Re: [Qemu-devel] [PATCH V3 01/10] net: Add vnet_hdr_len related callback in NetClientInfo

[Jason Wang <jasowang@redhat.com>]

On 2017年04月28日 17:47, Zhang Chen wrote:
> Add get_vnet_hdr_len and get_using_vnet_hdr callback
> that make we get vnet_hdr_len easily.
>
> Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
> ---
>   include/net/net.h |  6 ++++++
>   net/net.c         | 18 ++++++++++++++++++
>   2 files changed, 24 insertions(+)
>
> diff --git a/include/net/net.h b/include/net/net.h
> index 99b28d5..402d913 100644
> --- a/include/net/net.h
> +++ b/include/net/net.h
> @@ -57,7 +57,9 @@ typedef RxFilterInfo *(QueryRxFilter)(NetClientState *);
>   typedef bool (HasUfo)(NetClientState *);
>   typedef bool (HasVnetHdr)(NetClientState *);
>   typedef bool (HasVnetHdrLen)(NetClientState *, int);
> +typedef int (GetVnetHdrLen)(NetClientState *);
>   typedef void (UsingVnetHdr)(NetClientState *, bool);
> +typedef bool (GetUsingVnetHdr)(NetClientState *);
>   typedef void (SetOffload)(NetClientState *, int, int, int, int, int);
>   typedef void (SetVnetHdrLen)(NetClientState *, int);
>   typedef int (SetVnetLE)(NetClientState *, bool);
> @@ -79,7 +81,9 @@ typedef struct NetClientInfo {
>       HasUfo *has_ufo;
>       HasVnetHdr *has_vnet_hdr;
>       HasVnetHdrLen *has_vnet_hdr_len;
> +    GetVnetHdrLen *get_vnet_hdr_len;
>       UsingVnetHdr *using_vnet_hdr;
> +    GetUsingVnetHdr *get_using_vnet_hdr;
>       SetOffload *set_offload;
>       SetVnetHdrLen *set_vnet_hdr_len;
>       SetVnetLE *set_vnet_le;
> @@ -155,7 +159,9 @@ void qemu_format_nic_info_str(NetClientState *nc, uint8_t macaddr[6]);
>   bool qemu_has_ufo(NetClientState *nc);
>   bool qemu_has_vnet_hdr(NetClientState *nc);
>   bool qemu_has_vnet_hdr_len(NetClientState *nc, int len);
> +int qemu_get_vnet_hdr_len(NetClientState *nc);
>   void qemu_using_vnet_hdr(NetClientState *nc, bool enable);
> +bool qemu_get_using_vnet_hdr(NetClientState *nc);
>   void qemu_set_offload(NetClientState *nc, int csum, int tso4, int tso6,
>                         int ecn, int ufo);
>   void qemu_set_vnet_hdr_len(NetClientState *nc, int len);
> diff --git a/net/net.c b/net/net.c
> index 0ac3b9e..f69260f 100644
> --- a/net/net.c
> +++ b/net/net.c
> @@ -466,6 +466,15 @@ bool qemu_has_vnet_hdr_len(NetClientState *nc, int len)
>       return nc->info->has_vnet_hdr_len(nc, len);
>   }
>   
> +int qemu_get_vnet_hdr_len(NetClientState *nc)
> +{
> +    if (!nc || !nc->info->get_vnet_hdr_len) {
> +        return false;
> +    }
> +
> +    return nc->info->get_vnet_hdr_len(nc);
> +}
> +
>   void qemu_using_vnet_hdr(NetClientState *nc, bool enable)
>   {
>       if (!nc || !nc->info->using_vnet_hdr) {
> @@ -475,6 +484,15 @@ void qemu_using_vnet_hdr(NetClientState *nc, bool enable)
>       nc->info->using_vnet_hdr(nc, enable);
>   }
>   
> +bool qemu_get_using_vnet_hdr(NetClientState *nc)
> +{
> +    if (!nc || !nc->info->get_using_vnet_hdr) {
> +        return false;
> +    }
> +
> +    return nc->info->get_using_vnet_hdr(nc);
> +}

Looks like we can do this simply by:

Introduce two common fields in NetClientState:

bool using_vnet_hdr;
int vnet_hdr_len;

And set them during qemu_using_vnet_hdr() and qemu_set_vnet_hdr_len(). 
Then we can query them directly without introducing any new callbacks.

Thanks

> +
>   void qemu_set_offload(NetClientState *nc, int csum, int tso4, int tso6,
>                             int ecn, int ufo)
>   {