[PATCH iwl-net 0/2] fix reset issues

[PATCH iwl-net 0/2] fix reset issues

[Pavan Kumar Linga]

This series fixes reset related issues, especially the case
where the idpf is running on the host and the platform running
the device control plane is rebooted. The first patch fixes the
link_ksettings and the second patch fixes the error path in
idpf_vc_core_init function.

Pavan Kumar Linga (2):
  idpf: avoid vport access in idpf_get_link_ksettings
  idpf: fix idpf_vc_core_init error path

 drivers/net/ethernet/intel/idpf/idpf.h          |  4 ++--
 drivers/net/ethernet/intel/idpf/idpf_ethtool.c  | 11 +++--------
 drivers/net/ethernet/intel/idpf/idpf_lib.c      |  5 +++--
 drivers/net/ethernet/intel/idpf/idpf_virtchnl.c |  9 +--------
 4 files changed, 9 insertions(+), 20 deletions(-)

-- 
2.43.0

[PATCH iwl-net 1/2] idpf: avoid vport access in idpf_get_link_ksettings

[Pavan Kumar Linga]

When the device control plane is removed or the platform
running device control plane is rebooted, a reset is detected
on the driver. On driver reset, it releases the resources and
waits for the reset to complete. If the reset fails, it takes
the error path and releases the vport lock. At this time if the
monitoring tools tries to access link settings, it call traces
for accessing released vport pointer.

To avoid it, move link_speed_mbps to netdev_priv structure
which removes the dependency on vport pointer and the vport lock
in idpf_get_link_ksettings. Also use netif_carrier_ok()
to check the link status and adjust the offsetof to use link_up
instead of link_speed_mbps.

Fixes: 02cbfba1add5 ("idpf: add ethtool callbacks")
Cc: stable@vger.kernel.org # 6.7+
Reviewed-by: Tarun K Singh <tarun.k.singh@intel.com>
Signed-off-by: Pavan Kumar Linga <pavan.kumar.linga@intel.com>
---
 drivers/net/ethernet/intel/idpf/idpf.h          |  4 ++--
 drivers/net/ethernet/intel/idpf/idpf_ethtool.c  | 11 +++--------
 drivers/net/ethernet/intel/idpf/idpf_lib.c      |  4 ++--
 drivers/net/ethernet/intel/idpf/idpf_virtchnl.c |  2 +-
 4 files changed, 8 insertions(+), 13 deletions(-)

diff --git a/drivers/net/ethernet/intel/idpf/idpf.h b/drivers/net/ethernet/intel/idpf/idpf.h
index 2c31ad87587a..66544faab710 100644
--- a/drivers/net/ethernet/intel/idpf/idpf.h
+++ b/drivers/net/ethernet/intel/idpf/idpf.h
@@ -141,6 +141,7 @@ enum idpf_vport_state {
  * @adapter: Adapter back pointer
  * @vport: Vport back pointer
  * @vport_id: Vport identifier
+ * @link_speed_mbps: Link speed in mbps
  * @vport_idx: Relative vport index
  * @state: See enum idpf_vport_state
  * @netstats: Packet and byte stats
@@ -150,6 +151,7 @@ struct idpf_netdev_priv {
 	struct idpf_adapter *adapter;
 	struct idpf_vport *vport;
 	u32 vport_id;
+	u32 link_speed_mbps;
 	u16 vport_idx;
 	enum idpf_vport_state state;
 	struct rtnl_link_stats64 netstats;
@@ -287,7 +289,6 @@ struct idpf_port_stats {
  * @tx_itr_profile: TX profiles for Dynamic Interrupt Moderation
  * @port_stats: per port csum, header split, and other offload stats
  * @link_up: True if link is up
- * @link_speed_mbps: Link speed in mbps
  * @sw_marker_wq: workqueue for marker packets
  */
 struct idpf_vport {
@@ -331,7 +332,6 @@ struct idpf_vport {
 	struct idpf_port_stats port_stats;
 
 	bool link_up;
-	u32 link_speed_mbps;
 
 	wait_queue_head_t sw_marker_wq;
 };
diff --git a/drivers/net/ethernet/intel/idpf/idpf_ethtool.c b/drivers/net/ethernet/intel/idpf/idpf_ethtool.c
index 3806ddd3ce4a..59b1a1a09996 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_ethtool.c
+++ b/drivers/net/ethernet/intel/idpf/idpf_ethtool.c
@@ -1296,24 +1296,19 @@ static void idpf_set_msglevel(struct net_device *netdev, u32 data)
 static int idpf_get_link_ksettings(struct net_device *netdev,
 				   struct ethtool_link_ksettings *cmd)
 {
-	struct idpf_vport *vport;
-
-	idpf_vport_ctrl_lock(netdev);
-	vport = idpf_netdev_to_vport(netdev);
+	struct idpf_netdev_priv *np = netdev_priv(netdev);
 
 	ethtool_link_ksettings_zero_link_mode(cmd, supported);
 	cmd->base.autoneg = AUTONEG_DISABLE;
 	cmd->base.port = PORT_NONE;
-	if (vport->link_up) {
+	if (netif_carrier_ok(netdev)) {
 		cmd->base.duplex = DUPLEX_FULL;
-		cmd->base.speed = vport->link_speed_mbps;
+		cmd->base.speed = np->link_speed_mbps;
 	} else {
 		cmd->base.duplex = DUPLEX_UNKNOWN;
 		cmd->base.speed = SPEED_UNKNOWN;
 	}
 
-	idpf_vport_ctrl_unlock(netdev);
-
 	return 0;
 }
 
diff --git a/drivers/net/ethernet/intel/idpf/idpf_lib.c b/drivers/net/ethernet/intel/idpf/idpf_lib.c
index 4f20343e49a9..c3848e10e7db 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_lib.c
+++ b/drivers/net/ethernet/intel/idpf/idpf_lib.c
@@ -1860,7 +1860,7 @@ int idpf_initiate_soft_reset(struct idpf_vport *vport,
 	 * mess with. Nothing below should use those variables from new_vport
 	 * and should instead always refer to them in vport if they need to.
 	 */
-	memcpy(new_vport, vport, offsetof(struct idpf_vport, link_speed_mbps));
+	memcpy(new_vport, vport, offsetof(struct idpf_vport, link_up));
 
 	/* Adjust resource parameters prior to reallocating resources */
 	switch (reset_cause) {
@@ -1906,7 +1906,7 @@ int idpf_initiate_soft_reset(struct idpf_vport *vport,
 	/* Same comment as above regarding avoiding copying the wait_queues and
 	 * mutexes applies here. We do not want to mess with those if possible.
 	 */
-	memcpy(vport, new_vport, offsetof(struct idpf_vport, link_speed_mbps));
+	memcpy(vport, new_vport, offsetof(struct idpf_vport, link_up));
 
 	if (reset_cause == IDPF_SR_Q_CHANGE)
 		idpf_vport_alloc_vec_indexes(vport);
diff --git a/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c b/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c
index 70986e12da28..3be883726b87 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c
+++ b/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c
@@ -141,7 +141,7 @@ static void idpf_handle_event_link(struct idpf_adapter *adapter,
 	}
 	np = netdev_priv(vport->netdev);
 
-	vport->link_speed_mbps = le32_to_cpu(v2e->link_speed);
+	np->link_speed_mbps = le32_to_cpu(v2e->link_speed);
 
 	if (vport->link_up == v2e->link_status)
 		return;
-- 
2.43.0

[PATCH iwl-net 2/2] idpf: fix idpf_vc_core_init error path

[Pavan Kumar Linga]

In an event where the platform running the device control plane
is rebooted, reset is detected on the driver. It releases
all the resources and waits for the reset to complete. Once the
reset is done, it tries to build the resources back. At this
time if the device control plane is not yet started, then
the driver timeouts on the virtchnl message and retries to
establish the mailbox again.

In the retry flow, mailbox is deinitialized but the mailbox
workqueue is still alive and polling for the mailbox message.
This results in accessing the released control queue leading to
null-ptr-deref. Fix it by unrolling the work queue cancellation
and mailbox deinitialization in the order which they got
initialized.

Also remove the redundant scheduling of the mailbox task in
idpf_vc_core_init.

Fixes: 4930fbf419a7 ("idpf: add core init and interrupt request")
Fixes: 34c21fa894a1 ("idpf: implement virtchnl transaction manager")
Cc: stable@vger.kernel.org # 6.9+
Reviewed-by: Tarun K Singh <tarun.k.singh@intel.com>
Signed-off-by: Pavan Kumar Linga <pavan.kumar.linga@intel.com>
---
 drivers/net/ethernet/intel/idpf/idpf_lib.c      | 1 +
 drivers/net/ethernet/intel/idpf/idpf_virtchnl.c | 7 -------
 2 files changed, 1 insertion(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/intel/idpf/idpf_lib.c b/drivers/net/ethernet/intel/idpf/idpf_lib.c
index c3848e10e7db..b4fbb99bfad2 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_lib.c
+++ b/drivers/net/ethernet/intel/idpf/idpf_lib.c
@@ -1786,6 +1786,7 @@ static int idpf_init_hard_reset(struct idpf_adapter *adapter)
 	 */
 	err = idpf_vc_core_init(adapter);
 	if (err) {
+		cancel_delayed_work_sync(&adapter->mbx_task);
 		idpf_deinit_dflt_mbx(adapter);
 		goto unlock_mutex;
 	}
diff --git a/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c b/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c
index 3be883726b87..d77d6c3805e2 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c
+++ b/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c
@@ -3017,11 +3017,6 @@ int idpf_vc_core_init(struct idpf_adapter *adapter)
 		goto err_netdev_alloc;
 	}
 
-	/* Start the mailbox task before requesting vectors. This will ensure
-	 * vector information response from mailbox is handled
-	 */
-	queue_delayed_work(adapter->mbx_wq, &adapter->mbx_task, 0);
-
 	queue_delayed_work(adapter->serv_wq, &adapter->serv_task,
 			   msecs_to_jiffies(5 * (adapter->pdev->devfn & 0x07)));
 
@@ -3046,7 +3041,6 @@ int idpf_vc_core_init(struct idpf_adapter *adapter)
 
 err_intr_req:
 	cancel_delayed_work_sync(&adapter->serv_task);
-	cancel_delayed_work_sync(&adapter->mbx_task);
 	idpf_vport_params_buf_rel(adapter);
 err_netdev_alloc:
 	kfree(adapter->vports);
@@ -3070,7 +3064,6 @@ int idpf_vc_core_init(struct idpf_adapter *adapter)
 	adapter->state = __IDPF_VER_CHECK;
 	if (adapter->vcxn_mngr)
 		idpf_vc_xn_shutdown(adapter->vcxn_mngr);
-	idpf_deinit_dflt_mbx(adapter);
 	set_bit(IDPF_HR_DRV_LOAD, adapter->flags);
 	queue_delayed_work(adapter->vc_event_wq, &adapter->vc_event_task,
 			   msecs_to_jiffies(task_delay));
-- 
2.43.0

Re: [PATCH iwl-net 2/2] idpf: fix idpf_vc_core_init error path

[Simon Horman]

On Tue, Oct 22, 2024 at 10:35:27AM -0700, Pavan Kumar Linga wrote:
> In an event where the platform running the device control plane
> is rebooted, reset is detected on the driver. It releases
> all the resources and waits for the reset to complete. Once the
> reset is done, it tries to build the resources back. At this
> time if the device control plane is not yet started, then
> the driver timeouts on the virtchnl message and retries to
> establish the mailbox again.
> 
> In the retry flow, mailbox is deinitialized but the mailbox
> workqueue is still alive and polling for the mailbox message.
> This results in accessing the released control queue leading to
> null-ptr-deref. Fix it by unrolling the work queue cancellation
> and mailbox deinitialization in the order which they got
> initialized.
> 
> Also remove the redundant scheduling of the mailbox task in
> idpf_vc_core_init.

I think it might be better to move this last change into a separate patch
targeted at iwl rather than iwl-net. It isn't a fix, right?

> 
> Fixes: 4930fbf419a7 ("idpf: add core init and interrupt request")
> Fixes: 34c21fa894a1 ("idpf: implement virtchnl transaction manager")
> Cc: stable@vger.kernel.org # 6.9+
> Reviewed-by: Tarun K Singh <tarun.k.singh@intel.com>
> Signed-off-by: Pavan Kumar Linga <pavan.kumar.linga@intel.com>

...

Re: [PATCH iwl-net 2/2] idpf: fix idpf_vc_core_init error path

[Linga, Pavan Kumar]

On 10/24/2024 7:39 AM, Simon Horman wrote:
> On Tue, Oct 22, 2024 at 10:35:27AM -0700, Pavan Kumar Linga wrote:
>> In an event where the platform running the device control plane
>> is rebooted, reset is detected on the driver. It releases
>> all the resources and waits for the reset to complete. Once the
>> reset is done, it tries to build the resources back. At this
>> time if the device control plane is not yet started, then
>> the driver timeouts on the virtchnl message and retries to
>> establish the mailbox again.
>>
>> In the retry flow, mailbox is deinitialized but the mailbox
>> workqueue is still alive and polling for the mailbox message.
>> This results in accessing the released control queue leading to
>> null-ptr-deref. Fix it by unrolling the work queue cancellation
>> and mailbox deinitialization in the order which they got
>> initialized.
>>
>> Also remove the redundant scheduling of the mailbox task in
>> idpf_vc_core_init.
> 
> I think it might be better to move this last change into a separate patch
> targeted at iwl rather than iwl-net. It isn't a fix, right?
> 

If we do not make that change in this patch, it results in calling 
cancel_delayed_work_sync twice in case of an error in idpf_vc_core_init 
(err_intr_req). Looks like there aren't any side effects of calling 
cancel_delayed_work_sync twice. I will remove the said changes from this 
patch.

Thanks,
Pavan

>>
>> Fixes: 4930fbf419a7 ("idpf: add core init and interrupt request")
>> Fixes: 34c21fa894a1 ("idpf: implement virtchnl transaction manager")
>> Cc: stable@vger.kernel.org # 6.9+
>> Reviewed-by: Tarun K Singh <tarun.k.singh@intel.com>
>> Signed-off-by: Pavan Kumar Linga <pavan.kumar.linga@intel.com>
> 
> ...