xdp: add MEM_TYPE_ZERO_COPY

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 <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
Björn Töpel 2018-06-04 14:05:54 +02:00 committed by Daniel Borkmann
parent 74515c5750
commit 02b55e5657
2 changed files with 24 additions and 5 deletions

View file

@ -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);