1.1 --- a/xennet/xennet.c	Tue Nov 12 21:17:26 2013 +1100
     1.2 +++ b/xennet/xennet.c	Wed Nov 13 07:56:13 2013 +1100
     1.3 @@ -180,7 +180,7 @@ XenNet_Initialize(NDIS_HANDLE adapter_ha
     1.4  
     1.5    NdisInitUnicodeString(&config_param_name, L"ScatterGather");
     1.6    NdisReadConfiguration(&status, &config_param, config_handle, &config_param_name, NdisParameterInteger);
     1.7 -  if (!NT_SUCCESS(status))
     1.8 +  if (!NT_SUCCESS(status)) 
     1.9    {
    1.10      FUNCTION_MSG("Could not read ScatterGather value (%08x)\n", status);
    1.11      xi->frontend_sg_supported = TRUE;
    1.12 @@ -192,6 +192,16 @@ XenNet_Initialize(NDIS_HANDLE adapter_ha
    1.13      FUNCTION_MSG("No support for SG with NDIS 6.0, disabled\n");
    1.14      xi->frontend_sg_supported = FALSE;
    1.15    }
    1.16 +
    1.17 +  NdisInitUnicodeString(&config_param_name, L"RxCoalesce");
    1.18 +  NdisReadConfiguration(&status, &config_param, config_handle, &config_param_name, NdisParameterInteger);
    1.19 +  if (!NT_SUCCESS(status)) {
    1.20 +    FUNCTION_MSG("Could not read RxCoalesce value (%08x)\n", status);
    1.21 +    xi->config_rx_coalesce = TRUE;
    1.22 +  } else {
    1.23 +    FUNCTION_MSG("RxCoalesce = %d\n", config_param->ParameterData.IntegerData);
    1.24 +    xi->config_rx_coalesce = (BOOLEAN)!!config_param->ParameterData.IntegerData;
    1.25 +  }
    1.26    
    1.27    NdisInitUnicodeString(&config_param_name, L"LargeSendOffload");
    1.28    NdisReadConfiguration(&status, &config_param, config_handle, &config_param_name, NdisParameterInteger);

     2.1 --- a/xennet/xennet.h	Tue Nov 12 21:17:26 2013 +1100
     2.2 +++ b/xennet/xennet.h	Wed Nov 13 07:56:13 2013 +1100
     2.3 @@ -186,7 +186,9 @@ SET_NET_ULONG(PVOID ptr, ULONG data) {
     2.4  #define MAX_PKT_HEADER_LENGTH (MAX_ETH_HEADER_LENGTH + MAX_IP4_HEADER_LENGTH + MAX_TCP_HEADER_LENGTH)
     2.5  
     2.6  #define MIN_LOOKAHEAD_LENGTH (MAX_IP4_HEADER_LENGTH + MAX_TCP_HEADER_LENGTH)
     2.7 -#define MAX_LOOKAHEAD_LENGTH PAGE_SIZE
     2.8 +//#define MAX_LOOKAHEAD_LENGTH PAGE_SIZE
     2.9 +/* optimise the size of header buffers */
    2.10 +#define MAX_LOOKAHEAD_LENGTH (512 - sizeof(shared_buffer_t) - MAX_ETH_HEADER_LENGTH)
    2.11  
    2.12  #define LINUX_MAX_SG_ELEMENTS 18
    2.13  
    2.14 @@ -361,6 +363,7 @@ struct xennet_info
    2.15  
    2.16    BOOLEAN config_csum_rx_check;
    2.17    BOOLEAN config_csum_rx_dont_fix;
    2.18 +  BOOLEAN config_rx_coalesce;
    2.19  
    2.20    #if NTDDI_VERSION < NTDDI_VISTA
    2.21    NDIS_TASK_TCP_IP_CHECKSUM setting_csum;

     3.1 --- a/xennet/xennet.inx	Tue Nov 12 21:17:26 2013 +1100
     3.2 +++ b/xennet/xennet.inx	Wed Nov 13 07:56:13 2013 +1100
     3.3 @@ -74,6 +74,12 @@ HKR, Ndi\Params\ScatterGather, type, , "
     3.4  HKR, Ndi\Params\ScatterGather\enum, 0, , "Disabled"
     3.5  HKR, Ndi\Params\ScatterGather\enum, 1, , "Enabled"
     3.6  
     3.7 +HKR, Ndi\Params\RxCoalesce, ParamDesc, , "Rx Coalesce"
     3.8 +HKR, Ndi\Params\RxCoalesce, default, , "1"
     3.9 +HKR, Ndi\Params\RxCoalesce, type, , "enum"
    3.10 +HKR, Ndi\Params\RxCoalesce\enum, 0, , "Disabled"
    3.11 +HKR, Ndi\Params\RxCoalesce\enum, 1, , "Enabled"
    3.12 +
    3.13  HKR, Ndi\Params\NetworkAddress, ParamDesc, , "Locally Administered Address"
    3.14  HKR, Ndi\Params\NetworkAddress, Type, , "edit"
    3.15  HKR, Ndi\Params\NetworkAddress, LimitText, , "12"

     4.1 --- a/xennet/xennet_common.c	Tue Nov 12 21:17:26 2013 +1100
     4.2 +++ b/xennet/xennet_common.c	Wed Nov 13 07:56:13 2013 +1100
     4.3 @@ -41,8 +41,10 @@ XenNet_BuildHeader(packet_info_t *pi, PU
     4.4    }
     4.5  
     4.6    if (header == pi->first_mdl_virtual) {
     4.7 +    ASSERT(new_header_size <= PAGE_SIZE);
     4.8      /* still working in the first buffer */
     4.9      if (new_header_size <= pi->first_mdl_length) {
    4.10 +      /* Trivially expand header_length */
    4.11        pi->header_length = new_header_size;
    4.12        if (pi->header_length == pi->first_mdl_length) {
    4.13          #if NTDDI_VERSION < NTDDI_VISTA
    4.14 @@ -56,16 +58,12 @@ XenNet_BuildHeader(packet_info_t *pi, PU
    4.15        } else {
    4.16          pi->curr_mdl_offset = (USHORT)new_header_size;
    4.17        }
    4.18 -      //FUNCTION_EXIT();
    4.19 -      return TRUE;
    4.20 -    } else {
    4.21 -      memcpy(pi->header_data, header, pi->header_length);
    4.22 -      header = pi->header = pi->header_data;
    4.23      }
    4.24 +  } else {
    4.25 +    ASSERT(new_header_size <= MAX_LOOKAHEAD_LENGTH + MAX_ETH_HEADER_LENGTH);
    4.26    }
    4.27    
    4.28    bytes_remaining = new_header_size - pi->header_length;
    4.29 -  // TODO: if there are only a small number of bytes left in the current buffer then increase to consume that too... it would have to be no more than the size of header+mss though
    4.30  
    4.31    while (bytes_remaining && pi->curr_mdl) {
    4.32      ULONG copy_size;

     5.1 --- a/xennet/xennet_rx.c	Tue Nov 12 21:17:26 2013 +1100
     5.2 +++ b/xennet/xennet_rx.c	Wed Nov 13 07:56:13 2013 +1100
     5.3 @@ -376,10 +376,11 @@ XenNet_MakePacket(struct xennet_info *xi
     5.4    }
     5.5    #endif
     5.6  
     5.7 -  if (!pi->first_mdl->Next && !pi->split_required) {
     5.8 +  if ((!pi->first_mdl->Next || (xi->config_rx_coalesce && pi->total_length <= PAGE_SIZE)) && !pi->split_required) {
     5.9      /* a single buffer <= MTU */
    5.10      header_buf = NULL;
    5.11 -    XenNet_BuildHeader(pi, pi->first_mdl_virtual, pi->first_mdl_length);
    5.12 +    /* get all the packet into the header */
    5.13 +    XenNet_BuildHeader(pi, pi->first_mdl_virtual, PAGE_SIZE);
    5.14      #if NTDDI_VERSION < NTDDI_VISTA
    5.15      NdisChainBufferAtBack(packet, pi->first_mdl);
    5.16      PACKET_FIRST_PB(packet) = pi->first_pb;
    5.17 @@ -629,7 +630,7 @@ XenNet_MakePacket(struct xennet_info *xi
    5.18  static VOID
    5.19  XenNet_MakePackets(struct xennet_info *xi, rx_context_t *rc, packet_info_t *pi)
    5.20  {
    5.21 -  UCHAR psh;
    5.22 +  UCHAR tcp_flags;
    5.23    shared_buffer_t *page_buf;
    5.24  
    5.25    XenNet_ParsePacketHeader(pi, NULL, XN_HDR_SIZE + xi->current_lookahead);
    5.26 @@ -686,8 +687,14 @@ XenNet_MakePackets(struct xennet_info *x
    5.27    pi->tcp_remaining = pi->tcp_length;
    5.28  
    5.29    /* we can make certain assumptions here as the following code is only for tcp4 */
    5.30 -  psh = pi->header[XN_HDR_SIZE + pi->ip4_header_length + 13] & 8;
    5.31 +  tcp_flags = pi->header[XN_HDR_SIZE + pi->ip4_header_length + 13];
    5.32 +  /* clear all tcp flags except ack except for the last packet */
    5.33 +  pi->header[XN_HDR_SIZE + pi->ip4_header_length + 13] &= 0x10;
    5.34    while (pi->tcp_remaining) {
    5.35 +    if (pi->tcp_remaining <= pi->mss) {
    5.36 +      /* restore tcp flags for the last packet */
    5.37 +      pi->header[XN_HDR_SIZE + pi->ip4_header_length + 13] = tcp_flags;
    5.38 +    }
    5.39      if (!XenNet_MakePacket(xi, rc, pi)) {
    5.40        FUNCTION_MSG("Failed to make packet\n");
    5.41        #if NTDDI_VERSION < NTDDI_VISTA
    5.42 @@ -697,12 +704,6 @@ XenNet_MakePackets(struct xennet_info *x
    5.43        #endif
    5.44        break; /* we are out of memory - just drop the packets */
    5.45      }
    5.46 -    if (psh) {
    5.47 -      if (pi->tcp_remaining)
    5.48 -        pi->header[XN_HDR_SIZE + pi->ip4_header_length + 13] &= ~8;
    5.49 -      else
    5.50 -        pi->header[XN_HDR_SIZE + pi->ip4_header_length + 13] |= 8;
    5.51 -    }
    5.52    }
    5.53  done:
    5.54    page_buf = pi->first_pb;