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>
---
v2 -> v3:
- use bool type for tap_probe_has_tunnel()
- rebased on top of 2deec9ab7d ("virtio-net: Move
virtio_net_get_features() down")
- _array -> _ex
v1 -> v2:
- peer_has_tunnel return a bool
- move TUN_F definition in net/tun-linux.h
---
hw/net/virtio-net.c | 37 +++++++++++++++++++++++++++++++++++++
include/net/net.h | 3 +++
net/net.c | 9 +++++++++
net/tap-bsd.c | 5 +++++
net/tap-linux.c | 11 +++++++++++
net/tap-linux.h | 9 +++++++++
net/tap-solaris.c | 5 +++++
net/tap-stub.c | 5 +++++
net/tap.c | 11 +++++++++++
net/tap_int.h | 1 +
10 files changed, 96 insertions(+)
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 53413ec4d5..70c85f7f77 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -649,6 +649,15 @@ static int peer_has_uso(VirtIONet *n)
return qemu_has_uso(qemu_get_queue(n->nic)->peer);
}
+static bool peer_has_tunnel(VirtIONet *n)
+{
+ if (!peer_has_vnet_hdr(n)) {
+ return false;
+ }
+
+ 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)
{
@@ -3070,6 +3079,13 @@ static void virtio_net_get_features(VirtIODevice *vdev, uint64_t *features,
virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_USO4);
virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_USO6);
+ 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);
+
virtio_clear_feature_ex(features, VIRTIO_NET_F_HASH_REPORT);
}
@@ -3083,6 +3099,15 @@ static void virtio_net_get_features(VirtIODevice *vdev, uint64_t *features,
virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_USO6);
}
+ 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);
+ }
+
if (!get_vhost_net(nc->peer)) {
if (!use_own_hash) {
virtio_clear_feature_ex(features, VIRTIO_NET_F_HASH_REPORT);
@@ -4137,6 +4162,10 @@ static const VMStateDescription vmstate_virtio_net = {
.dev_unplug_pending = dev_unplug_pending,
};
+#define DEFINE_PROP_FEATURE(_name, _state, _field, _bit, _defval) \
+ DEFINE_PROP_BIT64(_name, _state, _field[VIRTIO_DWORD(_bit)], \
+ (_bit) % 64, _defval)
+
static const Property virtio_net_properties[] = {
DEFINE_PROP_BIT64("csum", VirtIONet, host_features,
VIRTIO_NET_F_CSUM, true),
@@ -4245,6 +4274,14 @@ static const Property virtio_net_properties[] = {
rss_data.specified_hash_types,
VIRTIO_NET_HASH_REPORT_UDPv6_EX - 1,
ON_OFF_AUTO_AUTO),
+ DEFINE_PROP_FEATURE("host_tunnel", VirtIONet, host_features_ex,
+ VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO, true),
+ DEFINE_PROP_FEATURE("host_tunnel_csum", VirtIONet, host_features_ex,
+ VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO_CSUM, true),
+ DEFINE_PROP_FEATURE("guest_tunnel", VirtIONet, host_features_ex,
+ VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO, true),
+ DEFINE_PROP_FEATURE("guest_tunnel_csum", VirtIONet, host_features_ex,
+ VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO_CSUM, true),
};
static void virtio_net_class_init(ObjectClass *klass, const void *data)
diff --git a/include/net/net.h b/include/net/net.h
index 48ba333d02..9a9084690d 100644
--- a/include/net/net.h
+++ b/include/net/net.h
@@ -65,6 +65,7 @@ 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 *, const NetOffloads *);
@@ -95,6 +96,7 @@ 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;
@@ -197,6 +199,7 @@ 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, const NetOffloads *ol);
diff --git a/net/net.c b/net/net.c
index 63872b6855..9536184a0c 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 86b6edee94..751d4c819c 100644
--- a/net/tap-bsd.c
+++ b/net/tap-bsd.c
@@ -217,6 +217,11 @@ int tap_probe_has_uso(int fd)
return 0;
}
+bool tap_probe_has_tunnel(int fd)
+{
+ return false;
+}
+
void tap_fd_set_vnet_hdr_len(int fd, int len)
{
}
diff --git a/net/tap-linux.c b/net/tap-linux.c
index a1c58f74f5..e2628be798 100644
--- a/net/tap-linux.c
+++ b/net/tap-linux.c
@@ -196,6 +196,17 @@ int tap_probe_has_uso(int fd)
return 1;
}
+bool 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 false;
+ }
+ return true;
+}
+
void tap_fd_set_vnet_hdr_len(int fd, int len)
{
if (ioctl(fd, TUNSETVNETHDRSZ, &len) == -1) {
diff --git a/net/tap-linux.h b/net/tap-linux.h
index 9a58cecb7f..8cd6b5874b 100644
--- a/net/tap-linux.h
+++ b/net/tap-linux.h
@@ -53,4 +53,13 @@
#define TUN_F_USO4 0x20 /* I can handle USO for IPv4 packets */
#define TUN_F_USO6 0x40 /* I can handle USO for IPv6 packets */
+/* I can handle TSO/USO for UDP tunneled packets */
+#define TUN_F_UDP_TUNNEL_GSO 0x080
+
+/*
+ * I can handle TSO/USO for UDP tunneled packets requiring csum offload for
+ * the outer header
+ */
+#define TUN_F_UDP_TUNNEL_GSO_CSUM 0x100
+
#endif /* QEMU_TAP_LINUX_H */
diff --git a/net/tap-solaris.c b/net/tap-solaris.c
index 833c066bee..ac1ae25761 100644
--- a/net/tap-solaris.c
+++ b/net/tap-solaris.c
@@ -222,6 +222,11 @@ int tap_probe_has_uso(int fd)
return 0;
}
+bool tap_probe_has_tunnel(int fd)
+{
+ return false;
+}
+
void tap_fd_set_vnet_hdr_len(int fd, int len)
{
}
diff --git a/net/tap-stub.c b/net/tap-stub.c
index 67d14ad4d5..f7a5e0c163 100644
--- a/net/tap-stub.c
+++ b/net/tap-stub.c
@@ -52,6 +52,11 @@ int tap_probe_has_uso(int fd)
return 0;
}
+bool tap_probe_has_tunnel(int fd)
+{
+ return false;
+}
+
void tap_fd_set_vnet_hdr_len(int fd, int len)
{
}
diff --git a/net/tap.c b/net/tap.c
index b49db19f83..23c6c118e7 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -76,6 +76,7 @@ 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;
@@ -241,6 +242,14 @@ 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);
@@ -369,6 +378,7 @@ 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,
@@ -398,6 +408,7 @@ 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, &ol);
/*
diff --git a/net/tap_int.h b/net/tap_int.h
index f8bbe1cb0c..b76a05044b 100644
--- a/net/tap_int.h
+++ b/net/tap_int.h
@@ -38,6 +38,7 @@ 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);
+bool tap_probe_has_tunnel(int fd);
void tap_fd_set_offload(int fd, const NetOffloads *ol);
void tap_fd_set_vnet_hdr_len(int fd, int len);
int tap_fd_set_vnet_le(int fd, int vnet_is_le);
--
2.50.0On 2025/07/18 17:52, 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>
> ---
> v2 -> v3:
> - use bool type for tap_probe_has_tunnel()
> - rebased on top of 2deec9ab7d ("virtio-net: Move
> virtio_net_get_features() down")
> - _array -> _ex
>
> v1 -> v2:
> - peer_has_tunnel return a bool
> - move TUN_F definition in net/tun-linux.h
> ---
> hw/net/virtio-net.c | 37 +++++++++++++++++++++++++++++++++++++
> include/net/net.h | 3 +++
> net/net.c | 9 +++++++++
> net/tap-bsd.c | 5 +++++
> net/tap-linux.c | 11 +++++++++++
> net/tap-linux.h | 9 +++++++++
> net/tap-solaris.c | 5 +++++
> net/tap-stub.c | 5 +++++
> net/tap.c | 11 +++++++++++
> net/tap_int.h | 1 +
> 10 files changed, 96 insertions(+)
>
> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> index 53413ec4d5..70c85f7f77 100644
> --- a/hw/net/virtio-net.c
> +++ b/hw/net/virtio-net.c
> @@ -649,6 +649,15 @@ static int peer_has_uso(VirtIONet *n)
> return qemu_has_uso(qemu_get_queue(n->nic)->peer);
> }
>
> +static bool peer_has_tunnel(VirtIONet *n)
> +{
> + if (!peer_has_vnet_hdr(n)) {
> + return false;
> + }
> +
> + 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)
> {
> @@ -3070,6 +3079,13 @@ static void virtio_net_get_features(VirtIODevice *vdev, uint64_t *features,
> virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_USO4);
> virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_USO6);
>
> + 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);
> +
> virtio_clear_feature_ex(features, VIRTIO_NET_F_HASH_REPORT);
> }
>
> @@ -3083,6 +3099,15 @@ static void virtio_net_get_features(VirtIODevice *vdev, uint64_t *features,
> virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_USO6);
> }
>
> + 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);
> + }
> +
> if (!get_vhost_net(nc->peer)) {
> if (!use_own_hash) {
> virtio_clear_feature_ex(features, VIRTIO_NET_F_HASH_REPORT);
> @@ -4137,6 +4162,10 @@ static const VMStateDescription vmstate_virtio_net = {
> .dev_unplug_pending = dev_unplug_pending,
> };
>
> +#define DEFINE_PROP_FEATURE(_name, _state, _field, _bit, _defval) \
> + DEFINE_PROP_BIT64(_name, _state, _field[VIRTIO_DWORD(_bit)], \
> + (_bit) % 64, _defval)
I suggest moving this to: include/hw/virtio/virtio-features.h
> +
> static const Property virtio_net_properties[] = {
> DEFINE_PROP_BIT64("csum", VirtIONet, host_features,
> VIRTIO_NET_F_CSUM, true),
> @@ -4245,6 +4274,14 @@ static const Property virtio_net_properties[] = {
> rss_data.specified_hash_types,
> VIRTIO_NET_HASH_REPORT_UDPv6_EX - 1,
> ON_OFF_AUTO_AUTO),
> + DEFINE_PROP_FEATURE("host_tunnel", VirtIONet, host_features_ex,
> + VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO, true),
> + DEFINE_PROP_FEATURE("host_tunnel_csum", VirtIONet, host_features_ex,
> + VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO_CSUM, true),
> + DEFINE_PROP_FEATURE("guest_tunnel", VirtIONet, host_features_ex,
> + VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO, true),
> + DEFINE_PROP_FEATURE("guest_tunnel_csum", VirtIONet, host_features_ex,
> + VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO_CSUM, true),
> };
>
> static void virtio_net_class_init(ObjectClass *klass, const void *data)
> diff --git a/include/net/net.h b/include/net/net.h
> index 48ba333d02..9a9084690d 100644
> --- a/include/net/net.h
> +++ b/include/net/net.h
> @@ -65,6 +65,7 @@ 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 *, const NetOffloads *);
> @@ -95,6 +96,7 @@ 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;
> @@ -197,6 +199,7 @@ 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, const NetOffloads *ol);
> diff --git a/net/net.c b/net/net.c
> index 63872b6855..9536184a0c 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 86b6edee94..751d4c819c 100644
> --- a/net/tap-bsd.c
> +++ b/net/tap-bsd.c
> @@ -217,6 +217,11 @@ int tap_probe_has_uso(int fd)
> return 0;
> }
>
> +bool tap_probe_has_tunnel(int fd)
> +{
> + return false;
> +}
> +
> void tap_fd_set_vnet_hdr_len(int fd, int len)
> {
> }
> diff --git a/net/tap-linux.c b/net/tap-linux.c
> index a1c58f74f5..e2628be798 100644
> --- a/net/tap-linux.c
> +++ b/net/tap-linux.c
> @@ -196,6 +196,17 @@ int tap_probe_has_uso(int fd)
> return 1;
> }
>
> +bool 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 false;
> + }
> + return true;
> +}
> +
> void tap_fd_set_vnet_hdr_len(int fd, int len)
> {
> if (ioctl(fd, TUNSETVNETHDRSZ, &len) == -1) {
> diff --git a/net/tap-linux.h b/net/tap-linux.h
> index 9a58cecb7f..8cd6b5874b 100644
> --- a/net/tap-linux.h
> +++ b/net/tap-linux.h
> @@ -53,4 +53,13 @@
> #define TUN_F_USO4 0x20 /* I can handle USO for IPv4 packets */
> #define TUN_F_USO6 0x40 /* I can handle USO for IPv6 packets */
>
> +/* I can handle TSO/USO for UDP tunneled packets */
> +#define TUN_F_UDP_TUNNEL_GSO 0x080
> +
> +/*
> + * I can handle TSO/USO for UDP tunneled packets requiring csum offload for
> + * the outer header
> + */
> +#define TUN_F_UDP_TUNNEL_GSO_CSUM 0x100
> +
> #endif /* QEMU_TAP_LINUX_H */
> diff --git a/net/tap-solaris.c b/net/tap-solaris.c
> index 833c066bee..ac1ae25761 100644
> --- a/net/tap-solaris.c
> +++ b/net/tap-solaris.c
> @@ -222,6 +222,11 @@ int tap_probe_has_uso(int fd)
> return 0;
> }
>
> +bool tap_probe_has_tunnel(int fd)
> +{
> + return false;
> +}
> +
> void tap_fd_set_vnet_hdr_len(int fd, int len)
> {
> }
> diff --git a/net/tap-stub.c b/net/tap-stub.c
> index 67d14ad4d5..f7a5e0c163 100644
> --- a/net/tap-stub.c
> +++ b/net/tap-stub.c
> @@ -52,6 +52,11 @@ int tap_probe_has_uso(int fd)
> return 0;
> }
>
> +bool tap_probe_has_tunnel(int fd)
> +{
> + return false;
> +}
> +
> void tap_fd_set_vnet_hdr_len(int fd, int len)
> {
> }
> diff --git a/net/tap.c b/net/tap.c
> index b49db19f83..23c6c118e7 100644
> --- a/net/tap.c
> +++ b/net/tap.c
> @@ -76,6 +76,7 @@ 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;
> @@ -241,6 +242,14 @@ 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);
> @@ -369,6 +378,7 @@ 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,
> @@ -398,6 +408,7 @@ 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, &ol);
> /*
> diff --git a/net/tap_int.h b/net/tap_int.h
> index f8bbe1cb0c..b76a05044b 100644
> --- a/net/tap_int.h
> +++ b/net/tap_int.h
> @@ -38,6 +38,7 @@ 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);
> +bool tap_probe_has_tunnel(int fd);
> void tap_fd_set_offload(int fd, const NetOffloads *ol);
> void tap_fd_set_vnet_hdr_len(int fd, int len);
> int tap_fd_set_vnet_le(int fd, int vnet_is_le);
On Fri, Jul 18, 2025 at 4:54 PM Paolo Abeni <pabeni@redhat.com> 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>
> ---
> v2 -> v3:
> - use bool type for tap_probe_has_tunnel()
> - rebased on top of 2deec9ab7d ("virtio-net: Move
> virtio_net_get_features() down")
> - _array -> _ex
>
> v1 -> v2:
> - peer_has_tunnel return a bool
> - move TUN_F definition in net/tun-linux.h
> ---
> hw/net/virtio-net.c | 37 +++++++++++++++++++++++++++++++++++++
> include/net/net.h | 3 +++
> net/net.c | 9 +++++++++
> net/tap-bsd.c | 5 +++++
> net/tap-linux.c | 11 +++++++++++
> net/tap-linux.h | 9 +++++++++
> net/tap-solaris.c | 5 +++++
> net/tap-stub.c | 5 +++++
> net/tap.c | 11 +++++++++++
> net/tap_int.h | 1 +
> 10 files changed, 96 insertions(+)
>
> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> index 53413ec4d5..70c85f7f77 100644
> --- a/hw/net/virtio-net.c
> +++ b/hw/net/virtio-net.c
> @@ -649,6 +649,15 @@ static int peer_has_uso(VirtIONet *n)
> return qemu_has_uso(qemu_get_queue(n->nic)->peer);
> }
>
> +static bool peer_has_tunnel(VirtIONet *n)
Nit: it looks better to use peer_has_udp_gso_tunnel().
> +{
> + if (!peer_has_vnet_hdr(n)) {
> + return false;
> + }
> +
> + 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)
> {
> @@ -3070,6 +3079,13 @@ static void virtio_net_get_features(VirtIODevice *vdev, uint64_t *features,
> virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_USO4);
> virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_USO6);
>
> + 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);
> +
> virtio_clear_feature_ex(features, VIRTIO_NET_F_HASH_REPORT);
> }
>
> @@ -3083,6 +3099,15 @@ static void virtio_net_get_features(VirtIODevice *vdev, uint64_t *features,
> virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_USO6);
> }
>
> + 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);
> + }
> +
> if (!get_vhost_net(nc->peer)) {
> if (!use_own_hash) {
> virtio_clear_feature_ex(features, VIRTIO_NET_F_HASH_REPORT);
> @@ -4137,6 +4162,10 @@ static const VMStateDescription vmstate_virtio_net = {
> .dev_unplug_pending = dev_unplug_pending,
> };
>
> +#define DEFINE_PROP_FEATURE(_name, _state, _field, _bit, _defval) \
> + DEFINE_PROP_BIT64(_name, _state, _field[VIRTIO_DWORD(_bit)], \
> + (_bit) % 64, _defval)
> +
> static const Property virtio_net_properties[] = {
> DEFINE_PROP_BIT64("csum", VirtIONet, host_features,
> VIRTIO_NET_F_CSUM, true),
> @@ -4245,6 +4274,14 @@ static const Property virtio_net_properties[] = {
> rss_data.specified_hash_types,
> VIRTIO_NET_HASH_REPORT_UDPv6_EX - 1,
> ON_OFF_AUTO_AUTO),
> + DEFINE_PROP_FEATURE("host_tunnel", VirtIONet, host_features_ex,
> + VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO, true),
> + DEFINE_PROP_FEATURE("host_tunnel_csum", VirtIONet, host_features_ex,
> + VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO_CSUM, true),
> + DEFINE_PROP_FEATURE("guest_tunnel", VirtIONet, host_features_ex,
> + VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO, true),
> + DEFINE_PROP_FEATURE("guest_tunnel_csum", VirtIONet, host_features_ex,
> + VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO_CSUM, true),
> };
Need compatibility work like:
d83f46d189 ("virtio-pci: compat page aligned ATS")
Thanks
On 7/22/25 5:50 AM, Jason Wang wrote:
> On Fri, Jul 18, 2025 at 4:54 PM Paolo Abeni <pabeni@redhat.com> 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>
>> ---
>> v2 -> v3:
>> - use bool type for tap_probe_has_tunnel()
>> - rebased on top of 2deec9ab7d ("virtio-net: Move
>> virtio_net_get_features() down")
>> - _array -> _ex
>>
>> v1 -> v2:
>> - peer_has_tunnel return a bool
>> - move TUN_F definition in net/tun-linux.h
>> ---
>> hw/net/virtio-net.c | 37 +++++++++++++++++++++++++++++++++++++
>> include/net/net.h | 3 +++
>> net/net.c | 9 +++++++++
>> net/tap-bsd.c | 5 +++++
>> net/tap-linux.c | 11 +++++++++++
>> net/tap-linux.h | 9 +++++++++
>> net/tap-solaris.c | 5 +++++
>> net/tap-stub.c | 5 +++++
>> net/tap.c | 11 +++++++++++
>> net/tap_int.h | 1 +
>> 10 files changed, 96 insertions(+)
>>
>> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
>> index 53413ec4d5..70c85f7f77 100644
>> --- a/hw/net/virtio-net.c
>> +++ b/hw/net/virtio-net.c
>> @@ -649,6 +649,15 @@ static int peer_has_uso(VirtIONet *n)
>> return qemu_has_uso(qemu_get_queue(n->nic)->peer);
>> }
>>
>> +static bool peer_has_tunnel(VirtIONet *n)
>
> Nit: it looks better to use peer_has_udp_gso_tunnel().
>
>> +{
>> + if (!peer_has_vnet_hdr(n)) {
>> + return false;
>> + }
>> +
>> + 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)
>> {
>> @@ -3070,6 +3079,13 @@ static void virtio_net_get_features(VirtIODevice *vdev, uint64_t *features,
>> virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_USO4);
>> virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_USO6);
>>
>> + 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);
>> +
>> virtio_clear_feature_ex(features, VIRTIO_NET_F_HASH_REPORT);
>> }
>>
>> @@ -3083,6 +3099,15 @@ static void virtio_net_get_features(VirtIODevice *vdev, uint64_t *features,
>> virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_USO6);
>> }
>>
>> + 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);
>> + }
>> +
>> if (!get_vhost_net(nc->peer)) {
>> if (!use_own_hash) {
>> virtio_clear_feature_ex(features, VIRTIO_NET_F_HASH_REPORT);
>> @@ -4137,6 +4162,10 @@ static const VMStateDescription vmstate_virtio_net = {
>> .dev_unplug_pending = dev_unplug_pending,
>> };
>>
>> +#define DEFINE_PROP_FEATURE(_name, _state, _field, _bit, _defval) \
>> + DEFINE_PROP_BIT64(_name, _state, _field[VIRTIO_DWORD(_bit)], \
>> + (_bit) % 64, _defval)
>> +
>> static const Property virtio_net_properties[] = {
>> DEFINE_PROP_BIT64("csum", VirtIONet, host_features,
>> VIRTIO_NET_F_CSUM, true),
>> @@ -4245,6 +4274,14 @@ static const Property virtio_net_properties[] = {
>> rss_data.specified_hash_types,
>> VIRTIO_NET_HASH_REPORT_UDPv6_EX - 1,
>> ON_OFF_AUTO_AUTO),
>> + DEFINE_PROP_FEATURE("host_tunnel", VirtIONet, host_features_ex,
>> + VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO, true),
>> + DEFINE_PROP_FEATURE("host_tunnel_csum", VirtIONet, host_features_ex,
>> + VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO_CSUM, true),
>> + DEFINE_PROP_FEATURE("guest_tunnel", VirtIONet, host_features_ex,
>> + VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO, true),
>> + DEFINE_PROP_FEATURE("guest_tunnel_csum", VirtIONet, host_features_ex,
>> + VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO_CSUM, true),
>> };
>
> Need compatibility work like:
>
> d83f46d189 ("virtio-pci: compat page aligned ATS")
If I read correctly the only missing pieces are the hw_compat_10_1
entries, am I correct?
If so, as mentioned here:
https://lists.gnu.org/archive/html/qemu-devel/2025-07/msg05032.html
I'll add the needed entries after that the hw_compat_10_1 will be created.
Thanks,
Paolo
On Tue, Jul 22, 2025 at 3:33 PM Paolo Abeni <pabeni@redhat.com> wrote:
>
> On 7/22/25 5:50 AM, Jason Wang wrote:
> > On Fri, Jul 18, 2025 at 4:54 PM Paolo Abeni <pabeni@redhat.com> 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>
> >> ---
> >> v2 -> v3:
> >> - use bool type for tap_probe_has_tunnel()
> >> - rebased on top of 2deec9ab7d ("virtio-net: Move
> >> virtio_net_get_features() down")
> >> - _array -> _ex
> >>
> >> v1 -> v2:
> >> - peer_has_tunnel return a bool
> >> - move TUN_F definition in net/tun-linux.h
> >> ---
> >> hw/net/virtio-net.c | 37 +++++++++++++++++++++++++++++++++++++
> >> include/net/net.h | 3 +++
> >> net/net.c | 9 +++++++++
> >> net/tap-bsd.c | 5 +++++
> >> net/tap-linux.c | 11 +++++++++++
> >> net/tap-linux.h | 9 +++++++++
> >> net/tap-solaris.c | 5 +++++
> >> net/tap-stub.c | 5 +++++
> >> net/tap.c | 11 +++++++++++
> >> net/tap_int.h | 1 +
> >> 10 files changed, 96 insertions(+)
> >>
> >> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> >> index 53413ec4d5..70c85f7f77 100644
> >> --- a/hw/net/virtio-net.c
> >> +++ b/hw/net/virtio-net.c
> >> @@ -649,6 +649,15 @@ static int peer_has_uso(VirtIONet *n)
> >> return qemu_has_uso(qemu_get_queue(n->nic)->peer);
> >> }
> >>
> >> +static bool peer_has_tunnel(VirtIONet *n)
> >
> > Nit: it looks better to use peer_has_udp_gso_tunnel().
> >
> >> +{
> >> + if (!peer_has_vnet_hdr(n)) {
> >> + return false;
> >> + }
> >> +
> >> + 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)
> >> {
> >> @@ -3070,6 +3079,13 @@ static void virtio_net_get_features(VirtIODevice *vdev, uint64_t *features,
> >> virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_USO4);
> >> virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_USO6);
> >>
> >> + 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);
> >> +
> >> virtio_clear_feature_ex(features, VIRTIO_NET_F_HASH_REPORT);
> >> }
> >>
> >> @@ -3083,6 +3099,15 @@ static void virtio_net_get_features(VirtIODevice *vdev, uint64_t *features,
> >> virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_USO6);
> >> }
> >>
> >> + 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);
> >> + }
> >> +
> >> if (!get_vhost_net(nc->peer)) {
> >> if (!use_own_hash) {
> >> virtio_clear_feature_ex(features, VIRTIO_NET_F_HASH_REPORT);
> >> @@ -4137,6 +4162,10 @@ static const VMStateDescription vmstate_virtio_net = {
> >> .dev_unplug_pending = dev_unplug_pending,
> >> };
> >>
> >> +#define DEFINE_PROP_FEATURE(_name, _state, _field, _bit, _defval) \
> >> + DEFINE_PROP_BIT64(_name, _state, _field[VIRTIO_DWORD(_bit)], \
> >> + (_bit) % 64, _defval)
> >> +
> >> static const Property virtio_net_properties[] = {
> >> DEFINE_PROP_BIT64("csum", VirtIONet, host_features,
> >> VIRTIO_NET_F_CSUM, true),
> >> @@ -4245,6 +4274,14 @@ static const Property virtio_net_properties[] = {
> >> rss_data.specified_hash_types,
> >> VIRTIO_NET_HASH_REPORT_UDPv6_EX - 1,
> >> ON_OFF_AUTO_AUTO),
> >> + DEFINE_PROP_FEATURE("host_tunnel", VirtIONet, host_features_ex,
> >> + VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO, true),
> >> + DEFINE_PROP_FEATURE("host_tunnel_csum", VirtIONet, host_features_ex,
> >> + VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO_CSUM, true),
> >> + DEFINE_PROP_FEATURE("guest_tunnel", VirtIONet, host_features_ex,
> >> + VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO, true),
> >> + DEFINE_PROP_FEATURE("guest_tunnel_csum", VirtIONet, host_features_ex,
> >> + VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO_CSUM, true),
> >> };
> >
> > Need compatibility work like:
> >
> > d83f46d189 ("virtio-pci: compat page aligned ATS")
>
> If I read correctly the only missing pieces are the hw_compat_10_1
> entries, am I correct?
>
> If so, as mentioned here:
>
> https://lists.gnu.org/archive/html/qemu-devel/2025-07/msg05032.html
Exactly.
>
> I'll add the needed entries after that the hw_compat_10_1 will be created.
>
> Thanks,
>
> Paolo
Thanks
>
On Fri, Jul 18, 2025 at 10:52:38AM +0200, 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>
>---
>v2 -> v3:
> - use bool type for tap_probe_has_tunnel()
> - rebased on top of 2deec9ab7d ("virtio-net: Move
> virtio_net_get_features() down")
> - _array -> _ex
>
>v1 -> v2:
> - peer_has_tunnel return a bool
> - move TUN_F definition in net/tun-linux.h
>---
> hw/net/virtio-net.c | 37 +++++++++++++++++++++++++++++++++++++
> include/net/net.h | 3 +++
> net/net.c | 9 +++++++++
> net/tap-bsd.c | 5 +++++
> net/tap-linux.c | 11 +++++++++++
> net/tap-linux.h | 9 +++++++++
> net/tap-solaris.c | 5 +++++
> net/tap-stub.c | 5 +++++
> net/tap.c | 11 +++++++++++
> net/tap_int.h | 1 +
> 10 files changed, 96 insertions(+)
>
>diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
>index 53413ec4d5..70c85f7f77 100644
>--- a/hw/net/virtio-net.c
>+++ b/hw/net/virtio-net.c
>@@ -649,6 +649,15 @@ static int peer_has_uso(VirtIONet *n)
> return qemu_has_uso(qemu_get_queue(n->nic)->peer);
> }
>
>+static bool peer_has_tunnel(VirtIONet *n)
>+{
>+ if (!peer_has_vnet_hdr(n)) {
>+ return false;
>+ }
>+
>+ 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)
> {
>@@ -3070,6 +3079,13 @@ static void virtio_net_get_features(VirtIODevice *vdev, uint64_t *features,
> virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_USO4);
> virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_USO6);
>
>+ 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);
>+
> virtio_clear_feature_ex(features, VIRTIO_NET_F_HASH_REPORT);
> }
>
>@@ -3083,6 +3099,15 @@ static void virtio_net_get_features(VirtIODevice *vdev, uint64_t *features,
> virtio_clear_feature_ex(features, VIRTIO_NET_F_GUEST_USO6);
> }
>
>+ 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);
>+ }
>+
> if (!get_vhost_net(nc->peer)) {
> if (!use_own_hash) {
> virtio_clear_feature_ex(features, VIRTIO_NET_F_HASH_REPORT);
>@@ -4137,6 +4162,10 @@ static const VMStateDescription vmstate_virtio_net = {
> .dev_unplug_pending = dev_unplug_pending,
> };
>
>+#define DEFINE_PROP_FEATURE(_name, _state, _field, _bit, _defval) \
>+ DEFINE_PROP_BIT64(_name, _state, _field[VIRTIO_DWORD(_bit)], \
>+ (_bit) % 64, _defval)
>+
> static const Property virtio_net_properties[] = {
> DEFINE_PROP_BIT64("csum", VirtIONet, host_features,
> VIRTIO_NET_F_CSUM, true),
>@@ -4245,6 +4274,14 @@ static const Property virtio_net_properties[] = {
> rss_data.specified_hash_types,
> VIRTIO_NET_HASH_REPORT_UDPv6_EX - 1,
> ON_OFF_AUTO_AUTO),
>+ DEFINE_PROP_FEATURE("host_tunnel", VirtIONet, host_features_ex,
>+ VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO, true),
>+ DEFINE_PROP_FEATURE("host_tunnel_csum", VirtIONet, host_features_ex,
>+ VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO_CSUM, true),
>+ DEFINE_PROP_FEATURE("guest_tunnel", VirtIONet, host_features_ex,
>+ VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO, true),
>+ DEFINE_PROP_FEATURE("guest_tunnel_csum", VirtIONet, host_features_ex,
>+ VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO_CSUM, true),
IIUC, to avoid issue with live-migration, we should disable all of them
in `hw_compat_10_0` in hw/core/machine.c (e.g. like `host_uso`,
`guest_uso*` in hw_compat_8_1).
Thanks,
Stefano
> };
>
> static void virtio_net_class_init(ObjectClass *klass, const void *data)
>diff --git a/include/net/net.h b/include/net/net.h
>index 48ba333d02..9a9084690d 100644
>--- a/include/net/net.h
>+++ b/include/net/net.h
>@@ -65,6 +65,7 @@ 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 *, const NetOffloads *);
>@@ -95,6 +96,7 @@ 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;
>@@ -197,6 +199,7 @@ 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, const NetOffloads *ol);
>diff --git a/net/net.c b/net/net.c
>index 63872b6855..9536184a0c 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 86b6edee94..751d4c819c 100644
>--- a/net/tap-bsd.c
>+++ b/net/tap-bsd.c
>@@ -217,6 +217,11 @@ int tap_probe_has_uso(int fd)
> return 0;
> }
>
>+bool tap_probe_has_tunnel(int fd)
>+{
>+ return false;
>+}
>+
> void tap_fd_set_vnet_hdr_len(int fd, int len)
> {
> }
>diff --git a/net/tap-linux.c b/net/tap-linux.c
>index a1c58f74f5..e2628be798 100644
>--- a/net/tap-linux.c
>+++ b/net/tap-linux.c
>@@ -196,6 +196,17 @@ int tap_probe_has_uso(int fd)
> return 1;
> }
>
>+bool 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 false;
>+ }
>+ return true;
>+}
>+
> void tap_fd_set_vnet_hdr_len(int fd, int len)
> {
> if (ioctl(fd, TUNSETVNETHDRSZ, &len) == -1) {
>diff --git a/net/tap-linux.h b/net/tap-linux.h
>index 9a58cecb7f..8cd6b5874b 100644
>--- a/net/tap-linux.h
>+++ b/net/tap-linux.h
>@@ -53,4 +53,13 @@
> #define TUN_F_USO4 0x20 /* I can handle USO for IPv4 packets */
> #define TUN_F_USO6 0x40 /* I can handle USO for IPv6 packets */
>
>+/* I can handle TSO/USO for UDP tunneled packets */
>+#define TUN_F_UDP_TUNNEL_GSO 0x080
>+
>+/*
>+ * I can handle TSO/USO for UDP tunneled packets requiring csum offload for
>+ * the outer header
>+ */
>+#define TUN_F_UDP_TUNNEL_GSO_CSUM 0x100
>+
> #endif /* QEMU_TAP_LINUX_H */
>diff --git a/net/tap-solaris.c b/net/tap-solaris.c
>index 833c066bee..ac1ae25761 100644
>--- a/net/tap-solaris.c
>+++ b/net/tap-solaris.c
>@@ -222,6 +222,11 @@ int tap_probe_has_uso(int fd)
> return 0;
> }
>
>+bool tap_probe_has_tunnel(int fd)
>+{
>+ return false;
>+}
>+
> void tap_fd_set_vnet_hdr_len(int fd, int len)
> {
> }
>diff --git a/net/tap-stub.c b/net/tap-stub.c
>index 67d14ad4d5..f7a5e0c163 100644
>--- a/net/tap-stub.c
>+++ b/net/tap-stub.c
>@@ -52,6 +52,11 @@ int tap_probe_has_uso(int fd)
> return 0;
> }
>
>+bool tap_probe_has_tunnel(int fd)
>+{
>+ return false;
>+}
>+
> void tap_fd_set_vnet_hdr_len(int fd, int len)
> {
> }
>diff --git a/net/tap.c b/net/tap.c
>index b49db19f83..23c6c118e7 100644
>--- a/net/tap.c
>+++ b/net/tap.c
>@@ -76,6 +76,7 @@ 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;
>@@ -241,6 +242,14 @@ 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);
>@@ -369,6 +378,7 @@ 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,
>@@ -398,6 +408,7 @@ 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, &ol);
> /*
>diff --git a/net/tap_int.h b/net/tap_int.h
>index f8bbe1cb0c..b76a05044b 100644
>--- a/net/tap_int.h
>+++ b/net/tap_int.h
>@@ -38,6 +38,7 @@ 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);
>+bool tap_probe_has_tunnel(int fd);
> void tap_fd_set_offload(int fd, const NetOffloads *ol);
> void tap_fd_set_vnet_hdr_len(int fd, int len);
> int tap_fd_set_vnet_le(int fd, int vnet_is_le);
>--
>2.50.0
>
On 7/18/25 1:17 PM, Stefano Garzarella wrote:
> On Fri, Jul 18, 2025 at 10:52:38AM +0200, Paolo Abeni wrote:
>> @@ -4245,6 +4274,14 @@ static const Property virtio_net_properties[] = {
>> rss_data.specified_hash_types,
>> VIRTIO_NET_HASH_REPORT_UDPv6_EX - 1,
>> ON_OFF_AUTO_AUTO),
>> + DEFINE_PROP_FEATURE("host_tunnel", VirtIONet, host_features_ex,
>> + VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO, true),
>> + DEFINE_PROP_FEATURE("host_tunnel_csum", VirtIONet, host_features_ex,
>> + VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO_CSUM, true),
>> + DEFINE_PROP_FEATURE("guest_tunnel", VirtIONet, host_features_ex,
>> + VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO, true),
>> + DEFINE_PROP_FEATURE("guest_tunnel_csum", VirtIONet, host_features_ex,
>> + VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO_CSUM, true),
>
> IIUC, to avoid issue with live-migration, we should disable all of them
> in `hw_compat_10_0` in hw/core/machine.c (e.g. like `host_uso`,
> `guest_uso*` in hw_compat_8_1).
I guess the relevant compat entry should be 10.1, right? AFAICS such
entry should added with a separate/specific before 10.1 will be tagged.
I'll add the relevant the entries after that the hw_compat_10_1 will be
added.
Thanks,
Paolo
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