[Intel-wired-lan] [PATCH net] ice: Fix not stopping Tx queues for VFs

[Intel-wired-lan] [PATCH net] ice: Fix not stopping Tx queues for VFs

[Brett Creeley]

When a VF is removed and/or reset its Tx queues need to be
stopped from the PF. This is done by calling the ice_dis_vf_qs()
function, which calls ice_vsi_stop_lan_tx_rings(). Currently
ice_dis_vf_qs() is protected by the VF state bit ICE_VF_STATE_QS_ENA.
Unfortunately, this is causing the Tx queues to not be disabled in some
cases and when the VF tries to re-enable/reconfigure its Tx queues over
virtchnl the op is failing. This is because a VF can be reset and/or
removed before the ICE_VF_STATE_QS_ENA bit is set, but the Tx queues
were already configured via ice_vsi_cfg_single_txq() in the
VIRTCHNL_OP_CONFIG_VSI_QUEUES op. However, the ICE_VF_STATE_QS_ENA bit
is set on a successful VIRTCHNL_OP_ENABLE_QUEUES, which will always
happen after the VIRTCHNL_OP_CONFIG_VSI_QUEUES op.

This was causing the following error message when loading the ice
driver, creating VFs, and modifying VF trust in an endless loop:

[35274.192484] ice 0000:88:00.0: Failed to set LAN Tx queue context, error: ICE_ERR_PARAM
[35274.193074] ice 0000:88:00.0: VF 0 failed opcode 6, retval: -5
[35274.193640] iavf 0000:88:01.0: PF returned error -5 (IAVF_ERR_PARAM) to our request 6

Fix this by always calling ice_dis_vf_qs() and silencing the error
message in ice_vsi_stop_tx_ring() since the calling code ignores the
return anyway. Also, all other places that call ice_vsi_stop_tx_ring()
catch the error, so this doesn't affect those flows since there was no
change to the values the function returns.

Other solutions were considered (i.e. tracking which VF queues had been
"started/configured" in VIRTCHNL_OP_CONFIG_VSI_QUEUES, but it seemed
more complicated than it was worth. This solution also brings in the
chance for other unexpected conditions due to invalid state bit checks.
So, the proposed solution seemed like the best option since there is no
harm in failing to stop Tx queues that were never started.

This issue can be seen using the following commands:

for i in {0..50}; do
        rmmod ice
        modprobe ice

        sleep 1

        echo 1 > /sys/class/net/ens785f0/device/sriov_numvfs
        echo 1 > /sys/class/net/ens785f1/device/sriov_numvfs

        ip link set ens785f1 vf 0 trust on
        ip link set ens785f0 vf 0 trust on

        sleep 2

        echo 0 > /sys/class/net/ens785f0/device/sriov_numvfs
        echo 0 > /sys/class/net/ens785f1/device/sriov_numvfs
        sleep 1
        echo 1 > /sys/class/net/ens785f0/device/sriov_numvfs
        echo 1 > /sys/class/net/ens785f1/device/sriov_numvfs

        ip link set ens785f1 vf 0 trust on
        ip link set ens785f0 vf 0 trust on
done

Fixes: 77ca27c ("ice: add support for virtchnl_queue_select.[tx|rx]_queues bitmap")
Signed-off-by: Brett Creeley <brett.creeley@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_base.c        | 2 +-
 drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c | 6 ++----
 2 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_base.c b/drivers/net/ethernet/intel/ice/ice_base.c
index c36057efc7ae..f74610442bda 100644
--- a/drivers/net/ethernet/intel/ice/ice_base.c
+++ b/drivers/net/ethernet/intel/ice/ice_base.c
@@ -909,7 +909,7 @@ ice_vsi_stop_tx_ring(struct ice_vsi *vsi, enum ice_disq_rst_src rst_src,
 	} else if (status == ICE_ERR_DOES_NOT_EXIST) {
 		dev_dbg(ice_pf_to_dev(vsi->back), "LAN Tx queues do not exist, nothing to disable\n");
 	} else if (status) {
-		dev_err(ice_pf_to_dev(vsi->back), "Failed to disable LAN Tx queues, error: %s\n",
+		dev_dbg(ice_pf_to_dev(vsi->back), "Failed to disable LAN Tx queues, error: %s\n",
 			ice_stat_str(status));
 		return -ENODEV;
 	}
diff --git a/drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c b/drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c
index 28b6013de425..e74ca81409b1 100644
--- a/drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c
+++ b/drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c
@@ -634,8 +634,7 @@ void ice_free_vfs(struct ice_pf *pf)
 
 	/* Avoid wait time by stopping all VFs at the same time */
 	ice_for_each_vf(pf, i)
-		if (test_bit(ICE_VF_STATE_QS_ENA, pf->vf[i].vf_states))
-			ice_dis_vf_qs(&pf->vf[i]);
+		ice_dis_vf_qs(&pf->vf[i]);
 
 	tmp = pf->num_alloc_vfs;
 	pf->num_qps_per_vf = 0;
@@ -1646,8 +1645,7 @@ bool ice_reset_vf(struct ice_vf *vf, bool is_vflr)
 
 	vsi = ice_get_vf_vsi(vf);
 
-	if (test_bit(ICE_VF_STATE_QS_ENA, vf->vf_states))
-		ice_dis_vf_qs(vf);
+	ice_dis_vf_qs(vf);
 
 	/* Call Disable LAN Tx queue AQ whether or not queues are
 	 * enabled. This is needed for successful completion of VFR.
-- 
2.26.3

[Intel-wired-lan] [PATCH net] ice: Fix race conditions between virtchnl handling and VF ndo ops

[Brett Creeley]

The VF can be configured via the PF's ndo ops at the same time the PF is
receiving/handling virtchnl messages. This has many issues, with
one of them being the ndo op could be actively resetting a VF (i.e.
resetting it to the default state and deleting/re-adding the VF's VSI)
while a virtchnl message is being handled. The following error was seen
because a VF ndo op was used to change a VF's trust setting while the
VIRTCHNL_OP_CONFIG_VSI_QUEUES was ongoing:

[35274.192484] ice 0000:88:00.0: Failed to set LAN Tx queue context, error: ICE_ERR_PARAM
[35274.193074] ice 0000:88:00.0: VF 0 failed opcode 6, retval: -5
[35274.193640] iavf 0000:88:01.0: PF returned error -5 (IAVF_ERR_PARAM) to our request 6

Fix this by making sure the virtchnl handling and VF ndo ops that
trigger VF resets cannot run concurrently. This is done by adding a
struct mutex cfg_lock to each VF structure. For VF ndo ops, the mutex
will be locked around the critical operations and VFR. Since the ndo ops
will trigger a VFR, the virtchnl thread will use mutex_trylock(). This
is done because if any other thread (i.e. VF ndo op) has the mutex, then
that means the current VF message being handled is no longer valid, so
just ignore it.

This issue can be seen using the following commands:

for i in {0..50}; do
        rmmod ice
        modprobe ice

        sleep 1

        echo 1 > /sys/class/net/ens785f0/device/sriov_numvfs
        echo 1 > /sys/class/net/ens785f1/device/sriov_numvfs

        ip link set ens785f1 vf 0 trust on
        ip link set ens785f0 vf 0 trust on

        sleep 2

        echo 0 > /sys/class/net/ens785f0/device/sriov_numvfs
        echo 0 > /sys/class/net/ens785f1/device/sriov_numvfs
        sleep 1
        echo 1 > /sys/class/net/ens785f0/device/sriov_numvfs
        echo 1 > /sys/class/net/ens785f1/device/sriov_numvfs

        ip link set ens785f1 vf 0 trust on
        ip link set ens785f0 vf 0 trust on
done

Fixes: 7c71086 ("ice: Add handlers for VF netdevice operations")
Signed-off-by: Brett Creeley <brett.creeley@intel.com>
---
 .../net/ethernet/intel/ice/ice_virtchnl_pf.c  | 25 +++++++++++++++++++
 .../net/ethernet/intel/ice/ice_virtchnl_pf.h  |  5 ++++
 2 files changed, 30 insertions(+)

diff --git a/drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c b/drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c
index e93430ab37f1..bf6bffbc2173 100644
--- a/drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c
+++ b/drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c
@@ -647,6 +647,8 @@ void ice_free_vfs(struct ice_pf *pf)
 			set_bit(ICE_VF_STATE_DIS, pf->vf[i].vf_states);
 			ice_free_vf_res(&pf->vf[i]);
 		}
+
+		mutex_destroy(&pf->vf[i].cfg_lock);
 	}
 
 	if (ice_sriov_free_msix_res(pf))
@@ -1894,6 +1896,8 @@ static void ice_set_dflt_settings_vfs(struct ice_pf *pf)
 		 */
 		ice_vf_ctrl_invalidate_vsi(vf);
 		ice_vf_fdir_init(vf);
+
+		mutex_init(&vf->cfg_lock);
 	}
 }
 
@@ -4078,6 +4082,8 @@ ice_set_vf_port_vlan(struct net_device *netdev, int vf_id, u16 vlan_id, u8 qos,
 		return 0;
 	}
 
+	mutex_lock(&vf->cfg_lock);
+
 	vf->port_vlan_info = vlanprio;
 
 	if (vf->port_vlan_info)
@@ -4087,6 +4093,7 @@ ice_set_vf_port_vlan(struct net_device *netdev, int vf_id, u16 vlan_id, u8 qos,
 		dev_info(dev, "Clearing port VLAN on VF %d\n", vf_id);
 
 	ice_vc_reset_vf(vf);
+	mutex_unlock(&vf->cfg_lock);
 
 	return 0;
 }
@@ -4461,6 +4468,15 @@ void ice_vc_process_vf_msg(struct ice_pf *pf, struct ice_rq_event_info *event)
 		return;
 	}
 
+	/* VF is being configured in another context that triggers a VFR, so no
+	 * need to process this message
+	 */
+	if (!mutex_trylock(&vf->cfg_lock)) {
+		dev_info(dev, "VF %u is being configured in another context that will trigger a VFR, so there is no need to handle this message\n",
+			 vf->vf_id);
+		return;
+	}
+
 	switch (v_opcode) {
 	case VIRTCHNL_OP_VERSION:
 		err = ice_vc_get_ver_msg(vf, msg);
@@ -4549,6 +4565,8 @@ void ice_vc_process_vf_msg(struct ice_pf *pf, struct ice_rq_event_info *event)
 		dev_info(dev, "PF failed to honor VF %d, opcode %d, error %d\n",
 			 vf_id, v_opcode, err);
 	}
+
+	mutex_unlock(&vf->cfg_lock);
 }
 
 /**
@@ -4664,6 +4682,8 @@ int ice_set_vf_mac(struct net_device *netdev, int vf_id, u8 *mac)
 		return -EINVAL;
 	}
 
+	mutex_lock(&vf->cfg_lock);
+
 	/* VF is notified of its new MAC via the PF's response to the
 	 * VIRTCHNL_OP_GET_VF_RESOURCES message after the VF has been reset
 	 */
@@ -4682,6 +4702,7 @@ int ice_set_vf_mac(struct net_device *netdev, int vf_id, u8 *mac)
 	}
 
 	ice_vc_reset_vf(vf);
+	mutex_unlock(&vf->cfg_lock);
 	return 0;
 }
 
@@ -4711,11 +4732,15 @@ int ice_set_vf_trust(struct net_device *netdev, int vf_id, bool trusted)
 	if (trusted == vf->trusted)
 		return 0;
 
+	mutex_lock(&vf->cfg_lock);
+
 	vf->trusted = trusted;
 	ice_vc_reset_vf(vf);
 	dev_info(ice_pf_to_dev(pf), "VF %u is now %strusted\n",
 		 vf_id, trusted ? "" : "un");
 
+	mutex_unlock(&vf->cfg_lock);
+
 	return 0;
 }
 
diff --git a/drivers/net/ethernet/intel/ice/ice_virtchnl_pf.h b/drivers/net/ethernet/intel/ice/ice_virtchnl_pf.h
index 842cb077df86..b7e24b5fd4df 100644
--- a/drivers/net/ethernet/intel/ice/ice_virtchnl_pf.h
+++ b/drivers/net/ethernet/intel/ice/ice_virtchnl_pf.h
@@ -74,6 +74,11 @@ struct ice_mdd_vf_events {
 struct ice_vf {
 	struct ice_pf *pf;
 
+	/* Used during virtchnl message handling and NDO ops against the VF
+	 * that will trigger a VFR
+	 */
+	struct mutex cfg_lock;
+
 	u16 vf_id;			/* VF ID in the PF space */
 	u16 lan_vsi_idx;		/* index into PF struct */
 	u16 ctrl_vsi_idx;
-- 
2.26.3

[Intel-wired-lan] [PATCH net] ice: Fix not stopping Tx queues for VFs

[Nguyen, Anthony L]

On Thu, 2021-09-09 at 12:27 -0700, Brett Creeley wrote:
> When a VF is removed and/or reset its Tx queues need to be
> stopped from the PF. This is done by calling the ice_dis_vf_qs()
> function, which calls ice_vsi_stop_lan_tx_rings(). Currently
> ice_dis_vf_qs() is protected by the VF state bit ICE_VF_STATE_QS_ENA.
> Unfortunately, this is causing the Tx queues to not be disabled in
> some
> cases and when the VF tries to re-enable/reconfigure its Tx queues
> over
> virtchnl the op is failing. This is because a VF can be reset and/or
> removed before the ICE_VF_STATE_QS_ENA bit is set, but the Tx queues
> were already configured via ice_vsi_cfg_single_txq() in the
> VIRTCHNL_OP_CONFIG_VSI_QUEUES op. However, the ICE_VF_STATE_QS_ENA
> bit
> is set on a successful VIRTCHNL_OP_ENABLE_QUEUES, which will always
> happen after the VIRTCHNL_OP_CONFIG_VSI_QUEUES op.
> 
> This was causing the following error message when loading the ice
> driver, creating VFs, and modifying VF trust in an endless loop:
> 
> [35274.192484] ice 0000:88:00.0: Failed to set LAN Tx queue context,
> error: ICE_ERR_PARAM
> [35274.193074] ice 0000:88:00.0: VF 0 failed opcode 6, retval: -5
> [35274.193640] iavf 0000:88:01.0: PF returned error -5
> (IAVF_ERR_PARAM) to our request 6
> 
> Fix this by always calling ice_dis_vf_qs() and silencing the error
> message in ice_vsi_stop_tx_ring() since the calling code ignores the
> return anyway. Also, all other places that call
> ice_vsi_stop_tx_ring()
> catch the error, so this doesn't affect those flows since there was
> no
> change to the values the function returns.
> 
> Other solutions were considered (i.e. tracking which VF queues had
> been
> "started/configured" in VIRTCHNL_OP_CONFIG_VSI_QUEUES, but it seemed
> more complicated than it was worth. This solution also brings in the
> chance for other unexpected conditions due to invalid state bit
> checks.
> So, the proposed solution seemed like the best option since there is
> no
> harm in failing to stop Tx queues that were never started.
> 
> This issue can be seen using the following commands:
> 
> for i in {0..50}; do
>         rmmod ice
>         modprobe ice
> 
>         sleep 1
> 
>         echo 1 > /sys/class/net/ens785f0/device/sriov_numvfs
>         echo 1 > /sys/class/net/ens785f1/device/sriov_numvfs
> 
>         ip link set ens785f1 vf 0 trust on
>         ip link set ens785f0 vf 0 trust on
> 
>         sleep 2
> 
>         echo 0 > /sys/class/net/ens785f0/device/sriov_numvfs
>         echo 0 > /sys/class/net/ens785f1/device/sriov_numvfs
>         sleep 1
>         echo 1 > /sys/class/net/ens785f0/device/sriov_numvfs
>         echo 1 > /sys/class/net/ens785f1/device/sriov_numvfs
> 
>         ip link set ens785f1 vf 0 trust on
>         ip link set ens785f0 vf 0 trust on
> done
> 
> Fixes: 77ca27c ("ice: add support for
> virtchnl_queue_select.[tx|rx]_queues bitmap")

The Fixes tag needs a little work:

Fixes tag: Fixes: 77ca27c ("ice: add support for
virtchnl_queue_select.[tx|rx]_queues bitmap")
	Has these problem(s):
		- SHA1 should be at least 12 digits long
		  Can be fixed by setting core.abbrev to 12 (or more) or (for
git v2.11
		  or later) just making sure it is not set (or set to "auto").


> Signed-off-by: Brett Creeley <brett.creeley@intel.com>