diff mbox series

[net-next,v6,3/6] virtio_net: Add a lock for the command VQ.

Message ID 20240503202445.1415560-4-danielj@nvidia.com (mailing list archive)
State Accepted
Commit 6f45ab3e0409cf7e573450c26b052871cea4e7a0
Delegated to: Netdev Maintainers
Headers show
Series Remove RTNL lock protection of CVQ | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 926 this patch: 926
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 8 of 8 maintainers
netdev/build_clang success Errors and warnings before: 937 this patch: 937
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 No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 937 this patch: 937
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 45 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
netdev/contest success net-next-2024-05-05--03-00 (tests: 1003)

Commit Message

Daniel Jurgens May 3, 2024, 8:24 p.m. UTC 
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 <danielj@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
---
 drivers/net/virtio_net.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)
diff mbox series

Patch

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,