[PATCH 1/4] virtio-net: convert rx mode setting to use workqueue

From: Jason Wang
Date: Mon Dec 26 2022 - 02:50:43 EST


This patch convert rx mode setting to be done in a workqueue, this is
a must for allow to sleep when waiting for the cvq command to
response since current code is executed under addr spin lock.

Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
---
drivers/net/virtio_net.c | 66 ++++++++++++++++++++++++++++++++++++++--
1 file changed, 63 insertions(+), 3 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 86e52454b5b5..efd9dd55828b 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -260,6 +260,15 @@ struct virtnet_info {
/* Work struct for config space updates */
struct work_struct config_work;

+ /* Work struct for config rx mode */
+ struct work_struct rx_mode_work;
+
+ /* Is rx_mode_work enabled? */
+ bool rx_mode_work_enabled;
+
+ /* The lock to synchronize the access to refill_enabled */
+ spinlock_t rx_mode_lock;
+
/* Does the affinity hint is set for virtqueues? */
bool affinity_hint_set;

@@ -383,6 +392,22 @@ static void disable_delayed_refill(struct virtnet_info *vi)
spin_unlock_bh(&vi->refill_lock);
}

+static void enable_rx_mode_work(struct virtnet_info *vi)
+{
+ spin_lock_bh(&vi->rx_mode_lock);
+ vi->rx_mode_work_enabled = true;
+ spin_unlock_bh(&vi->rx_mode_lock);
+}
+
+static void disable_rx_mode_work(struct virtnet_info *vi)
+{
+ spin_lock_bh(&vi->rx_mode_lock);
+ vi->rx_mode_work_enabled = false;
+ spin_unlock_bh(&vi->rx_mode_lock);
+
+ flush_work(&vi->rx_mode_work);
+}
+
static void virtqueue_napi_schedule(struct napi_struct *napi,
struct virtqueue *vq)
{
@@ -1974,6 +1999,8 @@ static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
/* Caller should know better */
BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));

+ ASSERT_RTNL();
+
vi->ctrl->status = ~0;
vi->ctrl->hdr.class = class;
vi->ctrl->hdr.cmd = cmd;
@@ -2160,9 +2187,11 @@ static int virtnet_close(struct net_device *dev)
return 0;
}

-static void virtnet_set_rx_mode(struct net_device *dev)
+static void virtnet_rx_mode_work(struct work_struct *work)
{
- struct virtnet_info *vi = netdev_priv(dev);
+ struct virtnet_info *vi =
+ container_of(work, struct virtnet_info, rx_mode_work);
+ struct net_device *dev = vi->dev;
struct scatterlist sg[2];
struct virtio_net_ctrl_mac *mac_data;
struct netdev_hw_addr *ha;
@@ -2175,8 +2204,12 @@ static void virtnet_set_rx_mode(struct net_device *dev)
if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
return;

+ rtnl_lock();
+
+ netif_addr_lock_bh(dev);
vi->ctrl->promisc = ((dev->flags & IFF_PROMISC) != 0);
vi->ctrl->allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
+ netif_addr_unlock_bh(dev);

sg_init_one(sg, &vi->ctrl->promisc, sizeof(vi->ctrl->promisc));

@@ -2192,14 +2225,19 @@ static void virtnet_set_rx_mode(struct net_device *dev)
dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
vi->ctrl->allmulti ? "en" : "dis");

+ netif_addr_lock_bh(dev);
+
uc_count = netdev_uc_count(dev);
mc_count = netdev_mc_count(dev);
/* MAC filter - use one buffer for both lists */
buf = kzalloc(((uc_count + mc_count) * ETH_ALEN) +
(2 * sizeof(mac_data->entries)), GFP_ATOMIC);
mac_data = buf;
- if (!buf)
+ if (!buf) {
+ netif_addr_unlock_bh(dev);
+ rtnl_unlock();
return;
+ }

sg_init_table(sg, 2);

@@ -2220,6 +2258,8 @@ static void virtnet_set_rx_mode(struct net_device *dev)
netdev_for_each_mc_addr(ha, dev)
memcpy(&mac_data->macs[i++][0], ha->addr, ETH_ALEN);

+ netif_addr_unlock_bh(dev);
+
sg_set_buf(&sg[1], mac_data,
sizeof(mac_data->entries) + (mc_count * ETH_ALEN));

@@ -2227,9 +2267,21 @@ static void virtnet_set_rx_mode(struct net_device *dev)
VIRTIO_NET_CTRL_MAC_TABLE_SET, sg))
dev_warn(&dev->dev, "Failed to set MAC filter table.\n");

+ rtnl_unlock();
+
kfree(buf);
}

+static void virtnet_set_rx_mode(struct net_device *dev)
+{
+ struct virtnet_info *vi = netdev_priv(dev);
+
+ spin_lock(&vi->rx_mode_lock);
+ if (vi->rx_mode_work_enabled)
+ schedule_work(&vi->rx_mode_work);
+ spin_unlock(&vi->rx_mode_lock);
+}
+
static int virtnet_vlan_rx_add_vid(struct net_device *dev,
__be16 proto, u16 vid)
{
@@ -3000,6 +3052,7 @@ static void virtnet_freeze_down(struct virtio_device *vdev)

/* Make sure no work handler is accessing the device */
flush_work(&vi->config_work);
+ disable_rx_mode_work(vi);

netif_tx_lock_bh(vi->dev);
netif_device_detach(vi->dev);
@@ -3022,6 +3075,8 @@ static int virtnet_restore_up(struct virtio_device *vdev)
virtio_device_ready(vdev);

enable_delayed_refill(vi);
+ enable_rx_mode_work(vi);
+ virtnet_set_rx_mode(vi->dev);

if (netif_running(vi->dev)) {
err = virtnet_open(vi->dev);
@@ -3799,7 +3854,9 @@ static int virtnet_probe(struct virtio_device *vdev)
vdev->priv = vi;

INIT_WORK(&vi->config_work, virtnet_config_changed_work);
+ INIT_WORK(&vi->rx_mode_work, virtnet_rx_mode_work);
spin_lock_init(&vi->refill_lock);
+ spin_lock_init(&vi->rx_mode_lock);

if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
vi->mergeable_rx_bufs = true;
@@ -3905,6 +3962,8 @@ static int virtnet_probe(struct virtio_device *vdev)
if (vi->has_rss || vi->has_rss_hash_report)
virtnet_init_default_rss(vi);

+ enable_rx_mode_work(vi);
+
/* serialize netdev register + virtio_device_ready() with ndo_open() */
rtnl_lock();

@@ -3984,6 +4043,7 @@ static void virtnet_remove(struct virtio_device *vdev)

/* Make sure no work handler is accessing the device. */
flush_work(&vi->config_work);
+ disable_rx_mode_work(vi);

unregister_netdev(vi->dev);

--
2.25.1