Revert "drivers/net: Disable UFO through virtio" in macvtap and tun

This reverts commit 88e0e0e5aa722b193c8758c8b45d041de5316924 for
the tap drivers, but leaves UFO disabled in virtio_net.

libvirt at least assumes that tap features will never be dropped
in new kernel versions, and doing so prevents migration of VMs to
the never kernel version while they are running with virtio net
devices.

Fixes: 88e0e0e5aa7a ("drivers/net: Disable UFO through virtio")
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Gbp-Pq: Topic bugfix/all
Gbp-Pq: Name revert-drivers-net-disable-ufo-through-virtio-in-macvtap-and-tun.patch

diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 880cc090dc44ecb0167682e951bedff7753aef94..1b0d1974662df8ae226c194357d856e7460816e0 100644 (file)
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -66,7 +66,7 @@ static struct cdev macvtap_cdev;
 static const struct proto_ops macvtap_socket_ops;
 
 #define TUN_OFFLOADS (NETIF_F_HW_CSUM | NETIF_F_TSO_ECN | NETIF_F_TSO | \
-                     NETIF_F_TSO6)
+                     NETIF_F_TSO6 | NETIF_F_UFO)
 #define RX_OFFLOADS (NETIF_F_GRO | NETIF_F_LRO)
 #define TAP_FEATURES (NETIF_F_GSO | NETIF_F_SG)
 
@@ -570,8 +570,6 @@ static int macvtap_skb_from_vnet_hdr(struct sk_buff *skb,
                        gso_type = SKB_GSO_TCPV6;
                        break;
                case VIRTIO_NET_HDR_GSO_UDP:
-                       pr_warn_once("macvtap: %s: using disabled UFO feature; please fix this program\n",
-                                    current->comm);
                        gso_type = SKB_GSO_UDP;
                        if (skb->protocol == htons(ETH_P_IPV6))
                                ipv6_proxy_select_ident(skb);
@@ -619,6 +617,8 @@ static void macvtap_skb_to_vnet_hdr(const struct sk_buff *skb,
                        vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
                else if (sinfo->gso_type & SKB_GSO_TCPV6)
                        vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
+               else if (sinfo->gso_type & SKB_GSO_UDP)
+                       vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;
                else
                        BUG();
                if (sinfo->gso_type & SKB_GSO_TCP_ECN)
@@ -955,6 +955,9 @@ static int set_offload(struct macvtap_queue *q, unsigned long arg)
                        if (arg & TUN_F_TSO6)
                                feature_mask |= NETIF_F_TSO6;
                }
+
+               if (arg & TUN_F_UFO)
+                       feature_mask |= NETIF_F_UFO;
        }
 
        /* tun/tap driver inverts the usage for TSO offloads, where
@@ -965,7 +968,7 @@ static int set_offload(struct macvtap_queue *q, unsigned long arg)
         * When user space turns off TSO, we turn off GSO/LRO so that
         * user-space will not receive TSO frames.
         */
-       if (feature_mask & (NETIF_F_TSO | NETIF_F_TSO6))
+       if (feature_mask & (NETIF_F_TSO | NETIF_F_TSO6 | NETIF_F_UFO))
                features |= RX_OFFLOADS;
        else
                features &= ~RX_OFFLOADS;
@@ -1066,7 +1069,7 @@ static long macvtap_ioctl(struct file *file, unsigned int cmd,
        case TUNSETOFFLOAD:
                /* let the user check for future flags */
                if (arg & ~(TUN_F_CSUM | TUN_F_TSO4 | TUN_F_TSO6 |
-                           TUN_F_TSO_ECN))
+                           TUN_F_TSO_ECN | TUN_F_UFO))
                        return -EINVAL;
 
                rtnl_lock();

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 9dd3746994a42cb73c585848876ff3e878963f24..24b9d0e1f0ad3866c241555188fe5589cce71ace 100644 (file)
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -175,7 +175,7 @@ struct tun_struct {
        struct net_device       *dev;
        netdev_features_t       set_features;
 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
-                         NETIF_F_TSO6)
+                         NETIF_F_TSO6|NETIF_F_UFO)
 
        int                     vnet_hdr_sz;
        int                     sndbuf;
@@ -1152,20 +1152,10 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
                        skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
                        break;
                case VIRTIO_NET_HDR_GSO_UDP:
-               {
-                       static bool warned;
-
-                       if (!warned) {
-                               warned = true;
-                               netdev_warn(tun->dev,
-                                           "%s: using disabled UFO feature; please fix this program\n",
-                                           current->comm);
-                       }
                        skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
                        if (skb->protocol == htons(ETH_P_IPV6))
                                ipv6_proxy_select_ident(skb);
                        break;
-               }
                default:
                        tun->dev->stats.rx_frame_errors++;
                        kfree_skb(skb);
@@ -1273,6 +1263,8 @@ static ssize_t tun_put_user(struct tun_struct *tun,
                                gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
                        else if (sinfo->gso_type & SKB_GSO_TCPV6)
                                gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
+                       else if (sinfo->gso_type & SKB_GSO_UDP)
+                               gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
                        else {
                                pr_err("unexpected GSO type: "
                                       "0x%x, gso_size %d, hdr_len %d\n",
@@ -1780,6 +1772,11 @@ static int set_offload(struct tun_struct *tun, unsigned long arg)
                                features |= NETIF_F_TSO6;
                        arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
                }
+
+               if (arg & TUN_F_UFO) {
+                       features |= NETIF_F_UFO;
+                       arg &= ~TUN_F_UFO;
+               }
        }
 
        /* This gives the user a way to test for new features in future by