| Message ID | 20230113145828.974604-1-rjarry@redhat.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [ovs-dev,v8] netdev-dpdk: add control plane protection support | expand |
| Context | Check | Description |
|---|---|---|
| ovsrobot/apply-robot | success | apply and check: success |
| ovsrobot/github-robot-_Build_and_Test | success | github build: passed |
| ovsrobot/intel-ovs-compilation | fail | test: fail |
Hi Robin, A few additional comments below. I saw in patchwork that there was a CI fail but I didn't examine it. Perhaps you could check and confirm about it. thanks, Kevin. On 13/01/2023 14:58, Robin Jarry wrote: > Some control protocols are used to maintain link status between > forwarding engines (e.g. LACP). When the system is not sized properly, > the PMD threads may not be able to process all incoming traffic from the > configured Rx queues. When a signaling packet of such protocols is > dropped, it can cause link flapping, worsening the situation. > > Use the RTE flow API to redirect these protocols into a dedicated Rx > queue. The assumption is made that the ratio between control protocol > traffic and user data traffic is very low and thus this dedicated Rx > queue will never get full. The RSS redirection table is re-programmed to > only use the other Rx queues. The RSS table size is stored in the > netdev_dpdk structure at port initialization to avoid requesting the > information again when changing the port configuration. > > The additional Rx queue will be assigned a PMD core like any other Rx > queue. Polling that extra queue may introduce increased latency and > a slight performance penalty at the benefit of preventing link flapping. > > This feature must be enabled per port on specific protocols via the > cp-protection option. This option takes a coma-separated list of > protocol names. It is only supported on ethernet ports. This feature is > experimental. > > If the user has already configured multiple Rx queues on the port, an > additional one will be allocated for control plane packets. If the > hardware cannot satisfy the requested number of requested Rx queues, the > last Rx queue will be assigned for control plane. If only one Rx queue > is available, the cp-protection feature will be disabled. If the > hardware does not support the RTE flow matchers/actions, the feature > will be disabled. > > It cannot be enabled when other_config:hw-offload=true as it may > conflict with the offloaded RTE flows. Similarly, if hw-offload is > enabled while some ports already have cp-protection enabled, RTE flow > offloading will be disabled on these ports. > I'm not sure if you are referring the features hw-offload and/or cp-prot when you say RTE flow offloading will be disabled on these ports. What I see is that if cp-prot is enabled on a port and then hw-offload is enabled by the user, hw-offload will not enable because of cp-prot AND cp-prot will also be disabled by virtue the user trying to enable hw-offload. I was not expecting that last part, even if they are mutually exclusive features I thought one would work. Perhaps that is intentional and what you meant above, I wasn't 100% clear. Anyway, I understand this is just experimental and there is a lot of scenarios to cover between the features (e.g. what if one of the features could not rte_flow_validate(), could the other be used then?) I think you would need to them tease out in the future and if they stay mutually exclusive that there is a clear precedence either by feature or order enabled etc. You might even need to put a table in docs to show the user. > Example use: > > ovs-vsctl add-bond br-phy bond0 phy0 phy1 -- \ > set interface phy0 type=dpdk options:dpdk-devargs=0000:ca:00.0 -- \ > set interface phy0 options:cp-protection=lacp -- \ > set interface phy1 type=dpdk options:dpdk-devargs=0000:ca:00.1 -- \ > set interface phy1 options:cp-protection=lacp > > As a starting point, only one protocol is supported: LACP. Other > protocols can be added in the future. NIC compatibility should be > checked. > > To validate that this works as intended, I used a traffic generator to > generate random traffic slightly above the machine capacity at line rate > on a two ports bond interface. OVS is configured to receive traffic on > two VLANs and pop/push them in a br-int bridge based on tags set on > patch ports. > > +----------------------+ > | DUT | > |+--------------------+| > || br-int || default flow, action=NORMAL > || || > || patch10 patch11 || > |+---|-----------|----+| > | | | | > |+---|-----------|----+| > || patch00 patch01 || > || tag:10 tag:20 || > || || > || br-phy || default flow, action=NORMAL > || || > || bond0 || balance-slb, lacp=passive, lacp-time=fast > || phy0 phy1 || > |+------|-----|-------+| > +-------|-----|--------+ > | | > +-------|-----|--------+ > | port0 port1 | balance L3/L4, lacp=active, lacp-time=fast > | lag | mode trunk VLANs 10, 20 > | | > | switch | > | | > | vlan 10 vlan 20 | mode access > | port2 port3 | > +-----|----------|-----+ > | | > +-----|----------|-----+ > | port0 port1 | Random traffic that is properly balanced > | | across the bond ports in both directions. > | traffic generator | > +----------------------+ > > Without cp-protection, the bond0 links are randomly switching to > "defaulted" when one of the LACP packets sent by the switch is dropped > because the RX queues are full and the PMD threads did not process them > fast enough. When that happens, all traffic must go through a single > link which causes above line rate traffic to be dropped. > > When cp-protection is enabled, no LACP packet is dropped and the bond > links remain enabled at all times, maximizing the throughput. > > This feature may be considered as "QoS". However, it does not work by > limiting the rate of traffic explicitly. It only guarantees that some > protocols have a lower chance of being dropped because the PMD cores > cannot keep up with regular traffic. > > The choice of protocols is limited on purpose. This is not meant to be > configurable by users. Some limited configurability could be considered > in the future but it would expose to more potential issues if users are > accidentally redirecting all traffic in the control plane queue. > > Cc: Christophe Fontaine <cfontain@redhat.com> > Cc: Kevin Traynor <ktraynor@redhat.com> > Cc: David Marchand <david.marchand@redhat.com> > Signed-off-by: Robin Jarry <rjarry@redhat.com> > --- > v6 -> v7: > > * Fixed double free in case of cp-protection configuration fail. > * Fixed segmentation fault when creating vhost user ports. > * Removed redundant rss reconfiguration before stopping, reconfiguring > and restarting the port (with or without cp protection enabled). > > Documentation/topics/dpdk/phy.rst | 77 ++++++++ > NEWS | 3 + > lib/netdev-dpdk.c | 300 +++++++++++++++++++++++++++++- > vswitchd/vswitch.xml | 26 +++ > 4 files changed, 403 insertions(+), 3 deletions(-) > > diff --git a/Documentation/topics/dpdk/phy.rst b/Documentation/topics/dpdk/phy.rst > index 4b0fe8dded3a..518b67134639 100644 > --- a/Documentation/topics/dpdk/phy.rst > +++ b/Documentation/topics/dpdk/phy.rst > @@ -131,6 +131,83 @@ possible with DPDK acceleration. It is possible to configure multiple Rx queues > for ``dpdk`` ports, thus ensuring this is not a bottleneck for performance. For > information on configuring PMD threads, refer to :doc:`pmd`. > > +Control Plane Protection > +------------------------ > + > +.. warning:: This feature is experimental. > + > +Some control protocols are used to maintain link status between forwarding > +engines. In SDN environments, these packets share the same physical network > +than the user data traffic. > + > +When the system is not sized properly, the PMD threads may not be able to > +process all incoming traffic from the configured Rx queues. When a signaling > +packet of such protocols is dropped, it can cause link flapping, worsening the > +situation. > + > +Some physical NICs can be programmed to put these protocols in a dedicated > +hardware Rx queue using the rte_flow__ API. > + > +__ https://doc.dpdk.org/guides-22.11/prog_guide/rte_flow.html > + > +The currently supported control plane protocols are: > + > +``lacp`` > + `Link Aggregation Control Protocol`__. Ether type ``0x8809``. > + > + __ https://www.ieee802.org/3/ad/public/mar99/seaman_1_0399.pdf > + > +.. warning:: > + > + This feature is not compatible with all NICs. Refer to the DPDK > + `compatibilty matrix`__ and vendor documentation for more details. > + > + __ https://doc.dpdk.org/guides-22.11/nics/overview.html > + > +Control plane protection must be enabled on specific protocols per port. The > +``cp-protection`` option requires a coma separated list of protocol names:: > + > + $ ovs-vsctl add-port br0 dpdk-p0 -- set Interface dpdk-p0 type=dpdk \ > + options:dpdk-devargs=0000:01:00.0 options:n_rxq=2 \ > + options:cp-protection=lacp > + > +.. note:: > + > + If multiple Rx queues are already configured, regular RSS (Receive Side > + Scaling) queue balancing is done on all but the extra control plane > + protection queue. > + > +.. tip:: > + > + You can check if control plane protection is supported on a port with the > + following command:: > + > + $ ovs-vsctl get interface dpdk-p0 status > + {cp_protection_queue="2", driver_name=..., rss_queues="0-1"} > + > + This will also show in ``ovs-vswitchd.log``:: > + > + INFO|dpdk-p0: cp-protection: redirecting lacp traffic to queue 2 > + INFO|dpdk-p0: cp-protection: applying rss on queues 0-1 > + > + If the hardware does not support redirecting control plane traffic to > + a dedicated queue, it will be explicit:: > + > + $ ovs-vsctl get interface dpdk-p0 status > + {cp_protection=unsupported, driver_name=...} > + > + More details can often be found in ``ovs-vswitchd.log``:: > + > + WARN|dpdk-p0: cp-protection: failed to add lacp flow: Unsupported pattern > + > +To disable control plane protection on a port, use the following command:: > + > + $ ovs-vsctl remove Interface dpdk-p0 options cp-protection > + > +You can see that it has been disabled in ``ovs-vswitchd.log``:: > + > + INFO|dpdk-p0: cp-protection: disabled > + > .. _dpdk-phy-flow-control: > > Flow Control > diff --git a/NEWS b/NEWS > index 2f6ededfe47d..685a9aae5427 100644 > --- a/NEWS > +++ b/NEWS > @@ -17,6 +17,9 @@ Post-v3.0.0 > * Conntrack IPv6 fragment support. > - DPDK: > * Add support for DPDK 22.11.1. > + * New experimental "cp-protection=<protocol>" option to redirect certain > + protocols (for now, only LACP) to a dedicated hardware queue using > + RTE flow. > - For the QoS max-rate and STP/RSTP path-cost configuration OVS now assumes > 10 Gbps link speed by default in case the actual link speed cannot be > determined. Previously it was 10 Mbps. Values can still be overridden > diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c > index 5e2d64651db3..2f4fa5b8535c 100644 > --- a/lib/netdev-dpdk.c > +++ b/lib/netdev-dpdk.c > @@ -414,6 +414,10 @@ enum dpdk_hw_ol_features { > NETDEV_TX_SCTP_CHECKSUM_OFFLOAD = 1 << 4, > }; > > +enum dpdk_cp_prot_flags { > + DPDK_CP_PROT_LACP = 1 << 0, > +}; > + > /* > * In order to avoid confusion in variables names, following naming convention > * should be used, if possible: > @@ -508,6 +512,9 @@ struct netdev_dpdk { > int requested_rxq_size; > int requested_txq_size; > > + /* User input for n_rxq (see netdev_dpdk_reconfigure). */ This comment is nice. minor: 'requested_n_rxq' could get a comment now that it is no longer the user requested value and isn't the same as the other requested_* members anymore. > + int user_n_rxq; . > + > /* Number of rx/tx descriptors for physical devices */ > int rxq_size; > int txq_size; > @@ -533,6 +540,13 @@ struct netdev_dpdk { > > /* VF configuration. */ > struct eth_addr requested_hwaddr; > + > + /* Requested control plane protection flags, > + * from the enum set 'dpdk_cp_prot_flags'. */ > + uint64_t requested_cp_prot_flags; > + uint64_t cp_prot_flags; > + size_t cp_prot_flows_num; > + struct rte_flow **cp_prot_flows; > ); > > PADDED_MEMBERS(CACHE_LINE_SIZE, > @@ -1309,9 +1323,14 @@ common_construct(struct netdev *netdev, dpdk_port_t port_no, > netdev->n_rxq = 0; > netdev->n_txq = 0; > dev->requested_n_rxq = NR_QUEUE; > + dev->user_n_rxq = NR_QUEUE; > dev->requested_n_txq = NR_QUEUE; > dev->requested_rxq_size = NIC_PORT_DEFAULT_RXQ_SIZE; > dev->requested_txq_size = NIC_PORT_DEFAULT_TXQ_SIZE; > + dev->requested_cp_prot_flags = 0; > + dev->cp_prot_flags = 0; > + dev->cp_prot_flows_num = 0; > + dev->cp_prot_flows = NULL; > > /* Initialize the flow control to NULL */ > memset(&dev->fc_conf, 0, sizeof dev->fc_conf); > @@ -1486,6 +1505,8 @@ common_destruct(struct netdev_dpdk *dev) > ovs_mutex_destroy(&dev->mutex); > } > > +static void dpdk_cp_prot_unconfigure(struct netdev_dpdk *dev); > + > static void > netdev_dpdk_destruct(struct netdev *netdev) > { > @@ -1493,6 +1514,9 @@ netdev_dpdk_destruct(struct netdev *netdev) > > ovs_mutex_lock(&dpdk_mutex); > > + /* Destroy any rte flows to allow RXQs to be removed. */ > + dpdk_cp_prot_unconfigure(dev); > + > rte_eth_dev_stop(dev->port_id); > dev->started = false; > > @@ -1907,8 +1931,8 @@ dpdk_set_rxq_config(struct netdev_dpdk *dev, const struct smap *args) > int new_n_rxq; > > new_n_rxq = MAX(smap_get_int(args, "n_rxq", NR_QUEUE), 1); > - if (new_n_rxq != dev->requested_n_rxq) { > - dev->requested_n_rxq = new_n_rxq; > + if (new_n_rxq != dev->user_n_rxq) { > + dev->user_n_rxq = new_n_rxq; > netdev_request_reconfigure(&dev->up); > } > } > @@ -1930,6 +1954,48 @@ dpdk_process_queue_size(struct netdev *netdev, const struct smap *args, > } > } > > +static void > +dpdk_cp_prot_set_config(struct netdev *netdev, struct netdev_dpdk *dev, > + const struct smap *args, char **errp) > +{ > + const char *arg = smap_get_def(args, "cp-protection", ""); > + char *token, *saveptr, *buf; > + uint64_t flags = 0; > + > + buf = xstrdup(arg); > + token = strtok_r(buf, ",", &saveptr); > + while (token) { > + if (strcmp(token, "lacp") == 0) { > + flags |= DPDK_CP_PROT_LACP; > + } else { > + VLOG_WARN_BUF(errp, "%s options:cp-protection " > + "unknown protocol '%s'", > + netdev_get_name(netdev), token); > + } > + token = strtok_r(NULL, ",", &saveptr); > + } > + free(buf); > + > + if (flags && dev->type != DPDK_DEV_ETH) { > + VLOG_WARN_BUF(errp, "%s options:cp-protection " > + "is only supported on ethernet ports", > + netdev_get_name(netdev)); > + flags = 0; > + } > + > + if (flags && netdev_is_flow_api_enabled()) { > + VLOG_WARN_BUF(errp, "%s options:cp-protection " > + "is incompatible with hw-offload", > + netdev_get_name(netdev)); > + flags = 0; > + } > + > + if (flags != dev->requested_cp_prot_flags) { > + dev->requested_cp_prot_flags = flags; > + netdev_request_reconfigure(netdev); > + } > +} > + > static int > netdev_dpdk_set_config(struct netdev *netdev, const struct smap *args, > char **errp) > @@ -1949,6 +2015,8 @@ netdev_dpdk_set_config(struct netdev *netdev, const struct smap *args, > ovs_mutex_lock(&dpdk_mutex); > ovs_mutex_lock(&dev->mutex); > > + dpdk_cp_prot_set_config(netdev, dev, args, errp); > + > dpdk_set_rxq_config(dev, args); > > dpdk_process_queue_size(netdev, args, "n_rxq_desc", > @@ -3825,9 +3893,12 @@ netdev_dpdk_get_status(const struct netdev *netdev, struct smap *args) > { > struct netdev_dpdk *dev = netdev_dpdk_cast(netdev); > struct rte_eth_dev_info dev_info; > + size_t cp_prot_flows_num; > + uint64_t cp_prot_flags; > const char *bus_info; > uint32_t link_speed; > uint32_t dev_flags; > + int n_rxq; > > if (!rte_eth_dev_is_valid_port(dev->port_id)) { > return ENODEV; > @@ -3839,6 +3910,9 @@ netdev_dpdk_get_status(const struct netdev *netdev, struct smap *args) > link_speed = dev->link.link_speed; > dev_flags = *dev_info.dev_flags; > bus_info = rte_dev_bus_info(dev_info.device); > + cp_prot_flags = dev->cp_prot_flags; > + cp_prot_flows_num = dev->cp_prot_flows_num; > + n_rxq = netdev->n_rxq; > ovs_mutex_unlock(&dev->mutex); > ovs_mutex_unlock(&dpdk_mutex); > > @@ -3881,6 +3955,19 @@ netdev_dpdk_get_status(const struct netdev *netdev, struct smap *args) > ETH_ADDR_ARGS(dev->hwaddr)); > } > > + if (cp_prot_flags) { > + if (!cp_prot_flows_num) { > + smap_add(args, "cp_protection", "unsupported"); > + } else { > + smap_add_format(args, "cp_protection_queue", "%d", n_rxq - 1); > + if (n_rxq > 2) { > + smap_add_format(args, "rss_queues", "0-%d", n_rxq - 2); > + } else { > + smap_add(args, "rss_queues", "0"); > + } > + } > + } > + > return 0; > } > > @@ -5105,16 +5192,197 @@ static const struct dpdk_qos_ops trtcm_policer_ops = { > .qos_queue_dump_state_init = trtcm_policer_qos_queue_dump_state_init > }; > > +static int > +dpdk_cp_prot_add_flow(struct netdev_dpdk *dev, > + const struct rte_flow_item items[], > + const char *desc) > +{ > + const struct rte_flow_attr attr = { .ingress = 1 }; > + const struct rte_flow_action actions[] = { > + { > + .type = RTE_FLOW_ACTION_TYPE_QUEUE, > + .conf = &(const struct rte_flow_action_queue) { > + .index = dev->up.n_rxq - 1, > + }, > + }, > + { .type = RTE_FLOW_ACTION_TYPE_END }, > + }; > + struct rte_flow_error error; > + struct rte_flow *flow; > + size_t num; > + int err; > + I have seen that ixgbe sets the error struct when returning success which seems a violation of the rte_flow_validation/create API ("PMDs initialize this structure in case of error only".) It's ok because you rightly ignore the error message, but it got me thinking that we should reset/validate the error messages. See below. + set_error(&error, RTE_FLOW_ERROR_TYPE_NONE); > + err = rte_flow_validate(dev->port_id, &attr, items, actions, &error); > + if (err) { > + VLOG_WARN("%s: cp-protection: device does not support %s flow: %s", > + netdev_get_name(&dev->up), desc, error.message); - netdev_get_name(&dev->up), desc, error.message); + netdev_get_name(&dev->up), desc, + error.message ? error.message : ""); > + goto out; > + } > + + set_error(&error, RTE_FLOW_ERROR_TYPE_NONE); > + flow = rte_flow_create(dev->port_id, &attr, items, actions, &error); > + if (flow == NULL) { > + VLOG_WARN("%s: cp-protection: failed to add %s flow: %s", > + netdev_get_name(&dev->up), desc, error.message); - netdev_get_name(&dev->up), desc, error.message); + netdev_get_name(&dev->up), desc, + error.message ? error.message : ""); > + err = rte_errno; > + goto out; > + } > + > + num = dev->cp_prot_flows_num + 1; > + dev->cp_prot_flows = xrealloc(dev->cp_prot_flows, sizeof(flow) * num); > + dev->cp_prot_flows[dev->cp_prot_flows_num] = flow; > + dev->cp_prot_flows_num = num; > + > + VLOG_INFO("%s: cp-protection: redirected %s traffic to rx queue %d", > + netdev_get_name(&dev->up), desc, dev->up.n_rxq - 1); > +out: > + return err; > +} > + > +#define RETA_CONF_SIZE (RTE_ETH_RSS_RETA_SIZE_512 / RTE_ETH_RETA_GROUP_SIZE) > + > +static int > +dpdk_cp_prot_rss_configure(struct netdev_dpdk *dev, int rss_n_rxq) > +{ > + struct rte_eth_rss_reta_entry64 reta_conf[RETA_CONF_SIZE]; > + struct rte_eth_dev_info info; > + int err; > + > + rte_eth_dev_info_get(dev->port_id, &info); > + > + if (info.reta_size % rss_n_rxq != 0 && > + info.reta_size < RTE_ETH_RSS_RETA_SIZE_128) { > + /* > + * Some drivers set reta_size equal to the total number of rxqs that > + * are configured when it is a power of two. Since we are actually > + * reconfiguring the redirection table to exclude the last rxq, we may > + * end up with an imbalanced redirection table. For example, such > + * configuration: > + * > + * options:n_rxq=3 options:cp-protection=lacp > + * > + * Will actually configure 4 rxqs on the NIC, and the default reta to: > + * > + * [0, 1, 2, 3] > + * > + * And dpdk_cp_prot_rss_configure() will reconfigure reta to: > + * > + * [0, 1, 2, 0] > + * > + * Causing queue 0 to receive twice as much traffic as queues 1 and 2. > + * > + * Work around that corner case by forcing a bigger redirection table > + * size to 128 entries when reta_size is not a multiple of rss_n_rxq > + * and when reta_size is less than 128. This value seems to be > + * supported by most of the drivers that also support rte flow. > + */ > + info.reta_size = RTE_ETH_RSS_RETA_SIZE_128; > + } > + > + memset(reta_conf, 0, sizeof(reta_conf)); > + for (uint16_t i = 0; i < info.reta_size; i++) { > + uint16_t idx = i / RTE_ETH_RETA_GROUP_SIZE; > + uint16_t shift = i % RTE_ETH_RETA_GROUP_SIZE; > + reta_conf[idx].mask |= 1ULL << shift; > + reta_conf[idx].reta[shift] = i % rss_n_rxq; > + } > + err = rte_eth_dev_rss_reta_update(dev->port_id, reta_conf, info.reta_size); > + if (err < 0) { > + VLOG_WARN("%s: failed to configure RSS redirection table: err=%d", > + netdev_get_name(&dev->up), err); > + } > + > + return err; > +} > + > +static int > +dpdk_cp_prot_configure(struct netdev_dpdk *dev) > +{ > + int err = 0; > + > + if (dev->up.n_rxq < 2) { > + err = ENOTSUP; > + VLOG_WARN("%s: cp-protection: not enough available rx queues", > + netdev_get_name(&dev->up)); > + goto out; > + } > + > + if (dev->requested_cp_prot_flags & DPDK_CP_PROT_LACP) { > + const struct rte_flow_item items[] = { > + { > + .type = RTE_FLOW_ITEM_TYPE_ETH, > + .spec = &(const struct rte_flow_item_eth){ > + .type = htons(ETH_TYPE_LACP), > + }, > + .mask = &(const struct rte_flow_item_eth){ > + .type = htons(0xffff), > + }, > + }, > + { .type = RTE_FLOW_ITEM_TYPE_END }, > + }; > + err = dpdk_cp_prot_add_flow(dev, items, "lacp"); > + if (err) { > + goto out; > + } > + } > + > + if (dev->cp_prot_flows_num) { > + /* Reconfigure RSS reta in all but the cp protection queue. */ > + err = dpdk_cp_prot_rss_configure(dev, dev->up.n_rxq - 1); > + if (!err) { > + if (dev->up.n_rxq == 2) { > + VLOG_INFO("%s: cp-protection: redirected other traffic to " > + "rx queue 0", netdev_get_name(&dev->up)); > + } else { > + VLOG_INFO("%s: cp-protection: applied rss on rx queue 0-%u", > + netdev_get_name(&dev->up), dev->up.n_rxq - 2); > + } > + } > + } > + > +out: > + return err; > +} > + > +static void > +dpdk_cp_prot_unconfigure(struct netdev_dpdk *dev) > +{ > + struct rte_flow_error error; > + > + if (!dev->cp_prot_flows_num) { > + return; > + } > + > + VLOG_DBG("%s: cp-protection: reset flows", netdev_get_name(&dev->up)); > + > + for (int i = 0; i < dev->cp_prot_flows_num; i++) { reset and validate error here also similar to rte_flow_validate/create. > + if (rte_flow_destroy(dev->port_id, dev->cp_prot_flows[i], &error)) { > + VLOG_DBG("%s: cp-protection: failed to destroy flow: %s", > + netdev_get_name(&dev->up), error.message); > + } > + } > + free(dev->cp_prot_flows); > + dev->cp_prot_flows_num = 0; > + dev->cp_prot_flows = NULL; > +} > + > static int > netdev_dpdk_reconfigure(struct netdev *netdev) > { > struct netdev_dpdk *dev = netdev_dpdk_cast(netdev); > + bool try_cp_prot; > int err = 0; > > ovs_mutex_lock(&dev->mutex); > > + try_cp_prot = dev->requested_cp_prot_flags != 0; > + dev->requested_n_rxq = dev->user_n_rxq; > + if (try_cp_prot) { > + dev->requested_n_rxq += 1; > + } > + > if (netdev->n_txq == dev->requested_n_txq > && netdev->n_rxq == dev->requested_n_rxq > + && dev->cp_prot_flags == dev->requested_cp_prot_flags > && dev->mtu == dev->requested_mtu > && dev->lsc_interrupt_mode == dev->requested_lsc_interrupt_mode > && dev->rxq_size == dev->requested_rxq_size > @@ -5127,6 +5395,9 @@ netdev_dpdk_reconfigure(struct netdev *netdev) > goto out; > } > > +retry: > + dpdk_cp_prot_unconfigure(dev); > + > if (dev->reset_needed) { > rte_eth_dev_reset(dev->port_id); > if_notifier_manual_report(); > @@ -5151,6 +5422,7 @@ netdev_dpdk_reconfigure(struct netdev *netdev) > dev->txq_size = dev->requested_txq_size; > > rte_free(dev->tx_q); > + dev->tx_q = NULL; > > if (!eth_addr_equals(dev->hwaddr, dev->requested_hwaddr)) { > err = netdev_dpdk_set_etheraddr__(dev, dev->requested_hwaddr); > @@ -5182,6 +5454,23 @@ netdev_dpdk_reconfigure(struct netdev *netdev) > */ > dev->requested_hwaddr = dev->hwaddr; > > + if (try_cp_prot) { > + err = dpdk_cp_prot_configure(dev); > + if (err) { > + /* No hw support, disable & recover gracefully. */ > + try_cp_prot = false; > + /* > + * The extra queue must be explicitly removed here to ensure that > + * it is unconfigured immediately. > + */ > + dev->requested_n_rxq = dev->user_n_rxq; > + goto retry; > + } > + } else { > + VLOG_INFO("%s: cp-protection: disabled", netdev_get_name(&dev->up)); > + } > + dev->cp_prot_flags = dev->requested_cp_prot_flags; > + > dev->tx_q = netdev_dpdk_alloc_txq(netdev->n_txq); > if (!dev->tx_q) { > err = ENOMEM; > @@ -5395,7 +5684,12 @@ netdev_dpdk_flow_api_supported(struct netdev *netdev) > ovs_mutex_lock(&dev->mutex); > if (dev->type == DPDK_DEV_ETH) { > /* TODO: Check if we able to offload some minimal flow. */ > - ret = true; > + if (dev->requested_cp_prot_flags) { > + VLOG_WARN("%s: hw-offload is mutually exclusive with " > + "cp-protection", netdev_get_name(netdev)); > + } else { > + ret = true; > + } > } > ovs_mutex_unlock(&dev->mutex); > out: > diff --git a/vswitchd/vswitch.xml b/vswitchd/vswitch.xml > index f9bdb2d92bec..e34a1728108f 100644 > --- a/vswitchd/vswitch.xml > +++ b/vswitchd/vswitch.xml > @@ -3430,6 +3430,32 @@ ovs-vsctl add-port br0 p0 -- set Interface p0 type=patch options:peer=p1 \ > <p>This option may only be used with dpdk VF representors.</p> > </column> > > + <column name="options" key="cp-protection" > + type='{"type": "string", "enum": ["set", ["lacp"]]}'> > + <p> > + Allocate an extra Rx queue for control plane packets of the specified > + protocol(s). > + </p> > + <p> > + If the user has already configured multiple > + <code>options:n_rxq</code> on the port, an additional one will be > + allocated for control plane packets. If the hardware cannot satisfy > + the requested number of requested Rx queues, the last Rx queue will > + be assigned for control plane. If only one Rx queue is available or > + if the hardware does not support the RTE flow matchers/actions > + required to redirect the selected protocols, > + <code>cp-protection</code> will be disabled. > + </p> > + <p> > + This feature is multually exclusive with > + <code>other_options:hw-offload</code> as it may conflict with the > + offloaded RTE flows. > + </p> > + <p> > + Disabled by default. > + </p> > + </column> > + > <column name="other_config" key="tx-steering" > type='{"type": "string", > "enum": ["set", ["thread", "hash"]]}'>
Hi Kevin, Kevin Traynor, Jan 17, 2023 at 19:38: > I saw in patchwork that there was a CI fail but I didn't examine it. > Perhaps you could check and confirm about it. Yes I saw it and I didn't understand what went wrong: 2023-01-13T15:44:29.422Z|00001|dpif_netdev(revalidator75)|ERR|internal error parsing flow key skb_priority(0),skb_mark(0),ct_state(0),ct_zone(0),ct_mark(0),ct_label(0),recirc_id(0),dp_hash(0),in_port(2),packet_type(ns=0,id=0),eth(src=5a:51:ee:7c:af:0d,dst=33:33:ff:7c:af:0d),eth_type(0x88a8),vlan(vid=4094,pcp=0),encap(eth_type(0x8100),vlan(vid=100,pcp=0),encap(eth_type(0x86dd),ipv6(src=::,dst=ff02::1:ff7c:af0d,label=0,proto=58,tclass=0,hlimit=255,frag=no),icmpv6(type=135,code=0),nd(target=fe80::5851:eeff:fe7c:af0d,sll=00:00:00:00:00:00,tll=00:00:00:00:00:00))) 2023-01-13T15:44:29.422Z|00002|dpif(revalidator75)|WARN|netdev at ovs-netdev: failed to put[modify] (Invalid argument) ufid:8ad5a583-080e-4333-9645-095cc328f6c3 skb_priority(0/0),skb_mark(0/0),ct_state(0/0),ct_zone(0/0),ct_mark(0/0),ct_label(0/0),recirc_id(0),dp_hash(0/0),in_port(2),packet_type(ns=0,id=0),eth(src=5a:51:ee:7c:af:0d,dst=33:33:ff:7c:af:0d),eth_type(0x88a8),vlan(vid=4094,pcp=0/0x0),encap(eth_type(0x8100),vlan(vid=100/0x0,pcp=0/0x0),encap(eth_type(0x86dd),ipv6(src=::/::,dst=ff02::1:ff7c:af0d/::,label=0/0,proto=58/0,tclass=0/0,hlimit=255/0,frag=no),icmpv6(type=135/0,code=0/0),nd(target=fe80::5851:eeff:fe7c:af0d/::,sll=00:00:00:00:00:00/00:00:00:00:00:00,tll=00:00:00:00:00:00/00:00:00:00:00:00))), actions:drop 151. system-traffic.at:7110: 151. 802.1ad - vlan_limit (system-traffic.at:7110): FAILED (system-traffic.at:7135) https://mail.openvswitch.org/pipermail/ovs-build/2023-January/027852.html It does not seem related to this patch but I could be wrong. > > It cannot be enabled when other_config:hw-offload=true as it may > > conflict with the offloaded RTE flows. Similarly, if hw-offload is > > enabled while some ports already have cp-protection enabled, RTE > > flow offloading will be disabled on these ports. > > I'm not sure if you are referring the features hw-offload and/or > cp-prot when you say RTE flow offloading will be disabled on these > ports. > > What I see is that if cp-prot is enabled on a port and then hw-offload > is enabled by the user, hw-offload will not enable because of cp-prot > AND cp-prot will also be disabled by virtue the user trying to enable > hw-offload. > > I was not expecting that last part, even if they are mutually > exclusive features I thought one would work. Perhaps that is > intentional and what you meant above, I wasn't 100% clear. This was not intentional. To be honest, I did not run extensive tests with hw-offload. I will have a look at this use case and see if I can at least leave cp-protection enabled. It may not be possible given that hw-offload is not enabled immediately upon the ovsdb update but asynchronously. Also, since cp-protection is a dpdk specific feature, and hw-offload is dpif-netdev, I'm not sure if there is a way to check anything when the user enables hw-offload. > Anyway, I understand this is just experimental and there is a lot of > scenarios to cover between the features (e.g. what if one of the > features could not rte_flow_validate(), could the other be used then?) > > I think you would need to them tease out in the future and if they > stay mutually exclusive that there is a clear precedence either by > feature or order enabled etc. You might even need to put a table in > docs to show the user. I think that making both features work without interference would not be easy. We would need a way to ensure that the cp-protection flow happens before the RSS flow that is inserted by hw-offload when a datapath flow cannot be offloaded because of missing matcher/action support in hw. That could be done via flow priorities/tables but these are only supported by a very limited number of NICs. That RSS flow would also need to be altered to only redirect on RXQs that are not reserved by the cp-protection flow. > > + /* User input for n_rxq (see netdev_dpdk_reconfigure). */ > > This comment is nice. minor: 'requested_n_rxq' could get a comment now > that it is no longer the user requested value and isn't the same as > the other requested_* members anymore. Sure that makes sense. > I have seen that ixgbe sets the error struct when returning success > which seems a violation of the rte_flow_validation/create API ("PMDs > initialize this structure in case of error only".) > > It's ok because you rightly ignore the error message, but it got me > thinking that we should reset/validate the error messages. See below. > > + set_error(&error, RTE_FLOW_ERROR_TYPE_NONE); Ack, I will add this. Thanks for the review.
On 17/01/2023 23:06, Robin Jarry wrote: > Hi Kevin, > > Kevin Traynor, Jan 17, 2023 at 19:38: >> I saw in patchwork that there was a CI fail but I didn't examine it. >> Perhaps you could check and confirm about it. > > Yes I saw it and I didn't understand what went wrong: > > 2023-01-13T15:44:29.422Z|00001|dpif_netdev(revalidator75)|ERR|internal error parsing flow key skb_priority(0),skb_mark(0),ct_state(0),ct_zone(0),ct_mark(0),ct_label(0),recirc_id(0),dp_hash(0),in_port(2),packet_type(ns=0,id=0),eth(src=5a:51:ee:7c:af:0d,dst=33:33:ff:7c:af:0d),eth_type(0x88a8),vlan(vid=4094,pcp=0),encap(eth_type(0x8100),vlan(vid=100,pcp=0),encap(eth_type(0x86dd),ipv6(src=::,dst=ff02::1:ff7c:af0d,label=0,proto=58,tclass=0,hlimit=255,frag=no),icmpv6(type=135,code=0),nd(target=fe80::5851:eeff:fe7c:af0d,sll=00:00:00:00:00:00,tll=00:00:00:00:00:00))) > > 2023-01-13T15:44:29.422Z|00002|dpif(revalidator75)|WARN|netdev at ovs-netdev: failed to put[modify] (Invalid argument) ufid:8ad5a583-080e-4333-9645-095cc328f6c3 skb_priority(0/0),skb_mark(0/0),ct_state(0/0),ct_zone(0/0),ct_mark(0/0),ct_label(0/0),recirc_id(0),dp_hash(0/0),in_port(2),packet_type(ns=0,id=0),eth(src=5a:51:ee:7c:af:0d,dst=33:33:ff:7c:af:0d),eth_type(0x88a8),vlan(vid=4094,pcp=0/0x0),encap(eth_type(0x8100),vlan(vid=100/0x0,pcp=0/0x0),encap(eth_type(0x86dd),ipv6(src=::/::,dst=ff02::1:ff7c:af0d/::,label=0/0,proto=58/0,tclass=0/0,hlimit=255/0,frag=no),icmpv6(type=135/0,code=0/0),nd(target=fe80::5851:eeff:fe7c:af0d/::,sll=00:00:00:00:00:00/00:00:00:00:00:00,tll=00:00:00:00:00:00/00:00:00:00:00:00))), actions:drop > > 151. system-traffic.at:7110: 151. 802.1ad - vlan_limit (system-traffic.at:7110): FAILED (system-traffic.at:7135) > > https://mail.openvswitch.org/pipermail/ovs-build/2023-January/027852.html > > It does not seem related to this patch but I could be wrong. > I agree it's not related. I ran the test locally with your patch and it passed. Also, this specific test is intended to be skipped (TESTSUITEFLAGS='-k !vlan_limit') and is skipped in the test list, but then reports as a fail. So there is something a bit odd going on. Chatted with Ian and Ilya about it and Michael might be able to take a look when he gets a chance. In context of this patch, i think we can ignore it. >>> It cannot be enabled when other_config:hw-offload=true as it may >>> conflict with the offloaded RTE flows. Similarly, if hw-offload is >>> enabled while some ports already have cp-protection enabled, RTE >>> flow offloading will be disabled on these ports. >> >> I'm not sure if you are referring the features hw-offload and/or >> cp-prot when you say RTE flow offloading will be disabled on these >> ports. >> >> What I see is that if cp-prot is enabled on a port and then hw-offload >> is enabled by the user, hw-offload will not enable because of cp-prot >> AND cp-prot will also be disabled by virtue the user trying to enable >> hw-offload. >> >> I was not expecting that last part, even if they are mutually >> exclusive features I thought one would work. Perhaps that is >> intentional and what you meant above, I wasn't 100% clear. > > This was not intentional. To be honest, I did not run extensive tests > with hw-offload. I will have a look at this use case and see if I can at > least leave cp-protection enabled. > > It may not be possible given that hw-offload is not enabled immediately > upon the ovsdb update but asynchronously. Also, since cp-protection is > a dpdk specific feature, and hw-offload is dpif-netdev, I'm not sure if > there is a way to check anything when the user enables hw-offload. > >> Anyway, I understand this is just experimental and there is a lot of >> scenarios to cover between the features (e.g. what if one of the >> features could not rte_flow_validate(), could the other be used then?) >> >> I think you would need to them tease out in the future and if they >> stay mutually exclusive that there is a clear precedence either by >> feature or order enabled etc. You might even need to put a table in >> docs to show the user. > > I think that making both features work without interference would not be > easy. We would need a way to ensure that the cp-protection flow happens > before the RSS flow that is inserted by hw-offload when a datapath flow > cannot be offloaded because of missing matcher/action support in hw. > That could be done via flow priorities/tables but these are only > supported by a very limited number of NICs. That RSS flow would also > need to be altered to only redirect on RXQs that are not reserved by the > cp-protection flow. > >>> + /* User input for n_rxq (see netdev_dpdk_reconfigure). */ >> >> This comment is nice. minor: 'requested_n_rxq' could get a comment now >> that it is no longer the user requested value and isn't the same as >> the other requested_* members anymore. > > Sure that makes sense. > >> I have seen that ixgbe sets the error struct when returning success >> which seems a violation of the rte_flow_validation/create API ("PMDs >> initialize this structure in case of error only".) >> >> It's ok because you rightly ignore the error message, but it got me >> thinking that we should reset/validate the error messages. See below. >> >> + set_error(&error, RTE_FLOW_ERROR_TYPE_NONE); > > Ack, I will add this. > > Thanks for the review. >
diff --git a/Documentation/topics/dpdk/phy.rst b/Documentation/topics/dpdk/phy.rst index 4b0fe8dded3a..518b67134639 100644 --- a/Documentation/topics/dpdk/phy.rst +++ b/Documentation/topics/dpdk/phy.rst @@ -131,6 +131,83 @@ possible with DPDK acceleration. It is possible to configure multiple Rx queues for ``dpdk`` ports, thus ensuring this is not a bottleneck for performance. For information on configuring PMD threads, refer to :doc:`pmd`. +Control Plane Protection +------------------------ + +.. warning:: This feature is experimental. + +Some control protocols are used to maintain link status between forwarding +engines. In SDN environments, these packets share the same physical network +than the user data traffic. + +When the system is not sized properly, the PMD threads may not be able to +process all incoming traffic from the configured Rx queues. When a signaling +packet of such protocols is dropped, it can cause link flapping, worsening the +situation. + +Some physical NICs can be programmed to put these protocols in a dedicated +hardware Rx queue using the rte_flow__ API. + +__ https://doc.dpdk.org/guides-22.11/prog_guide/rte_flow.html + +The currently supported control plane protocols are: + +``lacp`` + `Link Aggregation Control Protocol`__. Ether type ``0x8809``. + + __ https://www.ieee802.org/3/ad/public/mar99/seaman_1_0399.pdf + +.. warning:: + + This feature is not compatible with all NICs. Refer to the DPDK + `compatibilty matrix`__ and vendor documentation for more details. + + __ https://doc.dpdk.org/guides-22.11/nics/overview.html + +Control plane protection must be enabled on specific protocols per port. The +``cp-protection`` option requires a coma separated list of protocol names:: + + $ ovs-vsctl add-port br0 dpdk-p0 -- set Interface dpdk-p0 type=dpdk \ + options:dpdk-devargs=0000:01:00.0 options:n_rxq=2 \ + options:cp-protection=lacp + +.. note:: + + If multiple Rx queues are already configured, regular RSS (Receive Side + Scaling) queue balancing is done on all but the extra control plane + protection queue. + +.. tip:: + + You can check if control plane protection is supported on a port with the + following command:: + + $ ovs-vsctl get interface dpdk-p0 status + {cp_protection_queue="2", driver_name=..., rss_queues="0-1"} + + This will also show in ``ovs-vswitchd.log``:: + + INFO|dpdk-p0: cp-protection: redirecting lacp traffic to queue 2 + INFO|dpdk-p0: cp-protection: applying rss on queues 0-1 + + If the hardware does not support redirecting control plane traffic to + a dedicated queue, it will be explicit:: + + $ ovs-vsctl get interface dpdk-p0 status + {cp_protection=unsupported, driver_name=...} + + More details can often be found in ``ovs-vswitchd.log``:: + + WARN|dpdk-p0: cp-protection: failed to add lacp flow: Unsupported pattern + +To disable control plane protection on a port, use the following command:: + + $ ovs-vsctl remove Interface dpdk-p0 options cp-protection + +You can see that it has been disabled in ``ovs-vswitchd.log``:: + + INFO|dpdk-p0: cp-protection: disabled + .. _dpdk-phy-flow-control: Flow Control diff --git a/NEWS b/NEWS index 2f6ededfe47d..685a9aae5427 100644 --- a/NEWS +++ b/NEWS @@ -17,6 +17,9 @@ Post-v3.0.0 * Conntrack IPv6 fragment support. - DPDK: * Add support for DPDK 22.11.1. + * New experimental "cp-protection=<protocol>" option to redirect certain + protocols (for now, only LACP) to a dedicated hardware queue using + RTE flow. - For the QoS max-rate and STP/RSTP path-cost configuration OVS now assumes 10 Gbps link speed by default in case the actual link speed cannot be determined. Previously it was 10 Mbps. Values can still be overridden diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c index 5e2d64651db3..2f4fa5b8535c 100644 --- a/lib/netdev-dpdk.c +++ b/lib/netdev-dpdk.c @@ -414,6 +414,10 @@ enum dpdk_hw_ol_features { NETDEV_TX_SCTP_CHECKSUM_OFFLOAD = 1 << 4, }; +enum dpdk_cp_prot_flags { + DPDK_CP_PROT_LACP = 1 << 0, +}; + /* * In order to avoid confusion in variables names, following naming convention * should be used, if possible: @@ -508,6 +512,9 @@ struct netdev_dpdk { int requested_rxq_size; int requested_txq_size; + /* User input for n_rxq (see netdev_dpdk_reconfigure). */ + int user_n_rxq; + /* Number of rx/tx descriptors for physical devices */ int rxq_size; int txq_size; @@ -533,6 +540,13 @@ struct netdev_dpdk { /* VF configuration. */ struct eth_addr requested_hwaddr; + + /* Requested control plane protection flags, + * from the enum set 'dpdk_cp_prot_flags'. */ + uint64_t requested_cp_prot_flags; + uint64_t cp_prot_flags; + size_t cp_prot_flows_num; + struct rte_flow **cp_prot_flows; ); PADDED_MEMBERS(CACHE_LINE_SIZE, @@ -1309,9 +1323,14 @@ common_construct(struct netdev *netdev, dpdk_port_t port_no, netdev->n_rxq = 0; netdev->n_txq = 0; dev->requested_n_rxq = NR_QUEUE; + dev->user_n_rxq = NR_QUEUE; dev->requested_n_txq = NR_QUEUE; dev->requested_rxq_size = NIC_PORT_DEFAULT_RXQ_SIZE; dev->requested_txq_size = NIC_PORT_DEFAULT_TXQ_SIZE; + dev->requested_cp_prot_flags = 0; + dev->cp_prot_flags = 0; + dev->cp_prot_flows_num = 0; + dev->cp_prot_flows = NULL; /* Initialize the flow control to NULL */ memset(&dev->fc_conf, 0, sizeof dev->fc_conf); @@ -1486,6 +1505,8 @@ common_destruct(struct netdev_dpdk *dev) ovs_mutex_destroy(&dev->mutex); } +static void dpdk_cp_prot_unconfigure(struct netdev_dpdk *dev); + static void netdev_dpdk_destruct(struct netdev *netdev) { @@ -1493,6 +1514,9 @@ netdev_dpdk_destruct(struct netdev *netdev) ovs_mutex_lock(&dpdk_mutex); + /* Destroy any rte flows to allow RXQs to be removed. */ + dpdk_cp_prot_unconfigure(dev); + rte_eth_dev_stop(dev->port_id); dev->started = false; @@ -1907,8 +1931,8 @@ dpdk_set_rxq_config(struct netdev_dpdk *dev, const struct smap *args) int new_n_rxq; new_n_rxq = MAX(smap_get_int(args, "n_rxq", NR_QUEUE), 1); - if (new_n_rxq != dev->requested_n_rxq) { - dev->requested_n_rxq = new_n_rxq; + if (new_n_rxq != dev->user_n_rxq) { + dev->user_n_rxq = new_n_rxq; netdev_request_reconfigure(&dev->up); } } @@ -1930,6 +1954,48 @@ dpdk_process_queue_size(struct netdev *netdev, const struct smap *args, } } +static void +dpdk_cp_prot_set_config(struct netdev *netdev, struct netdev_dpdk *dev, + const struct smap *args, char **errp) +{ + const char *arg = smap_get_def(args, "cp-protection", ""); + char *token, *saveptr, *buf; + uint64_t flags = 0; + + buf = xstrdup(arg); + token = strtok_r(buf, ",", &saveptr); + while (token) { + if (strcmp(token, "lacp") == 0) { + flags |= DPDK_CP_PROT_LACP; + } else { + VLOG_WARN_BUF(errp, "%s options:cp-protection " + "unknown protocol '%s'", + netdev_get_name(netdev), token); + } + token = strtok_r(NULL, ",", &saveptr); + } + free(buf); + + if (flags && dev->type != DPDK_DEV_ETH) { + VLOG_WARN_BUF(errp, "%s options:cp-protection " + "is only supported on ethernet ports", + netdev_get_name(netdev)); + flags = 0; + } + + if (flags && netdev_is_flow_api_enabled()) { + VLOG_WARN_BUF(errp, "%s options:cp-protection " + "is incompatible with hw-offload", + netdev_get_name(netdev)); + flags = 0; + } + + if (flags != dev->requested_cp_prot_flags) { + dev->requested_cp_prot_flags = flags; + netdev_request_reconfigure(netdev); + } +} + static int netdev_dpdk_set_config(struct netdev *netdev, const struct smap *args, char **errp) @@ -1949,6 +2015,8 @@ netdev_dpdk_set_config(struct netdev *netdev, const struct smap *args, ovs_mutex_lock(&dpdk_mutex); ovs_mutex_lock(&dev->mutex); + dpdk_cp_prot_set_config(netdev, dev, args, errp); + dpdk_set_rxq_config(dev, args); dpdk_process_queue_size(netdev, args, "n_rxq_desc", @@ -3825,9 +3893,12 @@ netdev_dpdk_get_status(const struct netdev *netdev, struct smap *args) { struct netdev_dpdk *dev = netdev_dpdk_cast(netdev); struct rte_eth_dev_info dev_info; + size_t cp_prot_flows_num; + uint64_t cp_prot_flags; const char *bus_info; uint32_t link_speed; uint32_t dev_flags; + int n_rxq; if (!rte_eth_dev_is_valid_port(dev->port_id)) { return ENODEV; @@ -3839,6 +3910,9 @@ netdev_dpdk_get_status(const struct netdev *netdev, struct smap *args) link_speed = dev->link.link_speed; dev_flags = *dev_info.dev_flags; bus_info = rte_dev_bus_info(dev_info.device); + cp_prot_flags = dev->cp_prot_flags; + cp_prot_flows_num = dev->cp_prot_flows_num; + n_rxq = netdev->n_rxq; ovs_mutex_unlock(&dev->mutex); ovs_mutex_unlock(&dpdk_mutex); @@ -3881,6 +3955,19 @@ netdev_dpdk_get_status(const struct netdev *netdev, struct smap *args) ETH_ADDR_ARGS(dev->hwaddr)); } + if (cp_prot_flags) { + if (!cp_prot_flows_num) { + smap_add(args, "cp_protection", "unsupported"); + } else { + smap_add_format(args, "cp_protection_queue", "%d", n_rxq - 1); + if (n_rxq > 2) { + smap_add_format(args, "rss_queues", "0-%d", n_rxq - 2); + } else { + smap_add(args, "rss_queues", "0"); + } + } + } + return 0; } @@ -5105,16 +5192,197 @@ static const struct dpdk_qos_ops trtcm_policer_ops = { .qos_queue_dump_state_init = trtcm_policer_qos_queue_dump_state_init }; +static int +dpdk_cp_prot_add_flow(struct netdev_dpdk *dev, + const struct rte_flow_item items[], + const char *desc) +{ + const struct rte_flow_attr attr = { .ingress = 1 }; + const struct rte_flow_action actions[] = { + { + .type = RTE_FLOW_ACTION_TYPE_QUEUE, + .conf = &(const struct rte_flow_action_queue) { + .index = dev->up.n_rxq - 1, + }, + }, + { .type = RTE_FLOW_ACTION_TYPE_END }, + }; + struct rte_flow_error error; + struct rte_flow *flow; + size_t num; + int err; + + err = rte_flow_validate(dev->port_id, &attr, items, actions, &error); + if (err) { + VLOG_WARN("%s: cp-protection: device does not support %s flow: %s", + netdev_get_name(&dev->up), desc, error.message); + goto out; + } + + flow = rte_flow_create(dev->port_id, &attr, items, actions, &error); + if (flow == NULL) { + VLOG_WARN("%s: cp-protection: failed to add %s flow: %s", + netdev_get_name(&dev->up), desc, error.message); + err = rte_errno; + goto out; + } + + num = dev->cp_prot_flows_num + 1; + dev->cp_prot_flows = xrealloc(dev->cp_prot_flows, sizeof(flow) * num); + dev->cp_prot_flows[dev->cp_prot_flows_num] = flow; + dev->cp_prot_flows_num = num; + + VLOG_INFO("%s: cp-protection: redirected %s traffic to rx queue %d", + netdev_get_name(&dev->up), desc, dev->up.n_rxq - 1); +out: + return err; +} + +#define RETA_CONF_SIZE (RTE_ETH_RSS_RETA_SIZE_512 / RTE_ETH_RETA_GROUP_SIZE) + +static int +dpdk_cp_prot_rss_configure(struct netdev_dpdk *dev, int rss_n_rxq) +{ + struct rte_eth_rss_reta_entry64 reta_conf[RETA_CONF_SIZE]; + struct rte_eth_dev_info info; + int err; + + rte_eth_dev_info_get(dev->port_id, &info); + + if (info.reta_size % rss_n_rxq != 0 && + info.reta_size < RTE_ETH_RSS_RETA_SIZE_128) { + /* + * Some drivers set reta_size equal to the total number of rxqs that + * are configured when it is a power of two. Since we are actually + * reconfiguring the redirection table to exclude the last rxq, we may + * end up with an imbalanced redirection table. For example, such + * configuration: + * + * options:n_rxq=3 options:cp-protection=lacp + * + * Will actually configure 4 rxqs on the NIC, and the default reta to: + * + * [0, 1, 2, 3] + * + * And dpdk_cp_prot_rss_configure() will reconfigure reta to: + * + * [0, 1, 2, 0] + * + * Causing queue 0 to receive twice as much traffic as queues 1 and 2. + * + * Work around that corner case by forcing a bigger redirection table + * size to 128 entries when reta_size is not a multiple of rss_n_rxq + * and when reta_size is less than 128. This value seems to be + * supported by most of the drivers that also support rte flow. + */ + info.reta_size = RTE_ETH_RSS_RETA_SIZE_128; + } + + memset(reta_conf, 0, sizeof(reta_conf)); + for (uint16_t i = 0; i < info.reta_size; i++) { + uint16_t idx = i / RTE_ETH_RETA_GROUP_SIZE; + uint16_t shift = i % RTE_ETH_RETA_GROUP_SIZE; + reta_conf[idx].mask |= 1ULL << shift; + reta_conf[idx].reta[shift] = i % rss_n_rxq; + } + err = rte_eth_dev_rss_reta_update(dev->port_id, reta_conf, info.reta_size); + if (err < 0) { + VLOG_WARN("%s: failed to configure RSS redirection table: err=%d", + netdev_get_name(&dev->up), err); + } + + return err; +} + +static int +dpdk_cp_prot_configure(struct netdev_dpdk *dev) +{ + int err = 0; + + if (dev->up.n_rxq < 2) { + err = ENOTSUP; + VLOG_WARN("%s: cp-protection: not enough available rx queues", + netdev_get_name(&dev->up)); + goto out; + } + + if (dev->requested_cp_prot_flags & DPDK_CP_PROT_LACP) { + const struct rte_flow_item items[] = { + { + .type = RTE_FLOW_ITEM_TYPE_ETH, + .spec = &(const struct rte_flow_item_eth){ + .type = htons(ETH_TYPE_LACP), + }, + .mask = &(const struct rte_flow_item_eth){ + .type = htons(0xffff), + }, + }, + { .type = RTE_FLOW_ITEM_TYPE_END }, + }; + err = dpdk_cp_prot_add_flow(dev, items, "lacp"); + if (err) { + goto out; + } + } + + if (dev->cp_prot_flows_num) { + /* Reconfigure RSS reta in all but the cp protection queue. */ + err = dpdk_cp_prot_rss_configure(dev, dev->up.n_rxq - 1); + if (!err) { + if (dev->up.n_rxq == 2) { + VLOG_INFO("%s: cp-protection: redirected other traffic to " + "rx queue 0", netdev_get_name(&dev->up)); + } else { + VLOG_INFO("%s: cp-protection: applied rss on rx queue 0-%u", + netdev_get_name(&dev->up), dev->up.n_rxq - 2); + } + } + } + +out: + return err; +} + +static void +dpdk_cp_prot_unconfigure(struct netdev_dpdk *dev) +{ + struct rte_flow_error error; + + if (!dev->cp_prot_flows_num) { + return; + } + + VLOG_DBG("%s: cp-protection: reset flows", netdev_get_name(&dev->up)); + + for (int i = 0; i < dev->cp_prot_flows_num; i++) { + if (rte_flow_destroy(dev->port_id, dev->cp_prot_flows[i], &error)) { + VLOG_DBG("%s: cp-protection: failed to destroy flow: %s", + netdev_get_name(&dev->up), error.message); + } + } + free(dev->cp_prot_flows); + dev->cp_prot_flows_num = 0; + dev->cp_prot_flows = NULL; +} + static int netdev_dpdk_reconfigure(struct netdev *netdev) { struct netdev_dpdk *dev = netdev_dpdk_cast(netdev); + bool try_cp_prot; int err = 0; ovs_mutex_lock(&dev->mutex); + try_cp_prot = dev->requested_cp_prot_flags != 0; + dev->requested_n_rxq = dev->user_n_rxq; + if (try_cp_prot) { + dev->requested_n_rxq += 1; + } + if (netdev->n_txq == dev->requested_n_txq && netdev->n_rxq == dev->requested_n_rxq + && dev->cp_prot_flags == dev->requested_cp_prot_flags && dev->mtu == dev->requested_mtu && dev->lsc_interrupt_mode == dev->requested_lsc_interrupt_mode && dev->rxq_size == dev->requested_rxq_size @@ -5127,6 +5395,9 @@ netdev_dpdk_reconfigure(struct netdev *netdev) goto out; } +retry: + dpdk_cp_prot_unconfigure(dev); + if (dev->reset_needed) { rte_eth_dev_reset(dev->port_id); if_notifier_manual_report(); @@ -5151,6 +5422,7 @@ netdev_dpdk_reconfigure(struct netdev *netdev) dev->txq_size = dev->requested_txq_size; rte_free(dev->tx_q); + dev->tx_q = NULL; if (!eth_addr_equals(dev->hwaddr, dev->requested_hwaddr)) { err = netdev_dpdk_set_etheraddr__(dev, dev->requested_hwaddr); @@ -5182,6 +5454,23 @@ netdev_dpdk_reconfigure(struct netdev *netdev) */ dev->requested_hwaddr = dev->hwaddr; + if (try_cp_prot) { + err = dpdk_cp_prot_configure(dev); + if (err) { + /* No hw support, disable & recover gracefully. */ + try_cp_prot = false; + /* + * The extra queue must be explicitly removed here to ensure that + * it is unconfigured immediately. + */ + dev->requested_n_rxq = dev->user_n_rxq; + goto retry; + } + } else { + VLOG_INFO("%s: cp-protection: disabled", netdev_get_name(&dev->up)); + } + dev->cp_prot_flags = dev->requested_cp_prot_flags; + dev->tx_q = netdev_dpdk_alloc_txq(netdev->n_txq); if (!dev->tx_q) { err = ENOMEM; @@ -5395,7 +5684,12 @@ netdev_dpdk_flow_api_supported(struct netdev *netdev) ovs_mutex_lock(&dev->mutex); if (dev->type == DPDK_DEV_ETH) { /* TODO: Check if we able to offload some minimal flow. */ - ret = true; + if (dev->requested_cp_prot_flags) { + VLOG_WARN("%s: hw-offload is mutually exclusive with " + "cp-protection", netdev_get_name(netdev)); + } else { + ret = true; + } } ovs_mutex_unlock(&dev->mutex); out: diff --git a/vswitchd/vswitch.xml b/vswitchd/vswitch.xml index f9bdb2d92bec..e34a1728108f 100644 --- a/vswitchd/vswitch.xml +++ b/vswitchd/vswitch.xml @@ -3430,6 +3430,32 @@ ovs-vsctl add-port br0 p0 -- set Interface p0 type=patch options:peer=p1 \ <p>This option may only be used with dpdk VF representors.</p> </column> + <column name="options" key="cp-protection" + type='{"type": "string", "enum": ["set", ["lacp"]]}'> + <p> + Allocate an extra Rx queue for control plane packets of the specified + protocol(s). + </p> + <p> + If the user has already configured multiple + <code>options:n_rxq</code> on the port, an additional one will be + allocated for control plane packets. If the hardware cannot satisfy + the requested number of requested Rx queues, the last Rx queue will + be assigned for control plane. If only one Rx queue is available or + if the hardware does not support the RTE flow matchers/actions + required to redirect the selected protocols, + <code>cp-protection</code> will be disabled. + </p> + <p> + This feature is multually exclusive with + <code>other_options:hw-offload</code> as it may conflict with the + offloaded RTE flows. + </p> + <p> + Disabled by default. + </p> + </column> + <column name="other_config" key="tx-steering" type='{"type": "string", "enum": ["set", ["thread", "hash"]]}'>
Some control protocols are used to maintain link status between forwarding engines (e.g. LACP). When the system is not sized properly, the PMD threads may not be able to process all incoming traffic from the configured Rx queues. When a signaling packet of such protocols is dropped, it can cause link flapping, worsening the situation. Use the RTE flow API to redirect these protocols into a dedicated Rx queue. The assumption is made that the ratio between control protocol traffic and user data traffic is very low and thus this dedicated Rx queue will never get full. The RSS redirection table is re-programmed to only use the other Rx queues. The RSS table size is stored in the netdev_dpdk structure at port initialization to avoid requesting the information again when changing the port configuration. The additional Rx queue will be assigned a PMD core like any other Rx queue. Polling that extra queue may introduce increased latency and a slight performance penalty at the benefit of preventing link flapping. This feature must be enabled per port on specific protocols via the cp-protection option. This option takes a coma-separated list of protocol names. It is only supported on ethernet ports. This feature is experimental. If the user has already configured multiple Rx queues on the port, an additional one will be allocated for control plane packets. If the hardware cannot satisfy the requested number of requested Rx queues, the last Rx queue will be assigned for control plane. If only one Rx queue is available, the cp-protection feature will be disabled. If the hardware does not support the RTE flow matchers/actions, the feature will be disabled. It cannot be enabled when other_config:hw-offload=true as it may conflict with the offloaded RTE flows. Similarly, if hw-offload is enabled while some ports already have cp-protection enabled, RTE flow offloading will be disabled on these ports. Example use: ovs-vsctl add-bond br-phy bond0 phy0 phy1 -- \ set interface phy0 type=dpdk options:dpdk-devargs=0000:ca:00.0 -- \ set interface phy0 options:cp-protection=lacp -- \ set interface phy1 type=dpdk options:dpdk-devargs=0000:ca:00.1 -- \ set interface phy1 options:cp-protection=lacp As a starting point, only one protocol is supported: LACP. Other protocols can be added in the future. NIC compatibility should be checked. To validate that this works as intended, I used a traffic generator to generate random traffic slightly above the machine capacity at line rate on a two ports bond interface. OVS is configured to receive traffic on two VLANs and pop/push them in a br-int bridge based on tags set on patch ports. +----------------------+ | DUT | |+--------------------+| || br-int || default flow, action=NORMAL || || || patch10 patch11 || |+---|-----------|----+| | | | | |+---|-----------|----+| || patch00 patch01 || || tag:10 tag:20 || || || || br-phy || default flow, action=NORMAL || || || bond0 || balance-slb, lacp=passive, lacp-time=fast || phy0 phy1 || |+------|-----|-------+| +-------|-----|--------+ | | +-------|-----|--------+ | port0 port1 | balance L3/L4, lacp=active, lacp-time=fast | lag | mode trunk VLANs 10, 20 | | | switch | | | | vlan 10 vlan 20 | mode access | port2 port3 | +-----|----------|-----+ | | +-----|----------|-----+ | port0 port1 | Random traffic that is properly balanced | | across the bond ports in both directions. | traffic generator | +----------------------+ Without cp-protection, the bond0 links are randomly switching to "defaulted" when one of the LACP packets sent by the switch is dropped because the RX queues are full and the PMD threads did not process them fast enough. When that happens, all traffic must go through a single link which causes above line rate traffic to be dropped. When cp-protection is enabled, no LACP packet is dropped and the bond links remain enabled at all times, maximizing the throughput. This feature may be considered as "QoS". However, it does not work by limiting the rate of traffic explicitly. It only guarantees that some protocols have a lower chance of being dropped because the PMD cores cannot keep up with regular traffic. The choice of protocols is limited on purpose. This is not meant to be configurable by users. Some limited configurability could be considered in the future but it would expose to more potential issues if users are accidentally redirecting all traffic in the control plane queue. Cc: Christophe Fontaine <cfontain@redhat.com> Cc: Kevin Traynor <ktraynor@redhat.com> Cc: David Marchand <david.marchand@redhat.com> Signed-off-by: Robin Jarry <rjarry@redhat.com> --- v6 -> v7: * Fixed double free in case of cp-protection configuration fail. * Fixed segmentation fault when creating vhost user ports. * Removed redundant rss reconfiguration before stopping, reconfiguring and restarting the port (with or without cp protection enabled). Documentation/topics/dpdk/phy.rst | 77 ++++++++ NEWS | 3 + lib/netdev-dpdk.c | 300 +++++++++++++++++++++++++++++- vswitchd/vswitch.xml | 26 +++ 4 files changed, 403 insertions(+), 3 deletions(-)