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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Anatolii Gerasymenko <anatolii.gerasymenko@intel.com>,
        Konrad Jankowski <konrad0.jankowski@intel.com>,
        Alice Michael <alice.michael@intel.com>,
        Tony Nguyen <anthony.l.nguyen@intel.com>,
        Paolo Abeni <pabeni@redhat.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.16 186/285] ice: Do not skip not enabled queues in ice_vc_dis_qs_msg
Date:   Tue, 12 Apr 2022 08:30:43 +0200
Message-Id: <20220412062949.031574197@linuxfoundation.org>
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From: Anatolii Gerasymenko <anatolii.gerasymenko@intel.com>

[ Upstream commit 05ef6813b234db3196f083b91db3963f040b65bb ]

Disable check for queue being enabled in ice_vc_dis_qs_msg, because
there could be a case when queues were created, but were not enabled.
We still need to delete those queues.

Normal workflow for VF looks like:
Enable path:
VIRTCHNL_OP_ADD_ETH_ADDR (opcode 10)
VIRTCHNL_OP_CONFIG_VSI_QUEUES (opcode 6)
VIRTCHNL_OP_ENABLE_QUEUES (opcode 8)

Disable path:
VIRTCHNL_OP_DISABLE_QUEUES (opcode 9)
VIRTCHNL_OP_DEL_ETH_ADDR (opcode 11)

The issue appears only in stress conditions when VF is enabled and
disabled very fast.
Eventually there will be a case, when queues are created by
VIRTCHNL_OP_CONFIG_VSI_QUEUES, but are not enabled by
VIRTCHNL_OP_ENABLE_QUEUES.
In turn, these queues are not deleted by VIRTCHNL_OP_DISABLE_QUEUES,
because there is a check whether queues are enabled in
ice_vc_dis_qs_msg.

When we bring up the VF again, we will see the "Failed to set LAN Tx queue
context" error during VIRTCHNL_OP_CONFIG_VSI_QUEUES step. This
happens because old 16 queues were not deleted and VF requests to create
16 more, but ice_sched_get_free_qparent in ice_ena_vsi_txq would fail to
find a parent node for first newly requested queue (because all nodes
are allocated to 16 old queues).

Testing Hints:

Just enable and disable VF fast enough, so it would be disabled before
reaching VIRTCHNL_OP_ENABLE_QUEUES.

while true; do
        ip link set dev ens785f0v0 up
        sleep 0.065 # adjust delay value for you machine
        ip link set dev ens785f0v0 down
done

Fixes: 77ca27c41705 ("ice: add support for virtchnl_queue_select.[tx|rx]_queues bitmap")
Signed-off-by: Anatolii Gerasymenko <anatolii.gerasymenko@intel.com>
Tested-by: Konrad Jankowski <konrad0.jankowski@intel.com>
Signed-off-by: Alice Michael <alice.michael@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c b/drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c
index e17813fb71a1..91182a6bc137 100644
--- a/drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c
+++ b/drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c
@@ -3383,9 +3383,9 @@ static int ice_vc_dis_qs_msg(struct ice_vf *vf, u8 *msg)
 				goto error_param;
 			}
 
-			/* Skip queue if not enabled */
 			if (!test_bit(vf_q_id, vf->txq_ena))
-				continue;
+				dev_dbg(ice_pf_to_dev(vsi->back), "Queue %u on VSI %u is not enabled, but stopping it anyway\n",
+					vf_q_id, vsi->vsi_num);
 
 			ice_fill_txq_meta(vsi, ring, &txq_meta);
 
-- 
2.35.1