xsk: prepare 'options' in xdp_desc for multi-buffer use

Use the 'options' field in xdp_desc as a packet continuity marker. Since
'options' field was unused till now and was expected to be set to 0, the
'eop' descriptor will have it set to 0, while the non-eop descriptors
will have to set it to 1. This ensures legacy applications continue to
work without needing any change for single-buffer packets.

Add helper functions and extend xskq_prod_reserve_desc() to use the
'options' field.

Signed-off-by: Tirthendu Sarkar <tirthendu.sarkar@intel.com>
Link: https://lore.kernel.org/r/20230719132421.584801-2-maciej.fijalkowski@intel.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Tirthendu Sarkar 2023-07-19 15:23:58 +02:00 committed by Alexei Starovoitov
parent 492e797fda
commit 63a64a56bc
3 changed files with 20 additions and 7 deletions

View file

@ -108,4 +108,11 @@ struct xdp_desc {
/* UMEM descriptor is __u64 */
/* Flag indicating that the packet continues with the buffer pointed out by the
* next frame in the ring. The end of the packet is signalled by setting this
* bit to zero. For single buffer packets, every descriptor has 'options' set
* to 0 and this maintains backward compatibility.
*/
#define XDP_PKT_CONTD (1 << 0)
#endif /* _LINUX_IF_XDP_H */

View file

@ -135,14 +135,14 @@ int xsk_reg_pool_at_qid(struct net_device *dev, struct xsk_buff_pool *pool,
return 0;
}
static int __xsk_rcv_zc(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len)
static int __xsk_rcv_zc(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len, u32 flags)
{
struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp);
u64 addr;
int err;
addr = xp_get_handle(xskb);
err = xskq_prod_reserve_desc(xs->rx, addr, len);
err = xskq_prod_reserve_desc(xs->rx, addr, len, flags);
if (err) {
xs->rx_queue_full++;
return err;
@ -189,7 +189,7 @@ static int __xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
}
xsk_copy_xdp(xsk_xdp, xdp, len);
err = __xsk_rcv_zc(xs, xsk_xdp, len);
err = __xsk_rcv_zc(xs, xsk_xdp, len, 0);
if (err) {
xsk_buff_free(xsk_xdp);
return err;
@ -259,7 +259,7 @@ static int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
if (xdp->rxq->mem.type == MEM_TYPE_XSK_BUFF_POOL) {
len = xdp->data_end - xdp->data;
return __xsk_rcv_zc(xs, xdp, len);
return __xsk_rcv_zc(xs, xdp, len, 0);
}
err = __xsk_rcv(xs, xdp);

View file

@ -130,6 +130,11 @@ static inline bool xskq_cons_read_addr_unchecked(struct xsk_queue *q, u64 *addr)
return false;
}
static inline bool xp_unused_options_set(u32 options)
{
return options & ~XDP_PKT_CONTD;
}
static inline bool xp_aligned_validate_desc(struct xsk_buff_pool *pool,
struct xdp_desc *desc)
{
@ -141,7 +146,7 @@ static inline bool xp_aligned_validate_desc(struct xsk_buff_pool *pool,
if (desc->addr >= pool->addrs_cnt)
return false;
if (desc->options)
if (xp_unused_options_set(desc->options))
return false;
return true;
}
@ -158,7 +163,7 @@ static inline bool xp_unaligned_validate_desc(struct xsk_buff_pool *pool,
xp_desc_crosses_non_contig_pg(pool, addr, desc->len))
return false;
if (desc->options)
if (xp_unused_options_set(desc->options))
return false;
return true;
}
@ -360,7 +365,7 @@ static inline void xskq_prod_write_addr_batch(struct xsk_queue *q, struct xdp_de
}
static inline int xskq_prod_reserve_desc(struct xsk_queue *q,
u64 addr, u32 len)
u64 addr, u32 len, u32 flags)
{
struct xdp_rxtx_ring *ring = (struct xdp_rxtx_ring *)q->ring;
u32 idx;
@ -372,6 +377,7 @@ static inline int xskq_prod_reserve_desc(struct xsk_queue *q,
idx = q->cached_prod++ & q->ring_mask;
ring->desc[idx].addr = addr;
ring->desc[idx].len = len;
ring->desc[idx].options = flags;
return 0;
}