54:00:00:00:0e),eth_type(0x0800),ipv4(src=10.0.0.6,dst=10.0.0.1,proto=1,tos=0,ttl=64,frag=no),icmp(type=8,code=0)'])
> +ovs-appctl time/warp 200 100
> +sleep 1
> +AT_CHECK([grep 'in_port([[348]])' ovs-vswitchd.log | filter_flow_install | strip_xout], [0], [dnl
> +recirc_id(0),in_port(3),packet_type(ns=0,id=0),eth(src=50:54:00:00:00:09,dst=50:54:00:00:00:0a),eth_type(0x0800),ipv4(frag=no), actions: <del>
> +recirc_id(0),in_port(3),packet_type(ns=0,id=0),eth(src=50:54:00:00:00:0b,dst=50:54:00:00:00:0c),eth_type(0x0800),ipv4(frag=no), actions: <del>
> +recirc_id(0),in_port(4),packet_type(ns=0,id=0),eth(src=50:54:00:00:00:09,dst=50:54:00:00:00:0d),eth_type(0x0800),ipv4(frag=no), actions: <del>
> +recirc_id(0),in_port(4),packet_type(ns=0,id=0),eth(src=50:54:00:00:00:09,dst=50:54:00:00:00:0e),eth_type(0x0800),ipv4(frag=no), actions: <del>
> +recirc_id(0),in_port(4),packet_type(ns=0,id=0),eth(src=50:54:00:00:00:09,dst=ff:ff:ff:ff:ff:ff),eth_type(0x8035), actions: <del>
> +recirc_id(0),in_port(4),packet_type(ns=0,id=0),eth(src=50:54:00:00:00:0b,dst=ff:ff:ff:ff:ff:ff),eth_type(0x8035), actions: <del>
> +])
> +
> +ovs-appctl netdev-dummy/set-admin-state p1 up
> +AT_CHECK([ovs-appctl bond/show | STRIP_RECIRC_ID | STRIP_ACTIVE_SLAVE_MAC], [0], [dnl
> +---- bond0 ----
> +bond_mode: active-backup
> +bond may use recirculation: no, <del>
> +bond-hash-basis: 0
> +updelay: 0 ms
> +downdelay: 0 ms
> +lacp_status: off
> +lacp_fallback_ab: false
> +primary: p1
> +<active slave mac del>
> +
> +slave p1: enabled
> +  active slave
> +  may_enable: true
> +
> +slave p2: enabled
> +  may_enable: true
> +
> +])
> +
> +OVS_VSWITCHD_STOP
> +AT_CLEANUP
> +
> +AT_SETUP([ofproto-dpif - active-backup bonding (without primary)])
> # Create br0 with interfaces p1, p2 and p7, creating bond0 with p1 and p2
> #    and br1 with interfaces p3, p4 and p8.
> # toggle p1,p2 of bond0 up and down to test bonding in active-backup mode.
> @@ -46,6 +121,7 @@ OVS_VSWITCHD_START(
>    add-port br1 p4 -- set interface p4 type=dummy options:stream=unix:$OVS_RUNDIR/p2.sock ofport_request=4 -- \
>    add-port br1 p8 -- set interface p8 ofport_request=8 type=dummy --])
> WAIT_FOR_DUMMY_PORTS([p3], [p4])
> +AT_CHECK([test -n "`ovs-appctl bond/show | grep 'primary: <none>'`"])
> AT_CHECK([ovs-appctl vlog/set dpif:dbg dpif_netdev:dbg])
> 
> AT_CHECK([ovs-ofctl add-flow br0 action=normal])
> diff --git a/vswitchd/bridge.c b/vswitchd/bridge.c
> index fe73c38d4..5f30b7737 100644
> --- a/vswitchd/bridge.c
> +++ b/vswitchd/bridge.c
> @@ -4563,6 +4563,11 @@ port_configure_bond(struct port *port, struct bond_settings *s)
>                   port->name);
>     }
> 
> +    s->primary = NULL;
> +    if (s->balance == BM_AB) {
> +        s->primary = smap_get(&port->cfg->other_config, "bond-primary");
> +    }
> +
>     miimon_interval = smap_get_int(&port->cfg->other_config,
>                                    "bond-miimon-interval", 0);
>     if (miimon_interval <= 0) {
> diff --git a/vswitchd/vswitch.xml b/vswitchd/vswitch.xml
> index 4a74ed3ef..f20b3cb6a 100644
> --- a/vswitchd/vswitch.xml
> +++ b/vswitchd/vswitch.xml
> @@ -2016,6 +2016,14 @@
>           key="bond-detect-mode"/> is <code>miimon</code>.
>         </column>
> 
> +        <column name="other_config" key="bond-primary"
> +                type='{"type": "string"}'>
> +          If a slave interface with this name exists in the bond and
> +          is up, it will be made active.  Relevant only when <ref
> +          column="other_config" key="bond-mode"/> is
> +          <code>active-backup</code>.
> +        </column>
> +
>         <column name="bond_updelay">
>           <p>
>             The number of milliseconds for which the link must stay up on an
> -- 
> 2.22.0
>

Patch
diff mbox series

diff --git a/ofproto/bond.c b/ofproto/bond.c
index 405202fb6..2437246ca 100644
--- a/ofproto/bond.c
+++ b/ofproto/bond.c
@@ -93,6 +93,7 @@  struct bond_slave {
     /* Link status. */
     bool enabled;               /* May be chosen for flows? */
     bool may_enable;            /* Client considers this slave bondable. */
+    bool is_primary;            /* This slave is preferred over others. */
     long long delay_expires;    /* Time after which 'enabled' may change. */
 
     /* Rebalancing info.  Used only by bond_rebalance(). */
@@ -126,6 +127,7 @@  struct bond {
     enum lacp_status lacp_status; /* Status of LACP negotiations. */
     bool bond_revalidate;       /* True if flows need revalidation. */
     uint32_t basis;             /* Basis for flow hash function. */
+    char *primary;              /* Name of the primary slave interface. */
 
     /* SLB specific bonding info. */
     struct bond_entry *hash;     /* An array of BOND_BUCKETS elements. */
@@ -241,6 +243,7 @@  bond_create(const struct bond_settings *s, struct ofproto_dpif *ofproto)
 
     bond->active_slave_mac = eth_addr_zero;
     bond->active_slave_changed = false;
+    bond->primary = NULL;
 
     bond_reconfigure(bond, s);
     return bond;
@@ -290,6 +293,7 @@  bond_unref(struct bond *bond)
     update_recirc_rules__(bond);
 
     hmap_destroy(&bond->pr_rule_ops);
+    free(bond->primary);
     free(bond->name);
     free(bond);
 }
@@ -459,6 +463,31 @@  bond_reconfigure(struct bond *bond, const struct bond_settings *s)
         bond->bond_revalidate = false;
     }
 
+    /*
+     * If a primary interface is set on the new settings:
+     * 1. If the bond has no primary previously set, save it and
+     * revalidate.
+     * 2. If the bond has a different primary previously set, save the
+     * new one and revalidate.
+     * 3. If the bond has the same primary previously set, do nothing.
+     */
+    if (s->primary) {
+        bool changed = false;
+        if (bond->primary) {
+            if (strcmp(bond->primary, s->primary) != 0) {
+                free(bond->primary);
+                changed = true;
+            }
+        } else {
+            changed = true;
+        }
+
+        if (changed) {
+            bond->primary = xstrdup(s->primary);
+            revalidate = true;
+        }
+    }
+
     if (bond->balance != BM_AB) {
         if (!bond->recirc_id) {
             bond->recirc_id = recirc_alloc_id(bond->ofproto);
@@ -549,6 +578,12 @@  bond_slave_register(struct bond *bond, void *slave_,
         slave->name = xstrdup(netdev_get_name(netdev));
         bond->bond_revalidate = true;
 
+        if (bond->primary && strcmp(bond->primary, slave->name) == 0) {
+            slave->is_primary = true;
+        } else {
+            slave->is_primary = false;
+        }
+
         slave->enabled = false;
         bond_enable_slave(slave, netdev_get_carrier(netdev));
     }
@@ -644,6 +679,7 @@  bond_run(struct bond *bond, enum lacp_status lacp_status)
 {
     struct bond_slave *slave;
     bool revalidate;
+    struct bond_slave *primary;
 
     ovs_rwlock_wrlock(&rwlock);
     if (bond->lacp_status != lacp_status) {
@@ -659,11 +695,19 @@  bond_run(struct bond *bond, enum lacp_status lacp_status)
     }
 
     /* Enable slaves based on link status and LACP feedback. */
+    primary = NULL;
     HMAP_FOR_EACH (slave, hmap_node, &bond->slaves) {
         bond_link_status_update(slave);
         slave->change_seq = seq_read(connectivity_seq_get());
+
+        /* Discover if there is an active slave marked "primary". */
+        if (bond->balance == BM_AB && slave->is_primary && slave->enabled) {
+            primary = slave;
+        }
     }
-    if (!bond->active_slave || !bond->active_slave->enabled) {
+
+    if (!bond->active_slave || !bond->active_slave->enabled ||
+        (primary && bond->active_slave != primary)) {
         bond_choose_active_slave(bond);
     }
 
@@ -1393,6 +1437,11 @@  bond_print_details(struct ds *ds, const struct bond *bond)
     ds_put_format(ds, "lacp_fallback_ab: %s\n",
                   bond->lacp_fallback_ab ? "true" : "false");
 
+    if (bond->balance == BM_AB) {
+        ds_put_format(ds, "primary: %s\n",
+                      bond->primary ? bond->primary : "<none>");
+    }
+
     ds_put_cstr(ds, "active slave mac: ");
     ds_put_format(ds, ETH_ADDR_FMT, ETH_ADDR_ARGS(bond->active_slave_mac));
     slave = bond_find_slave_by_mac(bond, bond->active_slave_mac);
@@ -1862,6 +1911,13 @@  bond_choose_slave(const struct bond *bond)
 {
     struct bond_slave *slave, *best;
 
+    /* If there's a primary and it's active, return that. */
+    HMAP_FOR_EACH (slave, hmap_node, &bond->slaves) {
+        if (slave->is_primary && slave->enabled) {
+            return slave;
+        }
+    }
+
     /* Find the last active slave. */
     slave = bond_find_slave_by_mac(bond, bond->active_slave_mac);
     if (slave && slave->enabled) {
diff --git a/ofproto/bond.h b/ofproto/bond.h
index e7c3d9bc3..3a923dcfa 100644
--- a/ofproto/bond.h
+++ b/ofproto/bond.h
@@ -45,6 +45,7 @@  struct bond_settings {
 
     /* Balancing configuration. */
     enum bond_mode balance;
+    const char *primary;        /* For AB balance, primary interface name. */
     int rebalance_interval;     /* Milliseconds between rebalances.
                                    Zero to disable rebalancing. */
 
diff --git a/tests/lacp.at b/tests/lacp.at
index 7b460d7be..696ffc6d4 100644
--- a/tests/lacp.at
+++ b/tests/lacp.at
@@ -125,6 +125,7 @@  updelay: 0 ms
 downdelay: 0 ms
 lacp_status: negotiated
 lacp_fallback_ab: false
+primary: <none>
 active slave mac: 00:00:00:00:00:00(none)
 
 slave p1: disabled
diff --git a/tests/ofproto-dpif.at b/tests/ofproto-dpif.at
index d444cf084..de499bd9a 100644
--- a/tests/ofproto-dpif.at
+++ b/tests/ofproto-dpif.at
@@ -29,7 +29,82 @@  AT_CHECK([ovs-appctl revalidator/wait])
 OVS_VSWITCHD_STOP
 AT_CLEANUP
 
-AT_SETUP([ofproto-dpif - active-backup bonding])
+AT_SETUP([ofproto-dpif - active-backup bonding (with primary)])
+
+# Create br0 with interfaces p1, p2 and p7, creating bond0 with p1 and
+#    p2 (p1 as primary) and br1 with interfaces p3, p4 and p8.
+# toggle p1,p2 of bond0 up and down to test bonding in active-backup mode.
+# With p1 down and p2 up/active, bring p1 back up.  Since p1 is the primary,
+# it should become active.
+OVS_VSWITCHD_START(
+  [add-bond br0 bond0 p1 p2 bond_mode=active-backup \
+                other_config:bond-primary=p1 -- \
+   set interface p1 type=dummy options:pstream=punix:$OVS_RUNDIR/p1.sock ofport_request=1 -- \
+   set interface p2 type=dummy options:pstream=punix:$OVS_RUNDIR/p2.sock ofport_request=2 -- \
+   add-port br0 p7 -- set interface p7 ofport_request=7 type=dummy -- \
+   add-br br1 -- \
+   set bridge br1 other-config:hwaddr=aa:66:aa:66:00:00 -- \
+   set bridge br1 datapath-type=dummy other-config:datapath-id=1234 \
+                  fail-mode=secure -- \
+   add-port br1 p3 -- set interface p3 type=dummy options:stream=unix:$OVS_RUNDIR/p1.sock ofport_request=3 -- \
+   add-port br1 p4 -- set interface p4 type=dummy options:stream=unix:$OVS_RUNDIR/p2.sock ofport_request=4 -- \
+   add-port br1 p8 -- set interface p8 ofport_request=8 type=dummy --])
+WAIT_FOR_DUMMY_PORTS([p3], [p4])
+AT_CHECK([test -n "`ovs-appctl bond/show | grep 'primary: p1'`"])
+AT_CHECK([ovs-appctl vlog/set dpif:dbg dpif_netdev:dbg])
+
+AT_CHECK([ovs-ofctl add-flow br0 action=normal])
+AT_CHECK([ovs-ofctl add-flow br1 action=normal])
+ovs-appctl netdev-dummy/set-admin-state up
+ovs-appctl time/warp 100
+ovs-appctl netdev-dummy/set-admin-state p2 down
+ovs-appctl time/stop
+ovs-appctl time/warp 100
+AT_CHECK([ovs-appctl netdev-dummy/receive p7 'in_port(7),eth(src=50:54:00:00:00:09,dst=50:54:00:00:00:0a),eth_type(0x0800),ipv4(src=10.0.0.2,dst=10.0.0.1,proto=1,tos=0,ttl=64,frag=no),icmp(type=8,code=0)'])
+AT_CHECK([ovs-appctl netdev-dummy/receive p7 'in_port(7),eth(src=50:54:00:00:00:0b,dst=50:54:00:00:00:0c),eth_type(0x0800),ipv4(src=10.0.0.3,dst=10.0.0.4,proto=1,tos=0,ttl=64,frag=no),icmp(type=8,code=0)'])
+ovs-appctl time/warp 100
+ovs-appctl netdev-dummy/set-admin-state p2 up
+ovs-appctl netdev-dummy/set-admin-state p1 down
+wovs-appctl time/warp 100
+AT_CHECK([ovs-appctl netdev-dummy/receive p7 'in_port(7),eth(src=50:54:00:00:00:09,dst=50:54:00:00:00:0d),eth_type(0x0800),ipv4(src=10.0.0.5,dst=10.0.0.1,proto=1,tos=0,ttl=64,frag=no),icmp(type=8,code=0)'])
+AT_CHECK([ovs-appctl netdev-dummy/receive p7 'in_port(7),eth(src=50:54:00:00:00:09,dst=50:54:00:00:00:0e),eth_type(0x0800),ipv4(src=10.0.0.6,dst=10.0.0.1,proto=1,tos=0,ttl=64,frag=no),icmp(type=8,code=0)'])
+ovs-appctl time/warp 200 100
+sleep 1
+AT_CHECK([grep 'in_port([[348]])' ovs-vswitchd.log | filter_flow_install | strip_xout], [0], [dnl
+recirc_id(0),in_port(3),packet_type(ns=0,id=0),eth(src=50:54:00:00:00:09,dst=50:54:00:00:00:0a),eth_type(0x0800),ipv4(frag=no), actions: <del>
+recirc_id(0),in_port(3),packet_type(ns=0,id=0),eth(src=50:54:00:00:00:0b,dst=50:54:00:00:00:0c),eth_type(0x0800),ipv4(frag=no), actions: <del>
+recirc_id(0),in_port(4),packet_type(ns=0,id=0),eth(src=50:54:00:00:00:09,dst=50:54:00:00:00:0d),eth_type(0x0800),ipv4(frag=no), actions: <del>
+recirc_id(0),in_port(4),packet_type(ns=0,id=0),eth(src=50:54:00:00:00:09,dst=50:54:00:00:00:0e),eth_type(0x0800),ipv4(frag=no), actions: <del>
+recirc_id(0),in_port(4),packet_type(ns=0,id=0),eth(src=50:54:00:00:00:09,dst=ff:ff:ff:ff:ff:ff),eth_type(0x8035), actions: <del>
+recirc_id(0),in_port(4),packet_type(ns=0,id=0),eth(src=50:54:00:00:00:0b,dst=ff:ff:ff:ff:ff:ff),eth_type(0x8035), actions: <del>
+])
+
+ovs-appctl netdev-dummy/set-admin-state p1 up
+AT_CHECK([ovs-appctl bond/show | STRIP_RECIRC_ID | STRIP_ACTIVE_SLAVE_MAC], [0], [dnl
+---- bond0 ----
+bond_mode: active-backup
+bond may use recirculation: no, <del>
+bond-hash-basis: 0
+updelay: 0 ms
+downdelay: 0 ms
+lacp_status: off
+lacp_fallback_ab: false
+primary: p1
+<active slave mac del>
+
+slave p1: enabled
+  active slave
+  may_enable: true
+
+slave p2: enabled
+  may_enable: true
+
+])
+
+OVS_VSWITCHD_STOP
+AT_CLEANUP
+
+AT_SETUP([ofproto-dpif - active-backup bonding (without primary)])
 # Create br0 with interfaces p1, p2 and p7, creating bond0 with p1 and p2
 #    and br1 with interfaces p3, p4 and p8.
 # toggle p1,p2 of bond0 up and down to test bonding in active-backup mode.
@@ -46,6 +121,7 @@  OVS_VSWITCHD_START(
    add-port br1 p4 -- set interface p4 type=dummy options:stream=unix:$OVS_RUNDIR/p2.sock ofport_request=4 -- \
    add-port br1 p8 -- set interface p8 ofport_request=8 type=dummy --])
 WAIT_FOR_DUMMY_PORTS([p3], [p4])
+AT_CHECK([test -n "`ovs-appctl bond/show | grep 'primary: <none>'`"])
 AT_CHECK([ovs-appctl vlog/set dpif:dbg dpif_netdev:dbg])
 
 AT_CHECK([ovs-ofctl add-flow br0 action=normal])
diff --git a/vswitchd/bridge.c b/vswitchd/bridge.c
index fe73c38d4..5f30b7737 100644
--- a/vswitchd/bridge.c
+++ b/vswitchd/bridge.c
@@ -4563,6 +4563,11 @@  port_configure_bond(struct port *port, struct bond_settings *s)
                   port->name);
     }
 
+    s->primary = NULL;
+    if (s->balance == BM_AB) {
+        s->primary = smap_get(&port->cfg->other_config, "bond-primary");
+    }
+
     miimon_interval = smap_get_int(&port->cfg->other_config,
                                    "bond-miimon-interval", 0);
     if (miimon_interval <= 0) {
diff --git a/vswitchd/vswitch.xml b/vswitchd/vswitch.xml
index 4a74ed3ef..f20b3cb6a 100644
--- a/vswitchd/vswitch.xml
+++ b/vswitchd/vswitch.xml
@@ -2016,6 +2016,14 @@ 
           key="bond-detect-mode"/> is <code>miimon</code>.
         </column>
 
+        <column name="other_config" key="bond-primary"
+                type='{"type": "string"}'>
+          If a slave interface with this name exists in the bond and
+          is up, it will be made active.  Relevant only when <ref
+          column="other_config" key="bond-mode"/> is
+          <code>active-backup</code>.
+        </column>
+
         <column name="bond_updelay">
           <p>
             The number of milliseconds for which the link must stay up on an