Date: Tue, 9 Sep 2014 03:10:21 +0000 (UTC) From: Adrian Chadd <adrian@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r271297 - head/sys/netinet Message-ID: <201409090310.s893ALba076415@svn.freebsd.org>
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Author: adrian Date: Tue Sep 9 03:10:21 2014 New Revision: 271297 URL: http://svnweb.freebsd.org/changeset/base/271297 Log: Implement IPv4 RSS software hash functions to use during packet ingress and egress. * rss_mbuf_software_hash_v4 - look at the IPv4 mbuf to fetch the IPv4 details + direction to calculate a hash. * rss_proto_software_hash_v4 - hash the given source/destination IPv4 address, port and direction. * rss_soft_m2cpuid - map the given mbuf to an RSS CPU ("bucket" for now) These functions are intended to be used by the stack to support the following: * Not all NICs do RSS hashing, so we should support some way of doing a hash in software; * The NIC / driver may not hash frames the way we want (eg UDP 4-tuple hashing when the stack is only doing 2-tuple hashing for UDP); so we may need to re-hash frames; * .. same with IPv4 fragments - they will need to be re-hashed after reassembly; * .. and same with things like IP tunneling and such; * The transmit path for things like UDP, RAW and ICMP don't currently have any RSS information attached to them - so they'll need an RSS calculation performed before transmit. TODO: * Counters! Everywhere! * Add a debug mode that software hashes received frames and compares them to the hardware hash provided by the hardware to ensure they match. The IPv6 part of this is missing - I'm going to do some re-juggling of where various parts of the RSS framework live before I add the IPv6 code (read: the IPv6 code is going to go into netinet6/in6_rss.[ch], rather than living here.) Note: This API is still fluid. Please keep that in mind. Differential Revision: https://reviews.freebsd.org/D527 Reviewed by: grehan Modified: head/sys/netinet/in_rss.c head/sys/netinet/in_rss.h Modified: head/sys/netinet/in_rss.c ============================================================================== --- head/sys/netinet/in_rss.c Tue Sep 9 02:58:58 2014 (r271296) +++ head/sys/netinet/in_rss.c Tue Sep 9 03:10:21 2014 (r271297) @@ -57,6 +57,11 @@ __FBSDID("$FreeBSD$"); #include <netinet/in_var.h> #include <netinet/toeplitz.h> +/* for software rss hash support */ +#include <netinet/ip.h> +#include <netinet/tcp.h> +#include <netinet/udp.h> + /*- * Operating system parts of receiver-side scaling (RSS), which allows * network cards to direct flows to particular receive queues based on hashes @@ -170,6 +175,8 @@ struct rss_table_entry { }; static struct rss_table_entry rss_table[RSS_TABLE_MAXLEN]; +static inline u_int rss_gethashconfig_local(void); + static void rss_init(__unused void *arg) { @@ -491,6 +498,254 @@ rss_m2bucket(struct mbuf *m, uint32_t *b } /* + * Calculate an appropriate ipv4 2-tuple or 4-tuple given the given + * IPv4 source/destination address, UDP or TCP source/destination ports + * and the protocol type. + * + * The protocol code may wish to do a software hash of the given + * tuple. This depends upon the currently configured RSS hash types. + * + * This assumes that the packet in question isn't a fragment. + * + * It also assumes the packet source/destination address + * are in "incoming" packet order (ie, source is "far" address.) + */ +int +rss_proto_software_hash_v4(struct in_addr s, struct in_addr d, + u_short sp, u_short dp, int proto, + uint32_t *hashval, uint32_t *hashtype) +{ + uint32_t hash; + + /* + * Next, choose the hash type depending upon the protocol + * identifier. + */ + if ((proto == IPPROTO_TCP) && + (rss_gethashconfig_local() & RSS_HASHTYPE_RSS_TCP_IPV4)) { + hash = rss_hash_ip4_4tuple(s, sp, d, dp); + *hashval = hash; + *hashtype = M_HASHTYPE_RSS_TCP_IPV4; + return (0); + } else if ((proto == IPPROTO_UDP) && + (rss_gethashconfig_local() & RSS_HASHTYPE_RSS_UDP_IPV4)) { + hash = rss_hash_ip4_4tuple(s, sp, d, dp); + *hashval = hash; + *hashtype = M_HASHTYPE_RSS_UDP_IPV4; + return (0); + } else if (rss_gethashconfig_local() & RSS_HASHTYPE_RSS_IPV4) { + /* RSS doesn't hash on other protocols like SCTP; so 2-tuple */ + hash = rss_hash_ip4_2tuple(s, d); + *hashval = hash; + *hashtype = M_HASHTYPE_RSS_IPV4; + return (0); + } + + /* No configured available hashtypes! */ + printf("%s: no available hashtypes!\n", __func__); + return (-1); +} + +/* + * Do a software calculation of the RSS for the given mbuf. + * + * This is typically used by the input path to recalculate the RSS after + * some form of packet processing (eg de-capsulation, IP fragment reassembly.) + * + * dir is the packet direction - RSS_HASH_PKT_INGRESS for incoming and + * RSS_HASH_PKT_EGRESS for outgoing. + * + * Returns 0 if a hash was done, -1 if no hash was done, +1 if + * the mbuf already had a valid RSS flowid. + * + * This function doesn't modify the mbuf. It's up to the caller to + * assign flowid/flowtype as appropriate. + */ +int +rss_mbuf_software_hash_v4(const struct mbuf *m, int dir, uint32_t *hashval, + uint32_t *hashtype) +{ + const struct ip *ip; + const struct tcphdr *th; + const struct udphdr *uh; + uint8_t proto; + int iphlen; + int is_frag = 0; + + /* + * XXX For now this only handles hashing on incoming mbufs. + */ + if (dir != RSS_HASH_PKT_INGRESS) { + printf("%s: called on EGRESS packet!\n", __func__); + return (-1); + } + + /* + * First, validate that the mbuf we have is long enough + * to have an IPv4 header in it. + */ + if (m->m_pkthdr.len < (sizeof(struct ip))) { + printf("%s: short mbuf pkthdr\n", __func__); + return (-1); + } + if (m->m_len < (sizeof(struct ip))) { + printf("%s: short mbuf len\n", __func__); + return (-1); + } + + /* Ok, let's dereference that */ + ip = mtod(m, struct ip *); + proto = ip->ip_p; + iphlen = ip->ip_hl << 2; + + /* + * If this is a fragment then it shouldn't be four-tuple + * hashed just yet. Once it's reassembled into a full + * frame it should be re-hashed. + */ + if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) + is_frag = 1; + + /* + * If the mbuf flowid/flowtype matches the packet type, + * and we don't support the 4-tuple version of the given protocol, + * then signal to the owner that it can trust the flowid/flowtype + * details. + * + * This is a little picky - eg, if TCPv4 / UDPv4 hashing + * is supported but we got a TCP/UDP frame only 2-tuple hashed, + * then we shouldn't just "trust" the 2-tuple hash. We need + * a 4-tuple hash. + */ + if (m->m_flags & M_FLOWID) { + uint32_t flowid, flowtype; + + flowid = m->m_pkthdr.flowid; + flowtype = M_HASHTYPE_GET(m); + + switch (proto) { + case IPPROTO_UDP: + if ((rss_gethashconfig_local() & RSS_HASHTYPE_RSS_UDP_IPV4) && + (flowtype == M_HASHTYPE_RSS_UDP_IPV4) && + (is_frag == 0)) { + return (1); + } + /* + * Only allow 2-tuple for UDP frames if we don't also + * support 4-tuple for UDP. + */ + if ((rss_gethashconfig_local() & RSS_HASHTYPE_RSS_IPV4) && + ((rss_gethashconfig_local() & RSS_HASHTYPE_RSS_UDP_IPV4) == 0) && + flowtype == M_HASHTYPE_RSS_IPV4) { + return (1); + } + break; + case IPPROTO_TCP: + if ((rss_gethashconfig_local() & RSS_HASHTYPE_RSS_TCP_IPV4) && + (flowtype == M_HASHTYPE_RSS_TCP_IPV4) && + (is_frag == 0)) { + return (1); + } + /* + * Only allow 2-tuple for TCP frames if we don't also + * support 2-tuple for TCP. + */ + if ((rss_gethashconfig_local() & RSS_HASHTYPE_RSS_IPV4) && + ((rss_gethashconfig_local() & RSS_HASHTYPE_RSS_TCP_IPV4) == 0) && + flowtype == M_HASHTYPE_RSS_IPV4) { + return (1); + } + break; + default: + if ((rss_gethashconfig_local() & RSS_HASHTYPE_RSS_IPV4) && + flowtype == M_HASHTYPE_RSS_IPV4) { + return (1); + } + break; + } + } + + /* + * Decode enough information to make a hash decision. + * + * XXX TODO: does the hardware hash on 4-tuple if IP + * options are present? + */ + if (proto == IPPROTO_TCP && is_frag == 0) { + if (m->m_len < iphlen + sizeof(struct tcphdr)) { + printf("%s: short TCP frame?\n", __func__); + return (-1); + } + th = (struct tcphdr *)((caddr_t)ip + iphlen); + return rss_proto_software_hash_v4(ip->ip_src, ip->ip_dst, + th->th_sport, + th->th_dport, + proto, + hashval, + hashtype); + } else if (proto == IPPROTO_UDP && is_frag == 0) { + uh = (struct udphdr *)((caddr_t)ip + iphlen); + if (m->m_len < iphlen + sizeof(struct udphdr)) { + printf("%s: short UDP frame?\n", __func__); + return (-1); + } + return rss_proto_software_hash_v4(ip->ip_src, ip->ip_dst, + uh->uh_sport, + uh->uh_dport, + proto, + hashval, + hashtype); + } else { + /* Default to 2-tuple hash */ + return rss_proto_software_hash_v4(ip->ip_src, ip->ip_dst, + 0, /* source port */ + 0, /* destination port */ + 0, /* IPPROTO_IP */ + hashval, + hashtype); + } +} + +/* + * Similar to rss_m2cpuid, but designed to be used by the IP NETISR + * on incoming frames. + * + * If an existing RSS hash exists and it matches what the configured + * hashing is, then use it. + * + * If there's an existing RSS hash but the desired hash is different, + * or if there's no useful RSS hash, then calculate it via + * the software path. + * + * XXX TODO: definitely want statistics here! + */ +struct mbuf * +rss_soft_m2cpuid(struct mbuf *m, uintptr_t source, u_int *cpuid) +{ + uint32_t hash_val, hash_type; + int ret; + + M_ASSERTPKTHDR(m); + + ret = rss_mbuf_software_hash_v4(m, RSS_HASH_PKT_INGRESS, + &hash_val, &hash_type); + if (ret > 0) { + /* mbuf has a valid hash already; don't need to modify it */ + *cpuid = rss_hash2cpuid(m->m_pkthdr.flowid, M_HASHTYPE_GET(m)); + } else if (ret == 0) { + /* hash was done; update */ + m->m_pkthdr.flowid = hash_val; + M_HASHTYPE_SET(m, hash_type); + m->m_flags |= M_FLOWID; + *cpuid = rss_hash2cpuid(m->m_pkthdr.flowid, M_HASHTYPE_GET(m)); + } else { /* ret < 0 */ + /* no hash was done */ + *cpuid = NETISR_CPUID_NONE; + } + return (m); +} + +/* * Query the RSS hash algorithm. */ u_int @@ -538,15 +793,10 @@ rss_getnumcpus(void) return (rss_ncpus); } -/* - * Return the supported RSS hash configuration. - * - * NICs should query this to determine what to configure in their redirection - * matching table. - */ -u_int -rss_gethashconfig(void) +static inline u_int +rss_gethashconfig_local(void) { + /* Return 4-tuple for TCP; 2-tuple for others */ /* * UDP may fragment more often than TCP and thus we'll end up with @@ -573,6 +823,19 @@ rss_gethashconfig(void) } /* + * Return the supported RSS hash configuration. + * + * NICs should query this to determine what to configure in their redirection + * matching table. + */ +u_int +rss_gethashconfig(void) +{ + + return (rss_gethashconfig_local()); +} + +/* * XXXRW: Confirm that sysctl -a won't dump this keying material, don't want * it appearing in debugging output unnecessarily. */ Modified: head/sys/netinet/in_rss.h ============================================================================== --- head/sys/netinet/in_rss.h Tue Sep 9 02:58:58 2014 (r271296) +++ head/sys/netinet/in_rss.h Tue Sep 9 03:10:21 2014 (r271297) @@ -83,6 +83,16 @@ #define RSS_KEYSIZE 40 /* + * For RSS hash methods that do a software hash on an mbuf, the packet + * direction (ingress / egress) is required. + * + * The default direction (INGRESS) is the "receive into the NIC" - ie, + * what the hardware is hashing on. + */ +#define RSS_HASH_PKT_INGRESS 0 +#define RSS_HASH_PKT_EGRESS 1 + +/* * Device driver interfaces to query RSS properties that must be programmed * into hardware. */ @@ -116,4 +126,17 @@ int rss_hash2bucket(uint32_t hash_val, uint32_t *bucket_id); int rss_m2bucket(struct mbuf *m, uint32_t *bucket_id); +/* + * Functions to calculate a software RSS hash for a given mbuf or + * packet detail. + */ +int rss_mbuf_software_hash_v4(const struct mbuf *m, int dir, + uint32_t *hashval, uint32_t *hashtype); +int rss_proto_software_hash_v4(struct in_addr src, + struct in_addr dst, u_short src_port, u_short dst_port, + int proto, uint32_t *hashval, + uint32_t *hashtype); +struct mbuf * rss_soft_m2cpuid(struct mbuf *m, uintptr_t source, + u_int *cpuid); + #endif /* !_NETINET_IN_RSS_H_ */
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