Virtualization - Apr 2021 - [PATCH v6 09/10] vduse: Introduce VDUSE - vDPA Device in Userspace

? 2021/4/9 ??4:02, Yongji Xie ??:
>>>>> +};
>>>>> +
>>>>> +struct vduse_dev_config_data {
>>>>> +     __u32 offset; /* offset from the beginning of config
space */
>>>>> +     __u32 len; /* the length to read/write */
>>>>> +     __u8 data[VDUSE_CONFIG_DATA_LEN]; /* data buffer used
to read/write */
>>>> Note that since VDUSE_CONFIG_DATA_LEN is part of uAPI it means
we can
>>>> not change it in the future.
>>>>
>>>> So this might suffcient for future features or all type of
virtio devices.
>>>>
>>> Do you mean 256 is no enough here?
>> Yes.
>>
> But this request will be submitted multiple times if config lengh is
> larger than 256. So do you think whether we need to extent the size to
> 512 or larger?

So I think you'd better either:

1) document the limitation (256) in somewhere, (better both uapi and doc)

or

2) make it variable

Thanks

>