On 2019-05-04 20:25, Björn Töpel wrote:
> On Tue, 30 Apr 2019 at 20:12, Maxim Mikityanskiy <maximmi@xxxxxxxxxxxx> wrote:
>>
>> Make it possible for the application to determine whether the AF_XDP
>> socket is running in zero-copy mode. To achieve this, add a new
>> getsockopt option XDP_OPTIONS that returns flags. The only flag
>> supported for now is the zero-copy mode indicator.
>>
>> Signed-off-by: Maxim Mikityanskiy <maximmi@xxxxxxxxxxxx>
>> Reviewed-by: Tariq Toukan <tariqt@xxxxxxxxxxxx>
>> Acked-by: Saeed Mahameed <saeedm@xxxxxxxxxxxx>
>> ---
>> include/uapi/linux/if_xdp.h | 7 +++++++
>> net/xdp/xsk.c | 22 ++++++++++++++++++++++
>> tools/include/uapi/linux/if_xdp.h | 7 +++++++
>> 3 files changed, 36 insertions(+)
>>
>> diff --git a/include/uapi/linux/if_xdp.h b/include/uapi/linux/if_xdp.h
>> index caed8b1614ff..9ae4b4e08b68 100644
>> --- a/include/uapi/linux/if_xdp.h
>> +++ b/include/uapi/linux/if_xdp.h
>> @@ -46,6 +46,7 @@ struct xdp_mmap_offsets {
>> #define XDP_UMEM_FILL_RING 5
>> #define XDP_UMEM_COMPLETION_RING 6
>> #define XDP_STATISTICS 7
>> +#define XDP_OPTIONS 8
>>
>> struct xdp_umem_reg {
>> __u64 addr; /* Start of packet data area */
>> @@ -60,6 +61,12 @@ struct xdp_statistics {
>> __u64 tx_invalid_descs; /* Dropped due to invalid descriptor */
>> };
>>
>> +struct xdp_options {
>> + __u32 flags;
>> +};
>> +
>> +#define XDP_OPTIONS_FLAG_ZEROCOPY (1 << 0)
>
> Nit: The other flags doesn't use "FLAG" in its name, but that doesn't
> really matter.
>
>> +
>> /* Pgoff for mmaping the rings */
>> #define XDP_PGOFF_RX_RING 0
>> #define XDP_PGOFF_TX_RING 0x80000000
>> diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
>> index b68a380f50b3..998199109d5c 100644
>> --- a/net/xdp/xsk.c
>> +++ b/net/xdp/xsk.c
>> @@ -650,6 +650,28 @@ static int xsk_getsockopt(struct socket *sock, int level, int optname,
>>
>> return 0;
>> }
>> + case XDP_OPTIONS:
>> + {
>> + struct xdp_options opts;
>> +
>> + if (len < sizeof(opts))
>> + return -EINVAL;
>> +
>> + opts.flags = 0;
>
> Maybe get rid of this, in favor of "opts = {}" if the structure grows?
I'm OK with any of these options. Should I respin the series, or can I
follow up with the change in RCs if the series gets to 5.2?
Alexei, is it even possible to still make changes to this series? The
window appears closed.
>
>> +
>> + mutex_lock(&xs->mutex);
>> + if (xs->zc)
>> + opts.flags |= XDP_OPTIONS_FLAG_ZEROCOPY;
>> + mutex_unlock(&xs->mutex);
>> +
>> + len = sizeof(opts);
>> + if (copy_to_user(optval, &opts, len))
>> + return -EFAULT;
>> + if (put_user(len, optlen))
>> + return -EFAULT;
>> +
>> + return 0;
>> + }
>> default:
>> break;
>> }
>> diff --git a/tools/include/uapi/linux/if_xdp.h b/tools/include/uapi/linux/if_xdp.h
>> index caed8b1614ff..9ae4b4e08b68 100644
>> --- a/tools/include/uapi/linux/if_xdp.h
>> +++ b/tools/include/uapi/linux/if_xdp.h
>> @@ -46,6 +46,7 @@ struct xdp_mmap_offsets {
>> #define XDP_UMEM_FILL_RING 5
>> #define XDP_UMEM_COMPLETION_RING 6
>> #define XDP_STATISTICS 7
>> +#define XDP_OPTIONS 8
>>
>> struct xdp_umem_reg {
>> __u64 addr; /* Start of packet data area */
>> @@ -60,6 +61,12 @@ struct xdp_statistics {
>> __u64 tx_invalid_descs; /* Dropped due to invalid descriptor */
>> };
>>
>> +struct xdp_options {
>> + __u32 flags;
>> +};
>> +
>> +#define XDP_OPTIONS_FLAG_ZEROCOPY (1 << 0)
>> +
>> /* Pgoff for mmaping the rings */
>> #define XDP_PGOFF_RX_RING 0
>> #define XDP_PGOFF_TX_RING 0x80000000
>> --
>> 2.19.1
>>
