[PATCH RFC 13/16] net: implement tunnel probing

Paolo Abeni posted 16 patches 5 months, 4 weeks ago
There is a newer version of this series
[PATCH RFC 13/16] net: implement tunnel probing
Posted by Paolo Abeni 5 months, 4 weeks ago
Tap devices support GSO over UDP tunnel offload. Probe for such
feature in a similar manner to other offloads.

GSO over UDP tunnel needs to be enabled in addition to  a "plain"
offload (TSO or USO).

No need to check separately for the outer header checksum offload:
the kernel is going to support both of them or none.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
---
 hw/net/virtio-net.c | 39 +++++++++++++++++++++++++++++++++++++++
 include/net/net.h   |  3 +++
 net/net.c           |  9 +++++++++
 net/tap-bsd.c       |  5 +++++
 net/tap-linux.c     | 19 +++++++++++++++++++
 net/tap-solaris.c   |  5 +++++
 net/tap-stub.c      |  5 +++++
 net/tap.c           | 11 +++++++++++
 net/tap_int.h       |  1 +
 9 files changed, 97 insertions(+)

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 193469fc27..05cf23700f 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -646,6 +646,15 @@ static int peer_has_uso(VirtIONet *n)
     return qemu_has_uso(qemu_get_queue(n->nic)->peer);
 }
 
+static int peer_has_tunnel(VirtIONet *n)
+{
+    if (!peer_has_vnet_hdr(n)) {
+        return 0;
+    }
+
+    return qemu_has_tunnel(qemu_get_queue(n->nic)->peer);
+}
+
 static void virtio_net_set_mrg_rx_bufs(VirtIONet *n, int mergeable_rx_bufs,
                                        int version_1, int hash_report)
 {
@@ -789,6 +798,15 @@ static virtio_features_t virtio_net_get_features(VirtIODevice *vdev,
         virtio_clear_feature_ex(&features, VIRTIO_NET_F_GUEST_USO4);
         virtio_clear_feature_ex(&features, VIRTIO_NET_F_GUEST_USO6);
 
+#ifdef CONFIG_INT128
+        virtio_clear_feature_ex(&features, VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO);
+        virtio_clear_feature_ex(&features, VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO);
+        virtio_clear_feature_ex(&features,
+                                VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO_CSUM);
+        virtio_clear_feature_ex(&features,
+                                VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO_CSUM);
+#endif
+
         virtio_clear_feature_ex(&features, VIRTIO_NET_F_HASH_REPORT);
     }
 
@@ -803,6 +821,17 @@ static virtio_features_t virtio_net_get_features(VirtIODevice *vdev,
         virtio_clear_feature_ex(&features, VIRTIO_NET_F_GUEST_USO6);
     }
 
+#ifdef CONFIG_INT128
+    if (!peer_has_tunnel(n)) {
+        virtio_clear_feature_ex(&features, VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO);
+        virtio_clear_feature_ex(&features, VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO);
+        virtio_clear_feature_ex(&features,
+                                VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO_CSUM);
+        virtio_clear_feature_ex(&features,
+                                VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO_CSUM);
+    }
+#endif
+
     if (!get_vhost_net(nc->peer)) {
         return features;
     }
@@ -4153,6 +4182,16 @@ static const Property virtio_net_properties[] = {
                       VIRTIO_NET_F_GUEST_USO6, true),
     DEFINE_PROP_BIT64("host_uso", VirtIONet, host_features,
                       VIRTIO_NET_F_HOST_USO, true),
+#ifdef CONFIG_INT128
+    DEFINE_PROP_BITVF("host_tunnel", VirtIONet, host_features_ex,
+                      VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO, true),
+    DEFINE_PROP_BITVF("host_tunnel_csum", VirtIONet, host_features_ex,
+                      VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO_CSUM, true),
+    DEFINE_PROP_BITVF("guest_tunnel", VirtIONet, host_features_ex,
+                      VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO, true),
+    DEFINE_PROP_BITVF("guest_tunnel_csum", VirtIONet, host_features_ex,
+                      VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO_CSUM, true),
+#endif
 };
 
 static void virtio_net_class_init(ObjectClass *klass, const void *data)
diff --git a/include/net/net.h b/include/net/net.h
index cdd5b109b0..391d983e49 100644
--- a/include/net/net.h
+++ b/include/net/net.h
@@ -55,6 +55,7 @@ typedef void (NetClientDestructor)(NetClientState *);
 typedef RxFilterInfo *(QueryRxFilter)(NetClientState *);
 typedef bool (HasUfo)(NetClientState *);
 typedef bool (HasUso)(NetClientState *);
+typedef bool (HasTunnel)(NetClientState *);
 typedef bool (HasVnetHdr)(NetClientState *);
 typedef bool (HasVnetHdrLen)(NetClientState *, int);
 typedef void (SetOffload)(NetClientState *, int, int, int, int, int, int, int);
@@ -83,6 +84,7 @@ typedef struct NetClientInfo {
     NetPoll *poll;
     HasUfo *has_ufo;
     HasUso *has_uso;
+    HasTunnel *has_tunnel;
     HasVnetHdr *has_vnet_hdr;
     HasVnetHdrLen *has_vnet_hdr_len;
     SetOffload *set_offload;
@@ -183,6 +185,7 @@ void qemu_set_info_str(NetClientState *nc,
 void qemu_format_nic_info_str(NetClientState *nc, uint8_t macaddr[6]);
 bool qemu_has_ufo(NetClientState *nc);
 bool qemu_has_uso(NetClientState *nc);
+bool qemu_has_tunnel(NetClientState *nc);
 bool qemu_has_vnet_hdr(NetClientState *nc);
 bool qemu_has_vnet_hdr_len(NetClientState *nc, int len);
 void qemu_set_offload(NetClientState *nc, int csum, int tso4, int tso6,
diff --git a/net/net.c b/net/net.c
index 39d6f28158..9c83d3b137 100644
--- a/net/net.c
+++ b/net/net.c
@@ -522,6 +522,15 @@ bool qemu_has_uso(NetClientState *nc)
     return nc->info->has_uso(nc);
 }
 
+bool qemu_has_tunnel(NetClientState *nc)
+{
+    if (!nc || !nc->info->has_tunnel) {
+        return false;
+    }
+
+    return nc->info->has_tunnel(nc);
+}
+
 bool qemu_has_vnet_hdr(NetClientState *nc)
 {
     if (!nc || !nc->info->has_vnet_hdr) {
diff --git a/net/tap-bsd.c b/net/tap-bsd.c
index b4c84441ba..3f01c8921e 100644
--- a/net/tap-bsd.c
+++ b/net/tap-bsd.c
@@ -217,6 +217,11 @@ int tap_probe_has_uso(int fd)
     return 0;
 }
 
+int tap_probe_has_tunnel(int fd)
+{
+    return 0;
+}
+
 void tap_fd_set_vnet_hdr_len(int fd, int len)
 {
 }
diff --git a/net/tap-linux.c b/net/tap-linux.c
index 22ec2f45d2..2df601551e 100644
--- a/net/tap-linux.c
+++ b/net/tap-linux.c
@@ -37,6 +37,14 @@
 
 #define PATH_NET_TUN "/dev/net/tun"
 
+#ifndef TUN_F_UDP_TUNNEL_GSO
+#define TUN_F_UDP_TUNNEL_GSO       0x080
+#endif
+
+#ifndef TUN_F_UDP_TUNNEL_GSO_CSUM
+#define TUN_F_UDP_TUNNEL_GSO_CSUM  0x100
+#endif
+
 int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
              int vnet_hdr_required, int mq_required, Error **errp)
 {
@@ -196,6 +204,17 @@ int tap_probe_has_uso(int fd)
     return 1;
 }
 
+int tap_probe_has_tunnel(int fd)
+{
+    unsigned offload;
+
+    offload = TUN_F_CSUM | TUN_F_TSO4 | TUN_F_UDP_TUNNEL_GSO;
+    if (ioctl(fd, TUNSETOFFLOAD, offload) < 0) {
+        return 0;
+    }
+    return 1;
+}
+
 void tap_fd_set_vnet_hdr_len(int fd, int len)
 {
     if (ioctl(fd, TUNSETVNETHDRSZ, &len) == -1) {
diff --git a/net/tap-solaris.c b/net/tap-solaris.c
index 51b7830bef..b1aa40d46b 100644
--- a/net/tap-solaris.c
+++ b/net/tap-solaris.c
@@ -221,6 +221,11 @@ int tap_probe_has_uso(int fd)
     return 0;
 }
 
+int tap_probe_has_tunnel(int fd)
+{
+    return 0;
+}
+
 void tap_fd_set_vnet_hdr_len(int fd, int len)
 {
 }
diff --git a/net/tap-stub.c b/net/tap-stub.c
index 38673434cb..5f57d6baac 100644
--- a/net/tap-stub.c
+++ b/net/tap-stub.c
@@ -52,6 +52,11 @@ int tap_probe_has_uso(int fd)
     return 0;
 }
 
+int tap_probe_has_tunnel(int fd)
+{
+    return 0;
+}
+
 void tap_fd_set_vnet_hdr_len(int fd, int len)
 {
 }
diff --git a/net/tap.c b/net/tap.c
index ae1c7e3983..f6e8cd5f1c 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -58,6 +58,7 @@ typedef struct TAPState {
     bool using_vnet_hdr;
     bool has_ufo;
     bool has_uso;
+    bool has_tunnel;
     bool enabled;
     VHostNetState *vhost_net;
     unsigned host_vnet_hdr_len;
@@ -223,6 +224,14 @@ static bool tap_has_uso(NetClientState *nc)
     return s->has_uso;
 }
 
+static bool tap_has_tunnel(NetClientState *nc)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+
+    assert(nc->info->type == NET_CLIENT_DRIVER_TAP);
+    return s->has_tunnel;
+}
+
 static bool tap_has_vnet_hdr(NetClientState *nc)
 {
     TAPState *s = DO_UPCAST(TAPState, nc, nc);
@@ -340,6 +349,7 @@ static NetClientInfo net_tap_info = {
     .cleanup = tap_cleanup,
     .has_ufo = tap_has_ufo,
     .has_uso = tap_has_uso,
+    .has_tunnel = tap_has_tunnel,
     .has_vnet_hdr = tap_has_vnet_hdr,
     .has_vnet_hdr_len = tap_has_vnet_hdr_len,
     .set_offload = tap_set_offload,
@@ -367,6 +377,7 @@ static TAPState *net_tap_fd_init(NetClientState *peer,
     s->using_vnet_hdr = false;
     s->has_ufo = tap_probe_has_ufo(s->fd);
     s->has_uso = tap_probe_has_uso(s->fd);
+    s->has_tunnel = tap_probe_has_tunnel(s->fd);
     s->enabled = true;
     tap_set_offload(&s->nc, 0, 0, 0, 0, 0, 0, 0);
     /*
diff --git a/net/tap_int.h b/net/tap_int.h
index 8857ff299d..2a8aa3632f 100644
--- a/net/tap_int.h
+++ b/net/tap_int.h
@@ -37,6 +37,7 @@ void tap_set_sndbuf(int fd, const NetdevTapOptions *tap, Error **errp);
 int tap_probe_vnet_hdr(int fd, Error **errp);
 int tap_probe_has_ufo(int fd);
 int tap_probe_has_uso(int fd);
+int tap_probe_has_tunnel(int fd);
 void tap_fd_set_offload(int fd, int csum, int tso4, int tso6, int ecn, int ufo,
                         int uso4, int uso6);
 void tap_fd_set_vnet_hdr_len(int fd, int len);
-- 
2.49.0
Re: [PATCH RFC 13/16] net: implement tunnel probing
Posted by Akihiko Odaki 5 months, 3 weeks ago
On 2025/05/21 20:34, Paolo Abeni wrote:
> Tap devices support GSO over UDP tunnel offload. Probe for such
> feature in a similar manner to other offloads.
> 
> GSO over UDP tunnel needs to be enabled in addition to  a "plain"
> offload (TSO or USO).
> 
> No need to check separately for the outer header checksum offload:
> the kernel is going to support both of them or none.
> 
> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
> ---
>   hw/net/virtio-net.c | 39 +++++++++++++++++++++++++++++++++++++++
>   include/net/net.h   |  3 +++
>   net/net.c           |  9 +++++++++
>   net/tap-bsd.c       |  5 +++++
>   net/tap-linux.c     | 19 +++++++++++++++++++
>   net/tap-solaris.c   |  5 +++++
>   net/tap-stub.c      |  5 +++++
>   net/tap.c           | 11 +++++++++++
>   net/tap_int.h       |  1 +
>   9 files changed, 97 insertions(+)
> 
> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> index 193469fc27..05cf23700f 100644
> --- a/hw/net/virtio-net.c
> +++ b/hw/net/virtio-net.c
> @@ -646,6 +646,15 @@ static int peer_has_uso(VirtIONet *n)
>       return qemu_has_uso(qemu_get_queue(n->nic)->peer);
>   }
>   
> +static int peer_has_tunnel(VirtIONet *n)

Let's make this return a bool. Preceding functions like 
peer_has_vnet_hdr() returns int, but I think it's better to follow the 
convention more common across the codebase.

> +{
> +    if (!peer_has_vnet_hdr(n)) {
> +        return 0;
> +    }
> +
> +    return qemu_has_tunnel(qemu_get_queue(n->nic)->peer);
> +}
> +
>   static void virtio_net_set_mrg_rx_bufs(VirtIONet *n, int mergeable_rx_bufs,
>                                          int version_1, int hash_report)
>   {
> @@ -789,6 +798,15 @@ static virtio_features_t virtio_net_get_features(VirtIODevice *vdev,
>           virtio_clear_feature_ex(&features, VIRTIO_NET_F_GUEST_USO4);
>           virtio_clear_feature_ex(&features, VIRTIO_NET_F_GUEST_USO6);
>   
> +#ifdef CONFIG_INT128
> +        virtio_clear_feature_ex(&features, VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO);
> +        virtio_clear_feature_ex(&features, VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO);
> +        virtio_clear_feature_ex(&features,
> +                                VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO_CSUM);
> +        virtio_clear_feature_ex(&features,
> +                                VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO_CSUM);
> +#endif
> +
>           virtio_clear_feature_ex(&features, VIRTIO_NET_F_HASH_REPORT);
>       }
>   
> @@ -803,6 +821,17 @@ static virtio_features_t virtio_net_get_features(VirtIODevice *vdev,
>           virtio_clear_feature_ex(&features, VIRTIO_NET_F_GUEST_USO6);
>       }
>   
> +#ifdef CONFIG_INT128
> +    if (!peer_has_tunnel(n)) {
> +        virtio_clear_feature_ex(&features, VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO);
> +        virtio_clear_feature_ex(&features, VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO);
> +        virtio_clear_feature_ex(&features,
> +                                VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO_CSUM);
> +        virtio_clear_feature_ex(&features,
> +                                VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO_CSUM);
> +    }
> +#endif
> +
>       if (!get_vhost_net(nc->peer)) {
>           return features;
>       }
> @@ -4153,6 +4182,16 @@ static const Property virtio_net_properties[] = {
>                         VIRTIO_NET_F_GUEST_USO6, true),
>       DEFINE_PROP_BIT64("host_uso", VirtIONet, host_features,
>                         VIRTIO_NET_F_HOST_USO, true),
> +#ifdef CONFIG_INT128
> +    DEFINE_PROP_BITVF("host_tunnel", VirtIONet, host_features_ex,
> +                      VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO, true),
> +    DEFINE_PROP_BITVF("host_tunnel_csum", VirtIONet, host_features_ex,
> +                      VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO_CSUM, true),
> +    DEFINE_PROP_BITVF("guest_tunnel", VirtIONet, host_features_ex,
> +                      VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO, true),
> +    DEFINE_PROP_BITVF("guest_tunnel_csum", VirtIONet, host_features_ex,
> +                      VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO_CSUM, true),
> +#endif
>   };
>   
>   static void virtio_net_class_init(ObjectClass *klass, const void *data)
> diff --git a/include/net/net.h b/include/net/net.h
> index cdd5b109b0..391d983e49 100644
> --- a/include/net/net.h
> +++ b/include/net/net.h
> @@ -55,6 +55,7 @@ typedef void (NetClientDestructor)(NetClientState *);
>   typedef RxFilterInfo *(QueryRxFilter)(NetClientState *);
>   typedef bool (HasUfo)(NetClientState *);
>   typedef bool (HasUso)(NetClientState *);
> +typedef bool (HasTunnel)(NetClientState *);
>   typedef bool (HasVnetHdr)(NetClientState *);
>   typedef bool (HasVnetHdrLen)(NetClientState *, int);
>   typedef void (SetOffload)(NetClientState *, int, int, int, int, int, int, int);
> @@ -83,6 +84,7 @@ typedef struct NetClientInfo {
>       NetPoll *poll;
>       HasUfo *has_ufo;
>       HasUso *has_uso;
> +    HasTunnel *has_tunnel;
>       HasVnetHdr *has_vnet_hdr;
>       HasVnetHdrLen *has_vnet_hdr_len;
>       SetOffload *set_offload;
> @@ -183,6 +185,7 @@ void qemu_set_info_str(NetClientState *nc,
>   void qemu_format_nic_info_str(NetClientState *nc, uint8_t macaddr[6]);
>   bool qemu_has_ufo(NetClientState *nc);
>   bool qemu_has_uso(NetClientState *nc);
> +bool qemu_has_tunnel(NetClientState *nc);
>   bool qemu_has_vnet_hdr(NetClientState *nc);
>   bool qemu_has_vnet_hdr_len(NetClientState *nc, int len);
>   void qemu_set_offload(NetClientState *nc, int csum, int tso4, int tso6,
> diff --git a/net/net.c b/net/net.c
> index 39d6f28158..9c83d3b137 100644
> --- a/net/net.c
> +++ b/net/net.c
> @@ -522,6 +522,15 @@ bool qemu_has_uso(NetClientState *nc)
>       return nc->info->has_uso(nc);
>   }
>   
> +bool qemu_has_tunnel(NetClientState *nc)
> +{
> +    if (!nc || !nc->info->has_tunnel) {
> +        return false;
> +    }
> +
> +    return nc->info->has_tunnel(nc);
> +}
> +
>   bool qemu_has_vnet_hdr(NetClientState *nc)
>   {
>       if (!nc || !nc->info->has_vnet_hdr) {
> diff --git a/net/tap-bsd.c b/net/tap-bsd.c
> index b4c84441ba..3f01c8921e 100644
> --- a/net/tap-bsd.c
> +++ b/net/tap-bsd.c
> @@ -217,6 +217,11 @@ int tap_probe_has_uso(int fd)
>       return 0;
>   }
>   
> +int tap_probe_has_tunnel(int fd)
> +{
> +    return 0;
> +}
> +
>   void tap_fd_set_vnet_hdr_len(int fd, int len)
>   {
>   }
> diff --git a/net/tap-linux.c b/net/tap-linux.c
> index 22ec2f45d2..2df601551e 100644
> --- a/net/tap-linux.c
> +++ b/net/tap-linux.c
> @@ -37,6 +37,14 @@
>   
>   #define PATH_NET_TUN "/dev/net/tun"
>   
> +#ifndef TUN_F_UDP_TUNNEL_GSO
> +#define TUN_F_UDP_TUNNEL_GSO       0x080
> +#endif
> +
> +#ifndef TUN_F_UDP_TUNNEL_GSO_CSUM
> +#define TUN_F_UDP_TUNNEL_GSO_CSUM  0x100
> +#endif
> +

These should be added to net/tap-linux.h, which contains other UAPI 
definitions.

But perhaps it may be better to refactor it to add the real header file 
using scripts/update-linux-headers.sh. Such a refactoring can be done 
before this series gets ready to merge and will make this series a bit 
smaller.

>   int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
>                int vnet_hdr_required, int mq_required, Error **errp)
>   {
> @@ -196,6 +204,17 @@ int tap_probe_has_uso(int fd)
>       return 1;
>   }
>   
> +int tap_probe_has_tunnel(int fd)
> +{
> +    unsigned offload;
> +
> +    offload = TUN_F_CSUM | TUN_F_TSO4 | TUN_F_UDP_TUNNEL_GSO;
> +    if (ioctl(fd, TUNSETOFFLOAD, offload) < 0) {
> +        return 0;
> +    }
> +    return 1;
> +}
> +
>   void tap_fd_set_vnet_hdr_len(int fd, int len)
>   {
>       if (ioctl(fd, TUNSETVNETHDRSZ, &len) == -1) {
> diff --git a/net/tap-solaris.c b/net/tap-solaris.c
> index 51b7830bef..b1aa40d46b 100644
> --- a/net/tap-solaris.c
> +++ b/net/tap-solaris.c
> @@ -221,6 +221,11 @@ int tap_probe_has_uso(int fd)
>       return 0;
>   }
>   
> +int tap_probe_has_tunnel(int fd)
> +{
> +    return 0;
> +}
> +
>   void tap_fd_set_vnet_hdr_len(int fd, int len)
>   {
>   }
> diff --git a/net/tap-stub.c b/net/tap-stub.c
> index 38673434cb..5f57d6baac 100644
> --- a/net/tap-stub.c
> +++ b/net/tap-stub.c
> @@ -52,6 +52,11 @@ int tap_probe_has_uso(int fd)
>       return 0;
>   }
>   
> +int tap_probe_has_tunnel(int fd)
> +{
> +    return 0;
> +}
> +
>   void tap_fd_set_vnet_hdr_len(int fd, int len)
>   {
>   }
> diff --git a/net/tap.c b/net/tap.c
> index ae1c7e3983..f6e8cd5f1c 100644
> --- a/net/tap.c
> +++ b/net/tap.c
> @@ -58,6 +58,7 @@ typedef struct TAPState {
>       bool using_vnet_hdr;
>       bool has_ufo;
>       bool has_uso;
> +    bool has_tunnel;
>       bool enabled;
>       VHostNetState *vhost_net;
>       unsigned host_vnet_hdr_len;
> @@ -223,6 +224,14 @@ static bool tap_has_uso(NetClientState *nc)
>       return s->has_uso;
>   }
>   
> +static bool tap_has_tunnel(NetClientState *nc)
> +{
> +    TAPState *s = DO_UPCAST(TAPState, nc, nc);
> +
> +    assert(nc->info->type == NET_CLIENT_DRIVER_TAP);
> +    return s->has_tunnel;
> +}
> +
>   static bool tap_has_vnet_hdr(NetClientState *nc)
>   {
>       TAPState *s = DO_UPCAST(TAPState, nc, nc);
> @@ -340,6 +349,7 @@ static NetClientInfo net_tap_info = {
>       .cleanup = tap_cleanup,
>       .has_ufo = tap_has_ufo,
>       .has_uso = tap_has_uso,
> +    .has_tunnel = tap_has_tunnel,
>       .has_vnet_hdr = tap_has_vnet_hdr,
>       .has_vnet_hdr_len = tap_has_vnet_hdr_len,
>       .set_offload = tap_set_offload,
> @@ -367,6 +377,7 @@ static TAPState *net_tap_fd_init(NetClientState *peer,
>       s->using_vnet_hdr = false;
>       s->has_ufo = tap_probe_has_ufo(s->fd);
>       s->has_uso = tap_probe_has_uso(s->fd);
> +    s->has_tunnel = tap_probe_has_tunnel(s->fd);
>       s->enabled = true;
>       tap_set_offload(&s->nc, 0, 0, 0, 0, 0, 0, 0);
>       /*
> diff --git a/net/tap_int.h b/net/tap_int.h
> index 8857ff299d..2a8aa3632f 100644
> --- a/net/tap_int.h
> +++ b/net/tap_int.h
> @@ -37,6 +37,7 @@ void tap_set_sndbuf(int fd, const NetdevTapOptions *tap, Error **errp);
>   int tap_probe_vnet_hdr(int fd, Error **errp);
>   int tap_probe_has_ufo(int fd);
>   int tap_probe_has_uso(int fd);
> +int tap_probe_has_tunnel(int fd);
>   void tap_fd_set_offload(int fd, int csum, int tso4, int tso6, int ecn, int ufo,
>                           int uso4, int uso6);
>   void tap_fd_set_vnet_hdr_len(int fd, int len);
Re: [PATCH RFC 13/16] net: implement tunnel probing
Posted by Paolo Abeni 5 months, 3 weeks ago
On 5/23/25 9:39 AM, Akihiko Odaki wrote:
>> diff --git a/net/tap-linux.c b/net/tap-linux.c
>> index 22ec2f45d2..2df601551e 100644
>> --- a/net/tap-linux.c
>> +++ b/net/tap-linux.c
>> @@ -37,6 +37,14 @@
>>   
>>   #define PATH_NET_TUN "/dev/net/tun"
>>   
>> +#ifndef TUN_F_UDP_TUNNEL_GSO
>> +#define TUN_F_UDP_TUNNEL_GSO       0x080
>> +#endif
>> +
>> +#ifndef TUN_F_UDP_TUNNEL_GSO_CSUM
>> +#define TUN_F_UDP_TUNNEL_GSO_CSUM  0x100
>> +#endif
>> +
> 
> These should be added to net/tap-linux.h, which contains other UAPI 
> definitions.
> 
> But perhaps it may be better to refactor it to add the real header file 
> using scripts/update-linux-headers.sh. Such a refactoring can be done 
> before this series gets ready to merge and will make this series a bit 
> smaller.

I may be missing something, but I don't think such refactor will make
this series relevantly smaller?!? Also, it looks something quite
orthogonal to me.

I propose to just move the above definition in net/tap-linux.h, if possible.

Thanks,

Paolo
Re: [PATCH RFC 13/16] net: implement tunnel probing
Posted by Akihiko Odaki 5 months, 3 weeks ago
On 2025/05/23 19:24, Paolo Abeni wrote:
> On 5/23/25 9:39 AM, Akihiko Odaki wrote:
>>> diff --git a/net/tap-linux.c b/net/tap-linux.c
>>> index 22ec2f45d2..2df601551e 100644
>>> --- a/net/tap-linux.c
>>> +++ b/net/tap-linux.c
>>> @@ -37,6 +37,14 @@
>>>    
>>>    #define PATH_NET_TUN "/dev/net/tun"
>>>    
>>> +#ifndef TUN_F_UDP_TUNNEL_GSO
>>> +#define TUN_F_UDP_TUNNEL_GSO       0x080
>>> +#endif
>>> +
>>> +#ifndef TUN_F_UDP_TUNNEL_GSO_CSUM
>>> +#define TUN_F_UDP_TUNNEL_GSO_CSUM  0x100
>>> +#endif
>>> +
>>
>> These should be added to net/tap-linux.h, which contains other UAPI
>> definitions.
>>
>> But perhaps it may be better to refactor it to add the real header file
>> using scripts/update-linux-headers.sh. Such a refactoring can be done
>> before this series gets ready to merge and will make this series a bit
>> smaller.
> 
> I may be missing something, but I don't think such refactor will make
> this series relevantly smaller?!? Also, it looks something quite
> orthogonal to me.
> 
> I propose to just move the above definition in net/tap-linux.h, if possible.

You can get rid of this 8 lines and that's all. Just moving to 
net/tap-linux.h is also fine.

Regards,
Akihiko Odaki