Subject: Re: [PATCH qemu-kvm] Enable UFO on virtio-net/tap devices

From: Avi Kivity <[email-masked]>
Date: Sun, 07 Jun 2009 09:21:39 +0300

Sridhar Samudrala wrote:
> Enable UFO on the host tap device if supported and allow setting UFO
> on virtio-net in the guest.
>
> Signed-off-by: Sridhar Samudrala <[email-masked]>
>
>
> diff --git a/hw/virtio-net.c b/hw/virtio-net.c
> index 3c77b99..8a53e27 100644
> --- a/hw/virtio-net.c
> +++ b/hw/virtio-net.c
> @@ -134,7 +134,8 @@ static uint32_t virtio_net_get_features(VirtIODevice *vdev)
>          features |= (1 << VIRTIO_NET_F_HOST_TSO6);
>          features |= (1 << VIRTIO_NET_F_HOST_ECN);
>          features |= (1 << VIRTIO_NET_F_MRG_RXBUF);
> -        /* Kernel can't actually handle UFO in software currently. */
> +       // features |= (1 << VIRTIO_NET_F_HOST_UFO);
> +        features |= (1 << VIRTIO_NET_F_GUEST_UFO);
>   

Where are these defined?

> @@ -990,8 +990,13 @@ static int tap_probe_vnet_hdr(int fd)
>  }
>  
>  #ifdef TUNSETOFFLOAD
> +
> +#ifndef TUN_F_UFO
> +#define TUN_F_UFO	0x10
> +#endif
> +
>   

Should just use the definition in the kernel header.

-- 
Do not meddle in the internals of kernels, for they are subtle and quick to panic.