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net: implement bulk sending interface for virtio
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@gleb-cloudius
gleb-cloudius committed Jan 6, 2015
1 parent 77bd21c commit 72324f0
Showing 1 changed file with 59 additions and 52 deletions.
111 changes: 59 additions & 52 deletions net/virtio.cc
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Original file line number Diff line number Diff line change
Expand Up @@ -501,6 +501,7 @@ class qp : public net::qp {
};
qp& _dev;
vring<packet_as_buffer_chain, complete> _ring;
std::vector<packet_as_buffer_chain> _packets;
public:
txq(qp& dev, ring_config config);
void set_notifier(std::unique_ptr<notifier> notifier) {
Expand All @@ -512,7 +513,7 @@ class qp : public net::qp {
void wake_notifier_wait() {
_ring.wake_notifier_wait();
}
future<> post(packet p);
uint32_t post(circular_buffer<packet>& p);
};
class rxq {
struct buffer_and_virt : buffer {
Expand Down Expand Up @@ -562,65 +563,71 @@ class qp : public net::qp {
size_t vring_storage_size(size_t ring_size);
public:
explicit qp(device* dev, size_t rx_ring_size, size_t tx_ring_size);
virtual future<> send(packet p) override;
virtual future<> send(packet p) override {
abort();
}
virtual uint32_t send(circular_buffer<packet>& p) override;
virtual void rx_start() override;
};

qp::txq::txq(qp& dev, ring_config config)
: _dev(dev), _ring(config, complete{*this}) {
}

future<>
qp::txq::post(packet p) {
uint32_t
qp::txq::post(circular_buffer<packet>& pb) {
net_hdr_mrg vhdr = {};

// Handle TCP checksum offload
auto oi = p.offload_info();
if (_dev._dev->hw_features().tx_csum_l4_offload) {
auto eth_hdr_len = sizeof(eth_hdr);
auto ip_hdr_len = oi.ip_hdr_len;
auto mtu = _dev._dev->hw_features().mtu;
if (oi.protocol == ip_protocol_num::tcp) {
auto tcp_hdr_len = oi.tcp_hdr_len;
if (oi.needs_csum) {
vhdr.needs_csum = 1;
vhdr.csum_start = eth_hdr_len + ip_hdr_len;
// TCP checksum filed's offset within the TCP header is 16 bytes
vhdr.csum_offset = 16;
}
if (_dev._dev->hw_features().tx_tso && p.len() > mtu + eth_hdr_len) {
// IPv4 TCP TSO
vhdr.gso_type = net_hdr::gso_tcpv4;
// Sum of Ethernet, IP and TCP header size
vhdr.hdr_len = eth_hdr_len + ip_hdr_len + tcp_hdr_len;
// Maximum segment size of packet after the offload
vhdr.gso_size = mtu - ip_hdr_len - tcp_hdr_len;
}
} else if (oi.protocol == ip_protocol_num::udp) {
auto udp_hdr_len = oi.udp_hdr_len;
if (oi.needs_csum) {
vhdr.needs_csum = 1;
vhdr.csum_start = eth_hdr_len + ip_hdr_len;
// UDP checksum filed's offset within the UDP header is 6 bytes
vhdr.csum_offset = 6;
}
if (_dev._dev->hw_features().tx_ufo && p.len() > mtu + eth_hdr_len) {
vhdr.gso_type = net_hdr::gso_udp;
vhdr.hdr_len = eth_hdr_len + ip_hdr_len + udp_hdr_len;
vhdr.gso_size = mtu - ip_hdr_len - udp_hdr_len;
_packets.clear();

while (!pb.empty() && pb.front().nr_frags() + 1 <= _ring.available_descriptors().current()) {
auto p = std::move(pb.front());
pb.pop_front();
// Handle TCP checksum offload
auto oi = p.offload_info();
if (_dev._dev->hw_features().tx_csum_l4_offload) {
auto eth_hdr_len = sizeof(eth_hdr);
auto ip_hdr_len = oi.ip_hdr_len;
auto mtu = _dev._dev->hw_features().mtu;
if (oi.protocol == ip_protocol_num::tcp) {
auto tcp_hdr_len = oi.tcp_hdr_len;
if (oi.needs_csum) {
vhdr.needs_csum = 1;
vhdr.csum_start = eth_hdr_len + ip_hdr_len;
// TCP checksum filed's offset within the TCP header is 16 bytes
vhdr.csum_offset = 16;
}
if (_dev._dev->hw_features().tx_tso && p.len() > mtu + eth_hdr_len) {
// IPv4 TCP TSO
vhdr.gso_type = net_hdr::gso_tcpv4;
// Sum of Ethernet, IP and TCP header size
vhdr.hdr_len = eth_hdr_len + ip_hdr_len + tcp_hdr_len;
// Maximum segment size of packet after the offload
vhdr.gso_size = mtu - ip_hdr_len - tcp_hdr_len;
}
} else if (oi.protocol == ip_protocol_num::udp) {
auto udp_hdr_len = oi.udp_hdr_len;
if (oi.needs_csum) {
vhdr.needs_csum = 1;
vhdr.csum_start = eth_hdr_len + ip_hdr_len;
// UDP checksum filed's offset within the UDP header is 6 bytes
vhdr.csum_offset = 6;
}
if (_dev._dev->hw_features().tx_ufo && p.len() > mtu + eth_hdr_len) {
vhdr.gso_type = net_hdr::gso_udp;
vhdr.hdr_len = eth_hdr_len + ip_hdr_len + udp_hdr_len;
vhdr.gso_size = mtu - ip_hdr_len - udp_hdr_len;
}
}
}
// prepend virtio-net header
packet q = packet(fragment{reinterpret_cast<char*>(&vhdr), _dev._header_len},
std::move(p));
auto fut = _ring.available_descriptors().wait(q.nr_frags());
assert(fut.available()); // how it cannot?
_packets.emplace_back(packet_as_buffer_chain{ std::move(q) });
}

// prepend virtio-net header
packet q = packet(fragment{reinterpret_cast<char*>(&vhdr), _dev._header_len},
std::move(p));

auto nr_frags = q.nr_frags();
return _ring.available_descriptors().wait(nr_frags).then([this, nr_frags, p = std::move(q)] () mutable {
packet_as_buffer_chain vbc[1] { { std::move(p) } };
_ring.post(std::begin(vbc), std::end(vbc));
});
_ring.post(_packets.begin(), _packets.end());
return _packets.size();
}

qp::rxq::rxq(qp& dev, ring_config config)
Expand Down Expand Up @@ -742,9 +749,9 @@ qp::rx_start() {
_rxq.run();
}

future<>
qp::send(packet p) {
return _txq.post(std::move(p));
uint32_t
qp::send(circular_buffer<packet>& p) {
return _txq.post(p);
}

class qp_vhost : public qp {
Expand Down

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