[PATCH net-next v6 3/6] virtio_net: Add a lock for the command VQ.
From: Daniel Jurgens <hidden>
Date: 2024-05-03 20:25:11
Also in:
virtualization
Subsystem:
networking drivers, the rest, virtio net driver · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, "Michael S. Tsirkin", Jason Wang
The command VQ will no longer be protected by the RTNL lock. Use a mutex to protect the control buffer header and the VQ. Signed-off-by: Daniel Jurgens <redacted> Reviewed-by: Jiri Pirko <redacted> --- drivers/net/virtio_net.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 451879d570a8..d7bad74a395f 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c@@ -411,6 +411,9 @@ struct virtnet_info { /* Has control virtqueue */ bool has_cvq; + /* Lock to protect the control VQ */ + struct mutex cvq_lock; + /* Host can handle any s/g split between our header and packet data */ bool any_header_sg;
@@ -2675,6 +2678,7 @@ static bool virtnet_send_command_reply(struct virtnet_info *vi, u8 class, u8 cmd /* Caller should know better */ BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)); + mutex_lock(&vi->cvq_lock); vi->ctrl->status = ~0; vi->ctrl->hdr.class = class; vi->ctrl->hdr.cmd = cmd;
@@ -2697,11 +2701,12 @@ static bool virtnet_send_command_reply(struct virtnet_info *vi, u8 class, u8 cmd if (ret < 0) { dev_warn(&vi->vdev->dev, "Failed to add sgs for command vq: %d\n.", ret); + mutex_unlock(&vi->cvq_lock); return false; } if (unlikely(!virtqueue_kick(vi->cvq))) - return vi->ctrl->status == VIRTIO_NET_OK; + goto unlock; /* Spin for a response, the kick causes an ioport write, trapping * into the hypervisor, so the request should be handled immediately.
@@ -2712,6 +2717,8 @@ static bool virtnet_send_command_reply(struct virtnet_info *vi, u8 class, u8 cmd cpu_relax(); } +unlock: + mutex_unlock(&vi->cvq_lock); return vi->ctrl->status == VIRTIO_NET_OK; }
@@ -5736,6 +5743,8 @@ static int virtnet_probe(struct virtio_device *vdev) if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) vi->has_cvq = true; + mutex_init(&vi->cvq_lock); + if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) { mtu = virtio_cread16(vdev, offsetof(struct virtio_net_config,
--
2.44.0