From: Maxim Mikityanskiy <maximmi@mellanox.com>
To: "Björn Töpel" <bjorn.topel@intel.com>,
"Magnus Karlsson" <magnus.karlsson@intel.com>,
"Jeff Kirsher" <jeffrey.t.kirsher@intel.com>
Cc: "bpf@vger.kernel.org" <bpf@vger.kernel.org>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"intel-wired-lan@lists.osuosl.org"
<intel-wired-lan@lists.osuosl.org>,
"David S. Miller" <davem@davemloft.net>,
Saeed Mahameed <saeedm@mellanox.com>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Jakub Kicinski <jakub.kicinski@netronome.com>,
Jesper Dangaard Brouer <hawk@kernel.org>,
John Fastabend <john.fastabend@gmail.com>,
Jonathan Lemon <jonathan.lemon@gmail.com>,
Maxim Mikityanskiy <maximmi@mellanox.com>
Subject: [PATCH bpf 3/4] net/i40e: Fix concurrency issues between config flow and XSK
Date: Thu, 5 Dec 2019 15:51:15 +0000 [thread overview]
Message-ID: <20191205155028.28854-4-maximmi@mellanox.com> (raw)
In-Reply-To: <20191205155028.28854-1-maximmi@mellanox.com>
Use synchronize_rcu to wait until the XSK wakeup function finishes
before destroying the resources it uses:
1. i40e_down already calls synchronize_rcu. On i40e_down either
__I40E_VSI_DOWN or __I40E_CONFIG_BUSY is set. Check the latter in
i40e_xsk_async_xmit (the former is already checked there).
2. After switching the XDP program, call synchronize_rcu to let
i40e_xsk_async_xmit exit before the XDP program is freed.
3. Changing the number of channels brings the interface down (see
i40e_prep_for_reset and i40e_pf_quiesce_all_vsi).
4. Disabling UMEM sets __I40E_CONFIG_BUSY, too.
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
---
drivers/net/ethernet/intel/i40e/i40e_main.c | 7 +++++--
drivers/net/ethernet/intel/i40e/i40e_xsk.c | 4 ++++
2 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 1ccabeafa44c..afa3a99e68e1 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -6823,8 +6823,8 @@ void i40e_down(struct i40e_vsi *vsi)
for (i = 0; i < vsi->num_queue_pairs; i++) {
i40e_clean_tx_ring(vsi->tx_rings[i]);
if (i40e_enabled_xdp_vsi(vsi)) {
- /* Make sure that in-progress ndo_xdp_xmit
- * calls are completed.
+ /* Make sure that in-progress ndo_xdp_xmit and
+ * ndo_xsk_async_xmit calls are completed.
*/
synchronize_rcu();
i40e_clean_tx_ring(vsi->xdp_rings[i]);
@@ -12545,6 +12545,9 @@ static int i40e_xdp_setup(struct i40e_vsi *vsi,
i40e_prep_for_reset(pf, true);
old_prog = xchg(&vsi->xdp_prog, prog);
+ if (old_prog)
+ /* Wait until ndo_xsk_async_xmit completes. */
+ synchronize_rcu();
if (need_reset)
i40e_reset_and_rebuild(pf, true, true);
diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
index d07e1a890428..f73cd917c44f 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
@@ -787,8 +787,12 @@ int i40e_xsk_wakeup(struct net_device *dev, u32 queue_id, u32 flags)
{
struct i40e_netdev_priv *np = netdev_priv(dev);
struct i40e_vsi *vsi = np->vsi;
+ struct i40e_pf *pf = vsi->back;
struct i40e_ring *ring;
+ if (test_bit(__I40E_CONFIG_BUSY, pf->state))
+ return -ENETDOWN;
+
if (test_bit(__I40E_VSI_DOWN, vsi->state))
return -ENETDOWN;
--
2.20.1
next prev parent reply other threads:[~2019-12-05 15:51 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-05 15:51 [PATCH bpf 0/4] Fix concurrency issues between XSK wakeup and control path using RCU Maxim Mikityanskiy
2019-12-05 15:51 ` [PATCH bpf 1/4] xsk: Add rcu_read_lock around the XSK wakeup Maxim Mikityanskiy
2019-12-06 9:02 ` Björn Töpel
2019-12-05 15:51 ` [PATCH bpf 2/4] net/mlx5e: Fix concurrency issues between config flow and XSK Maxim Mikityanskiy
2019-12-06 9:03 ` Björn Töpel
2019-12-05 15:51 ` Maxim Mikityanskiy [this message]
2019-12-06 9:03 ` [PATCH bpf 3/4] net/i40e: " Björn Töpel
2019-12-10 14:26 ` Maxim Mikityanskiy
2019-12-11 10:08 ` Björn Töpel
2019-12-13 17:10 ` Maxim Mikityanskiy
2019-12-16 7:50 ` Björn Töpel
2019-12-05 15:51 ` [PATCH bpf 4/4] net/ixgbe: " Maxim Mikityanskiy
2019-12-06 9:03 ` Björn Töpel
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