From a4500432c2587cb2ae7554537886a4516ff2e7aa Mon Sep 17 00:00:00 2001 From: Magnus Karlsson Date: Wed, 14 Aug 2019 09:27:20 +0200 Subject: [PATCH] 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 Acked-by: Jonathan Lemon Signed-off-by: Daniel Borkmann --- tools/include/uapi/linux/if_xdp.h | 13 +++++++++++++ tools/lib/bpf/xsk.c | 4 ++++ tools/lib/bpf/xsk.h | 6 ++++++ 3 files changed, 23 insertions(+) diff --git a/tools/include/uapi/linux/if_xdp.h b/tools/include/uapi/linux/if_xdp.h index faaa5ca2a117..62b80d57b72a 100644 --- a/tools/include/uapi/linux/if_xdp.h +++ b/tools/include/uapi/linux/if_xdp.h @@ -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 { diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c index 680e63066cf3..17e8d79c11a8 100644 --- a/tools/lib/bpf/xsk.c +++ b/tools/lib/bpf/xsk.c @@ -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; } diff --git a/tools/lib/bpf/xsk.h b/tools/lib/bpf/xsk.h index 833a6e60d065..aa1d6122b7db 100644 --- a/tools/lib/bpf/xsk.h +++ b/tools/lib/bpf/xsk.h @@ -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; -- 2.30.2