[Qemu-devel] Re: [PATCH RFC] e1000: secrc support

[Alex Williamson <alex.williamson@redhat.com>]

On Mon, 2010-07-12 at 20:49 +0300, Michael S. Tsirkin wrote:
> Add support for secrc field. Reportedly needed by old RHEL guests.
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  hw/e1000.c |   11 ++++++++++-
>  1 files changed, 10 insertions(+), 1 deletions(-)
> 
> Anthony, Alex, please review.

Acked-by: Alex Williamson <alex.williamson@redhat.com>

> diff --git a/hw/e1000.c b/hw/e1000.c
> index 70aba11..8d87492 100644
> --- a/hw/e1000.c
> +++ b/hw/e1000.c
> @@ -344,6 +344,15 @@ is_vlan_txd(uint32_t txd_lower)
>      return ((txd_lower & E1000_TXD_CMD_VLE) != 0);
>  }
>  
> +/* FCS aka Ethernet CRC-32. We don't get it from backends and can't
> + * fill it in, just pad descriptor length by 4 bytes unless guest
> + * told us to trip it off the packet. */
> +static inline int
> +fcs_len(E1000State *s)
> +{
> +    return (s->mac_reg[RCTL] & E1000_RCTL_SECRC) ? 0 : 4;
> +}
> +
>  static void
>  xmit_seg(E1000State *s)
>  {
> @@ -662,7 +671,7 @@ e1000_receive(VLANClientState *nc, const uint8_t *buf, size_t size)
>          if (desc.buffer_addr) {
>              cpu_physical_memory_write(le64_to_cpu(desc.buffer_addr),
>                                        (void *)(buf + vlan_offset), size);
> -            desc.length = cpu_to_le16(size + 4 /* for FCS */);
> +            desc.length = cpu_to_le16(size + fcs_len(s));
>              desc.status |= E1000_RXD_STAT_EOP|E1000_RXD_STAT_IXSM;
>          } else // as per intel docs; skip descriptors with null buf addr
>              DBGOUT(RX, "Null RX descriptor!!\n");