594 lines
15 KiB
C
594 lines
15 KiB
C
/*-
|
|
* Copyright (c) 2010-2011 Juniper Networks, Inc.
|
|
* All rights reserved.
|
|
*
|
|
* This software was developed by Robert N. M. Watson under contract
|
|
* to Juniper Networks, Inc.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
#include "opt_inet6.h"
|
|
#include "opt_pcbgroup.h"
|
|
|
|
#ifndef PCBGROUP
|
|
#error "options RSS depends on options PCBGROUP"
|
|
#endif
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/mbuf.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/priv.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/smp.h>
|
|
#include <sys/sysctl.h>
|
|
#include <sys/sbuf.h>
|
|
|
|
#include <net/if.h>
|
|
#include <net/if_var.h>
|
|
#include <net/netisr.h>
|
|
|
|
#include <netinet/in.h>
|
|
#include <netinet/in_pcb.h>
|
|
#include <netinet/in_rss.h>
|
|
#include <netinet/in_var.h>
|
|
#include <netinet/toeplitz.h>
|
|
|
|
/*-
|
|
* Operating system parts of receiver-side scaling (RSS), which allows
|
|
* network cards to direct flows to particular receive queues based on hashes
|
|
* of header tuples. This implementation aligns RSS buckets with connection
|
|
* groups at the TCP/IP layer, so each bucket is associated with exactly one
|
|
* group. As a result, the group lookup structures (and lock) should have an
|
|
* effective affinity with exactly one CPU.
|
|
*
|
|
* Network device drivers needing to configure RSS will query this framework
|
|
* for parameters, such as the current RSS key, hashing policies, number of
|
|
* bits, and indirection table mapping hashes to buckets and CPUs. They may
|
|
* provide their own supplementary information, such as queue<->CPU bindings.
|
|
* It is the responsibility of the network device driver to inject packets
|
|
* into the stack on as close to the right CPU as possible, if playing by RSS
|
|
* rules.
|
|
*
|
|
* TODO:
|
|
*
|
|
* - Synchronization for rss_key and other future-configurable parameters.
|
|
* - Event handler drivers can register to pick up RSS configuration changes.
|
|
* - Should we allow rss_basecpu to be configured?
|
|
* - Randomize key on boot.
|
|
* - IPv6 support.
|
|
* - Statistics on how often there's a misalignment between hardware
|
|
* placement and pcbgroup expectations.
|
|
*/
|
|
|
|
SYSCTL_NODE(_net_inet, OID_AUTO, rss, CTLFLAG_RW, 0, "Receive-side steering");
|
|
|
|
/*
|
|
* Toeplitz is the only required hash function in the RSS spec, so use it by
|
|
* default.
|
|
*/
|
|
static u_int rss_hashalgo = RSS_HASH_TOEPLITZ;
|
|
SYSCTL_INT(_net_inet_rss, OID_AUTO, hashalgo, CTLFLAG_RDTUN, &rss_hashalgo, 0,
|
|
"RSS hash algorithm");
|
|
|
|
/*
|
|
* Size of the indirection table; at most 128 entries per the RSS spec. We
|
|
* size it to at least 2 times the number of CPUs by default to allow useful
|
|
* rebalancing. If not set explicitly with a loader tunable, we tune based
|
|
* on the number of CPUs present.
|
|
*
|
|
* XXXRW: buckets might be better to use for the tunable than bits.
|
|
*/
|
|
static u_int rss_bits;
|
|
SYSCTL_INT(_net_inet_rss, OID_AUTO, bits, CTLFLAG_RDTUN, &rss_bits, 0,
|
|
"RSS bits");
|
|
|
|
static u_int rss_mask;
|
|
SYSCTL_INT(_net_inet_rss, OID_AUTO, mask, CTLFLAG_RD, &rss_mask, 0,
|
|
"RSS mask");
|
|
|
|
static const u_int rss_maxbits = RSS_MAXBITS;
|
|
SYSCTL_INT(_net_inet_rss, OID_AUTO, maxbits, CTLFLAG_RD,
|
|
__DECONST(int *, &rss_maxbits), 0, "RSS maximum bits");
|
|
|
|
/*
|
|
* RSS's own count of the number of CPUs it could be using for processing.
|
|
* Bounded to 64 by RSS constants.
|
|
*/
|
|
static u_int rss_ncpus;
|
|
SYSCTL_INT(_net_inet_rss, OID_AUTO, ncpus, CTLFLAG_RD, &rss_ncpus, 0,
|
|
"Number of CPUs available to RSS");
|
|
|
|
#define RSS_MAXCPUS (1 << (RSS_MAXBITS - 1))
|
|
static const u_int rss_maxcpus = RSS_MAXCPUS;
|
|
SYSCTL_INT(_net_inet_rss, OID_AUTO, maxcpus, CTLFLAG_RD,
|
|
__DECONST(int *, &rss_maxcpus), 0, "RSS maximum CPUs that can be used");
|
|
|
|
/*
|
|
* Variable exists just for reporting rss_bits in a user-friendly way.
|
|
*/
|
|
static u_int rss_buckets;
|
|
SYSCTL_INT(_net_inet_rss, OID_AUTO, buckets, CTLFLAG_RD, &rss_buckets, 0,
|
|
"RSS buckets");
|
|
|
|
/*
|
|
* Base CPU number; devices will add this to all CPU numbers returned by the
|
|
* RSS indirection table. Currently unmodifable in FreeBSD.
|
|
*/
|
|
static const u_int rss_basecpu;
|
|
SYSCTL_INT(_net_inet_rss, OID_AUTO, basecpu, CTLFLAG_RD,
|
|
__DECONST(int *, &rss_basecpu), 0, "RSS base CPU");
|
|
|
|
/*
|
|
* RSS secret key, intended to prevent attacks on load-balancing. Its
|
|
* effectiveness may be limited by algorithm choice and available entropy
|
|
* during the boot.
|
|
*
|
|
* XXXRW: And that we don't randomize it yet!
|
|
*
|
|
* XXXRW: This default is actually the default key from Chelsio T3 cards, as
|
|
* it offers reasonable distribution, unlike all-0 keys which always
|
|
* generate a hash of 0 (upsettingly).
|
|
*/
|
|
static uint8_t rss_key[RSS_KEYSIZE] = {
|
|
0x43, 0xa3, 0x8f, 0xb0, 0x41, 0x67, 0x25, 0x3d,
|
|
0x25, 0x5b, 0x0e, 0xc2, 0x6d, 0x5a, 0x56, 0xda,
|
|
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
|
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
|
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
|
};
|
|
|
|
/*
|
|
* RSS hash->CPU table, which maps hashed packet headers to particular CPUs.
|
|
* Drivers may supplement this table with a seperate CPU<->queue table when
|
|
* programming devices.
|
|
*/
|
|
struct rss_table_entry {
|
|
uint8_t rte_cpu; /* CPU affinity of bucket. */
|
|
};
|
|
static struct rss_table_entry rss_table[RSS_TABLE_MAXLEN];
|
|
|
|
static void
|
|
rss_init(__unused void *arg)
|
|
{
|
|
u_int i;
|
|
u_int cpuid;
|
|
|
|
/*
|
|
* Validate tunables, coerce to sensible values.
|
|
*/
|
|
switch (rss_hashalgo) {
|
|
case RSS_HASH_TOEPLITZ:
|
|
case RSS_HASH_NAIVE:
|
|
break;
|
|
|
|
default:
|
|
printf("%s: invalid RSS hashalgo %u, coercing to %u",
|
|
__func__, rss_hashalgo, RSS_HASH_TOEPLITZ);
|
|
rss_hashalgo = RSS_HASH_TOEPLITZ;
|
|
}
|
|
|
|
/*
|
|
* Count available CPUs.
|
|
*
|
|
* XXXRW: Note incorrect assumptions regarding contiguity of this set
|
|
* elsewhere.
|
|
*/
|
|
rss_ncpus = 0;
|
|
for (i = 0; i <= mp_maxid; i++) {
|
|
if (CPU_ABSENT(i))
|
|
continue;
|
|
rss_ncpus++;
|
|
}
|
|
if (rss_ncpus > RSS_MAXCPUS)
|
|
rss_ncpus = RSS_MAXCPUS;
|
|
|
|
/*
|
|
* Tune RSS table entries to be no less than 2x the number of CPUs
|
|
* -- unless we're running uniprocessor, in which case there's not
|
|
* much point in having buckets to rearrange for load-balancing!
|
|
*/
|
|
if (rss_ncpus > 1) {
|
|
if (rss_bits == 0)
|
|
rss_bits = fls(rss_ncpus - 1) + 1;
|
|
|
|
/*
|
|
* Microsoft limits RSS table entries to 128, so apply that
|
|
* limit to both auto-detected CPU counts and user-configured
|
|
* ones.
|
|
*/
|
|
if (rss_bits == 0 || rss_bits > RSS_MAXBITS) {
|
|
printf("%s: RSS bits %u not valid, coercing to %u",
|
|
__func__, rss_bits, RSS_MAXBITS);
|
|
rss_bits = RSS_MAXBITS;
|
|
}
|
|
|
|
/*
|
|
* Figure out how many buckets to use; warn if less than the
|
|
* number of configured CPUs, although this is not a fatal
|
|
* problem.
|
|
*/
|
|
rss_buckets = (1 << rss_bits);
|
|
if (rss_buckets < rss_ncpus)
|
|
printf("%s: WARNING: rss_buckets (%u) less than "
|
|
"rss_ncpus (%u)\n", __func__, rss_buckets,
|
|
rss_ncpus);
|
|
rss_mask = rss_buckets - 1;
|
|
} else {
|
|
rss_bits = 0;
|
|
rss_buckets = 1;
|
|
rss_mask = 0;
|
|
}
|
|
|
|
/*
|
|
* Set up initial CPU assignments: round-robin by default.
|
|
*/
|
|
cpuid = CPU_FIRST();
|
|
for (i = 0; i < rss_buckets; i++) {
|
|
rss_table[i].rte_cpu = cpuid;
|
|
cpuid = CPU_NEXT(cpuid);
|
|
}
|
|
|
|
/*
|
|
* Randomize rrs_key.
|
|
*
|
|
* XXXRW: Not yet. If nothing else, will require an rss_isbadkey()
|
|
* loop to check for "bad" RSS keys.
|
|
*/
|
|
}
|
|
SYSINIT(rss_init, SI_SUB_SOFTINTR, SI_ORDER_SECOND, rss_init, NULL);
|
|
|
|
static uint32_t
|
|
rss_naive_hash(u_int keylen, const uint8_t *key, u_int datalen,
|
|
const uint8_t *data)
|
|
{
|
|
uint32_t v;
|
|
u_int i;
|
|
|
|
v = 0;
|
|
for (i = 0; i < keylen; i++)
|
|
v += key[i];
|
|
for (i = 0; i < datalen; i++)
|
|
v += data[i];
|
|
return (v);
|
|
}
|
|
|
|
static uint32_t
|
|
rss_hash(u_int datalen, const uint8_t *data)
|
|
{
|
|
|
|
switch (rss_hashalgo) {
|
|
case RSS_HASH_TOEPLITZ:
|
|
return (toeplitz_hash(sizeof(rss_key), rss_key, datalen,
|
|
data));
|
|
|
|
case RSS_HASH_NAIVE:
|
|
return (rss_naive_hash(sizeof(rss_key), rss_key, datalen,
|
|
data));
|
|
|
|
default:
|
|
panic("%s: unsupported/unknown hashalgo %d", __func__,
|
|
rss_hashalgo);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Hash an IPv4 2-tuple.
|
|
*/
|
|
uint32_t
|
|
rss_hash_ip4_2tuple(struct in_addr src, struct in_addr dst)
|
|
{
|
|
uint8_t data[sizeof(src) + sizeof(dst)];
|
|
u_int datalen;
|
|
|
|
datalen = 0;
|
|
bcopy(&src, &data[datalen], sizeof(src));
|
|
datalen += sizeof(src);
|
|
bcopy(&dst, &data[datalen], sizeof(dst));
|
|
datalen += sizeof(dst);
|
|
return (rss_hash(datalen, data));
|
|
}
|
|
|
|
/*
|
|
* Hash an IPv4 4-tuple.
|
|
*/
|
|
uint32_t
|
|
rss_hash_ip4_4tuple(struct in_addr src, u_short srcport, struct in_addr dst,
|
|
u_short dstport)
|
|
{
|
|
uint8_t data[sizeof(src) + sizeof(dst) + sizeof(srcport) +
|
|
sizeof(dstport)];
|
|
u_int datalen;
|
|
|
|
datalen = 0;
|
|
bcopy(&src, &data[datalen], sizeof(src));
|
|
datalen += sizeof(src);
|
|
bcopy(&dst, &data[datalen], sizeof(dst));
|
|
datalen += sizeof(dst);
|
|
bcopy(&srcport, &data[datalen], sizeof(srcport));
|
|
datalen += sizeof(srcport);
|
|
bcopy(&dstport, &data[datalen], sizeof(dstport));
|
|
datalen += sizeof(dstport);
|
|
return (rss_hash(datalen, data));
|
|
}
|
|
|
|
#ifdef INET6
|
|
/*
|
|
* Hash an IPv6 2-tuple.
|
|
*/
|
|
uint32_t
|
|
rss_hash_ip6_2tuple(struct in6_addr src, struct in6_addr dst)
|
|
{
|
|
uint8_t data[sizeof(src) + sizeof(dst)];
|
|
u_int datalen;
|
|
|
|
datalen = 0;
|
|
bcopy(&src, &data[datalen], sizeof(src));
|
|
datalen += sizeof(src);
|
|
bcopy(&dst, &data[datalen], sizeof(dst));
|
|
datalen += sizeof(dst);
|
|
return (rss_hash(datalen, data));
|
|
}
|
|
|
|
/*
|
|
* Hash an IPv6 4-tuple.
|
|
*/
|
|
uint32_t
|
|
rss_hash_ip6_4tuple(struct in6_addr src, u_short srcport,
|
|
struct in6_addr dst, u_short dstport)
|
|
{
|
|
uint8_t data[sizeof(src) + sizeof(dst) + sizeof(srcport) +
|
|
sizeof(dstport)];
|
|
u_int datalen;
|
|
|
|
datalen = 0;
|
|
bcopy(&src, &data[datalen], sizeof(src));
|
|
datalen += sizeof(src);
|
|
bcopy(&dst, &data[datalen], sizeof(dst));
|
|
datalen += sizeof(dst);
|
|
bcopy(&srcport, &data[datalen], sizeof(srcport));
|
|
datalen += sizeof(srcport);
|
|
bcopy(&dstport, &data[datalen], sizeof(dstport));
|
|
datalen += sizeof(dstport);
|
|
return (rss_hash(datalen, data));
|
|
}
|
|
#endif /* INET6 */
|
|
|
|
/*
|
|
* Query the number of RSS bits in use.
|
|
*/
|
|
u_int
|
|
rss_getbits(void)
|
|
{
|
|
|
|
return (rss_bits);
|
|
}
|
|
|
|
/*
|
|
* Query the RSS bucket associated with an RSS hash.
|
|
*/
|
|
u_int
|
|
rss_getbucket(u_int hash)
|
|
{
|
|
|
|
return (hash & rss_mask);
|
|
}
|
|
|
|
/*
|
|
* Query the RSS layer bucket associated with the given
|
|
* entry in the RSS hash space.
|
|
*
|
|
* The RSS indirection table is 0 .. rss_buckets-1,
|
|
* covering the low 'rss_bits' of the total 128 slot
|
|
* RSS indirection table. So just mask off rss_bits and
|
|
* return that.
|
|
*
|
|
* NIC drivers can then iterate over the 128 slot RSS
|
|
* indirection table and fetch which RSS bucket to
|
|
* map it to. This will typically be a CPU queue
|
|
*/
|
|
u_int
|
|
rss_get_indirection_to_bucket(u_int index)
|
|
{
|
|
|
|
return (index & rss_mask);
|
|
}
|
|
|
|
/*
|
|
* Query the RSS CPU associated with an RSS bucket.
|
|
*/
|
|
u_int
|
|
rss_getcpu(u_int bucket)
|
|
{
|
|
|
|
return (rss_table[bucket].rte_cpu);
|
|
}
|
|
|
|
/*
|
|
* netisr CPU affinity lookup given just the hash and hashtype.
|
|
*/
|
|
u_int
|
|
rss_hash2cpuid(uint32_t hash_val, uint32_t hash_type)
|
|
{
|
|
|
|
switch (hash_type) {
|
|
case M_HASHTYPE_RSS_IPV4:
|
|
case M_HASHTYPE_RSS_TCP_IPV4:
|
|
case M_HASHTYPE_RSS_IPV6:
|
|
case M_HASHTYPE_RSS_TCP_IPV6:
|
|
return (rss_getcpu(rss_getbucket(hash_val)));
|
|
default:
|
|
return (NETISR_CPUID_NONE);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Query the RSS bucket associated with the given hash value and
|
|
* type.
|
|
*/
|
|
int
|
|
rss_hash2bucket(uint32_t hash_val, uint32_t hash_type, uint32_t *bucket_id)
|
|
{
|
|
|
|
switch (hash_type) {
|
|
case M_HASHTYPE_RSS_IPV4:
|
|
case M_HASHTYPE_RSS_TCP_IPV4:
|
|
case M_HASHTYPE_RSS_IPV6:
|
|
case M_HASHTYPE_RSS_TCP_IPV6:
|
|
*bucket_id = rss_getbucket(hash_val);
|
|
return (0);
|
|
default:
|
|
return (-1);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* netisr CPU affinity lookup routine for use by protocols.
|
|
*/
|
|
struct mbuf *
|
|
rss_m2cpuid(struct mbuf *m, uintptr_t source, u_int *cpuid)
|
|
{
|
|
|
|
M_ASSERTPKTHDR(m);
|
|
*cpuid = rss_hash2cpuid(m->m_pkthdr.flowid, M_HASHTYPE_GET(m));
|
|
return (m);
|
|
}
|
|
|
|
int
|
|
rss_m2bucket(struct mbuf *m, uint32_t *bucket_id)
|
|
{
|
|
|
|
M_ASSERTPKTHDR(m);
|
|
|
|
return(rss_hash2bucket(m->m_pkthdr.flowid, M_HASHTYPE_GET(m),
|
|
bucket_id));
|
|
}
|
|
|
|
/*
|
|
* Query the RSS hash algorithm.
|
|
*/
|
|
u_int
|
|
rss_gethashalgo(void)
|
|
{
|
|
|
|
return (rss_hashalgo);
|
|
}
|
|
|
|
/*
|
|
* Query the current RSS key; likely to be used by device drivers when
|
|
* configuring hardware RSS. Caller must pass an array of size RSS_KEYSIZE.
|
|
*
|
|
* XXXRW: Perhaps we should do the accept-a-length-and-truncate thing?
|
|
*/
|
|
void
|
|
rss_getkey(uint8_t *key)
|
|
{
|
|
|
|
bcopy(rss_key, key, sizeof(rss_key));
|
|
}
|
|
|
|
/*
|
|
* Query the number of buckets; this may be used by both network device
|
|
* drivers, which will need to populate hardware shadows of the software
|
|
* indirection table, and the network stack itself (such as when deciding how
|
|
* many connection groups to allocate).
|
|
*/
|
|
u_int
|
|
rss_getnumbuckets(void)
|
|
{
|
|
|
|
return (rss_buckets);
|
|
}
|
|
|
|
/*
|
|
* Query the number of CPUs in use by RSS; may be useful to device drivers
|
|
* trying to figure out how to map a larger number of CPUs into a smaller
|
|
* number of receive queues.
|
|
*/
|
|
u_int
|
|
rss_getnumcpus(void)
|
|
{
|
|
|
|
return (rss_ncpus);
|
|
}
|
|
|
|
/*
|
|
* XXXRW: Confirm that sysctl -a won't dump this keying material, don't want
|
|
* it appearing in debugging output unnecessarily.
|
|
*/
|
|
static int
|
|
sysctl_rss_key(SYSCTL_HANDLER_ARGS)
|
|
{
|
|
uint8_t temp_rss_key[RSS_KEYSIZE];
|
|
int error;
|
|
|
|
error = priv_check(req->td, PRIV_NETINET_HASHKEY);
|
|
if (error)
|
|
return (error);
|
|
|
|
bcopy(rss_key, temp_rss_key, sizeof(temp_rss_key));
|
|
error = sysctl_handle_opaque(oidp, temp_rss_key,
|
|
sizeof(temp_rss_key), req);
|
|
if (error)
|
|
return (error);
|
|
if (req->newptr != NULL) {
|
|
/* XXXRW: Not yet. */
|
|
return (EINVAL);
|
|
}
|
|
return (0);
|
|
}
|
|
SYSCTL_PROC(_net_inet_rss, OID_AUTO, key,
|
|
CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0, sysctl_rss_key,
|
|
"", "RSS keying material");
|
|
|
|
static int
|
|
sysctl_rss_bucket_mapping(SYSCTL_HANDLER_ARGS)
|
|
{
|
|
struct sbuf *sb;
|
|
int error;
|
|
int i;
|
|
|
|
error = 0;
|
|
error = sysctl_wire_old_buffer(req, 0);
|
|
if (error != 0)
|
|
return (error);
|
|
sb = sbuf_new_for_sysctl(NULL, NULL, 512, req);
|
|
if (sb == NULL)
|
|
return (ENOMEM);
|
|
for (i = 0; i < rss_buckets; i++) {
|
|
sbuf_printf(sb, "%s%d:%d", i == 0 ? "" : " ",
|
|
i,
|
|
rss_getcpu(i));
|
|
}
|
|
error = sbuf_finish(sb);
|
|
sbuf_delete(sb);
|
|
|
|
return (error);
|
|
}
|
|
SYSCTL_PROC(_net_inet_rss, OID_AUTO, bucket_mapping,
|
|
CTLTYPE_STRING | CTLFLAG_RD, NULL, 0,
|
|
sysctl_rss_bucket_mapping, "", "RSS bucket -> CPU mapping");
|