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From: Jason Wang <jasowang@redhat.com>
To: rusty@rustcorp.com.au, mst@redhat.com,
	virtualization@lists.linux-foundation.org,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Jason Wang <jasowang@redhat.com>,
	Cornelia Huck <cornelia.huck@de.ibm.com>,
	Wanlong Gao <gaowanlong@cn.fujitsu.com>
Subject: [PATCH net V3] virtio-net: validate features during probe
Date: Thu, 20 Nov 2014 14:10:35 +0800	[thread overview]
Message-ID: <1416463835-7364-1-git-send-email-jasowang@redhat.com> (raw)

We currently trigger BUG when VIRTIO_NET_F_CTRL_VQ
is not set but one of features depending on it is.
That's not a friendly way to report errors to
hypervisors.
Let's check, and fail probe instead.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
Changes from V2:
- only check the features for ctrl vq (this fix the real bug)
- better error message and simplify API
---
 drivers/net/virtio_net.c | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index ec2a8b4..a6bcfce 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1673,6 +1673,40 @@ static const struct attribute_group virtio_net_mrg_rx_group = {
 };
 #endif
 
+static bool virtnet_fail_on_feature(struct virtio_device *vdev,
+				    unsigned int fbit,
+				    const char *fname, const char *dname)
+{
+	if (!virtio_has_feature(vdev, fbit))
+		return false;
+
+	dev_err(&vdev->dev, "Hypervisor bug: advertise feature %s but not %s",
+		fname, dname);
+
+	return true;
+}
+
+#define VIRTNET_FAIL_ON(vdev, fbit, dbit)			\
+	virtnet_fail_on_feature(vdev, fbit, #fbit, #dbit)
+
+static bool virtnet_validate_features(struct virtio_device *vdev)
+{
+	if (!virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) &&
+	    (VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_RX,
+			     VIRTIO_NET_F_CTRL_VQ) ||
+	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_VLAN,
+			     VIRTIO_NET_F_CTRL_VQ) ||
+	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE,
+			     VIRTIO_NET_F_TRL_VQ) ||
+	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_MQ, VIRTIO_NET_F_CTRL_VQ) ||
+	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR,
+			     VIRTIO_NET_F_CTRL_VQ))) {
+		return false;
+	}
+
+	return true;
+}
+
 static int virtnet_probe(struct virtio_device *vdev)
 {
 	int i, err;
@@ -1680,6 +1714,9 @@ static int virtnet_probe(struct virtio_device *vdev)
 	struct virtnet_info *vi;
 	u16 max_queue_pairs;
 
+	if (!virtnet_validate_features(vdev))
+		return -EINVAL;
+
 	/* Find if host supports multiqueue virtio_net device */
 	err = virtio_cread_feature(vdev, VIRTIO_NET_F_MQ,
 				   struct virtio_net_config,
-- 
1.9.1


             reply	other threads:[~2014-11-20  6:11 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-20  6:10 Jason Wang [this message]
2014-11-20  7:02 ` [PATCH net V3] virtio-net: validate features during probe Michael S. Tsirkin
2014-11-20  7:13   ` Jason Wang

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