There are some races between netvsc probe, set notifier, VF register,
and slave bit setting.
This patch set fixes them.
Haiyang Zhang (2):
hv_netvsc: fix race of netvsc and VF register_netdevice
hv_netvsc: Fix race of register_netdevice_notifier and VF register
Long Li (1):
hv_netvsc: Mark VF as slave before exposing it to user-mode
drivers/net/hyperv/netvsc_drv.c | 66 ++++++++++++++++++++++-----------
1 file changed, 45 insertions(+), 21 deletions(-)
--
2.34.1
From: Long Li <[email protected]>
When a VF is being exposed form the kernel, it should be marked as "slave"
before exposing to the user-mode. The VF is not usable without netvsc
running as master. The user-mode should never see a VF without the "slave"
flag.
This commit moves the code of setting the slave flag to the time before
VF is exposed to user-mode.
Cc: [email protected]
Fixes: 0c195567a8f6 ("netvsc: transparent VF management")
Signed-off-by: Long Li <[email protected]>
Signed-off-by: Haiyang Zhang <[email protected]>
---
v5:
Change function name netvsc_prepare_slave() to netvsc_prepare_bonding().
v4:
Add comments in get_netvsc_byslot() explaining the need to check dev_addr
v2:
Use a new function to handle NETDEV_POST_INIT.
---
drivers/net/hyperv/netvsc_drv.c | 32 +++++++++++++++++++++++---------
1 file changed, 23 insertions(+), 9 deletions(-)
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index b7dfd51f09e6..706ea5263e87 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -2206,9 +2206,6 @@ static int netvsc_vf_join(struct net_device *vf_netdev,
goto upper_link_failed;
}
- /* set slave flag before open to prevent IPv6 addrconf */
- vf_netdev->flags |= IFF_SLAVE;
-
schedule_delayed_work(&ndev_ctx->vf_takeover, VF_TAKEOVER_INT);
call_netdevice_notifiers(NETDEV_JOIN, vf_netdev);
@@ -2315,16 +2312,18 @@ static struct net_device *get_netvsc_byslot(const struct net_device *vf_netdev)
}
- /* Fallback path to check synthetic vf with
- * help of mac addr
+ /* Fallback path to check synthetic vf with help of mac addr.
+ * Because this function can be called before vf_netdev is
+ * initialized (NETDEV_POST_INIT) when its perm_addr has not been copied
+ * from dev_addr, also try to match to its dev_addr.
+ * Note: On Hyper-V and Azure, it's not possible to set a MAC address
+ * on a VF that matches to the MAC of a unrelated NETVSC device.
*/
list_for_each_entry(ndev_ctx, &netvsc_dev_list, list) {
ndev = hv_get_drvdata(ndev_ctx->device_ctx);
- if (ether_addr_equal(vf_netdev->perm_addr, ndev->perm_addr)) {
- netdev_notice(vf_netdev,
- "falling back to mac addr based matching\n");
+ if (ether_addr_equal(vf_netdev->perm_addr, ndev->perm_addr) ||
+ ether_addr_equal(vf_netdev->dev_addr, ndev->perm_addr))
return ndev;
- }
}
netdev_notice(vf_netdev,
@@ -2332,6 +2331,19 @@ static struct net_device *get_netvsc_byslot(const struct net_device *vf_netdev)
return NULL;
}
+static int netvsc_prepare_bonding(struct net_device *vf_netdev)
+{
+ struct net_device *ndev;
+
+ ndev = get_netvsc_byslot(vf_netdev);
+ if (!ndev)
+ return NOTIFY_DONE;
+
+ /* set slave flag before open to prevent IPv6 addrconf */
+ vf_netdev->flags |= IFF_SLAVE;
+ return NOTIFY_DONE;
+}
+
static int netvsc_register_vf(struct net_device *vf_netdev)
{
struct net_device_context *net_device_ctx;
@@ -2758,6 +2770,8 @@ static int netvsc_netdev_event(struct notifier_block *this,
return NOTIFY_DONE;
switch (event) {
+ case NETDEV_POST_INIT:
+ return netvsc_prepare_bonding(event_dev);
case NETDEV_REGISTER:
return netvsc_register_vf(event_dev);
case NETDEV_UNREGISTER:
--
2.34.1
On Sun, 19 Nov 2023 08:23:43 -0800
Haiyang Zhang <[email protected]> wrote:
> From: Long Li <[email protected]>
>
> When a VF is being exposed form the kernel, it should be marked as "slave"
> before exposing to the user-mode. The VF is not usable without netvsc
> running as master. The user-mode should never see a VF without the "slave"
> flag.
>
> This commit moves the code of setting the slave flag to the time before
> VF is exposed to user-mode.
>
> Cc: [email protected]
> Fixes: 0c195567a8f6 ("netvsc: transparent VF management")
> Signed-off-by: Long Li <[email protected]>
> Signed-off-by: Haiyang Zhang <[email protected]>
Acked-by: Stephen Hemminger <[email protected]>
> From: LKML haiyangz <[email protected]> On Behalf Of Haiyang
> Zhang
> [...]
> From: Long Li <[email protected]>
>
> When a VF is being exposed form the kernel, it should be marked as
> "slave"
> before exposing to the user-mode. The VF is not usable without netvsc
> running as master. The user-mode should never see a VF without the
> "slave"
> flag.
>
> This commit moves the code of setting the slave flag to the time before
> VF is exposed to user-mode.
>
> Cc: [email protected]
> Fixes: 0c195567a8f6 ("netvsc: transparent VF management")
> Signed-off-by: Long Li <[email protected]>
> Signed-off-by: Haiyang Zhang <[email protected]>
> ---
> v5:
> Change function name netvsc_prepare_slave() to
> netvsc_prepare_bonding().
> v4:
> Add comments in get_netvsc_byslot() explaining the need to check
> dev_addr
> v2:
> Use a new function to handle NETDEV_POST_INIT.
Acked-by: Dexuan Cui <[email protected]>
Hello:
This series was applied to netdev/net.git (main)
by Paolo Abeni <[email protected]>:
On Sun, 19 Nov 2023 08:23:40 -0800 you wrote:
> There are some races between netvsc probe, set notifier, VF register,
> and slave bit setting.
> This patch set fixes them.
>
> Haiyang Zhang (2):
> hv_netvsc: fix race of netvsc and VF register_netdevice
> hv_netvsc: Fix race of register_netdevice_notifier and VF register
>
> [...]
Here is the summary with links:
- [net,v5,1/3] hv_netvsc: fix race of netvsc and VF register_netdevice
https://git.kernel.org/netdev/net/c/d30fb712e529
- [net,v5,2/3] hv_netvsc: Fix race of register_netdevice_notifier and VF register
https://git.kernel.org/netdev/net/c/85520856466e
- [net,v5,3/3] hv_netvsc: Mark VF as slave before exposing it to user-mode
https://git.kernel.org/netdev/net/c/c807d6cd089d
You are awesome, thank you!
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