[PATCH] hv_netvsc: Mark VF as slave before exposing it to user-mode

From: longli
Date: Wed Oct 25 2023 - 18:50:59 EST


From: Long Li <longli@xxxxxxxxxxxxx>

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.

Signed-off-by: Long Li <longli@xxxxxxxxxxxxx>
---
drivers/net/hyperv/netvsc_drv.c | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index ec77fb9dcf89..045777a4971d 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);
@@ -2320,11 +2317,9 @@ static struct net_device *get_netvsc_byslot(const struct net_device *vf_netdev)
*/
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,
@@ -2332,7 +2327,7 @@ static struct net_device *get_netvsc_byslot(const struct net_device *vf_netdev)
return NULL;
}

-static int netvsc_register_vf(struct net_device *vf_netdev)
+static int netvsc_register_vf(struct net_device *vf_netdev, unsigned long event)
{
struct net_device_context *net_device_ctx;
struct netvsc_device *netvsc_dev;
@@ -2347,6 +2342,12 @@ static int netvsc_register_vf(struct net_device *vf_netdev)
if (!ndev)
return NOTIFY_DONE;

+ if (event == NETDEV_POST_INIT) {
+ /* set slave flag before open to prevent IPv6 addrconf */
+ vf_netdev->flags |= IFF_SLAVE;
+ return NOTIFY_DONE;
+ }
+
net_device_ctx = netdev_priv(ndev);
netvsc_dev = rtnl_dereference(net_device_ctx->nvdev);
if (!netvsc_dev || rtnl_dereference(net_device_ctx->vf_netdev))
@@ -2753,8 +2754,9 @@ static int netvsc_netdev_event(struct notifier_block *this,
return NOTIFY_DONE;

switch (event) {
+ case NETDEV_POST_INIT:
case NETDEV_REGISTER:
- return netvsc_register_vf(event_dev);
+ return netvsc_register_vf(event_dev, event);
case NETDEV_UNREGISTER:
return netvsc_unregister_vf(event_dev);
case NETDEV_UP:
--
2.34.1