Re: [Qemu-devel] [PATCH 15/32] net: reorganize headers

[Stefan Hajnoczi <stefanha@gmail.com>]

On Wed, Oct 24, 2012 at 02:58:45PM +0200, Paolo Bonzini wrote:
> +struct virtio_net_hdr
> +{
> +#define VIRTIO_NET_HDR_F_NEEDS_CSUM     1       // Use csum_start, csum_offset
> +#define VIRTIO_NET_HDR_F_DATA_VALID    2       // Csum is valid
> +    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)
> +#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;
> +};

Idea for a separate cleanup: net/tap.c doesn't need the definition of
struct virtio_net_hdr or virtio_net_hdr_mrg_rxbuf.  It should simply
negotiate vnet_hdr_size between hw/virtio-net.c and the kernel tun
driver.  The layout and contents of the struct are not needed by
net/tap.c itself.

Stefan