libbpf: add support for need_wakeup flag in AF_XDP part

This commit adds support for the new need_wakeup flag in AF_XDP. The
xsk_socket__create function is updated to handle this and a new
function is introduced called xsk_ring_prod__needs_wakeup(). This
function can be used by the application to check if Rx and/or Tx
processing needs to be explicitly woken up.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
Magnus Karlsson 2019-08-14 09:27:20 +02:00 committed by Daniel Borkmann
parent 5c129241e2
commit a4500432c2
3 changed files with 23 additions and 0 deletions

View File

@ -16,6 +16,15 @@
#define XDP_SHARED_UMEM (1 << 0)
#define XDP_COPY (1 << 1) /* Force copy-mode */
#define XDP_ZEROCOPY (1 << 2) /* Force zero-copy mode */
/* If this option is set, the driver might go sleep and in that case
* the XDP_RING_NEED_WAKEUP flag in the fill and/or Tx rings will be
* set. If it is set, the application need to explicitly wake up the
* driver with a poll() (Rx and Tx) or sendto() (Tx only). If you are
* running the driver and the application on the same core, you should
* use this option so that the kernel will yield to the user space
* application.
*/
#define XDP_USE_NEED_WAKEUP (1 << 3)
struct sockaddr_xdp {
__u16 sxdp_family;
@ -25,10 +34,14 @@ struct sockaddr_xdp {
__u32 sxdp_shared_umem_fd;
};
/* XDP_RING flags */
#define XDP_RING_NEED_WAKEUP (1 << 0)
struct xdp_ring_offset {
__u64 producer;
__u64 consumer;
__u64 desc;
__u64 flags;
};
struct xdp_mmap_offsets {

View File

@ -224,6 +224,7 @@ int xsk_umem__create(struct xsk_umem **umem_ptr, void *umem_area, __u64 size,
fill->size = umem->config.fill_size;
fill->producer = map + off.fr.producer;
fill->consumer = map + off.fr.consumer;
fill->flags = map + off.fr.flags;
fill->ring = map + off.fr.desc;
fill->cached_cons = umem->config.fill_size;
@ -241,6 +242,7 @@ int xsk_umem__create(struct xsk_umem **umem_ptr, void *umem_area, __u64 size,
comp->size = umem->config.comp_size;
comp->producer = map + off.cr.producer;
comp->consumer = map + off.cr.consumer;
comp->flags = map + off.cr.flags;
comp->ring = map + off.cr.desc;
*umem_ptr = umem;
@ -564,6 +566,7 @@ int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname,
rx->size = xsk->config.rx_size;
rx->producer = rx_map + off.rx.producer;
rx->consumer = rx_map + off.rx.consumer;
rx->flags = rx_map + off.rx.flags;
rx->ring = rx_map + off.rx.desc;
}
xsk->rx = rx;
@ -583,6 +586,7 @@ int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname,
tx->size = xsk->config.tx_size;
tx->producer = tx_map + off.tx.producer;
tx->consumer = tx_map + off.tx.consumer;
tx->flags = tx_map + off.tx.flags;
tx->ring = tx_map + off.tx.desc;
tx->cached_cons = xsk->config.tx_size;
}

View File

@ -32,6 +32,7 @@ struct name { \
__u32 *producer; \
__u32 *consumer; \
void *ring; \
__u32 *flags; \
}
DEFINE_XSK_RING(xsk_ring_prod);
@ -76,6 +77,11 @@ xsk_ring_cons__rx_desc(const struct xsk_ring_cons *rx, __u32 idx)
return &descs[idx & rx->mask];
}
static inline int xsk_ring_prod__needs_wakeup(const struct xsk_ring_prod *r)
{
return *r->flags & XDP_RING_NEED_WAKEUP;
}
static inline __u32 xsk_prod_nb_free(struct xsk_ring_prod *r, __u32 nb)
{
__u32 free_entries = r->cached_cons - r->cached_prod;