[PATCH 5/5] kvm: qemu: Add support for partial csums and GSO

[Mark McLoughlin <markmc@redhat.com>]

Signed-off-by: Mark McLoughlin <markmc@redhat.com>
---
 qemu/hw/virtio-net.c |   51 ++++++++++++++++++++++++++++++++++++++++++++-----
 qemu/net.h           |    2 +
 qemu/vl.c            |   24 +++++++++++++++++++++++
 3 files changed, 71 insertions(+), 6 deletions(-)

diff --git a/qemu/hw/virtio-net.c b/qemu/hw/virtio-net.c
index f3ff356..3952e90 100644
--- a/qemu/hw/virtio-net.c
+++ b/qemu/hw/virtio-net.c
@@ -23,9 +23,18 @@
 #define VIRTIO_ID_NET	1
 
 /* The feature bitmap for virtio net */
-#define VIRTIO_NET_F_NO_CSUM	0
-#define VIRTIO_NET_F_MAC	5
-#define VIRTIO_NET_F_GS0	6
+#define VIRTIO_NET_F_CSUM	0	/* Host handles pkts w/ partial csum */
+#define VIRTIO_NET_F_GUEST_CSUM	1	/* Guest handles pkts w/ partial csum */
+#define VIRTIO_NET_F_MAC	5	/* Host has given MAC address. */
+#define VIRTIO_NET_F_GSO	6	/* Host handles pkts w/ any GSO type */
+#define VIRTIO_NET_F_GUEST_TSO4	7	/* Guest can handle TSOv4 in. */
+#define VIRTIO_NET_F_GUEST_TSO6	8	/* Guest can handle TSOv6 in. */
+#define VIRTIO_NET_F_GUEST_ECN	9	/* Guest can handle TSO[6] w/ ECN in. */
+#define VIRTIO_NET_F_GUEST_UFO	10	/* Guest can handle UFO in. */
+#define VIRTIO_NET_F_HOST_TSO4	11	/* Host can handle TSOv4 in. */
+#define VIRTIO_NET_F_HOST_TSO6	12	/* Host can handle TSOv6 in. */
+#define VIRTIO_NET_F_HOST_ECN	13	/* Host can handle TSO[6] w/ ECN in. */
+#define VIRTIO_NET_F_HOST_UFO	14	/* Host can handle UFO in. */
 
 #define TX_TIMER_INTERVAL (1000 / 500)
 
@@ -43,8 +52,6 @@ struct virtio_net_hdr
     uint8_t flags;
 #define VIRTIO_NET_HDR_GSO_NONE		0	// Not a GSO frame
 #define VIRTIO_NET_HDR_GSO_TCPV4	1	// GSO frame, IPv4 TCP (TSO)
-/* FIXME: Do we need this?  If they said they can handle ECN, do they care? */
-#define VIRTIO_NET_HDR_GSO_TCPV4_ECN	2	// GSO frame, IPv4 TCP w/ ECN
 #define VIRTIO_NET_HDR_GSO_UDP		3	// GSO frame, IPv4 UDP (UFO)
 #define VIRTIO_NET_HDR_GSO_TCPV6	4	// GSO frame, IPv6 TCP
 #define VIRTIO_NET_HDR_GSO_ECN		0x80	// TCP has ECN set
@@ -86,7 +93,38 @@ static void virtio_net_update_config(VirtIODevice *vdev, uint8_t *config)
 
 static uint32_t virtio_net_get_features(VirtIODevice *vdev)
 {
-    return (1 << VIRTIO_NET_F_MAC);
+    uint32_t features = (1 << VIRTIO_NET_F_MAC);
+
+    if (vdev->vq[0].vringfd > 0) {
+	features |= (1 << VIRTIO_NET_F_CSUM);
+	features |= (1 << VIRTIO_NET_F_GUEST_CSUM);
+	features |= (1 << VIRTIO_NET_F_GUEST_TSO4);
+	features |= (1 << VIRTIO_NET_F_GUEST_TSO6);
+	features |= (1 << VIRTIO_NET_F_GUEST_ECN);
+	features |= (1 << VIRTIO_NET_F_GUEST_UFO);
+	features |= (1 << VIRTIO_NET_F_HOST_TSO4);
+	features |= (1 << VIRTIO_NET_F_HOST_TSO6);
+	features |= (1 << VIRTIO_NET_F_HOST_ECN);
+	/* Kernel can't actually handle UFO in software currently. */
+    }
+
+    return features;
+}
+
+static void virtio_net_set_features(VirtIODevice *vdev, uint32_t features)
+{
+    VirtIONet *n = to_virtio_net(vdev);
+    VLANClientState *host = n->vc->vlan->first_client;
+
+    if (n->rx_vq->vringfd <= 0 || !host->set_vring_features)
+	return;
+
+    host->set_vring_features(host,
+                             (features >> VIRTIO_NET_F_GUEST_CSUM) & 1,
+                             (features >> VIRTIO_NET_F_GUEST_TSO4) & 1,
+                             (features >> VIRTIO_NET_F_GUEST_TSO6) & 1,
+                             (features >> VIRTIO_NET_F_GUEST_ECN)  & 1,
+                             (features >> VIRTIO_NET_F_GUEST_UFO)  & 1);
 }
 
 /* RX */
@@ -325,6 +363,7 @@ PCIDevice *virtio_net_init(PCIBus *bus, NICInfo *nd, int devfn)
 
     n->vdev.update_config = virtio_net_update_config;
     n->vdev.get_features = virtio_net_get_features;
+    n->vdev.set_features = virtio_net_set_features;
     n->rx_vq = virtio_add_queue(&n->vdev, 128, virtio_net_handle_rx);
     n->tx_vq = virtio_add_queue(&n->vdev, 128, virtio_net_handle_tx);
     memcpy(n->mac, nd->macaddr, 6);
diff --git a/qemu/net.h b/qemu/net.h
index e8ed926..dd250ae 100644
--- a/qemu/net.h
+++ b/qemu/net.h
@@ -10,6 +10,7 @@ typedef ssize_t (IOReadvHandler)(void *, const struct iovec *, int);
 typedef struct VLANClientState VLANClientState;
 
 typedef int (SetVringFDs)(VLANClientState *, int, int);
+typedef void (SetVringFeatures)(VLANClientState *, int, int, int, int, int);
 
 struct VLANClientState {
     IOReadHandler *fd_read;
@@ -18,6 +19,7 @@ struct VLANClientState {
        rate-limit the slirp code.  */
     IOCanRWHandler *fd_can_read;
     SetVringFDs *set_vring_fds;
+    SetVringFeatures *set_vring_features;
     void *opaque;
     struct VLANClientState *next;
     struct VLANState *vlan;
diff --git a/qemu/vl.c b/qemu/vl.c
index d043ccd..249041c 100644
--- a/qemu/vl.c
+++ b/qemu/vl.c
@@ -4189,6 +4189,29 @@ static int tap_set_vring_fds(VLANClientState *vc, int recv, int xmit)
 
     return 1;
 }
+
+static void tap_set_vring_features(VLANClientState *vc, int csum, int tso4,
+                                   int tso6, int ecn, int ufo)
+{
+    TAPState *s = vc->opaque;
+    unsigned int features = 0;
+
+    if (csum) {
+        features |= TUN_F_CSUM;
+        if (tso4)
+            features |= TUN_F_TSO4;
+        if (tso6)
+            features |= TUN_F_TSO6;
+        if ((tso4 || tso6) && ecn)
+            features |= TUN_F_TSO_ECN;
+        if (ufo)
+            features |= TUN_F_UFO;
+    }
+
+    if (ioctl(s->fd, TUNSETFEATURES, features) != 0)
+        fprintf(stderr, "TUNSETFEATURES ioctl() failed: %s\n",
+                strerror(errno));
+}
 #endif
 
 /* fd support */
@@ -4205,6 +4228,7 @@ static TAPState *net_tap_fd_init(VLANState *vlan, int fd)
     s->vc->fd_readv = tap_readv;
 #ifdef TUNSETRECVVRING
     s->vc->set_vring_fds = tap_set_vring_fds;
+    s->vc->set_vring_features = tap_set_vring_features;
 #endif
     qemu_set_fd_handler2(s->fd, tap_can_send, tap_send, NULL, s);
     snprintf(s->vc->info_str, sizeof(s->vc->info_str), "tap: fd=%d", fd);
-- 
1.5.4.1