[ovs-dev] [slow path 10/11] ofproto-dpif: Introduce "slow path" datapath flows.
Ben Pfaff
blp at nicira.com
Sat May 5 18:10:47 UTC 2012
Most exact-match flows can be handled directly in the datapath, but
for various reasons, some cannot: every packet in these flows must
be sent separately to userspace. Until now, flows that cannot be
handled entirely in the kernel have been allowed to miss each time
in the datapath. This is generally OK, but it has a few
disadvantages:
* It can make troubleshooting at the level where one must look
at datapath flows a bit confusing in some cases, because
datapath misses due to genuinely new flows are mixed in with
datapath misses for known flows that cannot be set up.
* It means that the kernel-to-userspace packets for a given
input port always go to a single kernel-to-userspace queue,
even if we'd like to segregate out some of the packets for
known flows. (An upcoming commit has examples.)
This commit therefore introduces the concept of a "slow path" flow,
one that is installed in the datapath with a single action that
sends the flow's packets to userspace. To make troubleshooting
easier, the action includes a reason code (displayed by "ovs-dpctl
dump-flows") that explains why the flow has been slow-pathed.
Bug #7550.
Signed-off-by: Ben Pfaff <blp at nicira.com>
---
lib/odp-util.c | 93 ++++++++++-
lib/odp-util.h | 30 +++-
ofproto/ofproto-dpif.c | 434 ++++++++++++++++++++++++++++++++++--------------
tests/ofproto-dpif.at | 5 +-
4 files changed, 430 insertions(+), 132 deletions(-)
diff --git a/lib/odp-util.c b/lib/odp-util.c
index 78bcf64..d6fdfdf 100644
--- a/lib/odp-util.c
+++ b/lib/odp-util.c
@@ -166,6 +166,52 @@ format_odp_sample_action(struct ds *ds, const struct nlattr *attr)
ds_put_format(ds, "))");
}
+static const char *
+slow_path_reason_to_string(enum slow_path_reason bit)
+{
+ switch (bit) {
+ case SLOW_CONTROLLER:
+ return "controller";
+ case SLOW_CFM:
+ return "cfm";
+ case SLOW_LACP:
+ return "lacp";
+ case SLOW_STP:
+ return "stp";
+ case SLOW_IN_BAND:
+ return "in_band";
+ case SLOW_MATCH:
+ return "match";
+ default:
+ return NULL;
+ }
+}
+
+static void
+format_slow_path_reason(struct ds *ds, uint32_t slow)
+{
+ uint32_t bad = 0;
+
+ while (slow) {
+ uint32_t bit = rightmost_1bit(slow);
+ const char *s;
+
+ s = slow_path_reason_to_string(bit);
+ if (s) {
+ ds_put_format(ds, "%s,", s);
+ } else {
+ bad |= bit;
+ }
+
+ slow &= ~bit;
+ }
+
+ if (bad) {
+ ds_put_format(ds, "0x%"PRIx32",", bad);
+ }
+ ds_chomp(ds, ',');
+}
+
static void
format_odp_userspace_action(struct ds *ds, const struct nlattr *attr)
{
@@ -191,12 +237,19 @@ format_odp_userspace_action(struct ds *ds, const struct nlattr *attr)
switch (cookie.type) {
case USER_ACTION_COOKIE_SFLOW:
- ds_put_format(ds, ",sFlow,"
- "vid=%"PRIu16",pcp=%"PRIu8",output=%"PRIu32,
+ ds_put_format(ds, ",sFlow("
+ "vid=%"PRIu16",pcp=%"PRIu8",output=%"PRIu32")",
vlan_tci_to_vid(cookie.sflow.vlan_tci),
vlan_tci_to_pcp(cookie.sflow.vlan_tci),
cookie.sflow.output);
break;
+
+ case USER_ACTION_COOKIE_SLOW_PATH:
+ ds_put_cstr(ds, ",slow_path(");
+ if (cookie.slow_path.reason) {
+ format_slow_path_reason(ds, cookie.slow_path.reason);
+ }
+ ds_put_char(ds, ')');
break;
case USER_ACTION_COOKIE_UNSPEC:
@@ -346,8 +399,8 @@ parse_odp_action(const char *s, const struct shash *port_names,
if (sscanf(s, "userspace(pid=%lli)%n", &pid, &n) > 0 && n > 0) {
odp_put_userspace_action(pid, NULL, actions);
return n;
- } else if (sscanf(s, "userspace(pid=%lli,sFlow,vid=%i,"
- "pcp=%i,output=%lli)%n",
+ } else if (sscanf(s, "userspace(pid=%lli,sFlow(vid=%i,"
+ "pcp=%i,output=%lli))%n",
&pid, &vid, &pcp, &output, &n) > 0 && n > 0) {
union user_action_cookie cookie;
uint16_t tci;
@@ -362,6 +415,38 @@ parse_odp_action(const char *s, const struct shash *port_names,
cookie.sflow.output = output;
odp_put_userspace_action(pid, &cookie, actions);
return n;
+ } else if (sscanf(s, "userspace(pid=%lli,slow_path(%n", &pid, &n) > 0
+ && n > 0) {
+ union user_action_cookie cookie;
+
+ cookie.type = USER_ACTION_COOKIE_SLOW_PATH;
+ cookie.slow_path.unused = 0;
+ cookie.slow_path.reason = 0;
+
+ while (s[n] != ')') {
+ uint32_t bit;
+
+ for (bit = 1; ; bit <<= 1) {
+ const char *reason = slow_path_reason_to_string(bit);
+ size_t len = strlen(reason);
+
+ if (reason
+ && !strncmp(s + n, reason, len)
+ && (s[n + len] == ',' || s[n + len] == ')'))
+ {
+ cookie.slow_path.reason |= bit;
+ s += n + len + (s[n + len] == ',');
+ break;
+ }
+ }
+
+ if (!bit) {
+ return -EINVAL;
+ }
+ }
+
+ odp_put_userspace_action(pid, &cookie, actions);
+ return n;
} else if (sscanf(s, "userspace(pid=%lli,userdata="
"%31[x0123456789abcdefABCDEF])%n", &pid, userdata_s,
&n) > 0 && n > 0) {
diff --git a/lib/odp-util.h b/lib/odp-util.h
index c52e470..5e014ad 100644
--- a/lib/odp-util.h
+++ b/lib/odp-util.h
@@ -116,9 +116,20 @@ enum odp_key_fitness odp_flow_key_to_flow(const struct nlattr *, size_t,
struct flow *);
const char *odp_key_fitness_to_string(enum odp_key_fitness);
+void commit_odp_actions(const struct flow *, struct flow *base,
+ struct ofpbuf *odp_actions);
+
+/* ofproto-dpif interface.
+ *
+ * The following types and functions are logically part of ofproto-dpif.
+ * ofproto-dpif puts values of these types into the flows that it installs in
+ * the kernel datapath, though, so ovs-dpctl needs to interpret them so that
+ * it can print flows in a more human-readable manner. */
+
enum user_action_cookie_type {
USER_ACTION_COOKIE_UNSPEC,
USER_ACTION_COOKIE_SFLOW, /* Packet for sFlow sampling. */
+ USER_ACTION_COOKIE_SLOW_PATH /* Userspace must process this flow. */
};
/* user_action_cookie is passed as argument to OVS_ACTION_ATTR_USERSPACE.
@@ -131,14 +142,27 @@ union user_action_cookie {
ovs_be16 vlan_tci; /* Destination VLAN TCI. */
uint32_t output; /* SFL_FLOW_SAMPLE_TYPE 'output' value. */
} sflow;
-};
+ struct {
+ uint16_t type; /* USER_ACTION_COOKIE_SLOW_PATH. */
+ uint16_t unused;
+ uint32_t reason; /* enum slow_path_reason. */
+ } slow_path;
+};
BUILD_ASSERT_DECL(sizeof(union user_action_cookie) == 8);
size_t odp_put_userspace_action(uint32_t pid,
const union user_action_cookie *,
struct ofpbuf *odp_actions);
-void commit_odp_actions(const struct flow *, struct flow *base,
- struct ofpbuf *odp_actions);
+/* Reasons why a subfacet might not be fast-pathable. */
+enum slow_path_reason {
+ SLOW_CONTROLLER = 1 << 0, /* Packets must go to OpenFlow controller. */
+ SLOW_CFM = 1 << 1, /* CFM packets need per-packet processing. */
+ SLOW_LACP = 1 << 2, /* LACP packets need per-packet processing. */
+ SLOW_STP = 1 << 3, /* STP packets need per-packet processing. */
+ SLOW_IN_BAND = 1 << 4, /* In-band control needs every packet. */
+ SLOW_MATCH = 1 << 5, /* Datapath can't match specifically enough. */
+};
+
#endif /* odp-util.h */
diff --git a/ofproto/ofproto-dpif.c b/ofproto/ofproto-dpif.c
index 9dcfccd..486630c 100644
--- a/ofproto/ofproto-dpif.c
+++ b/ofproto/ofproto-dpif.c
@@ -254,8 +254,7 @@ struct action_xlate_ctx {
struct ofpbuf *odp_actions; /* Datapath actions. */
tag_type tags; /* Tags associated with actions. */
- bool may_set_up_flow; /* True ordinarily; false if the actions must
- * be reassessed for every packet. */
+ enum slow_path_reason slow; /* 0 if fast path may be used. */
bool has_learn; /* Actions include NXAST_LEARN? */
bool has_normal; /* Actions output to OFPP_NORMAL? */
bool has_fin_timeout; /* Actions include NXAST_FIN_TIMEOUT? */
@@ -288,6 +287,38 @@ static void xlate_actions_for_side_effects(struct action_xlate_ctx *,
const union ofp_action *in,
size_t n_in);
+static size_t put_userspace_action(const struct ofproto_dpif *,
+ struct ofpbuf *odp_actions,
+ const struct flow *,
+ const union user_action_cookie *);
+
+static void compose_slow_path(const struct ofproto_dpif *, const struct flow *,
+ enum slow_path_reason,
+ uint64_t *stub, size_t stub_size,
+ const struct nlattr **actionsp,
+ size_t *actions_lenp);
+
+/* A subfacet (see "struct subfacet" below) has three possible installation
+ * states:
+ *
+ * - SF_NOT_INSTALLED: Not installed in the datapath. This will only be the
+ * case just after the subfacet is created, just before the subfacet is
+ * destroyed, or if the datapath returns an error when we try to install a
+ * subfacet.
+ *
+ * - SF_FAST_PATH: The subfacet's actions are installed in the datapath.
+ *
+ * - SF_SLOW_PATH: An action that sends every packet for the subfacet through
+ * ofproto_dpif is installed in the datapath.
+ */
+enum subfacet_path {
+ SF_NOT_INSTALLED, /* No datapath flow for this subfacet. */
+ SF_FAST_PATH, /* Full actions are installed. */
+ SF_SLOW_PATH, /* Send-to-userspace action is installed. */
+};
+
+static const char *subfacet_path_to_string(enum subfacet_path);
+
/* A dpif flow and actions associated with a facet.
*
* See also the large comment on struct facet. */
@@ -318,7 +349,8 @@ struct subfacet {
size_t actions_len; /* Number of bytes in actions[]. */
struct nlattr *actions; /* Datapath actions. */
- bool installed; /* Installed in datapath? */
+ enum slow_path_reason slow; /* 0 if fast path may be used. */
+ enum subfacet_path path; /* Installed in datapath? */
/* This value is normally the same as ->facet->flow.vlan_tci. Only VLAN
* splinters can cause it to differ. This value should be removed when
@@ -345,9 +377,11 @@ static void subfacet_make_actions(struct subfacet *,
struct ofpbuf *odp_actions);
static int subfacet_install(struct subfacet *,
const struct nlattr *actions, size_t actions_len,
- struct dpif_flow_stats *);
+ struct dpif_flow_stats *, enum slow_path_reason);
static void subfacet_uninstall(struct subfacet *);
+static enum subfacet_path subfacet_want_path(enum slow_path_reason);
+
/* An exact-match instantiation of an OpenFlow flow.
*
* A facet associates a "struct flow", which represents the Open vSwitch
@@ -406,7 +440,6 @@ struct facet {
* between splintered and non-splintered subfacets due to the VLAN tag
* being initially different (present vs. absent). All of them have these
* properties in common so we just store one copy of them here. */
- bool may_install; /* Reassess actions for every packet? */
bool has_learn; /* Actions include NXAST_LEARN? */
bool has_normal; /* Actions output to OFPP_NORMAL? */
bool has_fin_timeout; /* Actions include NXAST_FIN_TIMEOUT? */
@@ -1037,7 +1070,7 @@ flush(struct ofproto *ofproto_)
struct subfacet *subfacet;
LIST_FOR_EACH (subfacet, list_node, &facet->subfacets) {
- subfacet->installed = false;
+ subfacet->path = SF_NOT_INSTALLED;
subfacet->dp_packet_count = 0;
subfacet->dp_byte_count = 0;
}
@@ -2599,6 +2632,7 @@ struct flow_miss {
size_t key_len;
ovs_be16 initial_tci;
struct list packets;
+ enum dpif_upcall_type upcall_type;
};
struct flow_miss_op {
@@ -2635,34 +2669,34 @@ send_packet_in_miss(struct ofproto_dpif *ofproto, const struct ofpbuf *packet,
connmgr_send_packet_in(ofproto->up.connmgr, &pin);
}
-static bool
+static enum slow_path_reason
process_special(struct ofproto_dpif *ofproto, const struct flow *flow,
const struct ofpbuf *packet)
{
struct ofport_dpif *ofport = get_ofp_port(ofproto, flow->in_port);
if (!ofport) {
- return false;
+ return 0;
}
if (ofport->cfm && cfm_should_process_flow(ofport->cfm, flow)) {
if (packet) {
cfm_process_heartbeat(ofport->cfm, packet);
}
- return true;
+ return SLOW_CFM;
} else if (ofport->bundle && ofport->bundle->lacp
&& flow->dl_type == htons(ETH_TYPE_LACP)) {
if (packet) {
lacp_process_packet(ofport->bundle->lacp, ofport, packet);
}
- return true;
+ return SLOW_LACP;
} else if (ofproto->stp && stp_should_process_flow(flow)) {
if (packet) {
stp_process_packet(ofport, packet);
}
- return true;
+ return SLOW_STP;
}
- return false;
+ return 0;
}
static struct flow_miss *
@@ -2807,6 +2841,8 @@ static void
handle_flow_miss_with_facet(struct flow_miss *miss, struct facet *facet,
struct flow_miss_op *ops, size_t *n_ops)
{
+ struct ofproto_dpif *ofproto = ofproto_dpif_cast(facet->rule->up.ofproto);
+ enum subfacet_path want_path;
struct subfacet *subfacet;
struct ofpbuf *packet;
@@ -2822,7 +2858,7 @@ handle_flow_miss_with_facet(struct flow_miss *miss, struct facet *facet,
handle_flow_miss_common(facet->rule, packet, &miss->flow);
ofpbuf_use_stub(&odp_actions, op->stub, sizeof op->stub);
- if (!facet->may_install || !subfacet->actions) {
+ if (!subfacet->actions || subfacet->slow) {
subfacet_make_actions(subfacet, packet, &odp_actions);
}
@@ -2834,7 +2870,7 @@ handle_flow_miss_with_facet(struct flow_miss *miss, struct facet *facet,
init_flow_miss_execute_op(miss, packet, op);
op->subfacet = subfacet;
- if (facet->may_install) {
+ if (!subfacet->slow) {
execute->actions = subfacet->actions;
execute->actions_len = subfacet->actions_len;
ofpbuf_uninit(&odp_actions);
@@ -2850,7 +2886,8 @@ handle_flow_miss_with_facet(struct flow_miss *miss, struct facet *facet,
}
}
- if (facet->may_install && subfacet->key_fitness != ODP_FIT_TOO_LITTLE) {
+ want_path = subfacet_want_path(subfacet->slow);
+ if (miss->upcall_type == DPIF_UC_MISS || subfacet->path != want_path) {
struct flow_miss_op *op = &ops[(*n_ops)++];
struct dpif_flow_put *put = &op->dpif_op.u.flow_put;
@@ -2860,8 +2897,14 @@ handle_flow_miss_with_facet(struct flow_miss *miss, struct facet *facet,
put->flags = DPIF_FP_CREATE | DPIF_FP_MODIFY;
put->key = miss->key;
put->key_len = miss->key_len;
- put->actions = subfacet->actions;
- put->actions_len = subfacet->actions_len;
+ if (want_path == SF_FAST_PATH) {
+ put->actions = subfacet->actions;
+ put->actions_len = subfacet->actions_len;
+ } else {
+ compose_slow_path(ofproto, &facet->flow, subfacet->slow,
+ op->stub, sizeof op->stub,
+ &put->actions, &put->actions_len);
+ }
put->stats = NULL;
}
}
@@ -2999,14 +3042,6 @@ handle_miss_upcalls(struct ofproto_dpif *ofproto, struct dpif_upcall *upcalls,
flow_extract(upcall->packet, miss->flow.skb_priority,
miss->flow.tun_id, miss->flow.in_port, &miss->flow);
- /* Handle 802.1ag, LACP, and STP specially. */
- if (process_special(ofproto, &miss->flow, upcall->packet)) {
- ofproto_update_local_port_stats(&ofproto->up,
- 0, upcall->packet->size);
- ofproto->n_matches++;
- continue;
- }
-
/* Add other packets to a to-do list. */
hash = flow_hash(&miss->flow, 0);
existing_miss = flow_miss_find(&todo, &miss->flow, hash);
@@ -3014,6 +3049,7 @@ handle_miss_upcalls(struct ofproto_dpif *ofproto, struct dpif_upcall *upcalls,
hmap_insert(&todo, &miss->hmap_node, hash);
miss->key = upcall->key;
miss->key_len = upcall->key_len;
+ miss->upcall_type = upcall->type;
list_init(&miss->packets);
n_misses++;
@@ -3047,7 +3083,7 @@ handle_miss_upcalls(struct ofproto_dpif *ofproto, struct dpif_upcall *upcalls,
case DPIF_OP_FLOW_PUT:
if (!op->dpif_op.error) {
- op->subfacet->installed = true;
+ op->subfacet->path = subfacet_want_path(op->subfacet->slow);
}
break;
@@ -3060,17 +3096,50 @@ handle_miss_upcalls(struct ofproto_dpif *ofproto, struct dpif_upcall *upcalls,
hmap_destroy(&todo);
}
+static enum { SFLOW_UPCALL, MISS_UPCALL, BAD_UPCALL }
+classify_upcall(const struct dpif_upcall *upcall)
+{
+ union user_action_cookie cookie;
+
+ /* First look at the upcall type. */
+ switch (upcall->type) {
+ case DPIF_UC_ACTION:
+ break;
+
+ case DPIF_UC_MISS:
+ return MISS_UPCALL;
+
+ case DPIF_N_UC_TYPES:
+ default:
+ VLOG_WARN_RL(&rl, "upcall has unexpected type %"PRIu32, upcall->type);
+ return BAD_UPCALL;
+ }
+
+ /* "action" upcalls need a closer look. */
+ memcpy(&cookie, &upcall->userdata, sizeof(cookie));
+ switch (cookie.type) {
+ case USER_ACTION_COOKIE_SFLOW:
+ return SFLOW_UPCALL;
+
+ case USER_ACTION_COOKIE_SLOW_PATH:
+ return MISS_UPCALL;
+
+ case USER_ACTION_COOKIE_UNSPEC:
+ default:
+ VLOG_WARN_RL(&rl, "invalid user cookie : 0x%"PRIx64, upcall->userdata);
+ return BAD_UPCALL;
+ }
+}
+
static void
-handle_userspace_upcall(struct ofproto_dpif *ofproto,
- struct dpif_upcall *upcall)
+handle_sflow_upcall(struct ofproto_dpif *ofproto,
+ const struct dpif_upcall *upcall)
{
union user_action_cookie cookie;
enum odp_key_fitness fitness;
ovs_be16 initial_tci;
struct flow flow;
- memcpy(&cookie, &upcall->userdata, sizeof(cookie));
-
fitness = ofproto_dpif_extract_flow_key(ofproto, upcall->key,
upcall->key_len, &flow,
&initial_tci, upcall->packet);
@@ -3078,19 +3147,8 @@ handle_userspace_upcall(struct ofproto_dpif *ofproto,
return;
}
- switch (cookie.type) {
- case USER_ACTION_COOKIE_SFLOW:
- if (ofproto->sflow) {
- dpif_sflow_received(ofproto->sflow, upcall->packet, &flow,
- &cookie);
- }
- break;
-
- case USER_ACTION_COOKIE_UNSPEC:
- default:
- VLOG_WARN_RL(&rl, "invalid user cookie : 0x%"PRIx64, upcall->userdata);
- break;
- }
+ memcpy(&cookie, &upcall->userdata, sizeof(cookie));
+ dpif_sflow_received(ofproto->sflow, upcall->packet, &flow, &cookie);
}
static int
@@ -3120,25 +3178,26 @@ handle_upcalls(struct ofproto_dpif *ofproto, unsigned int max_batch)
break;
}
- switch (upcall->type) {
- case DPIF_UC_ACTION:
- handle_userspace_upcall(ofproto, upcall);
- ofpbuf_uninit(buf);
- break;
-
- case DPIF_UC_MISS:
+ switch (classify_upcall(upcall)) {
+ case MISS_UPCALL:
/* Handle it later. */
n_misses++;
break;
- case DPIF_N_UC_TYPES:
- default:
- VLOG_WARN_RL(&rl, "upcall has unexpected type %"PRIu32,
- upcall->type);
+ case SFLOW_UPCALL:
+ if (ofproto->sflow) {
+ handle_sflow_upcall(ofproto, upcall);
+ }
+ ofpbuf_uninit(buf);
+ break;
+
+ case BAD_UPCALL:
+ ofpbuf_uninit(buf);
break;
}
}
+ /* Handle deferred MISS_UPCALL processing. */
handle_miss_upcalls(ofproto, misses, n_misses);
for (i = 0; i < n_misses; i++) {
ofpbuf_uninit(&miss_bufs[i]);
@@ -3277,10 +3336,19 @@ update_stats(struct ofproto_dpif *p)
struct subfacet *subfacet;
subfacet = subfacet_find(p, key, key_len);
- if (subfacet && subfacet->installed) {
+ switch (subfacet ? subfacet->path : SF_NOT_INSTALLED) {
+ case SF_FAST_PATH:
update_subfacet_stats(subfacet, stats);
- } else {
+ break;
+
+ case SF_SLOW_PATH:
+ /* Stats are updated per-packet. */
+ break;
+
+ case SF_NOT_INSTALLED:
+ default:
delete_unexpected_flow(p->dpif, key, key_len);
+ break;
}
}
dpif_flow_dump_done(&dump);
@@ -3398,7 +3466,7 @@ expire_batch(struct ofproto_dpif *ofproto, struct subfacet **subfacets, int n)
dpif_operate(ofproto->dpif, opsp, n);
for (i = 0; i < n; i++) {
subfacet_reset_dp_stats(subfacets[i], &stats[i]);
- subfacets[i]->installed = false;
+ subfacets[i]->path = SF_NOT_INSTALLED;
subfacet_destroy(subfacets[i]);
}
}
@@ -3416,7 +3484,7 @@ expire_subfacets(struct ofproto_dpif *ofproto, int dp_max_idle)
HMAP_FOR_EACH_SAFE (subfacet, next_subfacet, hmap_node,
&ofproto->subfacets) {
if (subfacet->used < cutoff) {
- if (subfacet->installed) {
+ if (subfacet->path != SF_NOT_INSTALLED) {
batch[n_batch++] = subfacet;
if (n_batch >= EXPIRE_MAX_BATCH) {
expire_batch(ofproto, batch, n_batch);
@@ -3735,6 +3803,44 @@ facet_lookup_valid(struct ofproto_dpif *ofproto, const struct flow *flow,
return facet;
}
+static const char *
+subfacet_path_to_string(enum subfacet_path path)
+{
+ switch (path) {
+ case SF_NOT_INSTALLED:
+ return "not installed";
+ case SF_FAST_PATH:
+ return "in fast path";
+ case SF_SLOW_PATH:
+ return "in slow path";
+ default:
+ return "<error>";
+ }
+}
+
+/* Returns the path in which a subfacet should be installed if its 'slow'
+ * member has the specified value. */
+static enum subfacet_path
+subfacet_want_path(enum slow_path_reason slow)
+{
+ return slow ? SF_SLOW_PATH : SF_FAST_PATH;
+}
+
+/* Returns true if 'subfacet' needs to have its datapath flow updated,
+ * supposing that its actions have been recalculated as 'want_actions' and that
+ * 'slow' is nonzero iff 'subfacet' should be in the slow path. */
+static bool
+subfacet_should_install(struct subfacet *subfacet, enum slow_path_reason slow,
+ const struct ofpbuf *want_actions)
+{
+ enum subfacet_path want_path = subfacet_want_path(slow);
+ return (want_path != subfacet->path
+ || (want_path == SF_FAST_PATH
+ && (subfacet->actions_len != want_actions->size
+ || memcmp(subfacet->actions, want_actions->data,
+ subfacet->actions_len))));
+}
+
static bool
facet_check_consistency(struct facet *facet)
{
@@ -3776,10 +3882,9 @@ facet_check_consistency(struct facet *facet)
/* Check the datapath actions for consistency. */
ofpbuf_use_stub(&odp_actions, odp_actions_stub, sizeof odp_actions_stub);
LIST_FOR_EACH (subfacet, list_node, &facet->subfacets) {
+ enum subfacet_path want_path;
struct odputil_keybuf keybuf;
struct action_xlate_ctx ctx;
- bool actions_changed;
- bool should_install;
struct ofpbuf key;
struct ds s;
@@ -3788,18 +3893,20 @@ facet_check_consistency(struct facet *facet)
xlate_actions(&ctx, rule->up.actions, rule->up.n_actions,
&odp_actions);
- should_install = (ctx.may_set_up_flow
- && subfacet->key_fitness != ODP_FIT_TOO_LITTLE);
- if (!should_install && !subfacet->installed) {
- /* The actions for uninstallable flows may vary from one packet to
- * the next, so don't compare the actions. */
+ if (subfacet->path == SF_NOT_INSTALLED) {
+ /* This only happens if the datapath reported an error when we
+ * tried to install the flow. Don't flag another error here. */
+ continue;
+ }
+
+ want_path = subfacet_want_path(subfacet->slow);
+ if (want_path == SF_SLOW_PATH && subfacet->path == SF_SLOW_PATH) {
+ /* The actions for slow-path flows may legitimately vary from one
+ * packet to the next. We're done. */
continue;
}
- actions_changed = (subfacet->actions_len != odp_actions.size
- || memcmp(subfacet->actions, odp_actions.data,
- subfacet->actions_len));
- if (should_install == subfacet->installed && !actions_changed) {
+ if (!subfacet_should_install(subfacet, subfacet->slow, &odp_actions)) {
continue;
}
@@ -3818,16 +3925,15 @@ facet_check_consistency(struct facet *facet)
odp_flow_key_format(key.data, key.size, &s);
ds_put_cstr(&s, ": inconsistency in subfacet");
- if (should_install != subfacet->installed) {
+ if (want_path != subfacet->path) {
enum odp_key_fitness fitness = subfacet->key_fitness;
- ds_put_format(&s, " (should%s have been installed)",
- should_install ? "" : " not");
- ds_put_format(&s, " (may_set_up_flow=%s, fitness=%s)",
- ctx.may_set_up_flow ? "true" : "false",
+ ds_put_format(&s, " (%s, fitness=%s)",
+ subfacet_path_to_string(subfacet->path),
odp_key_fitness_to_string(fitness));
- }
- if (actions_changed) {
+ ds_put_format(&s, " (should have been %s)",
+ subfacet_path_to_string(want_path));
+ } else if (want_path == SF_FAST_PATH) {
ds_put_cstr(&s, " (actions were: ");
format_odp_actions(&s, subfacet->actions,
subfacet->actions_len);
@@ -3871,7 +3977,6 @@ facet_revalidate(struct facet *facet)
struct rule_dpif *new_rule;
struct subfacet *subfacet;
- bool actions_changed;
int i;
COVERAGE_INC(facet_revalidate);
@@ -3891,28 +3996,20 @@ facet_revalidate(struct facet *facet)
memset(&ctx, 0, sizeof ctx);
ofpbuf_use_stub(&odp_actions, odp_actions_stub, sizeof odp_actions_stub);
LIST_FOR_EACH (subfacet, list_node, &facet->subfacets) {
- bool should_install;
+ enum slow_path_reason slow;
action_xlate_ctx_init(&ctx, ofproto, &facet->flow,
subfacet->initial_tci, new_rule, 0, NULL);
xlate_actions(&ctx, new_rule->up.actions, new_rule->up.n_actions,
&odp_actions);
- actions_changed = (subfacet->actions_len != odp_actions.size
- || memcmp(subfacet->actions, odp_actions.data,
- subfacet->actions_len));
-
- should_install = (ctx.may_set_up_flow
- && subfacet->key_fitness != ODP_FIT_TOO_LITTLE);
- if (actions_changed || should_install != subfacet->installed) {
- if (should_install) {
- struct dpif_flow_stats stats;
- subfacet_install(subfacet,
- odp_actions.data, odp_actions.size, &stats);
- subfacet_update_stats(subfacet, &stats);
- } else {
- subfacet_uninstall(subfacet);
- }
+ slow = (subfacet->slow & SLOW_MATCH) | ctx.slow;
+ if (subfacet_should_install(subfacet, slow, &odp_actions)) {
+ struct dpif_flow_stats stats;
+
+ subfacet_install(subfacet,
+ odp_actions.data, odp_actions.size, &stats, slow);
+ subfacet_update_stats(subfacet, &stats);
if (!new_actions) {
new_actions = xcalloc(list_size(&facet->subfacets),
@@ -3934,23 +4031,24 @@ facet_revalidate(struct facet *facet)
/* Update 'facet' now that we've taken care of all the old state. */
facet->tags = ctx.tags;
facet->nf_flow.output_iface = ctx.nf_output_iface;
- facet->may_install = ctx.may_set_up_flow;
facet->has_learn = ctx.has_learn;
facet->has_normal = ctx.has_normal;
facet->has_fin_timeout = ctx.has_fin_timeout;
facet->mirrors = ctx.mirrors;
- if (new_actions) {
- i = 0;
- LIST_FOR_EACH (subfacet, list_node, &facet->subfacets) {
- if (new_actions[i].odp_actions) {
- free(subfacet->actions);
- subfacet->actions = new_actions[i].odp_actions;
- subfacet->actions_len = new_actions[i].actions_len;
- }
- i++;
+
+ i = 0;
+ LIST_FOR_EACH (subfacet, list_node, &facet->subfacets) {
+ subfacet->slow = (subfacet->slow & SLOW_MATCH) | ctx.slow;
+
+ if (new_actions && new_actions[i].odp_actions) {
+ free(subfacet->actions);
+ subfacet->actions = new_actions[i].odp_actions;
+ subfacet->actions_len = new_actions[i].actions_len;
}
- free(new_actions);
+ i++;
}
+ free(new_actions);
+
if (facet->rule != new_rule) {
COVERAGE_INC(facet_changed_rule);
list_remove(&facet->list_node);
@@ -4102,7 +4200,10 @@ subfacet_create(struct facet *facet, enum odp_key_fitness key_fitness,
subfacet->dp_byte_count = 0;
subfacet->actions_len = 0;
subfacet->actions = NULL;
- subfacet->installed = false;
+ subfacet->slow = (subfacet->key_fitness == ODP_FIT_TOO_LITTLE
+ ? SLOW_MATCH
+ : 0);
+ subfacet->path = SF_NOT_INSTALLED;
subfacet->initial_tci = initial_tci;
return subfacet;
@@ -4191,13 +4292,13 @@ subfacet_make_actions(struct subfacet *subfacet, const struct ofpbuf *packet,
rule, 0, packet);
xlate_actions(&ctx, rule->up.actions, rule->up.n_actions, odp_actions);
facet->tags = ctx.tags;
- facet->may_install = ctx.may_set_up_flow;
facet->has_learn = ctx.has_learn;
facet->has_normal = ctx.has_normal;
facet->has_fin_timeout = ctx.has_fin_timeout;
facet->nf_flow.output_iface = ctx.nf_output_iface;
facet->mirrors = ctx.mirrors;
+ subfacet->slow = (subfacet->slow & SLOW_MATCH) | ctx.slow;
if (subfacet->actions_len != odp_actions->size
|| memcmp(subfacet->actions, odp_actions->data, odp_actions->size)) {
free(subfacet->actions);
@@ -4215,10 +4316,13 @@ subfacet_make_actions(struct subfacet *subfacet, const struct ofpbuf *packet,
static int
subfacet_install(struct subfacet *subfacet,
const struct nlattr *actions, size_t actions_len,
- struct dpif_flow_stats *stats)
+ struct dpif_flow_stats *stats,
+ enum slow_path_reason slow)
{
struct facet *facet = subfacet->facet;
struct ofproto_dpif *ofproto = ofproto_dpif_cast(facet->rule->up.ofproto);
+ enum subfacet_path path = subfacet_want_path(slow);
+ uint64_t slow_path_stub[128 / 8];
struct odputil_keybuf keybuf;
enum dpif_flow_put_flags flags;
struct ofpbuf key;
@@ -4229,6 +4333,12 @@ subfacet_install(struct subfacet *subfacet,
flags |= DPIF_FP_ZERO_STATS;
}
+ if (path == SF_SLOW_PATH) {
+ compose_slow_path(ofproto, &facet->flow, slow,
+ slow_path_stub, sizeof slow_path_stub,
+ &actions, &actions_len);
+ }
+
subfacet_get_key(subfacet, &keybuf, &key);
ret = dpif_flow_put(ofproto->dpif, flags, key.data, key.size,
actions, actions_len, stats);
@@ -4237,14 +4347,24 @@ subfacet_install(struct subfacet *subfacet,
subfacet_reset_dp_stats(subfacet, stats);
}
+ if (!ret) {
+ subfacet->path = path;
+ }
return ret;
}
+static int
+subfacet_reinstall(struct subfacet *subfacet, struct dpif_flow_stats *stats)
+{
+ return subfacet_install(subfacet, subfacet->actions, subfacet->actions_len,
+ stats, subfacet->slow);
+}
+
/* If 'subfacet' is installed in the datapath, uninstalls it. */
static void
subfacet_uninstall(struct subfacet *subfacet)
{
- if (subfacet->installed) {
+ if (subfacet->path != SF_NOT_INSTALLED) {
struct rule_dpif *rule = subfacet->facet->rule;
struct ofproto_dpif *ofproto = ofproto_dpif_cast(rule->up.ofproto);
struct odputil_keybuf keybuf;
@@ -4258,7 +4378,7 @@ subfacet_uninstall(struct subfacet *subfacet)
if (!error) {
subfacet_update_stats(subfacet, &stats);
}
- subfacet->installed = false;
+ subfacet->path = SF_NOT_INSTALLED;
} else {
assert(subfacet->dp_packet_count == 0);
assert(subfacet->dp_byte_count == 0);
@@ -4575,6 +4695,35 @@ static void do_xlate_actions(const union ofp_action *in, size_t n_in,
struct action_xlate_ctx *ctx);
static void xlate_normal(struct action_xlate_ctx *);
+/* Composes an ODP action for a "slow path" action for 'flow' within 'ofproto'.
+ * The action will state 'slow' as the reason that the action is in the slow
+ * path. (This is purely informational: it allows a human viewing "ovs-dpctl
+ * dump-flows" output to see why a flow is in the slow path.)
+ *
+ * The 'stub_size' bytes in 'stub' will be used to store the action.
+ * 'stub_size' must be large enough for the action.
+ *
+ * The action and its size will be stored in '*actionsp' and '*actions_lenp',
+ * respectively. */
+static void
+compose_slow_path(const struct ofproto_dpif *ofproto, const struct flow *flow,
+ enum slow_path_reason slow,
+ uint64_t *stub, size_t stub_size,
+ const struct nlattr **actionsp, size_t *actions_lenp)
+{
+ union user_action_cookie cookie;
+ struct ofpbuf buf;
+
+ cookie.type = USER_ACTION_COOKIE_SLOW_PATH;
+ cookie.slow_path.unused = 0;
+ cookie.slow_path.reason = slow;
+
+ ofpbuf_use_stack(&buf, stub, stub_size);
+ put_userspace_action(ofproto, &buf, flow, &cookie);
+ *actionsp = buf.data;
+ *actions_lenp = buf.size;
+}
+
static size_t
put_userspace_action(const struct ofproto_dpif *ofproto,
struct ofpbuf *odp_actions,
@@ -4844,7 +4993,7 @@ execute_controller_action(struct action_xlate_ctx *ctx, int len,
struct ofputil_packet_in pin;
struct ofpbuf *packet;
- ctx->may_set_up_flow = false;
+ ctx->slow |= SLOW_CONTROLLER;
if (!ctx->packet) {
return;
}
@@ -5397,6 +5546,8 @@ xlate_actions(struct action_xlate_ctx *ctx,
* tracing purposes. */
static bool hit_resubmit_limit;
+ enum slow_path_reason special;
+
COVERAGE_INC(ofproto_dpif_xlate);
ofpbuf_clear(odp_actions);
@@ -5404,7 +5555,7 @@ xlate_actions(struct action_xlate_ctx *ctx,
ctx->odp_actions = odp_actions;
ctx->tags = 0;
- ctx->may_set_up_flow = true;
+ ctx->slow = 0;
ctx->has_learn = false;
ctx->has_normal = false;
ctx->has_fin_timeout = false;
@@ -5449,8 +5600,9 @@ xlate_actions(struct action_xlate_ctx *ctx,
}
}
- if (process_special(ctx->ofproto, &ctx->flow, ctx->packet)) {
- ctx->may_set_up_flow = false;
+ special = process_special(ctx->ofproto, &ctx->flow, ctx->packet);
+ if (special) {
+ ctx->slow |= special;
} else {
static struct vlog_rate_limit trace_rl = VLOG_RATE_LIMIT_INIT(1, 1);
ovs_be16 initial_tci = ctx->base_flow.vlan_tci;
@@ -5477,7 +5629,7 @@ xlate_actions(struct action_xlate_ctx *ctx,
if (!connmgr_may_set_up_flow(ctx->ofproto->up.connmgr, &ctx->flow,
ctx->odp_actions->data,
ctx->odp_actions->size)) {
- ctx->may_set_up_flow = false;
+ ctx->slow |= SLOW_IN_BAND;
if (ctx->packet
&& connmgr_msg_in_hook(ctx->ofproto->up.connmgr, &ctx->flow,
ctx->packet)) {
@@ -6278,11 +6430,10 @@ send_active_timeout(struct ofproto_dpif *ofproto, struct facet *facet)
struct ofexpired expired;
LIST_FOR_EACH (subfacet, list_node, &facet->subfacets) {
- if (subfacet->installed) {
+ if (subfacet->path == SF_FAST_PATH) {
struct dpif_flow_stats stats;
- subfacet_install(subfacet, subfacet->actions,
- subfacet->actions_len, &stats);
+ subfacet_reinstall(subfacet, &stats);
subfacet_update_stats(subfacet, &stats);
}
}
@@ -6582,12 +6733,49 @@ ofproto_trace(struct ofproto_dpif *ofproto, const struct flow *flow,
format_odp_actions(ds, odp_actions.data, odp_actions.size);
ofpbuf_uninit(&odp_actions);
- if (!trace.ctx.may_set_up_flow) {
- if (packet) {
- ds_put_cstr(ds, "\nThis flow is not cachable.");
- } else {
- ds_put_cstr(ds, "\nThe datapath actions are incomplete--"
- "for complete actions, please supply a packet.");
+ if (trace.ctx.slow) {
+ enum slow_path_reason slow;
+
+ ds_put_cstr(ds, "\nThis flow is handled by the userspace "
+ "slow path because it:");
+ for (slow = trace.ctx.slow; slow; ) {
+ enum slow_path_reason bit = rightmost_1bit(slow);
+
+ switch (bit) {
+ case SLOW_CONTROLLER:
+ ds_put_cstr(ds, "\n\t- Sends \"packet-in\" messages "
+ "to the OpenFlow controller.");
+ break;
+ case SLOW_CFM:
+ ds_put_cstr(ds, "\n\t- Consists of CFM packets.");
+ break;
+ case SLOW_LACP:
+ ds_put_cstr(ds, "\n\t- Consists of LACP packets.");
+ break;
+ case SLOW_STP:
+ ds_put_cstr(ds, "\n\t- Consists of STP packets.");
+ break;
+ case SLOW_IN_BAND:
+ ds_put_cstr(ds, "\n\t- Needs in-band special case "
+ "processing.");
+ if (!packet) {
+ ds_put_cstr(ds, "\n\t (The datapath actions are "
+ "incomplete--for complete actions, "
+ "please supply a packet.)");
+ }
+ break;
+ case SLOW_MATCH:
+ ds_put_cstr(ds, "\n\t- Needs more specific matching "
+ "than the datapath supports.");
+ break;
+ }
+
+ slow &= ~bit;
+ }
+
+ if (slow & ~SLOW_MATCH) {
+ ds_put_cstr(ds, "\nThe datapath actions above do not reflect "
+ "the special slow-path processing.");
}
}
}
diff --git a/tests/ofproto-dpif.at b/tests/ofproto-dpif.at
index 2c5df96..3dab43e 100644
--- a/tests/ofproto-dpif.at
+++ b/tests/ofproto-dpif.at
@@ -78,9 +78,10 @@ table=1 in_port=1 action=dec_ttl,output:3
])
AT_CHECK([ovs-ofctl add-flows br0 flows.txt])
AT_CHECK([ovs-appctl ofproto/trace br0 'in_port(1),eth(src=50:54:00:00:00:05,dst=50:54:00:00:00:07),eth_type(0x0800),ipv4(src=192.168.0.1,dst=192.168.0.2,proto=1,tos=0,ttl=2,frag=no)' -generate], [0], [stdout])
-AT_CHECK([tail -2 stdout], [0],
+AT_CHECK([tail -3 stdout], [0],
[Datapath actions: set(ipv4(src=192.168.0.1,dst=192.168.0.2,proto=1,tos=0,ttl=1,frag=no)),2,4
-This flow is not cachable.
+This flow is handled by the userspace slow path because it:
+ - Sends "packet-in" messages to the OpenFlow controller.
])
AT_CHECK([ovs-appctl ofproto/trace br0 'in_port(1),eth(src=50:54:00:00:00:05,dst=50:54:00:00:00:07),eth_type(0x0800),ipv4(src=192.168.0.1,dst=192.168.0.2,proto=1,tos=0,ttl=3,frag=no)'], [0], [stdout])
AT_CHECK([tail -1 stdout], [0],
--
1.7.2.5
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