RE: [Qemu-devel] [PATCH 1/2] virtio-net: fix cross-endianness support

[Liu Yu-B13201]

> -----Original Message-----
> From: address@hidden 
> [mailto:address@hidden 
> On Behalf Of Aurelien Jarno
> Sent: Sunday, January 16, 2011 3:28 AM
> To: address@hidden
> Cc: Anthony Liguori; Aurelien Jarno
> Subject: [Qemu-devel] [PATCH 1/2] virtio-net: fix 
> cross-endianness support
> 
> virtio-net used to work on cross-endianness configurations, 
> but doesn't
> anymore with recent guest kernels, as the new features don't handle
> endianness correctly.
> 
> This patch fixes wrong conversion, and add missing ones to make
> virtio-net working. Tested on the following configurations:
> - i386 guest on x86_64 host
> - ppc guest on x86_64 host
> - i386 guest on mips host
> - ppc guest on mips host
> 
> Cc: Anthony Liguori <address@hidden>
> Signed-off-by: Aurelien Jarno <address@hidden>
> ---
>  hw/virtio-net.c |   13 +++++++------
>  1 files changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/hw/virtio-net.c b/hw/virtio-net.c
> index ec1bf8d..515fb19 100644
> --- a/hw/virtio-net.c
> +++ b/hw/virtio-net.c
> @@ -81,7 +81,7 @@ static void 
> virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
>      VirtIONet *n = to_virtio_net(vdev);
>      struct virtio_net_config netcfg;
>  
> -    netcfg.status = n->status;
> +    netcfg.status = lduw_p(&n->status);
>      memcpy(netcfg.mac, n->mac, ETH_ALEN);
>      memcpy(config, &netcfg, sizeof(netcfg));
>  }
> @@ -340,7 +340,7 @@ static int 
> virtio_net_handle_mac(VirtIONet *n, uint8_t cmd,
>      n->mac_table.multi_overflow = 0;
>      memset(n->mac_table.macs, 0, MAC_TABLE_ENTRIES * ETH_ALEN);
>  
> -    mac_data.entries = ldl_le_p(elem->out_sg[1].iov_base);
> +    mac_data.entries = ldl_p(elem->out_sg[1].iov_base);
>  
>      if (sizeof(mac_data.entries) +
>          (mac_data.entries * ETH_ALEN) > elem->out_sg[1].iov_len)
> @@ -356,7 +356,7 @@ static int 
> virtio_net_handle_mac(VirtIONet *n, uint8_t cmd,
>  
>      n->mac_table.first_multi = n->mac_table.in_use;
>  
> -    mac_data.entries = ldl_le_p(elem->out_sg[2].iov_base);
> +    mac_data.entries = ldl_p(elem->out_sg[2].iov_base);
>  

Hello Aurelien,

Not clear what is happen, but this commit break e500(PowerPC big endian) kvm.
Looks like e500 is happy to use ldl_le_p(), but this patch change it to use 
ldl_be_p().
Any thoughts about that?

Thanks,
Yu