Merge branch 'bpf-xdp-Report-bpf_prog-ID-in-IFLA_XDP'

Martin KaFai Lau says:

====================
bpf: xdp: Report bpf_prog ID in IFLA_XDP

This is the first usage of the new bpf_prog ID.  It is for
reporting the ID of a xdp_prog through netlink.

It rides on the existing IFLA_XDP.  This patch adds IFLA_XDP_PROG_ID
for the bpf_prog ID reporting.

It starts with changing the generic_xdp first.  After that,
the hardware driver is changed one by one.  Jakub Kicinski mentioned
that he will soon introduce XDP_ATTACHED_HW (on top of the existing
XDP_ATTACHED_DRV and XDP_ATTACHED_SKB)
and he is going to reuse the prog_attached for this purpose.
Hence, this patch set keeps the prog_attached even though
!!prog_id also implies there is xdp_prog attached.

I have tested with generic_xdp, mlx4 and mlx5.

v3:
1. Replace 'if' by '?' when checking the xdp_prog pointer
   as suggested by Jakub Kicinski (thanks!)

v2:
1. Remove READ_ONCE since it is alredy under rtnl lock
2. Keep prog_attached in 'struct netdev_xdp' as
   requested by Jakub Kicinski.  The existing prog_attached
   and the new prog_id are put under a struct for XDP_QUERY_PROG.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

8 files changed, 44 insertions, 11 deletions

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
index 8ce793a0d030..7d67552e70d7 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
@@ -218,6 +218,7 @@ int bnxt_xdp(struct net_device *dev, struct netdev_xdp *xdp)
 		break;
 	case XDP_QUERY_PROG:
 		xdp->prog_attached = !!bp->xdp_prog;
+		xdp->prog_id = bp->xdp_prog ? bp->xdp_prog->aux->id : 0;
 		rc = 0;
 		break;
 	default:
diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_main.c b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
index d6477af88085..573755b0a51b 100644
--- a/drivers/net/ethernet/cavium/thunder/nicvf_main.c
+++ b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
@@ -1763,6 +1763,7 @@ static int nicvf_xdp(struct net_device *netdev, struct netdev_xdp *xdp)
 		return nicvf_xdp_setup(nic, xdp->prog);
 	case XDP_QUERY_PROG:
 		xdp->prog_attached = !!nic->xdp_prog;
+		xdp->prog_id = nic->xdp_prog ? nic->xdp_prog->aux->id : 0;
 		return 0;
 	default:
 		return -EINVAL;
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index f3dc5dea9300..f1dbdf26d8e1 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -9815,6 +9815,8 @@ static int ixgbe_xdp(struct net_device *dev, struct netdev_xdp *xdp)
 		return ixgbe_xdp_setup(dev, xdp->prog);
 	case XDP_QUERY_PROG:
 		xdp->prog_attached = !!(adapter->xdp_prog);
+		xdp->prog_id = adapter->xdp_prog ?
+			adapter->xdp_prog->aux->id : 0;
 		return 0;
 	default:
 		return -EINVAL;
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
index 99c02bb4f302..18252a79a074 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
@@ -2825,11 +2825,25 @@ out:
 	return err;
 }
 
-static bool mlx4_xdp_attached(struct net_device *dev)
+static u32 mlx4_xdp_query(struct net_device *dev)
 {
 	struct mlx4_en_priv *priv = netdev_priv(dev);
+	struct mlx4_en_dev *mdev = priv->mdev;
+	const struct bpf_prog *xdp_prog;
+	u32 prog_id = 0;
+
+	if (!priv->tx_ring_num[TX_XDP])
+		return prog_id;
+
+	mutex_lock(&mdev->state_lock);
+	xdp_prog = rcu_dereference_protected(
+		priv->rx_ring[0]->xdp_prog,
+		lockdep_is_held(&mdev->state_lock));
+	if (xdp_prog)
+		prog_id = xdp_prog->aux->id;
+	mutex_unlock(&mdev->state_lock);
 
-	return !!priv->tx_ring_num[TX_XDP];
+	return prog_id;
 }
 
 static int mlx4_xdp(struct net_device *dev, struct netdev_xdp *xdp)
@@ -2838,7 +2852,8 @@ static int mlx4_xdp(struct net_device *dev, struct netdev_xdp *xdp)
 	case XDP_SETUP_PROG:
 		return mlx4_xdp_set(dev, xdp->prog);
 	case XDP_QUERY_PROG:
-		xdp->prog_attached = mlx4_xdp_attached(dev);
+		xdp->prog_id = mlx4_xdp_query(dev);
+		xdp->prog_attached = !!xdp->prog_id;
 		return 0;
 	default:
 		return -EINVAL;
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index 5afec0f4a658..c8f3aefe735d 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -3599,11 +3599,19 @@ unlock:
 	return err;
 }
 
-static bool mlx5e_xdp_attached(struct net_device *dev)
+static u32 mlx5e_xdp_query(struct net_device *dev)
 {
 	struct mlx5e_priv *priv = netdev_priv(dev);
+	const struct bpf_prog *xdp_prog;
+	u32 prog_id = 0;
 
-	return !!priv->channels.params.xdp_prog;
+	mutex_lock(&priv->state_lock);
+	xdp_prog = priv->channels.params.xdp_prog;
+	if (xdp_prog)
+		prog_id = xdp_prog->aux->id;
+	mutex_unlock(&priv->state_lock);
+
+	return prog_id;
 }
 
 static int mlx5e_xdp(struct net_device *dev, struct netdev_xdp *xdp)
@@ -3612,7 +3620,8 @@ static int mlx5e_xdp(struct net_device *dev, struct netdev_xdp *xdp)
 	case XDP_SETUP_PROG:
 		return mlx5e_xdp_set(dev, xdp->prog);
 	case XDP_QUERY_PROG:
-		xdp->prog_attached = mlx5e_xdp_attached(dev);
+		xdp->prog_id = mlx5e_xdp_query(dev);
+		xdp->prog_attached = !!xdp->prog_id;
 		return 0;
 	default:
 		return -EINVAL;
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
index 49d1756d6a8e..378512dec80d 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -3256,6 +3256,7 @@ static int nfp_net_xdp(struct net_device *netdev, struct netdev_xdp *xdp)
 		return nfp_net_xdp_setup(nn, xdp);
 	case XDP_QUERY_PROG:
 		xdp->prog_attached = !!nn->dp.xdp_prog;
+		xdp->prog_id = nn->dp.xdp_prog ? nn->dp.xdp_prog->aux->id : 0;
 		return 0;
 	default:
 		return -EINVAL;
diff --git a/drivers/net/ethernet/qlogic/qede/qede_filter.c b/drivers/net/ethernet/qlogic/qede/qede_filter.c
index 13955a3bd3b3..f939db5bac5f 100644
--- a/drivers/net/ethernet/qlogic/qede/qede_filter.c
+++ b/drivers/net/ethernet/qlogic/qede/qede_filter.c
@@ -1037,6 +1037,7 @@ int qede_xdp(struct net_device *dev, struct netdev_xdp *xdp)
 		return qede_xdp_set(edev, xdp->prog);
 	case XDP_QUERY_PROG:
 		xdp->prog_attached = !!edev->xdp_prog;
+		xdp->prog_id = edev->xdp_prog ? edev->xdp_prog->aux->id : 0;
 		return 0;
 	default:
 		return -EINVAL;
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 6bacbd2f0eca..5c6388fb7dd1 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1955,16 +1955,18 @@ virtio_reset_err:
 	return err;
 }
 
-static bool virtnet_xdp_query(struct net_device *dev)
+static u32 virtnet_xdp_query(struct net_device *dev)
 {
 	struct virtnet_info *vi = netdev_priv(dev);
+	const struct bpf_prog *xdp_prog;
 	int i;
 
 	for (i = 0; i < vi->max_queue_pairs; i++) {
-		if (vi->rq[i].xdp_prog)
-			return true;
+		xdp_prog = rtnl_dereference(vi->rq[i].xdp_prog);
+		if (xdp_prog)
+			return xdp_prog->aux->id;
 	}
-	return false;
+	return 0;
 }
 
 static int virtnet_xdp(struct net_device *dev, struct netdev_xdp *xdp)
@@ -1973,7 +1975,8 @@ static int virtnet_xdp(struct net_device *dev, struct netdev_xdp *xdp)
 	case XDP_SETUP_PROG:
 		return virtnet_xdp_set(dev, xdp->prog, xdp->extack);
 	case XDP_QUERY_PROG:
-		xdp->prog_attached = virtnet_xdp_query(dev);
+		xdp->prog_id = virtnet_xdp_query(dev);
+		xdp->prog_attached = !!xdp->prog_id;
 		return 0;
 	default:
 		return -EINVAL;