This is a note to let you know that I've just added the patch titled
hv_netvsc: Fix race between VF offering and VF association message from host
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
hv_netvsc-fix-race-between-vf-offering-and-vf-association-message-from-host.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 365e1ececb2905f94cc10a5817c5b644a32a3ae2 Mon Sep 17 00:00:00 2001
From: Gaurav Kohli <gauravkohli@xxxxxxxxxxxxxxxxxxx>
Date: Wed, 5 Oct 2022 22:52:59 -0700
Subject: hv_netvsc: Fix race between VF offering and VF association message from host
From: Gaurav Kohli <gauravkohli@xxxxxxxxxxxxxxxxxxx>
commit 365e1ececb2905f94cc10a5817c5b644a32a3ae2 upstream.
During vm boot, there might be possibility that vf registration
call comes before the vf association from host to vm.
And this might break netvsc vf path, To prevent the same block
vf registration until vf bind message comes from host.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 00d7ddba11436 ("hv_netvsc: pair VF based on serial number")
Reviewed-by: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
Signed-off-by: Gaurav Kohli <gauravkohli@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/hyperv/hyperv_net.h | 3 +++
drivers/net/hyperv/netvsc.c | 4 ++++
drivers/net/hyperv/netvsc_drv.c | 20 ++++++++++++++++++++
3 files changed, 27 insertions(+)
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -950,6 +950,9 @@ struct net_device_context {
u32 vf_alloc;
/* Serial number of the VF to team with */
u32 vf_serial;
+
+ /* completion variable to confirm vf association */
+ struct completion vf_add;
};
/* Per channel data */
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -1227,6 +1227,10 @@ static void netvsc_send_vf(struct net_de
net_device_ctx->vf_alloc = nvmsg->msg.v4_msg.vf_assoc.allocated;
net_device_ctx->vf_serial = nvmsg->msg.v4_msg.vf_assoc.serial;
+
+ if (net_device_ctx->vf_alloc)
+ complete(&net_device_ctx->vf_add);
+
netdev_info(ndev, "VF slot %u %s\n",
net_device_ctx->vf_serial,
net_device_ctx->vf_alloc ? "added" : "removed");
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -2121,6 +2121,7 @@ static struct net_device *get_netvsc_bys
{
struct device *parent = vf_netdev->dev.parent;
struct net_device_context *ndev_ctx;
+ struct net_device *ndev;
struct pci_dev *pdev;
u32 serial;
@@ -2147,6 +2148,18 @@ static struct net_device *get_netvsc_bys
return hv_get_drvdata(ndev_ctx->device_ctx);
}
+ /* Fallback path to check synthetic vf with
+ * help of mac addr
+ */
+ 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");
+ return ndev;
+ }
+ }
+
netdev_notice(vf_netdev,
"no netdev found for vf serial:%u\n", serial);
return NULL;
@@ -2216,6 +2229,11 @@ static int netvsc_vf_changed(struct net_
if (!netvsc_dev)
return NOTIFY_DONE;
+ if (vf_is_up && !net_device_ctx->vf_alloc) {
+ netdev_info(ndev, "Waiting for the VF association from host\n");
+ wait_for_completion(&net_device_ctx->vf_add);
+ }
+
netvsc_switch_datapath(ndev, vf_is_up);
netdev_info(ndev, "Data path switched %s VF: %s\n",
vf_is_up ? "to" : "from", vf_netdev->name);
@@ -2237,6 +2255,7 @@ static int netvsc_unregister_vf(struct n
netdev_info(ndev, "VF unregistering: %s\n", vf_netdev->name);
+ reinit_completion(&net_device_ctx->vf_add);
netdev_rx_handler_unregister(vf_netdev);
netdev_upper_dev_unlink(vf_netdev, ndev);
RCU_INIT_POINTER(net_device_ctx->vf_netdev, NULL);
@@ -2274,6 +2293,7 @@ static int netvsc_probe(struct hv_device
INIT_DELAYED_WORK(&net_device_ctx->dwork, netvsc_link_change);
+ init_completion(&net_device_ctx->vf_add);
spin_lock_init(&net_device_ctx->lock);
INIT_LIST_HEAD(&net_device_ctx->reconfig_events);
INIT_DELAYED_WORK(&net_device_ctx->vf_takeover, netvsc_vf_setup);
Patches currently in stable-queue which might be from gauravkohli@xxxxxxxxxxxxxxxxxxx are
queue-4.19/hv_netvsc-fix-race-between-vf-offering-and-vf-association-message-from-host.patch
