diff mbox series

[net,v5,3/3] hv_netvsc: Mark VF as slave before exposing it to user-mode

Message ID 1700411023-14317-4-git-send-email-haiyangz@microsoft.com (mailing list archive)
State Accepted
Commit c807d6cd089d2f4951baa838081ec5ae3e2360f8
Delegated to: Netdev Maintainers
Headers show
Series hv_netvsc: fix race of netvsc, VF register, and slave bit | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/codegen success Generated files up to date
netdev/tree_selection success Clearly marked for net
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1127 this patch: 1127
netdev/cc_maintainers success CCed 10 of 10 maintainers
netdev/build_clang success Errors and warnings before: 1154 this patch: 1154
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 1154 this patch: 1154
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 60 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Haiyang Zhang Nov. 19, 2023, 4:23 p.m. UTC 
From: Long Li <longli@microsoft.com>

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: stable@vger.kernel.org
Fixes: 0c195567a8f6 ("netvsc: transparent VF management")
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
---
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(-)

Comments

Stephen Hemminger Nov. 19, 2023, 4:53 p.m. UTC | #1 
On Sun, 19 Nov 2023 08:23:43 -0800
Haiyang Zhang <haiyangz@microsoft.com> wrote:

> From: Long Li <longli@microsoft.com>
> 
> 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: stable@vger.kernel.org
> Fixes: 0c195567a8f6 ("netvsc: transparent VF management")
> Signed-off-by: Long Li <longli@microsoft.com>
> Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>

Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Dexuan Cui Nov. 20, 2023, 7:28 p.m. UTC | #2 
> From: LKML haiyangz <lkmlhyz@microsoft.com> On Behalf Of Haiyang
> Zhang
> [...]
> From: Long Li <longli@microsoft.com>
> 
> 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: stable@vger.kernel.org
> Fixes: 0c195567a8f6 ("netvsc: transparent VF management")
> Signed-off-by: Long Li <longli@microsoft.com>
> Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
> ---
> 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 <decui@microsoft.com>
diff mbox series

Patch

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: