Re: [PATCH] public/io/netif.h: add a new extra type for XDP

[Denis Kirjanov <kda@xxxxxxxxxxxxxxxxx>]

On 5/18/20, Jürgen Groß <jgross@xxxxxxxx> wrote:
> On 18.05.20 10:24, Denis Kirjanov wrote:
>> The patch adds a new extra type to be able to diffirentiate
>> between RX responses on xen-netfront side with the adjusted offset
>> required for XDP processing.
>>
>> For Linux the offset value is going to be passed via xenstore.
>
> Why? I can only see disadvantages by using a different communication
> mechanism.
I see it like other features passed through xenstore and it requires
less changes to
other structures with the same final result.

>
>>
>> Signed-off-by: Denis Kirjanov <denis.kirjanov@xxxxxxxx>
>> ---
>>   xen/include/public/io/netif.h | 7 ++++++-
>>   1 file changed, 6 insertions(+), 1 deletion(-)
>>
>> diff --git a/xen/include/public/io/netif.h
>> b/xen/include/public/io/netif.h
>> index 9fcf91a..759c88a 100644
>> --- a/xen/include/public/io/netif.h
>> +++ b/xen/include/public/io/netif.h
>> @@ -985,7 +985,8 @@ typedef struct netif_tx_request netif_tx_request_t;
>>   #define XEN_NETIF_EXTRA_TYPE_MCAST_ADD (2)  /* u.mcast */
>>   #define XEN_NETIF_EXTRA_TYPE_MCAST_DEL (3)  /* u.mcast */
>>   #define XEN_NETIF_EXTRA_TYPE_HASH      (4)  /* u.hash */
>> -#define XEN_NETIF_EXTRA_TYPE_MAX       (5)
>> +#define XEN_NETIF_EXTRA_TYPE_XDP       (5)  /* u.xdp */
>> +#define XEN_NETIF_EXTRA_TYPE_MAX       (6)
>>
>>   /* netif_extra_info_t flags. */
>>   #define _XEN_NETIF_EXTRA_FLAG_MORE (0)
>> @@ -1018,6 +1019,10 @@ struct netif_extra_info {
>>               uint8_t algorithm;
>>               uint8_t value[4];
>>           } hash;
>> +        struct {
>> +            uint16_t headroom;
>> +            uint32_t pad;
>
> Please use uint16_t pad[2] in order to avoid padding holes.
>
> Additionally you are missing the addition of the related feature
> Xenstore nodes in the comment area further up in the same file.

Done.

>
>
> Juergen
>