If hv_netvsc driver is unloaded and reloaded, the NET_DEVICE_REGISTER
handler cannot perform VF register successfully as the register call
is received before netvsc_probe is finished. This is because we
register register_netdevice_notifier() very early( even before
vmbus_driver_register()).
To fix this, we try to register each such matching VF( if it is visible
as a netdevice) at the end of netvsc_probe.
Cc: [email protected]
Fixes: 85520856466e ("hv_netvsc: Fix race of register_netdevice_notifier and VF register")
Suggested-by: Dexuan Cui <[email protected]>
Signed-off-by: Shradha Gupta <[email protected]>
---
Changes in v2:
* Fixed the subject line of patch with branch details(net)
* Added the logic to attach just the one right vf during register
* Corrected comment messages
* Renamed the context marco with a more appropriate name
* Created a new function to avoid code repetition.
---
drivers/net/hyperv/netvsc_drv.c | 82 +++++++++++++++++++++++++--------
1 file changed, 62 insertions(+), 20 deletions(-)
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 273bd8a20122..11831a1c9762 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -42,6 +42,10 @@
#define LINKCHANGE_INT (2 * HZ)
#define VF_TAKEOVER_INT (HZ / 10)
+/* Macros to define the context of vf registration */
+#define VF_REG_IN_PROBE 1
+#define VF_REG_IN_NOTIFIER 2
+
static unsigned int ring_size __ro_after_init = 128;
module_param(ring_size, uint, 0444);
MODULE_PARM_DESC(ring_size, "Ring buffer size (# of 4K pages)");
@@ -2185,7 +2189,7 @@ static rx_handler_result_t netvsc_vf_handle_frame(struct sk_buff **pskb)
}
static int netvsc_vf_join(struct net_device *vf_netdev,
- struct net_device *ndev)
+ struct net_device *ndev, int context)
{
struct net_device_context *ndev_ctx = netdev_priv(ndev);
int ret;
@@ -2208,7 +2212,11 @@ static int netvsc_vf_join(struct net_device *vf_netdev,
goto upper_link_failed;
}
- schedule_delayed_work(&ndev_ctx->vf_takeover, VF_TAKEOVER_INT);
+ /* If this registration is called from probe context vf_takeover
+ * is taken care of later in probe itself.
+ */
+ if (context == VF_REG_IN_NOTIFIER)
+ schedule_delayed_work(&ndev_ctx->vf_takeover, VF_TAKEOVER_INT);
call_netdevice_notifiers(NETDEV_JOIN, vf_netdev);
@@ -2346,7 +2354,7 @@ static int netvsc_prepare_bonding(struct net_device *vf_netdev)
return NOTIFY_DONE;
}
-static int netvsc_register_vf(struct net_device *vf_netdev)
+static int netvsc_register_vf(struct net_device *vf_netdev, int context)
{
struct net_device_context *net_device_ctx;
struct netvsc_device *netvsc_dev;
@@ -2386,7 +2394,7 @@ static int netvsc_register_vf(struct net_device *vf_netdev)
netdev_info(ndev, "VF registering: %s\n", vf_netdev->name);
- if (netvsc_vf_join(vf_netdev, ndev) != 0)
+ if (netvsc_vf_join(vf_netdev, ndev, context) != 0)
return NOTIFY_DONE;
dev_hold(vf_netdev);
@@ -2484,10 +2492,31 @@ static int netvsc_unregister_vf(struct net_device *vf_netdev)
return NOTIFY_OK;
}
+static int check_dev_is_matching_vf(struct net_device *event_ndev)
+{
+ /* Skip NetVSC interfaces */
+ if (event_ndev->netdev_ops == &device_ops)
+ return -ENODEV;
+
+ /* Avoid non-Ethernet type devices */
+ if (event_ndev->type != ARPHRD_ETHER)
+ return -ENODEV;
+
+ /* Avoid Vlan dev with same MAC registering as VF */
+ if (is_vlan_dev(event_ndev))
+ return -ENODEV;
+
+ /* Avoid Bonding master dev with same MAC registering as VF */
+ if (netif_is_bond_master(event_ndev))
+ return -ENODEV;
+
+ return 0;
+}
+
static int netvsc_probe(struct hv_device *dev,
const struct hv_vmbus_device_id *dev_id)
{
- struct net_device *net = NULL;
+ struct net_device *net = NULL, *vf_netdev;
struct net_device_context *net_device_ctx;
struct netvsc_device_info *device_info = NULL;
struct netvsc_device *nvdev;
@@ -2599,6 +2628,30 @@ static int netvsc_probe(struct hv_device *dev,
}
list_add(&net_device_ctx->list, &netvsc_dev_list);
+
+ /* When the hv_netvsc driver is unloaded and reloaded, the
+ * NET_DEVICE_REGISTER for the vf device is replayed before probe
+ * is complete. This is because register_netdevice_notifier() gets
+ * registered before vmbus_driver_register() so that callback func
+ * is set before probe and we don't miss events like NETDEV_POST_INIT
+ * So, in this section we try to register the matching vf device that
+ * is present as a netdevice, knowing that its register call is not
+ * processed in the netvsc_netdev_notifier(as probing is progress and
+ * get_netvsc_byslot fails).
+ */
+ for_each_netdev(dev_net(net), vf_netdev) {
+ ret = check_dev_is_matching_vf(vf_netdev);
+ if (ret != 0)
+ continue;
+
+ if (net != get_netvsc_byslot(vf_netdev))
+ continue;
+
+ netvsc_prepare_bonding(vf_netdev);
+ netvsc_register_vf(vf_netdev, VF_REG_IN_PROBE);
+ __netvsc_vf_setup(net, vf_netdev);
+ break;
+ }
rtnl_unlock();
netvsc_devinfo_put(device_info);
@@ -2754,28 +2807,17 @@ static int netvsc_netdev_event(struct notifier_block *this,
unsigned long event, void *ptr)
{
struct net_device *event_dev = netdev_notifier_info_to_dev(ptr);
+ int ret = 0;
- /* Skip our own events */
- if (event_dev->netdev_ops == &device_ops)
- return NOTIFY_DONE;
-
- /* Avoid non-Ethernet type devices */
- if (event_dev->type != ARPHRD_ETHER)
- return NOTIFY_DONE;
-
- /* Avoid Vlan dev with same MAC registering as VF */
- if (is_vlan_dev(event_dev))
- return NOTIFY_DONE;
-
- /* Avoid Bonding master dev with same MAC registering as VF */
- if (netif_is_bond_master(event_dev))
+ ret = check_dev_is_matching_vf(event_dev);
+ if (ret != 0)
return NOTIFY_DONE;
switch (event) {
case NETDEV_POST_INIT:
return netvsc_prepare_bonding(event_dev);
case NETDEV_REGISTER:
- return netvsc_register_vf(event_dev);
+ return netvsc_register_vf(event_dev, VF_REG_IN_NOTIFIER);
case NETDEV_UNREGISTER:
return netvsc_unregister_vf(event_dev);
case NETDEV_UP:
--
2.34.1
> -----Original Message-----
> From: Shradha Gupta <[email protected]>
> Sent: Thursday, February 1, 2024 11:41 PM
> To: KY Srinivasan <[email protected]>; Haiyang Zhang
> <[email protected]>; Wei Liu <[email protected]>; Dexuan Cui
> <[email protected]>; David S. Miller <[email protected]>; Eric
> Dumazet <[email protected]>; Jakub Kicinski <[email protected]>; Paolo
> Abeni <[email protected]>; Wojciech Drewek <[email protected]>;
> [email protected]; [email protected]; linux-
> [email protected]
> Cc: Shradha Gupta <[email protected]>; Shradha Gupta
> <[email protected]>; [email protected]
> Subject: [PATCH net,v2] hv_netvsc: Register VF in netvsc_probe if
> NET_DEVICE_REGISTER missed
>
> If hv_netvsc driver is unloaded and reloaded, the NET_DEVICE_REGISTER
> handler cannot perform VF register successfully as the register call
> is received before netvsc_probe is finished. This is because we
> register register_netdevice_notifier() very early( even before
> vmbus_driver_register()).
> To fix this, we try to register each such matching VF( if it is visible
> as a netdevice) at the end of netvsc_probe.
>
> Cc: [email protected]
> Fixes: 85520856466e ("hv_netvsc: Fix race of register_netdevice_notifier
> and VF register")
> Suggested-by: Dexuan Cui <[email protected]>
> Signed-off-by: Shradha Gupta <[email protected]>
Reviewed-by: Haiyang Zhang <[email protected]>
> From: Haiyang Zhang <[email protected]>
> Sent: Friday, February 2, 2024 9:10 AM
> [...]
> Reviewed-by: Haiyang Zhang <[email protected]>
Reviewed-by: Dexuan Cui <[email protected]>
Hello:
This patch was applied to netdev/net.git (main)
by David S. Miller <[email protected]>:
On Thu, 1 Feb 2024 20:40:38 -0800 you wrote:
> If hv_netvsc driver is unloaded and reloaded, the NET_DEVICE_REGISTER
> handler cannot perform VF register successfully as the register call
> is received before netvsc_probe is finished. This is because we
> register register_netdevice_notifier() very early( even before
> vmbus_driver_register()).
> To fix this, we try to register each such matching VF( if it is visible
> as a netdevice) at the end of netvsc_probe.
>
> [...]
Here is the summary with links:
- [net,v2] hv_netvsc: Register VF in netvsc_probe if NET_DEVICE_REGISTER missed
https://git.kernel.org/netdev/net/c/9cae43da9867
You are awesome, thank you!
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