[PATCH bpf-next RFCv3 1/6] xsk: add xsk_umem_consume_tx_virtual.

[William Tu <u9012063@gmail.com>]

Currently the xsk_umem_consume_tx expects only the physical NICs so
the api returns a dma address.  This patch introduce the new function
to return the virtual address, when XSK is used by a virtual device.

Signed-off-by: William Tu <u9012063@gmail.com>
---
 include/net/xdp_sock.h |  7 +++++++
 net/xdp/xdp_umem.c     |  1 +
 net/xdp/xsk.c          | 38 +++++++++++++++++++++++++++++++-------
 3 files changed, 39 insertions(+), 7 deletions(-)

diff --git a/include/net/xdp_sock.h b/include/net/xdp_sock.h
index 13acb9803a6d..7fefe74f7fb5 100644
--- a/include/net/xdp_sock.h
+++ b/include/net/xdp_sock.h
@@ -81,6 +81,7 @@ u64 *xsk_umem_peek_addr(struct xdp_umem *umem, u64 *addr);
 void xsk_umem_discard_addr(struct xdp_umem *umem);
 void xsk_umem_complete_tx(struct xdp_umem *umem, u32 nb_entries);
 bool xsk_umem_consume_tx(struct xdp_umem *umem, dma_addr_t *dma, u32 *len);
+bool xsk_umem_consume_tx_virtual(struct xdp_umem *umem, void **addr, u32 *len);
 void xsk_umem_consume_tx_done(struct xdp_umem *umem);
 struct xdp_umem_fq_reuse *xsk_reuseq_prepare(u32 nentries);
 struct xdp_umem_fq_reuse *xsk_reuseq_swap(struct xdp_umem *umem,
@@ -165,6 +166,12 @@ static inline bool xsk_umem_consume_tx(struct xdp_umem *umem, dma_addr_t *dma,
 	return false;
 }
 
+static inline bool xsk_umem_consume_tx_virtual(struct xdp_umem *umem,
+					       void **vaddr, u32 *len)
+{
+	return false;
+}
+
 static inline void xsk_umem_consume_tx_done(struct xdp_umem *umem)
 {
 }
diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c
index a264cf2accd0..424ae2538f9f 100644
--- a/net/xdp/xdp_umem.c
+++ b/net/xdp/xdp_umem.c
@@ -60,6 +60,7 @@ struct xdp_umem *xdp_get_umem_from_qid(struct net_device *dev,
 
 	return NULL;
 }
+EXPORT_SYMBOL(xdp_get_umem_from_qid);
 
 static void xdp_clear_umem_at_qid(struct net_device *dev, u16 queue_id)
 {
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index 07156f43d295..0e252047f55f 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -170,22 +170,19 @@ void xsk_umem_consume_tx_done(struct xdp_umem *umem)
 }
 EXPORT_SYMBOL(xsk_umem_consume_tx_done);
 
-bool xsk_umem_consume_tx(struct xdp_umem *umem, dma_addr_t *dma, u32 *len)
+static __always_inline bool __xsk_umem_consume_tx(struct xdp_umem *umem,
+						  struct xdp_desc *desc)
 {
-	struct xdp_desc desc;
 	struct xdp_sock *xs;
 
 	rcu_read_lock();
 	list_for_each_entry_rcu(xs, &umem->xsk_list, list) {
-		if (!xskq_peek_desc(xs->tx, &desc))
+		if (!xskq_peek_desc(xs->tx, desc))
 			continue;
 
-		if (xskq_produce_addr_lazy(umem->cq, desc.addr))
+		if (xskq_produce_addr_lazy(umem->cq, desc->addr))
 			goto out;
 
-		*dma = xdp_umem_get_dma(umem, desc.addr);
-		*len = desc.len;
-
 		xskq_discard_desc(xs->tx);
 		rcu_read_unlock();
 		return true;
@@ -195,8 +192,35 @@ bool xsk_umem_consume_tx(struct xdp_umem *umem, dma_addr_t *dma, u32 *len)
 	rcu_read_unlock();
 	return false;
 }
+
+bool xsk_umem_consume_tx(struct xdp_umem *umem, dma_addr_t *dma, u32 *len)
+{
+	struct xdp_desc desc;
+
+	if (!__xsk_umem_consume_tx(umem, &desc))
+		return false;
+
+	*dma = xdp_umem_get_dma(umem, desc.addr);
+	*len = desc.len;
+
+	return true;
+}
 EXPORT_SYMBOL(xsk_umem_consume_tx);
 
+bool xsk_umem_consume_tx_virtual(struct xdp_umem *umem, void **vaddr, u32 *len)
+{
+	struct xdp_desc desc;
+
+	if (!__xsk_umem_consume_tx(umem, &desc))
+		return false;
+
+	*vaddr = xdp_umem_get_data(umem, desc.addr);
+	*len = desc.len;
+
+	return true;
+}
+EXPORT_SYMBOL(xsk_umem_consume_tx_virtual);
+
 static int xsk_zc_xmit(struct sock *sk)
 {
 	struct xdp_sock *xs = xdp_sk(sk);
-- 
2.7.4