blob: 240ad39fccc158df266dce56a65f11c494800099 [file] [log] [blame]
From a436b6a090299080c9974bf851e847d3c8c8c62a Mon Sep 17 00:00:00 2001
From: Maxim Mikityanskiy <maximmi@mellanox.com>
Date: Tue, 17 Dec 2019 16:20:45 +0000
Subject: [PATCH] net/i40e: Fix concurrency issues between config flow and XSK
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commit b3873a5be757b44d51af542a50a6f2a3b6f95284 upstream.
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_wakeup (the former is already checked there).
2. After switching the XDP program, call synchronize_rcu to let
i40e_xsk_wakeup 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>
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191217162023.16011-4-maximmi@mellanox.com
[PG: note async_xmit ---> wakeup rename in mainline 9116e5e2b1ff.]
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/drivers/net/ethernet/intel/i40e/i40e.h b/drivers/net/ethernet/intel/i40e/i40e.h
index 7ce42040b851..9ef2d3f86aff 100644
--- a/drivers/net/ethernet/intel/i40e/i40e.h
+++ b/drivers/net/ethernet/intel/i40e/i40e.h
@@ -1125,7 +1125,7 @@ void i40e_set_fec_in_flags(u8 fec_cfg, u32 *flags);
static inline bool i40e_enabled_xdp_vsi(struct i40e_vsi *vsi)
{
- return !!vsi->xdp_prog;
+ return !!READ_ONCE(vsi->xdp_prog);
}
int i40e_create_queue_channel(struct i40e_vsi *vsi, struct i40e_channel *ch);
diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index f86d66139ecc..6bfd0560a7e7 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -6789,8 +6789,8 @@ 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_wakeup calls are completed.
*/
synchronize_rcu();
i40e_clean_tx_ring(vsi->xdp_rings[i]);
@@ -12015,8 +12015,12 @@ static int i40e_xdp_setup(struct i40e_vsi *vsi,
old_prog = xchg(&vsi->xdp_prog, prog);
- if (need_reset)
+ if (need_reset) {
+ if (!prog)
+ /* Wait until ndo_xsk_wakeup completes. */
+ synchronize_rcu();
i40e_reset_and_rebuild(pf, true, true);
+ }
for (i = 0; i < vsi->num_queue_pairs; i++)
WRITE_ONCE(vsi->rx_rings[i]->xdp_prog, vsi->xdp_prog);
diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
index 1b17486543ac..30e731272df4 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
@@ -772,8 +772,12 @@ int i40e_xsk_async_xmit(struct net_device *dev, u32 queue_id)
{
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;
--
2.7.4