[bpf-next RFCv2 1/3] xsk: add xsk_umem_consume_tx_virtual.

[William Tu]

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 <u9012...@gmail.com>
---
 include/net/xdp_sock.h |  7 +++++++
 net/xdp/xdp_umem.c     |  1 +
 net/xdp/xsk.c          | 21 +++++++++++++++++++--
 3 files changed, 27 insertions(+), 2 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..a6ca0c0f0330 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -170,7 +170,8 @@ 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 bool __xsk_umem_consume_tx(struct xdp_umem *umem, dma_addr_t *dma,
+                            void **vaddr, u32 *len)
 {
        struct xdp_desc desc;
        struct xdp_sock *xs;
@@ -183,7 +184,12 @@ bool xsk_umem_consume_tx(struct xdp_umem *umem, dma_addr_t 
*dma, u32 *len)
                if (xskq_produce_addr_lazy(umem->cq, desc.addr))
                        goto out;
 
-               *dma = xdp_umem_get_dma(umem, desc.addr);
+               if (dma)
+                       *dma = xdp_umem_get_dma(umem, desc.addr);
+
+               if (vaddr)
+                       *vaddr = xdp_umem_get_data(umem, desc.addr);
+
                *len = desc.len;
 
                xskq_discard_desc(xs->tx);
@@ -195,8 +201,19 @@ 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)
+{
+       return __xsk_umem_consume_tx(umem, dma, NULL, len);
+}
 EXPORT_SYMBOL(xsk_umem_consume_tx);
 
+bool xsk_umem_consume_tx_virtual(struct xdp_umem *umem, void **addr, u32 *len)
+{
+       return __xsk_umem_consume_tx(umem, NULL, addr, len);
+}
+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