From 398f187d74b89d5ab198fcf9b8d86edbefecec4d Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Tue, 29 Jul 2008 09:58:37 -0500 Subject: [PATCH] lguest: Use GSO/IFF_VNET_HDR extensions on tun/tap Guest -> Host 1GB TCP: Before 20.1974 seconds xmit 214510 recv 5 timeout 214491 usec 278 After 8.43625 seconds xmit 95640 recv 198266 timeout 49771 usec 1252 Host -> Guest 1GB TCP: Before: Seconds 9.98854 xmit 172166 recv 5344 timeout 172157 usec 251 After: Seconds 5.72803 xmit 244322 recv 9919 timeout 244302 usec 156 Signed-off-by: Rusty Russell --- Documentation/lguest/lguest.c | 34 ++++++++++++++++++++-------------- 1 file changed, 20 insertions(+), 14 deletions(-) diff --git a/Documentation/lguest/lguest.c b/Documentation/lguest/lguest.c index 0d1b0265d8..dc49f50e04 100644 --- a/Documentation/lguest/lguest.c +++ b/Documentation/lguest/lguest.c @@ -929,11 +929,9 @@ static void handle_net_output(int fd, struct virtqueue *vq, bool timeout) while ((head = get_vq_desc(vq, iov, &out, &in)) != vq->vring.num) { if (in) errx(1, "Input buffers in output queue?"); - /* Check header, but otherwise ignore it (we told the Guest we - * supported no features, so it shouldn't have anything - * interesting). */ - (void)convert(&iov[0], struct virtio_net_hdr); - len = writev(vq->dev->fd, iov+1, out-1); + len = writev(vq->dev->fd, iov, out); + if (len < 0) + err(1, "Writing network packet to tun"); add_used_and_trigger(fd, vq, head, len); num++; } @@ -958,7 +956,6 @@ static bool handle_tun_input(int fd, struct device *dev) unsigned int head, in_num, out_num; int len; struct iovec iov[dev->vq->vring.num]; - struct virtio_net_hdr *hdr; /* First we need a network buffer from the Guests's recv virtqueue. */ head = get_vq_desc(dev->vq, iov, &out_num, &in_num); @@ -977,18 +974,13 @@ static bool handle_tun_input(int fd, struct device *dev) } else if (out_num) errx(1, "Output buffers in network recv queue?"); - /* First element is the header: we set it to 0 (no features). */ - hdr = convert(&iov[0], struct virtio_net_hdr); - hdr->flags = 0; - hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE; - /* Read the packet from the device directly into the Guest's buffer. */ - len = readv(dev->fd, iov+1, in_num-1); + len = readv(dev->fd, iov, in_num); if (len <= 0) err(1, "reading network"); /* Tell the Guest about the new packet. */ - add_used_and_trigger(fd, dev->vq, head, sizeof(*hdr) + len); + add_used_and_trigger(fd, dev->vq, head, len); verbose("tun input packet len %i [%02x %02x] (%s)\n", len, ((u8 *)iov[1].iov_base)[0], ((u8 *)iov[1].iov_base)[1], @@ -1490,11 +1482,15 @@ static int get_tun_device(char tapif[IFNAMSIZ]) * the truth, I completely blundered my way through this code, but it * works now! */ netfd = open_or_die("/dev/net/tun", O_RDWR); - ifr.ifr_flags = IFF_TAP | IFF_NO_PI; + ifr.ifr_flags = IFF_TAP | IFF_NO_PI | IFF_VNET_HDR; strcpy(ifr.ifr_name, "tap%d"); if (ioctl(netfd, TUNSETIFF, &ifr) != 0) err(1, "configuring /dev/net/tun"); + if (ioctl(netfd, TUNSETOFFLOAD, + TUN_F_CSUM|TUN_F_TSO4|TUN_F_TSO6|TUN_F_TSO_ECN) != 0) + err(1, "Could not set features for tun device"); + /* We don't need checksums calculated for packets coming in this * device: trust us! */ ioctl(netfd, TUNSETNOCSUM, 1); @@ -1561,6 +1557,16 @@ static void setup_tun_net(char *arg) /* Tell Guest what MAC address to use. */ add_feature(dev, VIRTIO_NET_F_MAC); add_feature(dev, VIRTIO_F_NOTIFY_ON_EMPTY); + /* Expect Guest to handle everything except UFO */ + add_feature(dev, VIRTIO_NET_F_CSUM); + add_feature(dev, VIRTIO_NET_F_GUEST_CSUM); + add_feature(dev, VIRTIO_NET_F_MAC); + add_feature(dev, VIRTIO_NET_F_GUEST_TSO4); + add_feature(dev, VIRTIO_NET_F_GUEST_TSO6); + add_feature(dev, VIRTIO_NET_F_GUEST_ECN); + add_feature(dev, VIRTIO_NET_F_HOST_TSO4); + add_feature(dev, VIRTIO_NET_F_HOST_TSO6); + add_feature(dev, VIRTIO_NET_F_HOST_ECN); set_config(dev, sizeof(conf), &conf); /* We don't need the socket any more; setup is done. */ -- 2.39.5