(Might not apply cleanly to current Linus, there are other lguest things
going on, but this gives you the idea at least).
Guest -> Host 1GB TCP:
Before: Seconds 16.6282 xmit 250498 recv 3 timeout 248355
After: Seconds 9.86102 xmit 241989 recv 192014 timeout 231224
Host -> Guest 1GB TCP:
Before: Seconds 11.0831 xmit 324742 recv 1910 timeout 323429
After: Seconds 10.6626 xmit 342489 recv 24 timeout 341173
Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
---
Documentation/lguest/lguest.c | 34 ++++++++++++++++++++--------------
1 file changed, 20 insertions(+), 14 deletions(-)
diff -r 7358caf10bd8 Documentation/lguest/lguest.c
--- a/Documentation/lguest/lguest.c Tue Jun 24 16:15:36 2008 +1000
+++ b/Documentation/lguest/lguest.c Wed Jun 25 00:29:31 2008 +1000
@@ -928,11 +928,9 @@ static void handle_net_output(int fd, st
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++;
}
@@ -949,7 +947,6 @@ static bool handle_tun_input(int fd, str
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);
@@ -970,18 +969,13 @@ static bool handle_tun_input(int fd, str
} 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],
@@ -1492,10 +1486,14 @@ static int get_tun_device(char tapif[IFN
* 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, TUNSETFEATURES,
+ 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! */
@@ -1563,6 +1561,16 @@ 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. */
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