@@ -483,6 +483,33 @@ For users wanting to do packet forwarding using kernel stack below are the steps
where `-L`: Changes the numbers of channels of the specified network device
and `combined`: Changes the number of multi-purpose channels.
+ 4. Enable OVS vHost client-mode & vHost reconnect (OPTIONAL)
+
+ By default, OVS DPDK acts as the vHost socket server and QEMU the
+ client. In QEMU v2.7 the option is available for QEMU to act as the
+ server. In order for this to work, OVS DPDK must be switched to 'client'
+ mode. This is possible by setting the 'vhost-driver-mode' DB entry to
+ 'client' like so:
+
+ ```
+ ovs-vsctl set Open_vSwitch . other_config:vhost-driver-mode="client"
+ ```
+
+ This must be done before the switch is launched. It cannot sucessfully
+ be changed after switch has launched.
+
+ One must also append ',server' to the 'chardev' arguments on the QEMU
+ command line, to instruct QEMU to use vHost server mode, like so:
+
+ ````
+ -chardev socket,id=char0,path=/usr/local/var/run/openvswitch/vhost0,server
+ ````
+
+ One benefit of using this mode is the ability for vHost ports to
+ 'reconnect' in event of the switch crashing or being brought down. Once
+ it is brought back up, the vHost ports will reconnect automatically and
+ normal service will resume.
+
- VM Configuration with libvirt
* change the user/group, access control policty and restart libvirtd.
@@ -70,6 +70,7 @@ Post-v2.5.0
fragmentation or NAT support yet)
* Support for DPDK 16.07
* Remove dpdkvhostcuse port type.
+ * OVS client mode for vHost and vHost reconnect (Requires QEMU 2.7)
- Increase number of registers to 16.
- ovs-benchmark: This utility has been removed due to lack of use and
bitrot.
@@ -136,7 +136,8 @@ BUILD_ASSERT_DECL((MAX_NB_MBUF / ROUND_DOWN_POW2(MAX_NB_MBUF/MIN_NB_MBUF))
#define OVS_VHOST_QUEUE_DISABLED (-2) /* Queue was disabled by guest and not
* yet mapped to another queue. */
-static char *vhost_sock_dir = NULL; /* Location of vhost-user sockets */
+static char *vhost_sock_dir = NULL; /* Location of vhost-user sockets */
+static uint64_t vhost_driver_flags = 0; /* Denote whether client/server mode */
#define VHOST_ENQ_RETRY_NUM 8
#define IF_NAME_SZ (PATH_MAX > IFNAMSIZ ? PATH_MAX : IFNAMSIZ)
@@ -833,7 +834,6 @@ netdev_dpdk_vhost_user_construct(struct netdev *netdev)
struct netdev_dpdk *dev = netdev_dpdk_cast(netdev);
const char *name = netdev->name;
int err;
- uint64_t flags = 0;
/* 'name' is appended to 'vhost_sock_dir' and used to create a socket in
* the file system. '/' or '\' would traverse directories, so they're not
@@ -856,14 +856,17 @@ netdev_dpdk_vhost_user_construct(struct netdev *netdev)
snprintf(dev->vhost_id, sizeof(dev->vhost_id), "%s/%s",
vhost_sock_dir, name);
- err = rte_vhost_driver_register(dev->vhost_id, flags);
+ err = rte_vhost_driver_register(dev->vhost_id, vhost_driver_flags);
if (err) {
VLOG_ERR("vhost-user socket device setup failure for socket %s\n",
dev->vhost_id);
} else {
- fatal_signal_add_file_to_unlink(dev->vhost_id);
- VLOG_INFO("Socket %s created for vhost-user port %s\n",
- dev->vhost_id, name);
+ if (!(vhost_driver_flags & RTE_VHOST_USER_CLIENT)) {
+ /* OVS server mode - OVS may delete the socket */
+ fatal_signal_add_file_to_unlink(dev->vhost_id);
+ VLOG_INFO("Socket %s created for vhost-user port %s\n",
+ dev->vhost_id, name);
+ }
err = netdev_dpdk_init(netdev, -1, DPDK_DEV_VHOST);
}
@@ -927,7 +930,8 @@ netdev_dpdk_vhost_destruct(struct netdev *netdev)
if (rte_vhost_driver_unregister(dev->vhost_id)) {
VLOG_ERR("Unable to remove vhost-user socket %s", dev->vhost_id);
- } else {
+ } else if (!(vhost_driver_flags & RTE_VHOST_USER_CLIENT)) {
+ /* OVS server mode - OVS may delete the socket */
fatal_signal_remove_file_to_unlink(dev->vhost_id);
}
@@ -3181,6 +3185,7 @@ dpdk_init__(const struct smap *ovs_other_config)
int err = 0;
cpu_set_t cpuset;
char *sock_dir_subcomponent;
+ const char *val;
if (!smap_get_bool(ovs_other_config, "dpdk-init", false)) {
VLOG_INFO("DPDK Disabled - to change this requires a restart.\n");
@@ -3211,6 +3216,15 @@ dpdk_init__(const struct smap *ovs_other_config)
} else {
vhost_sock_dir = sock_dir_subcomponent;
}
+ val = smap_get(ovs_other_config, "vhost-driver-mode");
+ if (val != NULL && strncmp(val, "client", strlen(val)) == 0) {
+ vhost_driver_flags |= RTE_VHOST_USER_CLIENT;
+ VLOG_INFO("OVS client mode (QEMU server mode) selected for vHost");
+ } else {
+ /* default case */
+ vhost_driver_flags &= ~RTE_VHOST_USER_CLIENT;
+ VLOG_INFO("OVS server mode (QEMU client mode) selected for vHost");
+ }
argv = grow_argv(&argv, 0, 1);
argc = 1;
@@ -299,6 +299,19 @@
</p>
</column>
+ <column name="other_config" key="vhost-driver-mode"
+ type='{"type": "string", "enum": ["set", ["server", "client"]]}'>
+ <p>
+ Specifies which mode OVS will use for vHost. In 'server' mode, OVS
+ creates and destroys the vHost User sockets. In 'client' mode, OVS
+ attaches to sockets created by QEMU.
+ </p>
+ <p>
+ Defaults to 'server' mode. Changing this value requires restarting
+ the daemon.
+ </p>
+ </column>
+
<column name="other_config" key="n-handler-threads"
type='{"type": "integer", "minInteger": 1}'>
<p>
A new other_config DB option has been added called 'vhost-driver-mode'. By default this is set to 'server' which is the mode of operation OVS with DPDK has used up until this point - whereby OVS creates and manages vHost user sockets. If set to 'client', OVS will act as the vHost client and connect to sockets created and managed by QEMU which acts as the server. This mode allows for reconnect capability, which allows vHost ports to resume normal connectivity in event of switch reset. QEMU v2.7.0+ is required when using OVS in client mode and QEMU in server mode. Signed-off-by: Ciara Loftus <ciara.loftus@intel.com> --- INSTALL.DPDK-ADVANCED.md | 27 +++++++++++++++++++++++++++ NEWS | 1 + lib/netdev-dpdk.c | 28 +++++++++++++++++++++------- vswitchd/vswitch.xml | 13 +++++++++++++ 4 files changed, 62 insertions(+), 7 deletions(-)