Re: [Qemu-devel] [ RFC Patch v6 2/3] virtio-net rsc: support coalescing ipv6 tcp traffic

[Wei Xu]

On 2016年05月30日 12:25, Jason Wang wrote:



On 2016年05月29日 00:37, w...@redhat.com wrote:

From: Wei Xu 

Most stuffs are like ipv4 2 differences between ipv4 and ipv6.

1. Fragment length in ipv4 header includes itself, while it's not
included for ipv6, thus means ipv6 can carry a real '65535' payload.

2. IPv6 header does not need calculate header checksum.

Signed-off-by: Wei Xu 
---
  hw/net/virtio-net.c | 152
+---
  1 file changed, 144 insertions(+), 8 deletions(-)

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index b3bb63b..cc8cbe4 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -53,6 +53,10 @@
  /* header length value in ip header without option */
  #define VIRTIO_NET_IP4_HEADER_LENGTH 5
+#define ETH_IP6_HDR_SZ (ETH_HDR_SZ + IP6_HDR_SZ)
+#define VIRTIO_NET_IP6_ADDR_SIZE   32  /* ipv6 saddr + daddr */
+#define VIRTIO_NET_MAX_IP6_PAYLOAD VIRTIO_NET_MAX_TCP_PAYLOAD
+
  /* Purge coalesced packets timer interval, This value affects the
performance
 a lot, and should be tuned carefully, '30'(300us) is the
recommended
 value to pass the WHQL test, '5' can gain 2x netperf
throughput with
@@ -1724,6 +1728,25 @@ static void
virtio_net_rsc_extract_unit4(NetRscChain *chain,
  unit->payload = htons(*unit->ip_plen) - ip_hdrlen -
unit->tcp_hdrlen;
  }
+static void virtio_net_rsc_extract_unit6(NetRscChain *chain,
+ const uint8_t *buf,
NetRscUnit* unit)
+{
+uint16_t hdr_len;
+struct ip6_header *ip6;
+
+hdr_len = ((VirtIONet *)(chain->n))->guest_hdr_len;
+ip6 = (struct ip6_header *)(buf + hdr_len + sizeof(struct
eth_header));
+unit->ip = ip6;
+unit->ip_plen = &(ip6->ip6_ctlun.ip6_un1.ip6_un1_plen);
+unit->tcp = (struct tcp_header *)(((uint8_t *)unit->ip)\
++ sizeof(struct ip6_header));
+unit->tcp_hdrlen = (htons(unit->tcp->th_offset_flags) & 0xF000)
>> 10;
+
+/* There is a difference between payload lenght in ipv4 and v6,
+   ip header is excluded in ipv6 */
+unit->payload = htons(*unit->ip_plen) - unit->tcp_hdrlen;
+}
+
  static void virtio_net_rsc_ipv4_checksum(struct virtio_net_hdr *vhdr,
   struct ip_header *ip)
  {
@@ -1742,7 +1765,9 @@ static size_t
virtio_net_rsc_drain_seg(NetRscChain *chain, NetRscSeg *seg)
  struct virtio_net_hdr *h;
  h = (struct virtio_net_hdr *)seg->buf;
-virtio_net_rsc_ipv4_checksum(h, seg->unit.ip);
+if ((chain->proto == ETH_P_IP) && seg->is_coalesced) {
+virtio_net_rsc_ipv4_checksum(h, seg->unit.ip);
+}
  ret = virtio_net_do_receive(seg->nc, seg->buf, seg->size);
  QTAILQ_REMOVE(>buffers, seg, next);
  g_free(seg->buf);
@@ -1798,7 +1823,7 @@ static void virtio_net_rsc_cache_buf(NetRscChain
*chain, NetClientState *nc,
  hdr_len = chain->n->guest_hdr_len;
  seg = g_malloc(sizeof(NetRscSeg));
  seg->buf = g_malloc(hdr_len + sizeof(struct eth_header)\
-   + VIRTIO_NET_MAX_TCP_PAYLOAD);
+   + sizeof(struct ip6_header) +
VIRTIO_NET_MAX_TCP_PAYLOAD);
  memcpy(seg->buf, buf, size);
  seg->size = size;
  seg->packets = 1;
@@ -1809,7 +1834,18 @@ static void
virtio_net_rsc_cache_buf(NetRscChain *chain, NetClientState *nc,
  QTAILQ_INSERT_TAIL(>buffers, seg, next);
  chain->stat.cache++;
-virtio_net_rsc_extract_unit4(chain, seg->buf, >unit);
+switch (chain->proto) {
+case ETH_P_IP:
+virtio_net_rsc_extract_unit4(chain, seg->buf, >unit);
+break;
+
+case ETH_P_IPV6:
+virtio_net_rsc_extract_unit6(chain, seg->buf, >unit);
+break;
+
+default:
+g_assert_not_reached();
+}
  }
  static int32_t virtio_net_rsc_handle_ack(NetRscChain *chain,
@@ -1929,6 +1965,24 @@ static int32_t
virtio_net_rsc_coalesce4(NetRscChain *chain, NetRscSeg *seg,
  return virtio_net_rsc_coalesce_data(chain, seg, buf, unit);
  }
+static int32_t virtio_net_rsc_coalesce6(NetRscChain *chain, NetRscSeg
*seg,
+const uint8_t *buf, size_t size, NetRscUnit
*unit)
+{
+struct ip6_header *ip1, *ip2;
+
+ip1 = (struct ip6_header *)(unit->ip);
+ip2 = (struct ip6_header *)(seg->unit.ip);
+if (memcmp(>ip6_src, >ip6_src, sizeof(struct in6_address))
+|| memcmp(>ip6_dst, >ip6_dst, sizeof(struct
in6_address))
+|| (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,
@@ -1981,7 +2035,11 @@ static size_t
virtio_net_rsc_do_coalesce(NetRscChain *chain, NetClientState *nc,

Re: [Qemu-devel] [ RFC Patch v6 2/3] virtio-net rsc: support coalescing ipv6 tcp traffic

[Jason Wang]

On 2016年05月29日 00:37, w...@redhat.com wrote:

From: Wei Xu 

Most stuffs are like ipv4 2 differences between ipv4 and ipv6.

1. Fragment length in ipv4 header includes itself, while it's not
included for ipv6, thus means ipv6 can carry a real '65535' payload.

2. IPv6 header does not need calculate header checksum.

Signed-off-by: Wei Xu 
---
  hw/net/virtio-net.c | 152 +---
  1 file changed, 144 insertions(+), 8 deletions(-)

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index b3bb63b..cc8cbe4 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -53,6 +53,10 @@
  /* header length value in ip header without option */
  #define VIRTIO_NET_IP4_HEADER_LENGTH 5
  
+#define ETH_IP6_HDR_SZ (ETH_HDR_SZ + IP6_HDR_SZ)

+#define VIRTIO_NET_IP6_ADDR_SIZE   32  /* ipv6 saddr + daddr */
+#define VIRTIO_NET_MAX_IP6_PAYLOAD VIRTIO_NET_MAX_TCP_PAYLOAD
+
  /* Purge coalesced packets timer interval, This value affects the performance
 a lot, and should be tuned carefully, '30'(300us) is the recommended
 value to pass the WHQL test, '5' can gain 2x netperf throughput with
@@ -1724,6 +1728,25 @@ static void virtio_net_rsc_extract_unit4(NetRscChain 
*chain,
  unit->payload = htons(*unit->ip_plen) - ip_hdrlen - unit->tcp_hdrlen;
  }
  
+static void virtio_net_rsc_extract_unit6(NetRscChain *chain,

+ const uint8_t *buf, NetRscUnit* unit)
+{
+uint16_t hdr_len;
+struct ip6_header *ip6;
+
+hdr_len = ((VirtIONet *)(chain->n))->guest_hdr_len;
+ip6 = (struct ip6_header *)(buf + hdr_len + sizeof(struct eth_header));
+unit->ip = ip6;
+unit->ip_plen = &(ip6->ip6_ctlun.ip6_un1.ip6_un1_plen);
+unit->tcp = (struct tcp_header *)(((uint8_t *)unit->ip)\
++ sizeof(struct ip6_header));
+unit->tcp_hdrlen = (htons(unit->tcp->th_offset_flags) & 0xF000) >> 10;
+
+/* There is a difference between payload lenght in ipv4 and v6,
+   ip header is excluded in ipv6 */
+unit->payload = htons(*unit->ip_plen) - unit->tcp_hdrlen;
+}
+
  static void virtio_net_rsc_ipv4_checksum(struct virtio_net_hdr *vhdr,
   struct ip_header *ip)
  {
@@ -1742,7 +1765,9 @@ static size_t virtio_net_rsc_drain_seg(NetRscChain 
*chain, NetRscSeg *seg)
  struct virtio_net_hdr *h;
  
  h = (struct virtio_net_hdr *)seg->buf;

-virtio_net_rsc_ipv4_checksum(h, seg->unit.ip);
+if ((chain->proto == ETH_P_IP) && seg->is_coalesced) {
+virtio_net_rsc_ipv4_checksum(h, seg->unit.ip);
+}
  ret = virtio_net_do_receive(seg->nc, seg->buf, seg->size);
  QTAILQ_REMOVE(>buffers, seg, next);
  g_free(seg->buf);
@@ -1798,7 +1823,7 @@ static void virtio_net_rsc_cache_buf(NetRscChain *chain, 
NetClientState *nc,
  hdr_len = chain->n->guest_hdr_len;
  seg = g_malloc(sizeof(NetRscSeg));
  seg->buf = g_malloc(hdr_len + sizeof(struct eth_header)\
-   + VIRTIO_NET_MAX_TCP_PAYLOAD);
+   + sizeof(struct ip6_header) + VIRTIO_NET_MAX_TCP_PAYLOAD);
  memcpy(seg->buf, buf, size);
  seg->size = size;
  seg->packets = 1;
@@ -1809,7 +1834,18 @@ static void virtio_net_rsc_cache_buf(NetRscChain *chain, 
NetClientState *nc,
  QTAILQ_INSERT_TAIL(>buffers, seg, next);
  chain->stat.cache++;
  
-virtio_net_rsc_extract_unit4(chain, seg->buf, >unit);

+switch (chain->proto) {
+case ETH_P_IP:
+virtio_net_rsc_extract_unit4(chain, seg->buf, >unit);
+break;
+
+case ETH_P_IPV6:
+virtio_net_rsc_extract_unit6(chain, seg->buf, >unit);
+break;
+
+default:
+g_assert_not_reached();
+}
  }
  
  static int32_t virtio_net_rsc_handle_ack(NetRscChain *chain,

@@ -1929,6 +1965,24 @@ static int32_t virtio_net_rsc_coalesce4(NetRscChain 
*chain, NetRscSeg *seg,
  return virtio_net_rsc_coalesce_data(chain, seg, buf, unit);
  }
  
+static int32_t virtio_net_rsc_coalesce6(NetRscChain *chain, NetRscSeg *seg,

+const uint8_t *buf, size_t size, NetRscUnit *unit)
+{
+struct ip6_header *ip1, *ip2;
+
+ip1 = (struct ip6_header *)(unit->ip);
+ip2 = (struct ip6_header *)(seg->unit.ip);
+if (memcmp(>ip6_src, >ip6_src, sizeof(struct in6_address))
+|| memcmp(>ip6_dst, >ip6_dst, sizeof(struct in6_address))
+|| (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,
@@ -1981,7 +2035,11 @@ static size_t virtio_net_rsc_do_coalesce(NetRscChain 
*chain, NetClientState *nc,