[virtio] Add legacy driver for KVM virtio-net

This patch adds support for the virtio-net adapter provided by KVM.

Written by Laurent Vivier <Laurent.Vivier@bull.net> for Etherboot.
Wrapped as legacy driver for gPXE by Stefan Hajnoczi
<stefanha@gmail.com>.

1 files changed, 44 insertions, 0 deletions

diff --git a/src/drivers/net/virtio-net.h b/src/drivers/net/virtio-net.h
new file mode 100644
index 000000000..3abef28ea
--- /dev/null
+++ b/src/drivers/net/virtio-net.h
@@ -0,0 +1,44 @@
+#ifndef _VIRTIO_NET_H_
+# define _VIRTIO_NET_H_
+
+/* The feature bitmap for virtio net */
+#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. */
+
+struct virtio_net_config
+{
+   /* The config defining mac address (if VIRTIO_NET_F_MAC) */
+   u8 mac[6];
+} __attribute__((packed));
+
+/* This is the first element of the scatter-gather list.  If you don't
+ * specify GSO or CSUM features, you can simply ignore the header. */
+
+struct virtio_net_hdr
+{
+#define VIRTIO_NET_HDR_F_NEEDS_CSUM     1       // Use csum_start, csum_offset
+   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
+   uint8_t gso_type;
+   uint16_t hdr_len;
+   uint16_t gso_size;
+   uint16_t csum_start;
+   uint16_t csum_offset;
+};
+#endif /* _VIRTIO_NET_H_ */