netdev - [PATCH net] virtio_net: Avoid sending unnecessary vq coalescing commands

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20240729124755.35719-1-hengqi@linux.alibaba.com>
Date: Mon, 29 Jul 2024 20:47:55 +0800
From: Heng Qi <hengqi@...ux.alibaba.com>
To: netdev@...r.kernel.org,
	"Michael S. Tsirkin" <mst@...hat.com>,
	Jason Wang <jasowang@...hat.com>
Cc: virtualization@...ts.linux.dev,
	Eugenio Pérez <eperezma@...hat.com>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>,
	Paolo Abeni <pabeni@...hat.com>,
	Xuan Zhuo <xuanzhuo@...ux.alibaba.com>
Subject: [PATCH net] virtio_net: Avoid sending unnecessary vq coalescing commands

>From the virtio spec:

	The driver MUST have negotiated the VIRTIO_NET_F_VQ_NOTF_COAL
	feature when issuing commands VIRTIO_NET_CTRL_NOTF_COAL_VQ_SET
	and VIRTIO_NET_CTRL_NOTF_COAL_VQ_GET.

The driver must not send vq notification coalescing commands if
VIRTIO_NET_F_VQ_NOTF_COAL is not negotiated. This limitation of course
applies to vq resize.

Fixes: f61fe5f081cf ("virtio-net: fix the vq coalescing setting for vq resize")
Signed-off-by: Heng Qi <hengqi@...ux.alibaba.com>
---
 drivers/net/virtio_net.c | 29 +++++++++++++++++------------
 1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 0383a3e136d6..eb115e807882 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -3708,6 +3708,7 @@ static int virtnet_set_ringparam(struct net_device *dev,
 	u32 rx_pending, tx_pending;
 	struct receive_queue *rq;
 	struct send_queue *sq;
+	u32 pkts, usecs;
 	int i, err;
 
 	if (ring->rx_mini_pending || ring->rx_jumbo_pending)
@@ -3740,11 +3741,13 @@ static int virtnet_set_ringparam(struct net_device *dev,
 			 * through the VIRTIO_NET_CTRL_NOTF_COAL_TX_SET command, or, if the driver
 			 * did not set any TX coalescing parameters, to 0.
 			 */
-			err = virtnet_send_tx_ctrl_coal_vq_cmd(vi, i,
-							       vi->intr_coal_tx.max_usecs,
-							       vi->intr_coal_tx.max_packets);
-			if (err)
-				return err;
+			if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_VQ_NOTF_COAL)) {
+				usecs = vi->intr_coal_tx.max_usecs;
+				pkts = vi->intr_coal_tx.max_packets;
+				err = virtnet_send_tx_ctrl_coal_vq_cmd(vi, i, usecs, pkts);
+				if (err)
+					return err;
+			}
 		}
 
 		if (ring->rx_pending != rx_pending) {
@@ -3753,13 +3756,15 @@ static int virtnet_set_ringparam(struct net_device *dev,
 				return err;
 
 			/* The reason is same as the transmit virtqueue reset */
-			mutex_lock(&vi->rq[i].dim_lock);
-			err = virtnet_send_rx_ctrl_coal_vq_cmd(vi, i,
-							       vi->intr_coal_rx.max_usecs,
-							       vi->intr_coal_rx.max_packets);
-			mutex_unlock(&vi->rq[i].dim_lock);
-			if (err)
-				return err;
+			if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_VQ_NOTF_COAL)) {
+				usecs = vi->intr_coal_rx.max_usecs;
+				pkts = vi->intr_coal_rx.max_packets;
+				mutex_lock(&vi->rq[i].dim_lock);
+				err = virtnet_send_rx_ctrl_coal_vq_cmd(vi, i, usecs, pkts);
+				mutex_unlock(&vi->rq[i].dim_lock);
+				if (err)
+					return err;
+			}
 		}
 	}
 
-- 
2.32.0.3.g01195cf9f