| Message ID | 1459711556-10273-3-git-send-email-wexu@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 04/04/2016 03:25 AM, wexu@redhat.com wrote: > From: Wei Xu <wexu@redhat.com> > > All the data packets in a tcp connection will be cached to a big buffer > in every receive interval, and will be sent out via a timer, the > 'virtio_net_rsc_timeout' controls the interval, the value will influent the > performance and response of tcp connection extremely, 50000(50us) is a > experience value to gain a performance improvement, since the whql test > sends packets every 100us, so '300000(300us)' can pass the test case, > this is also the default value, it's gonna to be tunable. > > The timer will only be triggered if the packets pool is not empty, > and it'll drain off all the cached packets > > 'NetRscChain' is used to save the segments of different protocols in a > VirtIONet device. > > The main handler of TCP includes TCP window update, duplicated ACK check > and the real data coalescing if the new segment passed sanity check > and is identified as an 'wanted' one. > > An 'wanted' segment means: > 1. Segment is within current window and the sequence is the expected one. > 2. ACK of the segment is in the valid window. > 3. If the ACK in the segment is a duplicated one, then it must less than 2, > this is to notify upper layer TCP starting retransmission due to the spec. > > Sanity check includes: > 1. Incorrect version in IP header > 2. IP options & IP fragment > 3. Not a TCP packets > 4. Sanity size check to prevent buffer overflow attack. > > There maybe more cases should be considered such as ip identification other > flags, while it broke the test because windows set it to the same even it's > not a fragment. > > Normally it includes 2 typical ways to handle a TCP control flag, 'bypass' > and 'finalize', 'bypass' means should be sent out directly, and 'finalize' > means the packets should also be bypassed, and this should be done > after searching for the same connection packets in the pool and sending > all of them out, this is to avoid out of data. > > All the 'SYN' packets will be bypassed since this always begin a new' > connection, other flags such 'FIN/RST' will trigger a finalization, because > this normally happens upon a connection is going to be closed, an 'URG' packet > also finalize current coalescing unit. > > Statistics can be used to monitor the basic coalescing status, the 'out of order' > and 'out of window' means how many retransmitting packets, thus describe the > performance intuitively. > > Signed-off-by: Wei Xu <wexu@redhat.com> > --- > hw/net/virtio-net.c | 480 ++++++++++++++++++++++++++++++++++++++++- > include/hw/virtio/virtio-net.h | 1 + > include/hw/virtio/virtio.h | 72 +++++++ > 3 files changed, 552 insertions(+), 1 deletion(-) > > diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c > index bd91a4b..81e8e71 100644 > --- a/hw/net/virtio-net.c > +++ b/hw/net/virtio-net.c > @@ -15,10 +15,12 @@ > #include "qemu/iov.h" > #include "hw/virtio/virtio.h" > #include "net/net.h" > +#include "net/eth.h" > #include "net/checksum.h" > #include "net/tap.h" > #include "qemu/error-report.h" > #include "qemu/timer.h" > +#include "qemu/sockets.h" > #include "hw/virtio/virtio-net.h" > #include "net/vhost_net.h" > #include "hw/virtio/virtio-bus.h" > @@ -38,6 +40,24 @@ > #define endof(container, field) \ > (offsetof(container, field) + sizeof(((container *)0)->field)) > > +#define VIRTIO_NET_IP4_ADDR_SIZE 8 /* ipv4 saddr + daddr */ > +#define VIRTIO_NET_TCP_PORT_SIZE 4 /* sport + dport */ > + > +/* IPv4 max payload, 16 bits in the header */ > +#define VIRTIO_NET_MAX_IP4_PAYLOAD (65535 - sizeof(struct ip_header)) > +#define VIRTIO_NET_MAX_TCP_PAYLOAD 65535 > + > +/* header lenght value in ip header without option */ typo here. > +#define VIRTIO_NET_IP4_HEADER_LENGTH 5 > + > +/* Purge coalesced packets timer interval */ > +#define VIRTIO_NET_RSC_INTERVAL 300000 > + > +/* This value affects the performance a lot, and should be tuned carefully, > + '300000'(300us) is the recommended value to pass the WHQL test, '50000' can > + gain 2x netperf throughput with tso/gso/gro 'off'. */ > +static uint32_t virtio_net_rsc_timeout = VIRTIO_NET_RSC_INTERVAL; Like we've discussed in previous versions, need we add another property for this? > + > typedef struct VirtIOFeature { > uint32_t flags; > size_t end; > @@ -1688,11 +1708,467 @@ static int virtio_net_load_device(VirtIODevice *vdev, QEMUFile *f, > return 0; > } > > +static void virtio_net_rsc_extract_unit4(NetRscChain *chain, > + const uint8_t *buf, NetRscUnit* unit) > +{ > + uint16_t hdr_len; > + uint16_t ip_hdrlen; > + struct ip_header *ip; > + > + hdr_len = ((VirtIONet *)(chain->n))->guest_hdr_len; The case seems odd. Why not just use VirtIONet * for chain->n? > + ip = (struct ip_header *)(buf + hdr_len + sizeof(struct eth_header)); > + unit->ip = (void *)ip; > + ip_hdrlen = (ip->ip_ver_len & 0xF) << 2; > + unit->ip_plen = &ip->ip_len; > + unit->tcp = (struct tcp_header *)(((uint8_t *)unit->ip) + ip_hdrlen); > + unit->tcp_hdrlen = (htons(unit->tcp->th_offset_flags) & 0xF000) >> 10; > + unit->payload = htons(*unit->ip_plen) - ip_hdrlen - unit->tcp_hdrlen; > +} > + > +static void virtio_net_rsc_ipv4_checksum(struct ip_header *ip) > +{ > + uint32_t sum; > + > + ip->ip_sum = 0; > + sum = net_checksum_add_cont(sizeof(struct ip_header), (uint8_t *)ip, 0); > + ip->ip_sum = cpu_to_be16(net_checksum_finish(sum)); Should we set VIRTIO_NET_HDR_F_DATA_VALID for hdr.flags here? > +} > + > +static size_t virtio_net_rsc_drain_seg(NetRscChain *chain, NetRscSeg *seg) > +{ > + int ret; > + > + virtio_net_rsc_ipv4_checksum(seg->unit.ip); > + ret = virtio_net_do_receive(seg->nc, seg->buf, seg->size); > + QTAILQ_REMOVE(&chain->buffers, seg, next); > + g_free(seg->buf); > + g_free(seg); > + > + return ret; > +} > + > +static void virtio_net_rsc_purge(void *opq) > +{ > + NetRscChain *chain = (NetRscChain *)opq; > + NetRscSeg *seg, *rn; > + > + QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, rn) { > + if (virtio_net_rsc_drain_seg(chain, seg) == 0) { > + chain->stat.purge_failed++; > + continue; Is it better to break here, consider we fail to do the receive? > + } > + } > + > + chain->stat.timer++; > + if (!QTAILQ_EMPTY(&chain->buffers)) { > + timer_mod(chain->drain_timer, > + qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + virtio_net_rsc_timeout); > + } > +} > + > +static void virtio_net_rsc_cleanup(VirtIONet *n) > +{ > + NetRscChain *chain, *rn_chain; > + NetRscSeg *seg, *rn_seg; > + > + QTAILQ_FOREACH_SAFE(chain, &n->rsc_chains, next, rn_chain) { > + QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, rn_seg) { > + QTAILQ_REMOVE(&chain->buffers, seg, next); > + g_free(seg->buf); > + g_free(seg); > + } > + > + timer_del(chain->drain_timer); > + timer_free(chain->drain_timer); > + QTAILQ_REMOVE(&n->rsc_chains, chain, next); > + g_free(chain); > + } > +} > + > +static void virtio_net_rsc_cache_buf(NetRscChain *chain, NetClientState *nc, > + const uint8_t *buf, size_t size) > +{ > + uint16_t hdr_len; > + NetRscSeg *seg; > + > + hdr_len = ((VirtIONet *)(chain->n))->guest_hdr_len; > + seg = g_malloc(sizeof(NetRscSeg)); > + seg->buf = g_malloc(hdr_len + sizeof(struct eth_header)\ > + + sizeof(struct ip6_header) + VIRTIO_NET_MAX_TCP_PAYLOAD); Why ip6_header here? > + memcpy(seg->buf, buf, size); > + seg->size = size; > + seg->dup_ack_count = 0; > + seg->is_coalesced = 0; > + seg->nc = nc; > + > + QTAILQ_INSERT_TAIL(&chain->buffers, seg, next); > + chain->stat.cache++; > + > + virtio_net_rsc_extract_unit4(chain, seg->buf, &seg->unit); > +} > + > +static int32_t virtio_net_rsc_handle_ack(NetRscChain *chain, NetRscSeg *seg, > + const uint8_t *buf, struct tcp_header *n_tcp, > + struct tcp_header *o_tcp) > +{ > + uint32_t nack, oack; > + uint16_t nwin, owin; > + > + nack = htonl(n_tcp->th_ack); > + nwin = htons(n_tcp->th_win); > + oack = htonl(o_tcp->th_ack); > + owin = htons(o_tcp->th_win); > + > + if ((nack - oack) >= VIRTIO_NET_MAX_TCP_PAYLOAD) { > + chain->stat.ack_out_of_win++; > + return RSC_FINAL; > + } else if (nack == oack) { > + /* duplicated ack or window probe */ > + if (nwin == owin) { > + /* duplicated ack, add dup ack count due to whql test up to 1 */ > + chain->stat.dup_ack++; > + > + if (seg->dup_ack_count == 0) { > + seg->dup_ack_count++; > + chain->stat.dup_ack1++; > + return RSC_COALESCE; > + } else { > + /* Spec says should send it directly */ Better quote the what spec said here or just remove the above comment. > + chain->stat.dup_ack2++; > + return RSC_FINAL; > + } > + } else { > + /* Coalesce window update */ > + o_tcp->th_win = n_tcp->th_win; > + chain->stat.win_update++; > + return RSC_COALESCE; > + } > + } else { > + /* pure ack, update ack */ > + o_tcp->th_ack = n_tcp->th_ack; > + chain->stat.pure_ack++; > + return RSC_COALESCE; > + } > +} > + > +static int32_t virtio_net_rsc_coalesce_data(NetRscChain *chain, NetRscSeg *seg, > + const uint8_t *buf, NetRscUnit *n_unit) > +{ > + void *data; > + uint16_t o_ip_len; > + uint32_t nseq, oseq; > + NetRscUnit *o_unit; > + > + o_unit = &seg->unit; > + o_ip_len = htons(*o_unit->ip_plen); > + nseq = htonl(n_unit->tcp->th_seq); > + oseq = htonl(o_unit->tcp->th_seq); > + > + if (n_unit->tcp_hdrlen > sizeof(struct tcp_header)) { > + /* Log this only for debugging observation */ > + chain->stat.tcp_option++; > + } > + > + /* Ignore packet with more/larger tcp options */ > + if (n_unit->tcp_hdrlen > o_unit->tcp_hdrlen) { > + chain->stat.tcp_larger_option++; > + return RSC_FINAL; > + } > + > + /* Remember larger/smaller options may behave different,so keep a > + separate statitics for each of them for debugging convenience. */ > + if (n_unit->tcp_hdrlen < o_unit->tcp_hdrlen) { > + chain->stat.tcp_smaller_option++; > + return RSC_FINAL; > + } > + > + /* out of order or retransmitted. */ > + if ((nseq - oseq) > VIRTIO_NET_MAX_TCP_PAYLOAD) { > + chain->stat.data_out_of_win++; > + return RSC_FINAL; > + } > + > + data = ((uint8_t *)n_unit->tcp) + n_unit->tcp_hdrlen; > + if (nseq == oseq) { > + if ((0 == o_unit->payload) && n_unit->payload) { o_unit->payload == 0 please. > + /* From no payload to payload, normal case, not a dup ack or etc */ > + chain->stat.data_after_pure_ack++; > + goto coalesce; > + } else { > + return virtio_net_rsc_handle_ack(chain, seg, buf, > + n_unit->tcp, o_unit->tcp); > + } > + } else if ((nseq - oseq) != o_unit->payload) { > + /* Not a consistent packet, out of order */ > + chain->stat.data_out_of_order++; > + return RSC_FINAL; > + } else { > +coalesce: > + if ((o_ip_len + n_unit->payload) > chain->max_payload) { > + chain->stat.over_size++; > + return RSC_FINAL; > + } > + > + /* Here comes the right data, the payload lengh in v4/v6 is different, > + so use the field value to update and record the new data len */ > + o_unit->payload += n_unit->payload; /* update new data len */ > + > + /* update field in ip header */ > + *o_unit->ip_plen = htons(o_ip_len + n_unit->payload); > + > + /* Bring 'PUSH' big, the whql test guide says 'PUSH' can be coalesced > + for windows guest, while this may change the behavior for linux > + guest. */ In the future, need to measure TCP_RR performance in this case to see the impact on Linux guests. > + o_unit->tcp->th_offset_flags = n_unit->tcp->th_offset_flags; > + > + o_unit->tcp->th_ack = n_unit->tcp->th_ack; > + o_unit->tcp->th_win = n_unit->tcp->th_win; > + > + memmove(seg->buf + seg->size, data, n_unit->payload); > + seg->size += n_unit->payload; > + chain->stat.coalesced++; > + return RSC_COALESCE; > + } > +} > + > +static int32_t virtio_net_rsc_coalesce4(NetRscChain *chain, NetRscSeg *seg, > + const uint8_t *buf, size_t size, NetRscUnit *unit) indentation is wrong here. > +{ > + struct ip_header *ip1, *ip2; > + > + ip1 = (struct ip_header *)(unit->ip); > + ip2 = (struct ip_header *)(seg->unit.ip); > + if ((ip1->ip_src ^ ip2->ip_src) || (ip1->ip_dst ^ ip2->ip_dst) > + || (unit->tcp->th_sport ^ seg->unit.tcp->th_sport) > + || (unit->tcp->th_dport ^ seg->unit.tcp->th_dport)) { > + chain->stat.no_match++; > + return RSC_NO_MATCH; > + } > + > + return virtio_net_rsc_coalesce_data(chain, seg, buf, unit); > +} > + > +/* Pakcets with 'SYN' should bypass, other flag should be sent after drain > + * to prevent out of order */ > +static int virtio_net_rsc_tcp_ctrl_check(NetRscChain *chain, > + struct tcp_header *tcp) > +{ > + uint16_t tcp_flag; > + > + tcp_flag = htons(tcp->th_offset_flags) & 0x3F; > + if (tcp_flag & TH_SYN) { > + chain->stat.tcp_syn++; > + return RSC_BYPASS; > + } > + > + if (tcp_flag & (TH_FIN | TH_URG | TH_RST)) { > + chain->stat.tcp_ctrl_drain++; > + return RSC_FINAL; > + } > + > + return RSC_WANT; > +} > + > +static bool virtio_net_rsc_empty_cache(NetRscChain *chain, NetClientState *nc, > + const uint8_t *buf, size_t size) > +{ > + if (QTAILQ_EMPTY(&chain->buffers)) { > + chain->stat.empty_cache++; > + virtio_net_rsc_cache_buf(chain, nc, buf, size); > + timer_mod(chain->drain_timer, > + qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + virtio_net_rsc_timeout); > + return 1; > + } > + > + return 0; > +} > + > +static size_t virtio_net_rsc_do_coalesce(NetRscChain *chain, NetClientState *nc, > + const uint8_t *buf, size_t size, > + NetRscUnit *unit) > +{ > + int ret; > + NetRscSeg *seg, *nseg; > + > + QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, nseg) { > + ret = virtio_net_rsc_coalesce4(chain, seg, buf, size, unit); > + > + if (ret == RSC_FINAL) { > + if (virtio_net_rsc_drain_seg(chain, seg) == 0) { > + /* Send failed */ > + chain->stat.final_failed++; > + return 0; > + } > + > + /* Send current packet */ > + return virtio_net_do_receive(nc, buf, size); > + } else if (ret == RSC_NO_MATCH) { > + continue; > + } else { > + /* Coalesced, mark coalesced flag to tell calc cksum for ipv4 */ > + seg->is_coalesced = 1; > + return size; > + } > + } > + > + chain->stat.no_match_cache++; > + virtio_net_rsc_cache_buf(chain, nc, buf, size); Can we rework the code to make it a little bit more readable here? RSC_BYPASS, RSC_WANT was checked by the caller (virtio_net_rsc_receive4()). and the rest were checked here. Can we do all the check in one function with a switch...case? Maybe you can introduce sanity check and tcp check callback for each chain. > + return size; > +} > + > +/* Drain a connection data, this is to avoid out of order segments */ > +static size_t virtio_net_rsc_drain_flow(NetRscChain *chain, NetClientState *nc, > + const uint8_t *buf, size_t size, uint16_t ip_start, > + uint16_t ip_size, uint16_t tcp_port, uint16_t port_size) indentation is wrong. > +{ > + NetRscSeg *seg, *nseg; > + > + QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, nseg) { > + if (memcmp(buf + ip_start, seg->buf + ip_start, ip_size) > + || memcmp(buf + tcp_port, seg->buf + tcp_port, port_size)) { > + continue; May consider to optimize (e.g not using linear search) in the future. > + } > + if (virtio_net_rsc_drain_seg(chain, seg) == 0) { > + chain->stat.drain_failed++; > + } > + > + break; > + } > + > + return virtio_net_do_receive(nc, buf, size); > +} > + > +static int32_t virtio_net_rsc_sanity_check4(NetRscChain *chain, > + struct ip_header *ip, const uint8_t *buf, size_t size)+ chain->stat.ip_option++; indentation. > +{ > + uint16_t ip_len; > + uint16_t hdr_len; > + > + hdr_len = ((VirtIONet *)(chain->n))->guest_hdr_len; > + if (size < (hdr_len + sizeof(struct eth_header) + sizeof(struct ip_header) > + + sizeof(struct tcp_header))) { > + return RSC_BYPASS; > + } > + > + /* Not an ipv4 one */ > + if (((ip->ip_ver_len & 0xF0) >> 4) != IP_HEADER_VERSION_4) { > + chain->stat.ip_option++; > + return RSC_BYPASS; > + } > + > + /* Don't handle packets with ip option */ > + if (VIRTIO_NET_IP4_HEADER_LENGTH != (ip->ip_ver_len & 0xF)) { > + chain->stat.ip_option++; > + return RSC_BYPASS; > + } > + > + /* Don't handle packets with ip fragment */ > + if (!(htons(ip->ip_off) & IP_DF)) { > + chain->stat.ip_frag++; > + return RSC_BYPASS; > + } > + > + if (ip->ip_p != IPPROTO_TCP) { > + chain->stat.bypass_not_tcp++; > + return RSC_BYPASS; > + } > + > + ip_len = htons(ip->ip_len); > + if (ip_len < (sizeof(struct ip_header) + sizeof(struct tcp_header)) > + || ip_len > (size - hdr_len - sizeof(struct eth_header))) { > + chain->stat.ip_hacked++; > + return RSC_BYPASS; > + } > + > + return RSC_WANT; > +} > + > +static size_t virtio_net_rsc_receive4(void *opq, NetClientState* nc, Why use void * here? > + const uint8_t *buf, size_t size) > +{ > + int32_t ret; > + uint16_t hdr_len; > + NetRscChain *chain; > + NetRscUnit unit; > + > + chain = (NetRscChain *)opq; > + hdr_len = ((VirtIONet *)(chain->n))->guest_hdr_len; > + virtio_net_rsc_extract_unit4(chain, buf, &unit); > + if (RSC_WANT != virtio_net_rsc_sanity_check4(chain, unit.ip, buf, size)) { > + return virtio_net_do_receive(nc, buf, size); > + } > + > + ret = virtio_net_rsc_tcp_ctrl_check(chain, unit.tcp); > + if (ret == RSC_BYPASS) { > + return virtio_net_do_receive(nc, buf, size); > + } else if (ret == RSC_FINAL) { > + return virtio_net_rsc_drain_flow(chain, nc, buf, size, > + ((hdr_len + sizeof(struct eth_header)) + 12), > + VIRTIO_NET_IP4_ADDR_SIZE, > + hdr_len + sizeof(struct eth_header) + sizeof(struct ip_header), > + VIRTIO_NET_TCP_PORT_SIZE); > + } > + > + if (virtio_net_rsc_empty_cache(chain, nc, buf, size)) { > + return size; > + } > + > + return virtio_net_rsc_do_coalesce(chain, nc, buf, size, &unit); > +} > + > +static NetRscChain *virtio_net_rsc_lookup_chain(VirtIONet * n, > + NetClientState *nc, > + uint16_t proto) > +{ > + NetRscChain *chain; > + > + if (proto != (uint16_t)ETH_P_IP) { > + return NULL; > + } > + > + QTAILQ_FOREACH(chain, &n->rsc_chains, next) { > + if (chain->proto == proto) { > + return chain; > + } > + } > + > + chain = g_malloc(sizeof(*chain)); > + chain->n = n; > + chain->proto = proto; > + chain->max_payload = VIRTIO_NET_MAX_IP4_PAYLOAD; > + chain->drain_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, > + virtio_net_rsc_purge, chain); > + memset(&chain->stat, 0, sizeof(chain->stat)); > + > + QTAILQ_INIT(&chain->buffers); > + QTAILQ_INSERT_TAIL(&n->rsc_chains, chain, next); > + > + return chain; > +} > > static ssize_t virtio_net_rsc_receive(NetClientState *nc, > const uint8_t *buf, size_t size) > { > - return virtio_net_do_receive(nc, buf, size); > + uint16_t proto; > + NetRscChain *chain; > + struct eth_header *eth; > + VirtIONet *n; > + > + n = qemu_get_nic_opaque(nc); > + if (size < (n->guest_hdr_len + sizeof(struct eth_header))) { > + return virtio_net_do_receive(nc, buf, size); > + } > + > + eth = (struct eth_header *)(buf + n->guest_hdr_len); > + proto = htons(eth->h_proto); > + > + chain = virtio_net_rsc_lookup_chain(n, nc, proto); > + if (!chain) { > + return virtio_net_do_receive(nc, buf, size); > + } else { > + chain->stat.received++; > + return virtio_net_rsc_receive4(chain, nc, buf, size); > + } > } > > static ssize_t virtio_net_receive(NetClientState *nc, > @@ -1837,6 +2313,7 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp) > nc = qemu_get_queue(n->nic); > nc->rxfilter_notify_enabled = 1; > > + QTAILQ_INIT(&n->rsc_chains); > n->qdev = dev; > register_savevm(dev, "virtio-net", -1, VIRTIO_NET_VM_VERSION, > virtio_net_save, virtio_net_load, n); > @@ -1871,6 +2348,7 @@ static void virtio_net_device_unrealize(DeviceState *dev, Error **errp) > g_free(n->vqs); > qemu_del_nic(n->nic); > virtio_cleanup(vdev); > + virtio_net_rsc_cleanup(n); > } > > static void virtio_net_instance_init(Object *obj) > diff --git a/include/hw/virtio/virtio-net.h b/include/hw/virtio/virtio-net.h > index 0cabdb6..6939e92 100644 > --- a/include/hw/virtio/virtio-net.h > +++ b/include/hw/virtio/virtio-net.h > @@ -59,6 +59,7 @@ typedef struct VirtIONet { > VirtIONetQueue *vqs; > VirtQueue *ctrl_vq; > NICState *nic; > + QTAILQ_HEAD(, NetRscChain) rsc_chains; > uint32_t tx_timeout; > int32_t tx_burst; > uint32_t has_vnet_hdr; > diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h > index 2b5b248..6be1463 100644 > --- a/include/hw/virtio/virtio.h > +++ b/include/hw/virtio/virtio.h > @@ -128,6 +128,78 @@ typedef struct VirtioDeviceClass { > int (*load)(VirtIODevice *vdev, QEMUFile *f, int version_id); > } VirtioDeviceClass; > > +/* Coalesced packets type & status */ > +typedef enum { > + RSC_COALESCE, /* Data been coalesced */ > + RSC_FINAL, /* Will terminate current connection */ > + RSC_NO_MATCH, /* No matched in the buffer pool */ > + RSC_BYPASS, /* Packet to be bypass, not tcp, tcp ctrl, etc */ > + RSC_WANT /* Data want to be coalesced */ > +} COALESCE_STATUS; > + > +typedef struct NetRscStat { > + uint32_t received; > + uint32_t coalesced; > + uint32_t over_size; > + uint32_t cache; > + uint32_t empty_cache; > + uint32_t no_match_cache; > + uint32_t win_update; > + uint32_t no_match; > + uint32_t tcp_syn; > + uint32_t tcp_ctrl_drain; > + uint32_t dup_ack; > + uint32_t dup_ack1; > + uint32_t dup_ack2; > + uint32_t pure_ack; > + uint32_t ack_out_of_win; > + uint32_t data_out_of_win; > + uint32_t data_out_of_order; > + uint32_t data_after_pure_ack; > + uint32_t bypass_not_tcp; > + uint32_t tcp_option; > + uint32_t tcp_larger_option; > + uint32_t tcp_smaller_option; > + uint32_t ip_frag; > + uint32_t ip_hacked; > + uint32_t ip_option; > + uint32_t purge_failed; > + uint32_t drain_failed; > + uint32_t final_failed; > + int64_t timer; > +} NetRscStat; > + > +/* Rsc unit general info used to checking if can coalescing */ > +typedef struct NetRscUnit { > + void *ip; /* ip header */ > + uint16_t *ip_plen; /* data len pointer in ip header field */ > + struct tcp_header *tcp; /* tcp header */ > + uint16_t tcp_hdrlen; /* tcp header len */ > + uint16_t payload; /* pure payload without virtio/eth/ip/tcp */ > +} NetRscUnit; > + > +/* Coalesced segmant */ > +typedef struct NetRscSeg { > + QTAILQ_ENTRY(NetRscSeg) next; > + void *buf; > + size_t size; > + uint32_t dup_ack_count; > + bool is_coalesced; /* need recal ipv4 header checksum, mark here */ > + NetRscUnit unit; > + NetClientState *nc; > +} NetRscSeg; > + > +/* Chain is divided by protocol(ipv4/v6) and NetClientInfo */ > +typedef struct NetRscChain { > + QTAILQ_ENTRY(NetRscChain) next; > + void *n; /* VirtIONet */ > + uint16_t proto; > + uint16_t max_payload; > + QEMUTimer *drain_timer; > + QTAILQ_HEAD(, NetRscSeg) buffers; > + NetRscStat stat; > +} NetRscChain; > + > void virtio_instance_init_common(Object *proxy_obj, void *data, > size_t vdev_size, const char *vdev_name); >
On 2016?04?05? 10:47, Jason Wang wrote: > > On 04/04/2016 03:25 AM, wexu@redhat.com wrote: >> From: Wei Xu <wexu@redhat.com> >> >> All the data packets in a tcp connection will be cached to a big buffer >> in every receive interval, and will be sent out via a timer, the >> 'virtio_net_rsc_timeout' controls the interval, the value will influent the >> performance and response of tcp connection extremely, 50000(50us) is a >> experience value to gain a performance improvement, since the whql test >> sends packets every 100us, so '300000(300us)' can pass the test case, >> this is also the default value, it's gonna to be tunable. >> >> The timer will only be triggered if the packets pool is not empty, >> and it'll drain off all the cached packets >> >> 'NetRscChain' is used to save the segments of different protocols in a >> VirtIONet device. >> >> The main handler of TCP includes TCP window update, duplicated ACK check >> and the real data coalescing if the new segment passed sanity check >> and is identified as an 'wanted' one. >> >> An 'wanted' segment means: >> 1. Segment is within current window and the sequence is the expected one. >> 2. ACK of the segment is in the valid window. >> 3. If the ACK in the segment is a duplicated one, then it must less than 2, >> this is to notify upper layer TCP starting retransmission due to the spec. >> >> Sanity check includes: >> 1. Incorrect version in IP header >> 2. IP options & IP fragment >> 3. Not a TCP packets >> 4. Sanity size check to prevent buffer overflow attack. >> >> There maybe more cases should be considered such as ip identification other >> flags, while it broke the test because windows set it to the same even it's >> not a fragment. >> >> Normally it includes 2 typical ways to handle a TCP control flag, 'bypass' >> and 'finalize', 'bypass' means should be sent out directly, and 'finalize' >> means the packets should also be bypassed, and this should be done >> after searching for the same connection packets in the pool and sending >> all of them out, this is to avoid out of data. >> >> All the 'SYN' packets will be bypassed since this always begin a new' >> connection, other flags such 'FIN/RST' will trigger a finalization, because >> this normally happens upon a connection is going to be closed, an 'URG' packet >> also finalize current coalescing unit. >> >> Statistics can be used to monitor the basic coalescing status, the 'out of order' >> and 'out of window' means how many retransmitting packets, thus describe the >> performance intuitively. >> >> Signed-off-by: Wei Xu <wexu@redhat.com> >> --- >> hw/net/virtio-net.c | 480 ++++++++++++++++++++++++++++++++++++++++- >> include/hw/virtio/virtio-net.h | 1 + >> include/hw/virtio/virtio.h | 72 +++++++ >> 3 files changed, 552 insertions(+), 1 deletion(-) >> >> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c >> index bd91a4b..81e8e71 100644 >> --- a/hw/net/virtio-net.c >> +++ b/hw/net/virtio-net.c >> @@ -15,10 +15,12 @@ >> #include "qemu/iov.h" >> #include "hw/virtio/virtio.h" >> #include "net/net.h" >> +#include "net/eth.h" >> #include "net/checksum.h" >> #include "net/tap.h" >> #include "qemu/error-report.h" >> #include "qemu/timer.h" >> +#include "qemu/sockets.h" >> #include "hw/virtio/virtio-net.h" >> #include "net/vhost_net.h" >> #include "hw/virtio/virtio-bus.h" >> @@ -38,6 +40,24 @@ >> #define endof(container, field) \ >> (offsetof(container, field) + sizeof(((container *)0)->field)) >> >> +#define VIRTIO_NET_IP4_ADDR_SIZE 8 /* ipv4 saddr + daddr */ >> +#define VIRTIO_NET_TCP_PORT_SIZE 4 /* sport + dport */ >> + >> +/* IPv4 max payload, 16 bits in the header */ >> +#define VIRTIO_NET_MAX_IP4_PAYLOAD (65535 - sizeof(struct ip_header)) >> +#define VIRTIO_NET_MAX_TCP_PAYLOAD 65535 >> + >> +/* header lenght value in ip header without option */ > typo here. Thanks. > >> +#define VIRTIO_NET_IP4_HEADER_LENGTH 5 >> + >> +/* Purge coalesced packets timer interval */ >> +#define VIRTIO_NET_RSC_INTERVAL 300000 >> + >> +/* This value affects the performance a lot, and should be tuned carefully, >> + '300000'(300us) is the recommended value to pass the WHQL test, '50000' can >> + gain 2x netperf throughput with tso/gso/gro 'off'. */ >> +static uint32_t virtio_net_rsc_timeout = VIRTIO_NET_RSC_INTERVAL; > Like we've discussed in previous versions, need we add another property > for this? Do you know how to make this a tunable parameter to guest? can this parameter be set via control queue? > >> + >> typedef struct VirtIOFeature { >> uint32_t flags; >> size_t end; >> @@ -1688,11 +1708,467 @@ static int virtio_net_load_device(VirtIODevice *vdev, QEMUFile *f, >> return 0; >> } >> >> +static void virtio_net_rsc_extract_unit4(NetRscChain *chain, >> + const uint8_t *buf, NetRscUnit* unit) >> +{ >> + uint16_t hdr_len; >> + uint16_t ip_hdrlen; >> + struct ip_header *ip; >> + >> + hdr_len = ((VirtIONet *)(chain->n))->guest_hdr_len; > The case seems odd. Why not just use VirtIONet * for chain->n? OK, will take it. > >> + ip = (struct ip_header *)(buf + hdr_len + sizeof(struct eth_header)); >> + unit->ip = (void *)ip; >> + ip_hdrlen = (ip->ip_ver_len & 0xF) << 2; >> + unit->ip_plen = &ip->ip_len; >> + unit->tcp = (struct tcp_header *)(((uint8_t *)unit->ip) + ip_hdrlen); >> + unit->tcp_hdrlen = (htons(unit->tcp->th_offset_flags) & 0xF000) >> 10; >> + unit->payload = htons(*unit->ip_plen) - ip_hdrlen - unit->tcp_hdrlen; >> +} >> + >> +static void virtio_net_rsc_ipv4_checksum(struct ip_header *ip) >> +{ >> + uint32_t sum; >> + >> + ip->ip_sum = 0; >> + sum = net_checksum_add_cont(sizeof(struct ip_header), (uint8_t *)ip, 0); >> + ip->ip_sum = cpu_to_be16(net_checksum_finish(sum)); > > Should we set VIRTIO_NET_HDR_F_DATA_VALID for hdr.flags here? have a look at the code, seems should set it, packets will be dropped by guest if don't calculate checksum here with this patch, looks there is an inexplicit logical check, will check it out and test again, thanks. > >> +} >> + >> +static size_t virtio_net_rsc_drain_seg(NetRscChain *chain, NetRscSeg *seg) >> +{ >> + int ret; >> + >> + virtio_net_rsc_ipv4_checksum(seg->unit.ip); >> + ret = virtio_net_do_receive(seg->nc, seg->buf, seg->size); >> + QTAILQ_REMOVE(&chain->buffers, seg, next); >> + g_free(seg->buf); >> + g_free(seg); >> + >> + return ret; >> +} >> + >> +static void virtio_net_rsc_purge(void *opq) >> +{ >> + NetRscChain *chain = (NetRscChain *)opq; >> + NetRscSeg *seg, *rn; >> + >> + QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, rn) { >> + if (virtio_net_rsc_drain_seg(chain, seg) == 0) { >> + chain->stat.purge_failed++; >> + continue; > Is it better to break here, consider we fail to do the receive? Actually this fails only when receive fails according to the test, but should drain all the segments here, if break here, then will have to free all the buffers, is it possible a successful receiving followed by a failed one? if that does happens, i preferred give it a shot other than free it directly. > >> + } >> + } >> + >> + chain->stat.timer++; >> + if (!QTAILQ_EMPTY(&chain->buffers)) { >> + timer_mod(chain->drain_timer, >> + qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + virtio_net_rsc_timeout); >> + } >> +} >> + >> +static void virtio_net_rsc_cleanup(VirtIONet *n) >> +{ >> + NetRscChain *chain, *rn_chain; >> + NetRscSeg *seg, *rn_seg; >> + >> + QTAILQ_FOREACH_SAFE(chain, &n->rsc_chains, next, rn_chain) { >> + QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, rn_seg) { >> + QTAILQ_REMOVE(&chain->buffers, seg, next); >> + g_free(seg->buf); >> + g_free(seg); >> + } >> + >> + timer_del(chain->drain_timer); >> + timer_free(chain->drain_timer); >> + QTAILQ_REMOVE(&n->rsc_chains, chain, next); >> + g_free(chain); >> + } >> +} >> + >> +static void virtio_net_rsc_cache_buf(NetRscChain *chain, NetClientState *nc, >> + const uint8_t *buf, size_t size) >> +{ >> + uint16_t hdr_len; >> + NetRscSeg *seg; >> + >> + hdr_len = ((VirtIONet *)(chain->n))->guest_hdr_len; >> + seg = g_malloc(sizeof(NetRscSeg)); >> + seg->buf = g_malloc(hdr_len + sizeof(struct eth_header)\ >> + + sizeof(struct ip6_header) + VIRTIO_NET_MAX_TCP_PAYLOAD); > Why ip6_header here? ipv6 packets can carry 65535(2^16) bytes pure data payload, that means the header is not included. but ipv4 is included, i choose the maximum here. > >> + memcpy(seg->buf, buf, size); >> + seg->size = size; >> + seg->dup_ack_count = 0; >> + seg->is_coalesced = 0; >> + seg->nc = nc; >> + >> + QTAILQ_INSERT_TAIL(&chain->buffers, seg, next); >> + chain->stat.cache++; >> + >> + virtio_net_rsc_extract_unit4(chain, seg->buf, &seg->unit); >> +} >> + >> +static int32_t virtio_net_rsc_handle_ack(NetRscChain *chain, NetRscSeg *seg, >> + const uint8_t *buf, struct tcp_header *n_tcp, >> + struct tcp_header *o_tcp) >> +{ >> + uint32_t nack, oack; >> + uint16_t nwin, owin; >> + >> + nack = htonl(n_tcp->th_ack); >> + nwin = htons(n_tcp->th_win); >> + oack = htonl(o_tcp->th_ack); >> + owin = htons(o_tcp->th_win); >> + >> + if ((nack - oack) >= VIRTIO_NET_MAX_TCP_PAYLOAD) { >> + chain->stat.ack_out_of_win++; >> + return RSC_FINAL; >> + } else if (nack == oack) { >> + /* duplicated ack or window probe */ >> + if (nwin == owin) { >> + /* duplicated ack, add dup ack count due to whql test up to 1 */ >> + chain->stat.dup_ack++; >> + >> + if (seg->dup_ack_count == 0) { >> + seg->dup_ack_count++; >> + chain->stat.dup_ack1++; >> + return RSC_COALESCE; >> + } else { >> + /* Spec says should send it directly */ > Better quote the what spec said here or just remove the above comment. OK. > >> + chain->stat.dup_ack2++; >> + return RSC_FINAL; >> + } >> + } else { >> + /* Coalesce window update */ >> + o_tcp->th_win = n_tcp->th_win; >> + chain->stat.win_update++; >> + return RSC_COALESCE; >> + } >> + } else { >> + /* pure ack, update ack */ >> + o_tcp->th_ack = n_tcp->th_ack; >> + chain->stat.pure_ack++; >> + return RSC_COALESCE; >> + } >> +} >> + >> +static int32_t virtio_net_rsc_coalesce_data(NetRscChain *chain, NetRscSeg *seg, >> + const uint8_t *buf, NetRscUnit *n_unit) >> +{ >> + void *data; >> + uint16_t o_ip_len; >> + uint32_t nseq, oseq; >> + NetRscUnit *o_unit; >> + >> + o_unit = &seg->unit; >> + o_ip_len = htons(*o_unit->ip_plen); >> + nseq = htonl(n_unit->tcp->th_seq); >> + oseq = htonl(o_unit->tcp->th_seq); >> + >> + if (n_unit->tcp_hdrlen > sizeof(struct tcp_header)) { >> + /* Log this only for debugging observation */ >> + chain->stat.tcp_option++; >> + } >> + >> + /* Ignore packet with more/larger tcp options */ >> + if (n_unit->tcp_hdrlen > o_unit->tcp_hdrlen) { >> + chain->stat.tcp_larger_option++; >> + return RSC_FINAL; >> + } >> + >> + /* Remember larger/smaller options may behave different,so keep a >> + separate statitics for each of them for debugging convenience. */ >> + if (n_unit->tcp_hdrlen < o_unit->tcp_hdrlen) { >> + chain->stat.tcp_smaller_option++; >> + return RSC_FINAL; >> + } >> + >> + /* out of order or retransmitted. */ >> + if ((nseq - oseq) > VIRTIO_NET_MAX_TCP_PAYLOAD) { >> + chain->stat.data_out_of_win++; >> + return RSC_FINAL; >> + } >> + >> + data = ((uint8_t *)n_unit->tcp) + n_unit->tcp_hdrlen; >> + if (nseq == oseq) { >> + if ((0 == o_unit->payload) && n_unit->payload) { > o_unit->payload == 0 please. ok, sorry. > >> + /* From no payload to payload, normal case, not a dup ack or etc */ >> + chain->stat.data_after_pure_ack++; >> + goto coalesce; >> + } else { >> + return virtio_net_rsc_handle_ack(chain, seg, buf, >> + n_unit->tcp, o_unit->tcp); >> + } >> + } else if ((nseq - oseq) != o_unit->payload) { >> + /* Not a consistent packet, out of order */ >> + chain->stat.data_out_of_order++; >> + return RSC_FINAL; >> + } else { >> +coalesce: >> + if ((o_ip_len + n_unit->payload) > chain->max_payload) { >> + chain->stat.over_size++; >> + return RSC_FINAL; >> + } >> + >> + /* Here comes the right data, the payload lengh in v4/v6 is different, >> + so use the field value to update and record the new data len */ >> + o_unit->payload += n_unit->payload; /* update new data len */ >> + >> + /* update field in ip header */ >> + *o_unit->ip_plen = htons(o_ip_len + n_unit->payload); >> + >> + /* Bring 'PUSH' big, the whql test guide says 'PUSH' can be coalesced >> + for windows guest, while this may change the behavior for linux >> + guest. */ > In the future, need to measure TCP_RR performance in this case to see > the impact on Linux guests. OK. > >> + o_unit->tcp->th_offset_flags = n_unit->tcp->th_offset_flags; >> + >> + o_unit->tcp->th_ack = n_unit->tcp->th_ack; >> + o_unit->tcp->th_win = n_unit->tcp->th_win; >> + >> + memmove(seg->buf + seg->size, data, n_unit->payload); >> + seg->size += n_unit->payload; >> + chain->stat.coalesced++; >> + return RSC_COALESCE; >> + } >> +} >> + >> +static int32_t virtio_net_rsc_coalesce4(NetRscChain *chain, NetRscSeg *seg, >> + const uint8_t *buf, size_t size, NetRscUnit *unit) > indentation is wrong here. Should it be aligned from parameter begin? i was going to save an extra line parameter. > >> +{ >> + struct ip_header *ip1, *ip2; >> + >> + ip1 = (struct ip_header *)(unit->ip); >> + ip2 = (struct ip_header *)(seg->unit.ip); >> + if ((ip1->ip_src ^ ip2->ip_src) || (ip1->ip_dst ^ ip2->ip_dst) >> + || (unit->tcp->th_sport ^ seg->unit.tcp->th_sport) >> + || (unit->tcp->th_dport ^ seg->unit.tcp->th_dport)) { >> + chain->stat.no_match++; >> + return RSC_NO_MATCH; >> + } >> + >> + return virtio_net_rsc_coalesce_data(chain, seg, buf, unit); >> +} >> + >> +/* Pakcets with 'SYN' should bypass, other flag should be sent after drain >> + * to prevent out of order */ >> +static int virtio_net_rsc_tcp_ctrl_check(NetRscChain *chain, >> + struct tcp_header *tcp) >> +{ >> + uint16_t tcp_flag; >> + >> + tcp_flag = htons(tcp->th_offset_flags) & 0x3F; >> + if (tcp_flag & TH_SYN) { >> + chain->stat.tcp_syn++; >> + return RSC_BYPASS; >> + } >> + >> + if (tcp_flag & (TH_FIN | TH_URG | TH_RST)) { >> + chain->stat.tcp_ctrl_drain++; >> + return RSC_FINAL; >> + } >> + >> + return RSC_WANT; >> +} >> + >> +static bool virtio_net_rsc_empty_cache(NetRscChain *chain, NetClientState *nc, >> + const uint8_t *buf, size_t size) >> +{ >> + if (QTAILQ_EMPTY(&chain->buffers)) { >> + chain->stat.empty_cache++; >> + virtio_net_rsc_cache_buf(chain, nc, buf, size); >> + timer_mod(chain->drain_timer, >> + qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + virtio_net_rsc_timeout); >> + return 1; >> + } >> + >> + return 0; >> +} >> + >> +static size_t virtio_net_rsc_do_coalesce(NetRscChain *chain, NetClientState *nc, >> + const uint8_t *buf, size_t size, >> + NetRscUnit *unit) >> +{ >> + int ret; >> + NetRscSeg *seg, *nseg; >> + >> + QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, nseg) { >> + ret = virtio_net_rsc_coalesce4(chain, seg, buf, size, unit); >> + >> + if (ret == RSC_FINAL) { >> + if (virtio_net_rsc_drain_seg(chain, seg) == 0) { >> + /* Send failed */ >> + chain->stat.final_failed++; >> + return 0; >> + } >> + >> + /* Send current packet */ >> + return virtio_net_do_receive(nc, buf, size); >> + } else if (ret == RSC_NO_MATCH) { >> + continue; >> + } else { >> + /* Coalesced, mark coalesced flag to tell calc cksum for ipv4 */ >> + seg->is_coalesced = 1; >> + return size; >> + } >> + } >> + >> + chain->stat.no_match_cache++; >> + virtio_net_rsc_cache_buf(chain, nc, buf, size); > Can we rework the code to make it a little bit more readable here? > > RSC_BYPASS, RSC_WANT was checked by the caller > (virtio_net_rsc_receive4()). and the rest were checked here. Can we do > all the check in one function with a switch...case? > > Maybe you can introduce sanity check and tcp check callback for each chain. OK, will check it out. > > >> + return size; >> +} >> + >> +/* Drain a connection data, this is to avoid out of order segments */ >> +static size_t virtio_net_rsc_drain_flow(NetRscChain *chain, NetClientState *nc, >> + const uint8_t *buf, size_t size, uint16_t ip_start, >> + uint16_t ip_size, uint16_t tcp_port, uint16_t port_size) > indentation is wrong. OK. >> +{ >> + NetRscSeg *seg, *nseg; >> + >> + QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, nseg) { >> + if (memcmp(buf + ip_start, seg->buf + ip_start, ip_size) >> + || memcmp(buf + tcp_port, seg->buf + tcp_port, port_size)) { >> + continue; > May consider to optimize (e.g not using linear search) in the future. Yes. > >> + } >> + if (virtio_net_rsc_drain_seg(chain, seg) == 0) { >> + chain->stat.drain_failed++; >> + } >> + >> + break; >> + } >> + >> + return virtio_net_do_receive(nc, buf, size); >> +} >> + >> +static int32_t virtio_net_rsc_sanity_check4(NetRscChain *chain, >> + struct ip_header *ip, const uint8_t *buf, size_t size)+ chain->stat.ip_option++; > indentation. OK. > >> +{ >> + uint16_t ip_len; >> + uint16_t hdr_len; >> + >> + hdr_len = ((VirtIONet *)(chain->n))->guest_hdr_len; >> + if (size < (hdr_len + sizeof(struct eth_header) + sizeof(struct ip_header) >> + + sizeof(struct tcp_header))) { >> + return RSC_BYPASS; >> + } >> + >> + /* Not an ipv4 one */ >> + if (((ip->ip_ver_len & 0xF0) >> 4) != IP_HEADER_VERSION_4) { >> + chain->stat.ip_option++; >> + return RSC_BYPASS; >> + } >> + >> + /* Don't handle packets with ip option */ >> + if (VIRTIO_NET_IP4_HEADER_LENGTH != (ip->ip_ver_len & 0xF)) { >> + chain->stat.ip_option++; >> + return RSC_BYPASS; >> + } >> + >> + /* Don't handle packets with ip fragment */ >> + if (!(htons(ip->ip_off) & IP_DF)) { >> + chain->stat.ip_frag++; >> + return RSC_BYPASS; >> + } >> + >> + if (ip->ip_p != IPPROTO_TCP) { >> + chain->stat.bypass_not_tcp++; >> + return RSC_BYPASS; >> + } >> + >> + ip_len = htons(ip->ip_len); >> + if (ip_len < (sizeof(struct ip_header) + sizeof(struct tcp_header)) >> + || ip_len > (size - hdr_len - sizeof(struct eth_header))) { >> + chain->stat.ip_hacked++; >> + return RSC_BYPASS; >> + } >> + >> + return RSC_WANT; >> +} >> + >> +static size_t virtio_net_rsc_receive4(void *opq, NetClientState* nc, > Why use void * here? Seems there is a type definition error before, will check it out. > >> + const uint8_t *buf, size_t size) >> +{ >> + int32_t ret; >> + uint16_t hdr_len; >> + NetRscChain *chain; >> + NetRscUnit unit; >> + >> + chain = (NetRscChain *)opq; >> + hdr_len = ((VirtIONet *)(chain->n))->guest_hdr_len; >> + virtio_net_rsc_extract_unit4(chain, buf, &unit); >> + if (RSC_WANT != virtio_net_rsc_sanity_check4(chain, unit.ip, buf, size)) { >> + return virtio_net_do_receive(nc, buf, size); >> + } >> + >> + ret = virtio_net_rsc_tcp_ctrl_check(chain, unit.tcp); >> + if (ret == RSC_BYPASS) { >> + return virtio_net_do_receive(nc, buf, size); >> + } else if (ret == RSC_FINAL) { >> + return virtio_net_rsc_drain_flow(chain, nc, buf, size, >> + ((hdr_len + sizeof(struct eth_header)) + 12), >> + VIRTIO_NET_IP4_ADDR_SIZE, >> + hdr_len + sizeof(struct eth_header) + sizeof(struct ip_header), >> + VIRTIO_NET_TCP_PORT_SIZE); >> + } >> + >> + if (virtio_net_rsc_empty_cache(chain, nc, buf, size)) { >> + return size;r >> + } >> + >> + return virtio_net_rsc_do_coalesce(chain, nc, buf, size, &unit); >> +} >> + >> +static NetRscChain *virtio_net_rsc_lookup_chain(VirtIONet * n, >> + NetClientState *nc, >> + uint16_t proto) >> +{ >> + NetRscChain *chain; >> + >> + if (proto != (uint16_t)ETH_P_IP) { >> + return NULL; >> + } >> + >> + QTAILQ_FOREACH(chain, &n->rsc_chains, next) { >> + if (chain->proto == proto) { >> + return chain; >> + } >> + } >> + >> + chain = g_malloc(sizeof(*chain)); >> + chain->n = n; >> + chain->proto = proto; >> + chain->max_payload = VIRTIO_NET_MAX_IP4_PAYLOAD; >> + chain->drain_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, >> + virtio_net_rsc_purge, chain); >> + memset(&chain->stat, 0, sizeof(chain->stat)); >> + >> + QTAILQ_INIT(&chain->buffers); >> + QTAILQ_INSERT_TAIL(&n->rsc_chains, chain, next); >> + >> + return chain; >> +} >> >> static ssize_t virtio_net_rsc_receive(NetClientState *nc, >> const uint8_t *buf, size_t size) >> { >> - return virtio_net_do_receive(nc, buf, size); >> + uint16_t proto; >> + NetRscChain *chain; >> + struct eth_header *eth; >> + VirtIONet *n; >> + >> + n = qemu_get_nic_opaque(nc); >> + if (size < (n->guest_hdr_len + sizeof(struct eth_header))) { >> + return virtio_net_do_receive(nc, buf, size); >> + } >> + >> + eth = (struct eth_header *)(buf + n->guest_hdr_len); >> + proto = htons(eth->h_proto); >> + >> + chain = virtio_net_rsc_lookup_chain(n, nc, proto); >> + if (!chain) { >> + return virtio_net_do_receive(nc, buf, size); >> + } else { >> + chain->stat.received++; >> + return virtio_net_rsc_receive4(chain, nc, buf, size); >> + } >> } >> >> static ssize_t virtio_net_receive(NetClientState *nc, >> @@ -1837,6 +2313,7 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp) >> nc = qemu_get_queue(n->nic); >> nc->rxfilter_notify_enabled = 1; >> >> + QTAILQ_INIT(&n->rsc_chains); >> n->qdev = dev; >> register_savevm(dev, "virtio-net", -1, VIRTIO_NET_VM_VERSION, >> virtio_net_save, virtio_net_load, n); >> @@ -1871,6 +2348,7 @@ static void virtio_net_device_unrealize(DeviceState *dev, Error **errp) >> g_free(n->vqs); >> qemu_del_nic(n->nic); >> virtio_cleanup(vdev); >> + virtio_net_rsc_cleanup(n); >> } >> >> static void virtio_net_instance_init(Object *obj) >> diff --git a/include/hw/virtio/virtio-net.h b/include/hw/virtio/virtio-net.h >> index 0cabdb6..6939e92 100644 >> --- a/include/hw/virtio/virtio-net.h >> +++ b/include/hw/virtio/virtio-net.h >> @@ -59,6 +59,7 @@ typedef struct VirtIONet { >> VirtIONetQueue *vqs; >> VirtQueue *ctrl_vq; >> NICState *nic; >> + QTAILQ_HEAD(, NetRscChain) rsc_chains; >> uint32_t tx_timeout; >> int32_t tx_burst; >> uint32_t has_vnet_hdr; >> diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h >> index 2b5b248..6be1463 100644 >> --- a/include/hw/virtio/virtio.h >> +++ b/include/hw/virtio/virtio.h >> @@ -128,6 +128,78 @@ typedef struct VirtioDeviceClass { >> int (*load)(VirtIODevice *vdev, QEMUFile *f, int version_id); >> } VirtioDeviceClass; >> >> +/* Coalesced packets type & status */ >> +typedef enum { >> + RSC_COALESCE, /* Data been coalesced */ >> + RSC_FINAL, /* Will terminate current connection */ >> + RSC_NO_MATCH, /* No matched in the buffer pool */ >> + RSC_BYPASS, /* Packet to be bypass, not tcp, tcp ctrl, etc */ >> + RSC_WANT /* Data want to be coalesced */ >> +} COALESCE_STATUS; >> + >> +typedef struct NetRscStat { >> + uint32_t received; >> + uint32_t coalesced; >> + uint32_t over_size; >> + uint32_t cache; >> + uint32_t empty_cache; >> + uint32_t no_match_cache; >> + uint32_t win_update; >> + uint32_t no_match; >> + uint32_t tcp_syn; >> + uint32_t tcp_ctrl_drain; >> + uint32_t dup_ack; >> + uint32_t dup_ack1; >> + uint32_t dup_ack2; >> + uint32_t pure_ack; >> + uint32_t ack_out_of_win; >> + uint32_t data_out_of_win; >> + uint32_t data_out_of_order; >> + uint32_t data_after_pure_ack; >> + uint32_t bypass_not_tcp; >> + uint32_t tcp_option; >> + uint32_t tcp_larger_option; >> + uint32_t tcp_smaller_option; >> + uint32_t ip_frag; >> + uint32_t ip_hacked; >> + uint32_t ip_option; >> + uint32_t purge_failed; >> + uint32_t drain_failed; >> + uint32_t final_failed; >> + int64_t timer; >> +} NetRscStat; >> + >> +/* Rsc unit general info used to checking if can coalescing */ >> +typedef struct NetRscUnit { >> + void *ip; /* ip header */ >> + uint16_t *ip_plen; /* data len pointer in ip header field */ >> + struct tcp_header *tcp; /* tcp header */ >> + uint16_t tcp_hdrlen; /* tcp header len */ >> + uint16_t payload; /* pure payload without virtio/eth/ip/tcp */ >> +} NetRscUnit; >> + >> +/* Coalesced segmant */ >> +typedef struct NetRscSeg { >> + QTAILQ_ENTRY(NetRscSeg) next; >> + void *buf; >> + size_t size; >> + uint32_t dup_ack_count; >> + bool is_coalesced; /* need recal ipv4 header checksum, mark here */ >> + NetRscUnit unit; >> + NetClientState *nc; >> +} NetRscSeg; >> + >> +/* Chain is divided by protocol(ipv4/v6) and NetClientInfo */ >> +typedef struct NetRscChain { >> + QTAILQ_ENTRY(NetRscChain) next; >> + void *n; /* VirtIONet */ >> + uint16_t proto; >> + uint16_t max_payload; >> + QEMUTimer *drain_timer; >> + QTAILQ_HEAD(, NetRscSeg) buffers; >> + NetRscStat stat; >> +} NetRscChain; >> + >> void virtio_instance_init_common(Object *proxy_obj, void *data, >> size_t vdev_size, const char *vdev_name); >> >
On 04/08/2016 03:47 PM, Wei Xu wrote: > > > On 2016?04?05? 10:47, Jason Wang wrote: >> >> On 04/04/2016 03:25 AM, wexu@redhat.com wrote: >>> From: Wei Xu <wexu@redhat.com> >>> >>> All the data packets in a tcp connection will be cached to a big buffer >>> in every receive interval, and will be sent out via a timer, the >>> 'virtio_net_rsc_timeout' controls the interval, the value will >>> influent the >>> performance and response of tcp connection extremely, 50000(50us) is a >>> experience value to gain a performance improvement, since the whql test >>> sends packets every 100us, so '300000(300us)' can pass the test case, >>> this is also the default value, it's gonna to be tunable. >>> >>> The timer will only be triggered if the packets pool is not empty, >>> and it'll drain off all the cached packets >>> >>> 'NetRscChain' is used to save the segments of different protocols in a >>> VirtIONet device. >>> >>> The main handler of TCP includes TCP window update, duplicated ACK >>> check >>> and the real data coalescing if the new segment passed sanity check >>> and is identified as an 'wanted' one. >>> >>> An 'wanted' segment means: >>> 1. Segment is within current window and the sequence is the expected >>> one. >>> 2. ACK of the segment is in the valid window. >>> 3. If the ACK in the segment is a duplicated one, then it must less >>> than 2, >>> this is to notify upper layer TCP starting retransmission due to >>> the spec. >>> >>> Sanity check includes: >>> 1. Incorrect version in IP header >>> 2. IP options & IP fragment >>> 3. Not a TCP packets >>> 4. Sanity size check to prevent buffer overflow attack. >>> >>> There maybe more cases should be considered such as ip >>> identification other >>> flags, while it broke the test because windows set it to the same >>> even it's >>> not a fragment. >>> >>> Normally it includes 2 typical ways to handle a TCP control flag, >>> 'bypass' >>> and 'finalize', 'bypass' means should be sent out directly, and >>> 'finalize' >>> means the packets should also be bypassed, and this should be done >>> after searching for the same connection packets in the pool and sending >>> all of them out, this is to avoid out of data. >>> >>> All the 'SYN' packets will be bypassed since this always begin a new' >>> connection, other flags such 'FIN/RST' will trigger a finalization, >>> because >>> this normally happens upon a connection is going to be closed, an >>> 'URG' packet >>> also finalize current coalescing unit. >>> >>> Statistics can be used to monitor the basic coalescing status, the >>> 'out of order' >>> and 'out of window' means how many retransmitting packets, thus >>> describe the >>> performance intuitively. >>> >>> Signed-off-by: Wei Xu <wexu@redhat.com> >>> --- >>> hw/net/virtio-net.c | 480 >>> ++++++++++++++++++++++++++++++++++++++++- >>> include/hw/virtio/virtio-net.h | 1 + >>> include/hw/virtio/virtio.h | 72 +++++++ >>> 3 files changed, 552 insertions(+), 1 deletion(-) >>> >>> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c >>> index bd91a4b..81e8e71 100644 >>> --- a/hw/net/virtio-net.c >>> +++ b/hw/net/virtio-net.c >>> @@ -15,10 +15,12 @@ >>> #include "qemu/iov.h" >>> #include "hw/virtio/virtio.h" >>> #include "net/net.h" >>> +#include "net/eth.h" >>> #include "net/checksum.h" >>> #include "net/tap.h" >>> #include "qemu/error-report.h" >>> #include "qemu/timer.h" >>> +#include "qemu/sockets.h" >>> #include "hw/virtio/virtio-net.h" >>> #include "net/vhost_net.h" >>> #include "hw/virtio/virtio-bus.h" >>> @@ -38,6 +40,24 @@ >>> #define endof(container, field) \ >>> (offsetof(container, field) + sizeof(((container *)0)->field)) >>> +#define VIRTIO_NET_IP4_ADDR_SIZE 8 /* ipv4 saddr + daddr */ >>> +#define VIRTIO_NET_TCP_PORT_SIZE 4 /* sport + dport */ >>> + >>> +/* IPv4 max payload, 16 bits in the header */ >>> +#define VIRTIO_NET_MAX_IP4_PAYLOAD (65535 - sizeof(struct ip_header)) >>> +#define VIRTIO_NET_MAX_TCP_PAYLOAD 65535 >>> + >>> +/* header lenght value in ip header without option */ >> typo here. > Thanks. >> >>> +#define VIRTIO_NET_IP4_HEADER_LENGTH 5 >>> + >>> +/* Purge coalesced packets timer interval */ >>> +#define VIRTIO_NET_RSC_INTERVAL 300000 >>> + >>> +/* This value affects the performance a lot, and should be tuned >>> carefully, >>> + '300000'(300us) is the recommended value to pass the WHQL test, >>> '50000' can >>> + gain 2x netperf throughput with tso/gso/gro 'off'. */ >>> +static uint32_t virtio_net_rsc_timeout = VIRTIO_NET_RSC_INTERVAL; >> Like we've discussed in previous versions, need we add another property >> for this? > Do you know how to make this a tunable parameter to guest? can this > parameter be set via control queue? It's possible I think. [...] >>> + >>> +static void virtio_net_rsc_purge(void *opq) >>> +{ >>> + NetRscChain *chain = (NetRscChain *)opq; >>> + NetRscSeg *seg, *rn; >>> + >>> + QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, rn) { >>> + if (virtio_net_rsc_drain_seg(chain, seg) == 0) { >>> + chain->stat.purge_failed++; >>> + continue; >> Is it better to break here, consider we fail to do the receive? > Actually this fails only when receive fails according to the test, but > should drain all the segments here, > if break here, then will have to free all the buffers, is it possible > a successful receiving followed by a failed one? I'd say it's possible, e.g guest just finish rx buffer refills. > if that does happens, i preferred give it a shot other than free it > directly. Ok. [...] >>> + >>> +static void virtio_net_rsc_cache_buf(NetRscChain *chain, >>> NetClientState *nc, >>> + const uint8_t *buf, size_t size) >>> +{ >>> + uint16_t hdr_len; >>> + NetRscSeg *seg; >>> + >>> + hdr_len = ((VirtIONet *)(chain->n))->guest_hdr_len; >>> + seg = g_malloc(sizeof(NetRscSeg)); >>> + seg->buf = g_malloc(hdr_len + sizeof(struct eth_header)\ >>> + + sizeof(struct ip6_header) + >>> VIRTIO_NET_MAX_TCP_PAYLOAD); >> Why ip6_header here? > ipv6 packets can carry 65535(2^16) bytes pure data payload, that means > the header is not included. > but ipv4 is included, i choose the maximum here. Let's add a comment here, since the patch's title is to implement ipv4 coalescing. [...] >>> + >>> +static int32_t virtio_net_rsc_coalesce4(NetRscChain *chain, >>> NetRscSeg *seg, >>> + const uint8_t *buf, size_t size, NetRscUnit >>> *unit) >> indentation is wrong here. > Should it be aligned from parameter begin? Looks like we'd better do this. > i was going to save an extra line parameter. [...]
On 2016?04?08? 16:31, Jason Wang wrote: > > On 04/08/2016 03:47 PM, Wei Xu wrote: >> >> On 2016?04?05? 10:47, Jason Wang wrote: >>> On 04/04/2016 03:25 AM, wexu@redhat.com wrote: >>>> From: Wei Xu <wexu@redhat.com> >>>> >>>> All the data packets in a tcp connection will be cached to a big buffer >>>> in every receive interval, and will be sent out via a timer, the >>>> 'virtio_net_rsc_timeout' controls the interval, the value will >>>> influent the >>>> performance and response of tcp connection extremely, 50000(50us) is a >>>> experience value to gain a performance improvement, since the whql test >>>> sends packets every 100us, so '300000(300us)' can pass the test case, >>>> this is also the default value, it's gonna to be tunable. >>>> >>>> The timer will only be triggered if the packets pool is not empty, >>>> and it'll drain off all the cached packets >>>> >>>> 'NetRscChain' is used to save the segments of different protocols in a >>>> VirtIONet device. >>>> >>>> The main handler of TCP includes TCP window update, duplicated ACK >>>> check >>>> and the real data coalescing if the new segment passed sanity check >>>> and is identified as an 'wanted' one. >>>> >>>> An 'wanted' segment means: >>>> 1. Segment is within current window and the sequence is the expected >>>> one. >>>> 2. ACK of the segment is in the valid window. >>>> 3. If the ACK in the segment is a duplicated one, then it must less >>>> than 2, >>>> this is to notify upper layer TCP starting retransmission due to >>>> the spec. >>>> >>>> Sanity check includes: >>>> 1. Incorrect version in IP header >>>> 2. IP options & IP fragment >>>> 3. Not a TCP packets >>>> 4. Sanity size check to prevent buffer overflow attack. >>>> >>>> There maybe more cases should be considered such as ip >>>> identification other >>>> flags, while it broke the test because windows set it to the same >>>> even it's >>>> not a fragment. >>>> >>>> Normally it includes 2 typical ways to handle a TCP control flag, >>>> 'bypass' >>>> and 'finalize', 'bypass' means should be sent out directly, and >>>> 'finalize' >>>> means the packets should also be bypassed, and this should be done >>>> after searching for the same connection packets in the pool and sending >>>> all of them out, this is to avoid out of data. >>>> >>>> All the 'SYN' packets will be bypassed since this always begin a new' >>>> connection, other flags such 'FIN/RST' will trigger a finalization, >>>> because >>>> this normally happens upon a connection is going to be closed, an >>>> 'URG' packet >>>> also finalize current coalescing unit. >>>> >>>> Statistics can be used to monitor the basic coalescing status, the >>>> 'out of order' >>>> and 'out of window' means how many retransmitting packets, thus >>>> describe the >>>> performance intuitively. >>>> >>>> Signed-off-by: Wei Xu <wexu@redhat.com> >>>> --- >>>> hw/net/virtio-net.c | 480 >>>> ++++++++++++++++++++++++++++++++++++++++- >>>> include/hw/virtio/virtio-net.h | 1 + >>>> include/hw/virtio/virtio.h | 72 +++++++ >>>> 3 files changed, 552 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c >>>> index bd91a4b..81e8e71 100644 >>>> --- a/hw/net/virtio-net.c >>>> +++ b/hw/net/virtio-net.c >>>> @@ -15,10 +15,12 @@ >>>> #include "qemu/iov.h" >>>> #include "hw/virtio/virtio.h" >>>> #include "net/net.h" >>>> +#include "net/eth.h" >>>> #include "net/checksum.h" >>>> #include "net/tap.h" >>>> #include "qemu/error-report.h" >>>> #include "qemu/timer.h" >>>> +#include "qemu/sockets.h" >>>> #include "hw/virtio/virtio-net.h" >>>> #include "net/vhost_net.h" >>>> #include "hw/virtio/virtio-bus.h" >>>> @@ -38,6 +40,24 @@ >>>> #define endof(container, field) \ >>>> (offsetof(container, field) + sizeof(((container *)0)->field)) >>>> +#define VIRTIO_NET_IP4_ADDR_SIZE 8 /* ipv4 saddr + daddr */ >>>> +#define VIRTIO_NET_TCP_PORT_SIZE 4 /* sport + dport */ >>>> + >>>> +/* IPv4 max payload, 16 bits in the header */ >>>> +#define VIRTIO_NET_MAX_IP4_PAYLOAD (65535 - sizeof(struct ip_header)) >>>> +#define VIRTIO_NET_MAX_TCP_PAYLOAD 65535 >>>> + >>>> +/* header lenght value in ip header without option */ >>> typo here. >> Thanks. >>>> +#define VIRTIO_NET_IP4_HEADER_LENGTH 5 >>>> + >>>> +/* Purge coalesced packets timer interval */ >>>> +#define VIRTIO_NET_RSC_INTERVAL 300000 >>>> + >>>> +/* This value affects the performance a lot, and should be tuned >>>> carefully, >>>> + '300000'(300us) is the recommended value to pass the WHQL test, >>>> '50000' can >>>> + gain 2x netperf throughput with tso/gso/gro 'off'. */ >>>> +static uint32_t virtio_net_rsc_timeout = VIRTIO_NET_RSC_INTERVAL; >>> Like we've discussed in previous versions, need we add another property >>> for this? >> Do you know how to make this a tunable parameter to guest? can this >> parameter be set via control queue? > It's possible I think. > > > [...] > >>>> + >>>> +static void virtio_net_rsc_purge(void *opq) >>>> +{ >>>> + NetRscChain *chain = (NetRscChain *)opq; >>>> + NetRscSeg *seg, *rn; >>>> + >>>> + QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, rn) { >>>> + if (virtio_net_rsc_drain_seg(chain, seg) == 0) { >>>> + chain->stat.purge_failed++; >>>> + continue; >>> Is it better to break here, consider we fail to do the receive? >> Actually this fails only when receive fails according to the test, but >> should drain all the segments here, >> if break here, then will have to free all the buffers, is it possible >> a successful receiving followed by a failed one? > I'd say it's possible, e.g guest just finish rx buffer refills. > >> if that does happens, i preferred give it a shot other than free it >> directly. > Ok. > > [...] > >>>> + >>>> +static void virtio_net_rsc_cache_buf(NetRscChain *chain, >>>> NetClientState *nc, >>>> + const uint8_t *buf, size_t size) >>>> +{ >>>> + uint16_t hdr_len; >>>> + NetRscSeg *seg; >>>> + >>>> + hdr_len = ((VirtIONet *)(chain->n))->guest_hdr_len; >>>> + seg = g_malloc(sizeof(NetRscSeg)); >>>> + seg->buf = g_malloc(hdr_len + sizeof(struct eth_header)\ >>>> + + sizeof(struct ip6_header) + >>>> VIRTIO_NET_MAX_TCP_PAYLOAD); >>> Why ip6_header here? >> ipv6 packets can carry 65535(2^16) bytes pure data payload, that means >> the header is not included. >> but ipv4 is included, i choose the maximum here. > Let's add a comment here, since the patch's title is to implement ipv4 > coalescing. ok. > [...] > >>>> + >>>> +static int32_t virtio_net_rsc_coalesce4(NetRscChain *chain, >>>> NetRscSeg *seg, >>>> + const uint8_t *buf, size_t size, NetRscUnit >>>> *unit) >>> indentation is wrong here. >> Should it be aligned from parameter begin? > Looks like we'd better do this. ok. > >> i was going to save an extra line parameter. > [...] >
On Mon, Apr 04, 2016 at 03:25:55AM +0800, wexu@redhat.com wrote: > From: Wei Xu <wexu@redhat.com> > > All the data packets in a tcp connection will be cached to a big buffer > in every receive interval, and will be sent out via a timer, the > 'virtio_net_rsc_timeout' controls the interval, the value will influent the > performance and response of tcp connection extremely, 50000(50us) is a > experience value to gain a performance improvement, since the whql test > sends packets every 100us, so '300000(300us)' can pass the test case, > this is also the default value, it's gonna to be tunable. > > The timer will only be triggered if the packets pool is not empty, > and it'll drain off all the cached packets > > 'NetRscChain' is used to save the segments of different protocols in a > VirtIONet device. > > The main handler of TCP includes TCP window update, duplicated ACK check > and the real data coalescing if the new segment passed sanity check > and is identified as an 'wanted' one. > > An 'wanted' segment means: > 1. Segment is within current window and the sequence is the expected one. > 2. ACK of the segment is in the valid window. > 3. If the ACK in the segment is a duplicated one, then it must less than 2, > this is to notify upper layer TCP starting retransmission due to the spec. > > Sanity check includes: > 1. Incorrect version in IP header > 2. IP options & IP fragment > 3. Not a TCP packets > 4. Sanity size check to prevent buffer overflow attack. > > There maybe more cases should be considered such as ip identification other > flags, while it broke the test because windows set it to the same even it's > not a fragment. > > Normally it includes 2 typical ways to handle a TCP control flag, 'bypass' > and 'finalize', 'bypass' means should be sent out directly, and 'finalize' > means the packets should also be bypassed, and this should be done > after searching for the same connection packets in the pool and sending > all of them out, this is to avoid out of data. > > All the 'SYN' packets will be bypassed since this always begin a new' > connection, other flags such 'FIN/RST' will trigger a finalization, because > this normally happens upon a connection is going to be closed, an 'URG' packet > also finalize current coalescing unit. > > Statistics can be used to monitor the basic coalescing status, the 'out of order' > and 'out of window' means how many retransmitting packets, thus describe the > performance intuitively. > > Signed-off-by: Wei Xu <wexu@redhat.com> Yan pointed out that VIRTIO_NET_HDR_GSO_* is never used in this patch, nor is gso_type ever set in virtio net header. This seems strange.
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index bd91a4b..81e8e71 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -15,10 +15,12 @@ #include "qemu/iov.h" #include "hw/virtio/virtio.h" #include "net/net.h" +#include "net/eth.h" #include "net/checksum.h" #include "net/tap.h" #include "qemu/error-report.h" #include "qemu/timer.h" +#include "qemu/sockets.h" #include "hw/virtio/virtio-net.h" #include "net/vhost_net.h" #include "hw/virtio/virtio-bus.h" @@ -38,6 +40,24 @@ #define endof(container, field) \ (offsetof(container, field) + sizeof(((container *)0)->field)) +#define VIRTIO_NET_IP4_ADDR_SIZE 8 /* ipv4 saddr + daddr */ +#define VIRTIO_NET_TCP_PORT_SIZE 4 /* sport + dport */ + +/* IPv4 max payload, 16 bits in the header */ +#define VIRTIO_NET_MAX_IP4_PAYLOAD (65535 - sizeof(struct ip_header)) +#define VIRTIO_NET_MAX_TCP_PAYLOAD 65535 + +/* header lenght value in ip header without option */ +#define VIRTIO_NET_IP4_HEADER_LENGTH 5 + +/* Purge coalesced packets timer interval */ +#define VIRTIO_NET_RSC_INTERVAL 300000 + +/* This value affects the performance a lot, and should be tuned carefully, + '300000'(300us) is the recommended value to pass the WHQL test, '50000' can + gain 2x netperf throughput with tso/gso/gro 'off'. */ +static uint32_t virtio_net_rsc_timeout = VIRTIO_NET_RSC_INTERVAL; + typedef struct VirtIOFeature { uint32_t flags; size_t end; @@ -1688,11 +1708,467 @@ static int virtio_net_load_device(VirtIODevice *vdev, QEMUFile *f, return 0; } +static void virtio_net_rsc_extract_unit4(NetRscChain *chain, + const uint8_t *buf, NetRscUnit* unit) +{ + uint16_t hdr_len; + uint16_t ip_hdrlen; + struct ip_header *ip; + + hdr_len = ((VirtIONet *)(chain->n))->guest_hdr_len; + ip = (struct ip_header *)(buf + hdr_len + sizeof(struct eth_header)); + unit->ip = (void *)ip; + ip_hdrlen = (ip->ip_ver_len & 0xF) << 2; + unit->ip_plen = &ip->ip_len; + unit->tcp = (struct tcp_header *)(((uint8_t *)unit->ip) + ip_hdrlen); + unit->tcp_hdrlen = (htons(unit->tcp->th_offset_flags) & 0xF000) >> 10; + unit->payload = htons(*unit->ip_plen) - ip_hdrlen - unit->tcp_hdrlen; +} + +static void virtio_net_rsc_ipv4_checksum(struct ip_header *ip) +{ + uint32_t sum; + + ip->ip_sum = 0; + sum = net_checksum_add_cont(sizeof(struct ip_header), (uint8_t *)ip, 0); + ip->ip_sum = cpu_to_be16(net_checksum_finish(sum)); +} + +static size_t virtio_net_rsc_drain_seg(NetRscChain *chain, NetRscSeg *seg) +{ + int ret; + + virtio_net_rsc_ipv4_checksum(seg->unit.ip); + ret = virtio_net_do_receive(seg->nc, seg->buf, seg->size); + QTAILQ_REMOVE(&chain->buffers, seg, next); + g_free(seg->buf); + g_free(seg); + + return ret; +} + +static void virtio_net_rsc_purge(void *opq) +{ + NetRscChain *chain = (NetRscChain *)opq; + NetRscSeg *seg, *rn; + + QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, rn) { + if (virtio_net_rsc_drain_seg(chain, seg) == 0) { + chain->stat.purge_failed++; + continue; + } + } + + chain->stat.timer++; + if (!QTAILQ_EMPTY(&chain->buffers)) { + timer_mod(chain->drain_timer, + qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + virtio_net_rsc_timeout); + } +} + +static void virtio_net_rsc_cleanup(VirtIONet *n) +{ + NetRscChain *chain, *rn_chain; + NetRscSeg *seg, *rn_seg; + + QTAILQ_FOREACH_SAFE(chain, &n->rsc_chains, next, rn_chain) { + QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, rn_seg) { + QTAILQ_REMOVE(&chain->buffers, seg, next); + g_free(seg->buf); + g_free(seg); + } + + timer_del(chain->drain_timer); + timer_free(chain->drain_timer); + QTAILQ_REMOVE(&n->rsc_chains, chain, next); + g_free(chain); + } +} + +static void virtio_net_rsc_cache_buf(NetRscChain *chain, NetClientState *nc, + const uint8_t *buf, size_t size) +{ + uint16_t hdr_len; + NetRscSeg *seg; + + hdr_len = ((VirtIONet *)(chain->n))->guest_hdr_len; + seg = g_malloc(sizeof(NetRscSeg)); + seg->buf = g_malloc(hdr_len + sizeof(struct eth_header)\ + + sizeof(struct ip6_header) + VIRTIO_NET_MAX_TCP_PAYLOAD); + memcpy(seg->buf, buf, size); + seg->size = size; + seg->dup_ack_count = 0; + seg->is_coalesced = 0; + seg->nc = nc; + + QTAILQ_INSERT_TAIL(&chain->buffers, seg, next); + chain->stat.cache++; + + virtio_net_rsc_extract_unit4(chain, seg->buf, &seg->unit); +} + +static int32_t virtio_net_rsc_handle_ack(NetRscChain *chain, NetRscSeg *seg, + const uint8_t *buf, struct tcp_header *n_tcp, + struct tcp_header *o_tcp) +{ + uint32_t nack, oack; + uint16_t nwin, owin; + + nack = htonl(n_tcp->th_ack); + nwin = htons(n_tcp->th_win); + oack = htonl(o_tcp->th_ack); + owin = htons(o_tcp->th_win); + + if ((nack - oack) >= VIRTIO_NET_MAX_TCP_PAYLOAD) { + chain->stat.ack_out_of_win++; + return RSC_FINAL; + } else if (nack == oack) { + /* duplicated ack or window probe */ + if (nwin == owin) { + /* duplicated ack, add dup ack count due to whql test up to 1 */ + chain->stat.dup_ack++; + + if (seg->dup_ack_count == 0) { + seg->dup_ack_count++; + chain->stat.dup_ack1++; + return RSC_COALESCE; + } else { + /* Spec says should send it directly */ + chain->stat.dup_ack2++; + return RSC_FINAL; + } + } else { + /* Coalesce window update */ + o_tcp->th_win = n_tcp->th_win; + chain->stat.win_update++; + return RSC_COALESCE; + } + } else { + /* pure ack, update ack */ + o_tcp->th_ack = n_tcp->th_ack; + chain->stat.pure_ack++; + return RSC_COALESCE; + } +} + +static int32_t virtio_net_rsc_coalesce_data(NetRscChain *chain, NetRscSeg *seg, + const uint8_t *buf, NetRscUnit *n_unit) +{ + void *data; + uint16_t o_ip_len; + uint32_t nseq, oseq; + NetRscUnit *o_unit; + + o_unit = &seg->unit; + o_ip_len = htons(*o_unit->ip_plen); + nseq = htonl(n_unit->tcp->th_seq); + oseq = htonl(o_unit->tcp->th_seq); + + if (n_unit->tcp_hdrlen > sizeof(struct tcp_header)) { + /* Log this only for debugging observation */ + chain->stat.tcp_option++; + } + + /* Ignore packet with more/larger tcp options */ + if (n_unit->tcp_hdrlen > o_unit->tcp_hdrlen) { + chain->stat.tcp_larger_option++; + return RSC_FINAL; + } + + /* Remember larger/smaller options may behave different,so keep a + separate statitics for each of them for debugging convenience. */ + if (n_unit->tcp_hdrlen < o_unit->tcp_hdrlen) { + chain->stat.tcp_smaller_option++; + return RSC_FINAL; + } + + /* out of order or retransmitted. */ + if ((nseq - oseq) > VIRTIO_NET_MAX_TCP_PAYLOAD) { + chain->stat.data_out_of_win++; + return RSC_FINAL; + } + + data = ((uint8_t *)n_unit->tcp) + n_unit->tcp_hdrlen; + if (nseq == oseq) { + if ((0 == o_unit->payload) && n_unit->payload) { + /* From no payload to payload, normal case, not a dup ack or etc */ + chain->stat.data_after_pure_ack++; + goto coalesce; + } else { + return virtio_net_rsc_handle_ack(chain, seg, buf, + n_unit->tcp, o_unit->tcp); + } + } else if ((nseq - oseq) != o_unit->payload) { + /* Not a consistent packet, out of order */ + chain->stat.data_out_of_order++; + return RSC_FINAL; + } else { +coalesce: + if ((o_ip_len + n_unit->payload) > chain->max_payload) { + chain->stat.over_size++; + return RSC_FINAL; + } + + /* Here comes the right data, the payload lengh in v4/v6 is different, + so use the field value to update and record the new data len */ + o_unit->payload += n_unit->payload; /* update new data len */ + + /* update field in ip header */ + *o_unit->ip_plen = htons(o_ip_len + n_unit->payload); + + /* Bring 'PUSH' big, the whql test guide says 'PUSH' can be coalesced + for windows guest, while this may change the behavior for linux + guest. */ + o_unit->tcp->th_offset_flags = n_unit->tcp->th_offset_flags; + + o_unit->tcp->th_ack = n_unit->tcp->th_ack; + o_unit->tcp->th_win = n_unit->tcp->th_win; + + memmove(seg->buf + seg->size, data, n_unit->payload); + seg->size += n_unit->payload; + chain->stat.coalesced++; + return RSC_COALESCE; + } +} + +static int32_t virtio_net_rsc_coalesce4(NetRscChain *chain, NetRscSeg *seg, + const uint8_t *buf, size_t size, NetRscUnit *unit) +{ + struct ip_header *ip1, *ip2; + + ip1 = (struct ip_header *)(unit->ip); + ip2 = (struct ip_header *)(seg->unit.ip); + if ((ip1->ip_src ^ ip2->ip_src) || (ip1->ip_dst ^ ip2->ip_dst) + || (unit->tcp->th_sport ^ seg->unit.tcp->th_sport) + || (unit->tcp->th_dport ^ seg->unit.tcp->th_dport)) { + chain->stat.no_match++; + return RSC_NO_MATCH; + } + + return virtio_net_rsc_coalesce_data(chain, seg, buf, unit); +} + +/* Pakcets with 'SYN' should bypass, other flag should be sent after drain + * to prevent out of order */ +static int virtio_net_rsc_tcp_ctrl_check(NetRscChain *chain, + struct tcp_header *tcp) +{ + uint16_t tcp_flag; + + tcp_flag = htons(tcp->th_offset_flags) & 0x3F; + if (tcp_flag & TH_SYN) { + chain->stat.tcp_syn++; + return RSC_BYPASS; + } + + if (tcp_flag & (TH_FIN | TH_URG | TH_RST)) { + chain->stat.tcp_ctrl_drain++; + return RSC_FINAL; + } + + return RSC_WANT; +} + +static bool virtio_net_rsc_empty_cache(NetRscChain *chain, NetClientState *nc, + const uint8_t *buf, size_t size) +{ + if (QTAILQ_EMPTY(&chain->buffers)) { + chain->stat.empty_cache++; + virtio_net_rsc_cache_buf(chain, nc, buf, size); + timer_mod(chain->drain_timer, + qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + virtio_net_rsc_timeout); + return 1; + } + + return 0; +} + +static size_t virtio_net_rsc_do_coalesce(NetRscChain *chain, NetClientState *nc, + const uint8_t *buf, size_t size, + NetRscUnit *unit) +{ + int ret; + NetRscSeg *seg, *nseg; + + QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, nseg) { + ret = virtio_net_rsc_coalesce4(chain, seg, buf, size, unit); + + if (ret == RSC_FINAL) { + if (virtio_net_rsc_drain_seg(chain, seg) == 0) { + /* Send failed */ + chain->stat.final_failed++; + return 0; + } + + /* Send current packet */ + return virtio_net_do_receive(nc, buf, size); + } else if (ret == RSC_NO_MATCH) { + continue; + } else { + /* Coalesced, mark coalesced flag to tell calc cksum for ipv4 */ + seg->is_coalesced = 1; + return size; + } + } + + chain->stat.no_match_cache++; + virtio_net_rsc_cache_buf(chain, nc, buf, size); + return size; +} + +/* Drain a connection data, this is to avoid out of order segments */ +static size_t virtio_net_rsc_drain_flow(NetRscChain *chain, NetClientState *nc, + const uint8_t *buf, size_t size, uint16_t ip_start, + uint16_t ip_size, uint16_t tcp_port, uint16_t port_size) +{ + NetRscSeg *seg, *nseg; + + QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, nseg) { + if (memcmp(buf + ip_start, seg->buf + ip_start, ip_size) + || memcmp(buf + tcp_port, seg->buf + tcp_port, port_size)) { + continue; + } + if (virtio_net_rsc_drain_seg(chain, seg) == 0) { + chain->stat.drain_failed++; + } + + break; + } + + return virtio_net_do_receive(nc, buf, size); +} + +static int32_t virtio_net_rsc_sanity_check4(NetRscChain *chain, + struct ip_header *ip, const uint8_t *buf, size_t size) +{ + uint16_t ip_len; + uint16_t hdr_len; + + hdr_len = ((VirtIONet *)(chain->n))->guest_hdr_len; + if (size < (hdr_len + sizeof(struct eth_header) + sizeof(struct ip_header) + + sizeof(struct tcp_header))) { + return RSC_BYPASS; + } + + /* Not an ipv4 one */ + if (((ip->ip_ver_len & 0xF0) >> 4) != IP_HEADER_VERSION_4) { + chain->stat.ip_option++; + return RSC_BYPASS; + } + + /* Don't handle packets with ip option */ + if (VIRTIO_NET_IP4_HEADER_LENGTH != (ip->ip_ver_len & 0xF)) { + chain->stat.ip_option++; + return RSC_BYPASS; + } + + /* Don't handle packets with ip fragment */ + if (!(htons(ip->ip_off) & IP_DF)) { + chain->stat.ip_frag++; + return RSC_BYPASS; + } + + if (ip->ip_p != IPPROTO_TCP) { + chain->stat.bypass_not_tcp++; + return RSC_BYPASS; + } + + ip_len = htons(ip->ip_len); + if (ip_len < (sizeof(struct ip_header) + sizeof(struct tcp_header)) + || ip_len > (size - hdr_len - sizeof(struct eth_header))) { + chain->stat.ip_hacked++; + return RSC_BYPASS; + } + + return RSC_WANT; +} + +static size_t virtio_net_rsc_receive4(void *opq, NetClientState* nc, + const uint8_t *buf, size_t size) +{ + int32_t ret; + uint16_t hdr_len; + NetRscChain *chain; + NetRscUnit unit; + + chain = (NetRscChain *)opq; + hdr_len = ((VirtIONet *)(chain->n))->guest_hdr_len; + virtio_net_rsc_extract_unit4(chain, buf, &unit); + if (RSC_WANT != virtio_net_rsc_sanity_check4(chain, unit.ip, buf, size)) { + return virtio_net_do_receive(nc, buf, size); + } + + ret = virtio_net_rsc_tcp_ctrl_check(chain, unit.tcp); + if (ret == RSC_BYPASS) { + return virtio_net_do_receive(nc, buf, size); + } else if (ret == RSC_FINAL) { + return virtio_net_rsc_drain_flow(chain, nc, buf, size, + ((hdr_len + sizeof(struct eth_header)) + 12), + VIRTIO_NET_IP4_ADDR_SIZE, + hdr_len + sizeof(struct eth_header) + sizeof(struct ip_header), + VIRTIO_NET_TCP_PORT_SIZE); + } + + if (virtio_net_rsc_empty_cache(chain, nc, buf, size)) { + return size; + } + + return virtio_net_rsc_do_coalesce(chain, nc, buf, size, &unit); +} + +static NetRscChain *virtio_net_rsc_lookup_chain(VirtIONet * n, + NetClientState *nc, + uint16_t proto) +{ + NetRscChain *chain; + + if (proto != (uint16_t)ETH_P_IP) { + return NULL; + } + + QTAILQ_FOREACH(chain, &n->rsc_chains, next) { + if (chain->proto == proto) { + return chain; + } + } + + chain = g_malloc(sizeof(*chain)); + chain->n = n; + chain->proto = proto; + chain->max_payload = VIRTIO_NET_MAX_IP4_PAYLOAD; + chain->drain_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, + virtio_net_rsc_purge, chain); + memset(&chain->stat, 0, sizeof(chain->stat)); + + QTAILQ_INIT(&chain->buffers); + QTAILQ_INSERT_TAIL(&n->rsc_chains, chain, next); + + return chain; +} static ssize_t virtio_net_rsc_receive(NetClientState *nc, const uint8_t *buf, size_t size) { - return virtio_net_do_receive(nc, buf, size); + uint16_t proto; + NetRscChain *chain; + struct eth_header *eth; + VirtIONet *n; + + n = qemu_get_nic_opaque(nc); + if (size < (n->guest_hdr_len + sizeof(struct eth_header))) { + return virtio_net_do_receive(nc, buf, size); + } + + eth = (struct eth_header *)(buf + n->guest_hdr_len); + proto = htons(eth->h_proto); + + chain = virtio_net_rsc_lookup_chain(n, nc, proto); + if (!chain) { + return virtio_net_do_receive(nc, buf, size); + } else { + chain->stat.received++; + return virtio_net_rsc_receive4(chain, nc, buf, size); + } } static ssize_t virtio_net_receive(NetClientState *nc, @@ -1837,6 +2313,7 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp) nc = qemu_get_queue(n->nic); nc->rxfilter_notify_enabled = 1; + QTAILQ_INIT(&n->rsc_chains); n->qdev = dev; register_savevm(dev, "virtio-net", -1, VIRTIO_NET_VM_VERSION, virtio_net_save, virtio_net_load, n); @@ -1871,6 +2348,7 @@ static void virtio_net_device_unrealize(DeviceState *dev, Error **errp) g_free(n->vqs); qemu_del_nic(n->nic); virtio_cleanup(vdev); + virtio_net_rsc_cleanup(n); } static void virtio_net_instance_init(Object *obj) diff --git a/include/hw/virtio/virtio-net.h b/include/hw/virtio/virtio-net.h index 0cabdb6..6939e92 100644 --- a/include/hw/virtio/virtio-net.h +++ b/include/hw/virtio/virtio-net.h @@ -59,6 +59,7 @@ typedef struct VirtIONet { VirtIONetQueue *vqs; VirtQueue *ctrl_vq; NICState *nic; + QTAILQ_HEAD(, NetRscChain) rsc_chains; uint32_t tx_timeout; int32_t tx_burst; uint32_t has_vnet_hdr; diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h index 2b5b248..6be1463 100644 --- a/include/hw/virtio/virtio.h +++ b/include/hw/virtio/virtio.h @@ -128,6 +128,78 @@ typedef struct VirtioDeviceClass { int (*load)(VirtIODevice *vdev, QEMUFile *f, int version_id); } VirtioDeviceClass; +/* Coalesced packets type & status */ +typedef enum { + RSC_COALESCE, /* Data been coalesced */ + RSC_FINAL, /* Will terminate current connection */ + RSC_NO_MATCH, /* No matched in the buffer pool */ + RSC_BYPASS, /* Packet to be bypass, not tcp, tcp ctrl, etc */ + RSC_WANT /* Data want to be coalesced */ +} COALESCE_STATUS; + +typedef struct NetRscStat { + uint32_t received; + uint32_t coalesced; + uint32_t over_size; + uint32_t cache; + uint32_t empty_cache; + uint32_t no_match_cache; + uint32_t win_update; + uint32_t no_match; + uint32_t tcp_syn; + uint32_t tcp_ctrl_drain; + uint32_t dup_ack; + uint32_t dup_ack1; + uint32_t dup_ack2; + uint32_t pure_ack; + uint32_t ack_out_of_win; + uint32_t data_out_of_win; + uint32_t data_out_of_order; + uint32_t data_after_pure_ack; + uint32_t bypass_not_tcp; + uint32_t tcp_option; + uint32_t tcp_larger_option; + uint32_t tcp_smaller_option; + uint32_t ip_frag; + uint32_t ip_hacked; + uint32_t ip_option; + uint32_t purge_failed; + uint32_t drain_failed; + uint32_t final_failed; + int64_t timer; +} NetRscStat; + +/* Rsc unit general info used to checking if can coalescing */ +typedef struct NetRscUnit { + void *ip; /* ip header */ + uint16_t *ip_plen; /* data len pointer in ip header field */ + struct tcp_header *tcp; /* tcp header */ + uint16_t tcp_hdrlen; /* tcp header len */ + uint16_t payload; /* pure payload without virtio/eth/ip/tcp */ +} NetRscUnit; + +/* Coalesced segmant */ +typedef struct NetRscSeg { + QTAILQ_ENTRY(NetRscSeg) next; + void *buf; + size_t size; + uint32_t dup_ack_count; + bool is_coalesced; /* need recal ipv4 header checksum, mark here */ + NetRscUnit unit; + NetClientState *nc; +} NetRscSeg; + +/* Chain is divided by protocol(ipv4/v6) and NetClientInfo */ +typedef struct NetRscChain { + QTAILQ_ENTRY(NetRscChain) next; + void *n; /* VirtIONet */ + uint16_t proto; + uint16_t max_payload; + QEMUTimer *drain_timer; + QTAILQ_HEAD(, NetRscSeg) buffers; + NetRscStat stat; +} NetRscChain; + void virtio_instance_init_common(Object *proxy_obj, void *data, size_t vdev_size, const char *vdev_name);