From: Laurent Vivier <lvivier@redhat.com>
Date: Fri, 27 Jan 2023 20:44:59 +0000 (+0100)
Subject: virtio_net: disable VIRTIO_NET_F_STANDBY if VIRTIO_NET_F_MAC is not set
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=7c06458c102ee66068c03780527fcfc9b954ad91;p=users%2Fjedix%2Flinux-maple.git

virtio_net: disable VIRTIO_NET_F_STANDBY if VIRTIO_NET_F_MAC is not set

failover relies on the MAC address to pair the primary and the standby
devices:

  "[...] the hypervisor needs to enable VIRTIO_NET_F_STANDBY
   feature on the virtio-net interface and assign the same MAC address
   to both virtio-net and VF interfaces."

  Documentation/networking/net_failover.rst

This patch disables the STANDBY feature if the MAC address is not
provided by the hypervisor.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 7e1a98430190..a2fad99b06ad 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -3813,6 +3813,12 @@ static int virtnet_validate(struct virtio_device *vdev)
 			__virtio_clear_bit(vdev, VIRTIO_NET_F_MTU);
 	}
 
+	if (virtio_has_feature(vdev, VIRTIO_NET_F_STANDBY) &&
+	    !virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
+		dev_warn(&vdev->dev, "device advertises feature VIRTIO_NET_F_STANDBY but not VIRTIO_NET_F_MAC, disabling standby");
+		__virtio_clear_bit(vdev, VIRTIO_NET_F_STANDBY);
+	}
+
 	return 0;
 }