From 02b55e5657c3a569fc681ba851e464cfa6b90d4f Mon Sep 17 00:00:00 2001 From: =?utf8?q?Bj=C3=B6rn=20T=C3=B6pel?= Date: Mon, 4 Jun 2018 14:05:54 +0200 Subject: [PATCH] xdp: add MEM_TYPE_ZERO_COPY MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Here, a new type of allocator support is added to the XDP return API. A zero-copy allocated xdp_buff cannot be converted to an xdp_frame. Instead is the buff has to be copied. This is not supported at all in this commit. Also, an opaque "handle" is added to xdp_buff. This can be used as a context for the zero-copy allocator implementation. Signed-off-by: Björn Töpel Signed-off-by: Daniel Borkmann --- include/net/xdp.h | 10 ++++++++++ net/core/xdp.c | 19 ++++++++++++++----- 2 files changed, 24 insertions(+), 5 deletions(-) diff --git a/include/net/xdp.h b/include/net/xdp.h index a3b71a4dd71d..2deea7166a34 100644 --- a/include/net/xdp.h +++ b/include/net/xdp.h @@ -37,6 +37,7 @@ enum xdp_mem_type { MEM_TYPE_PAGE_SHARED = 0, /* Split-page refcnt based model */ MEM_TYPE_PAGE_ORDER0, /* Orig XDP full page model */ MEM_TYPE_PAGE_POOL, + MEM_TYPE_ZERO_COPY, MEM_TYPE_MAX, }; @@ -51,6 +52,10 @@ struct xdp_mem_info { struct page_pool; +struct zero_copy_allocator { + void (*free)(struct zero_copy_allocator *zca, unsigned long handle); +}; + struct xdp_rxq_info { struct net_device *dev; u32 queue_index; @@ -63,6 +68,7 @@ struct xdp_buff { void *data_end; void *data_meta; void *data_hard_start; + unsigned long handle; struct xdp_rxq_info *rxq; }; @@ -86,6 +92,10 @@ struct xdp_frame *convert_to_xdp_frame(struct xdp_buff *xdp) int metasize; int headroom; + /* TODO: implement clone, copy, use "native" MEM_TYPE */ + if (xdp->rxq->mem.type == MEM_TYPE_ZERO_COPY) + return NULL; + /* Assure headroom is available for storing info */ headroom = xdp->data - xdp->data_hard_start; metasize = xdp->data - xdp->data_meta; diff --git a/net/core/xdp.c b/net/core/xdp.c index cb8c4e061a5a..9d1f22072d5d 100644 --- a/net/core/xdp.c +++ b/net/core/xdp.c @@ -31,6 +31,7 @@ struct xdp_mem_allocator { union { void *allocator; struct page_pool *page_pool; + struct zero_copy_allocator *zc_alloc; }; struct rhash_head node; struct rcu_head rcu; @@ -261,7 +262,7 @@ int xdp_rxq_info_reg_mem_model(struct xdp_rxq_info *xdp_rxq, xdp_rxq->mem.type = type; if (!allocator) { - if (type == MEM_TYPE_PAGE_POOL) + if (type == MEM_TYPE_PAGE_POOL || type == MEM_TYPE_ZERO_COPY) return -EINVAL; /* Setup time check page_pool req */ return 0; } @@ -314,7 +315,8 @@ EXPORT_SYMBOL_GPL(xdp_rxq_info_reg_mem_model); * is used for those calls sites. Thus, allowing for faster recycling * of xdp_frames/pages in those cases. */ -static void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct) +static void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct, + unsigned long handle) { struct xdp_mem_allocator *xa; struct page *page; @@ -338,6 +340,13 @@ static void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct) page = virt_to_page(data); /* Assumes order0 page*/ put_page(page); break; + case MEM_TYPE_ZERO_COPY: + /* NB! Only valid from an xdp_buff! */ + rcu_read_lock(); + /* mem->id is valid, checked in xdp_rxq_info_reg_mem_model() */ + xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params); + xa->zc_alloc->free(xa->zc_alloc, handle); + rcu_read_unlock(); default: /* Not possible, checked in xdp_rxq_info_reg_mem_model() */ break; @@ -346,18 +355,18 @@ static void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct) void xdp_return_frame(struct xdp_frame *xdpf) { - __xdp_return(xdpf->data, &xdpf->mem, false); + __xdp_return(xdpf->data, &xdpf->mem, false, 0); } EXPORT_SYMBOL_GPL(xdp_return_frame); void xdp_return_frame_rx_napi(struct xdp_frame *xdpf) { - __xdp_return(xdpf->data, &xdpf->mem, true); + __xdp_return(xdpf->data, &xdpf->mem, true, 0); } EXPORT_SYMBOL_GPL(xdp_return_frame_rx_napi); void xdp_return_buff(struct xdp_buff *xdp) { - __xdp_return(xdp->data, &xdp->rxq->mem, true); + __xdp_return(xdp->data, &xdp->rxq->mem, true, xdp->handle); } EXPORT_SYMBOL_GPL(xdp_return_buff); -- 2.11.0