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Andrew Melnychenko

2022-Jan-25 08:46 UTC

[RFC PATCH 0/5] TUN/VirtioNet USO features support.

Added new offloads for TUN devices TUN_F_USO4 and TUN_F_USO6.
Technically they enable NETIF_F_GSO_UDP_L4
(and only if USO4 & USO6 are set simultaneously).
It allows to transmission of large UDP packets.

Different features USO4 and USO6 are required for qemu where Windows guests can
enable disable USO receives for IPv4 and IPv6 separately.
On the other side, Linux can't really differentiate USO4 and USO6, for now.
For now, to enable USO for TUN it requires enabling USO4 and USO6 together.
In the future, there would be a mechanism to control UDP_L4 GSO separately.

Test it WIP Qemu https://github.com/daynix/qemu/tree/Dev_USOv2

New types for VirtioNet already on mailing:
https://lists.oasis-open.org/archives/virtio-comment/202110/msg00010.html

Also, there is a known issue with transmitting packages between two guests.
Without hacks with skb's GSO - packages are still segmented on the
host's postrouting.

Andrew Melnychenko (5):
  uapi/linux/if_tun.h: Added new ioctl for tun/tap.
  driver/net/tun: Added features for USO.
  uapi/linux/virtio_net.h: Added USO types.
  linux/virtio_net.h: Added Support for GSO_UDP_L4 offload.
  drivers/net/virtio_net.c: Added USO support.

 drivers/net/tap.c               | 18 ++++++++++++++++--
 drivers/net/tun.c               | 15 ++++++++++++++-
 drivers/net/virtio_net.c        | 22 ++++++++++++++++++----
 include/linux/virtio_net.h      | 11 +++++++++++
 include/uapi/linux/if_tun.h     |  3 +++
 include/uapi/linux/virtio_net.h |  4 ++++
 6 files changed, 66 insertions(+), 7 deletions(-)

-- 
2.34.1

Andrew Melnychenko

2022-Jan-25 08:46 UTC

head link

[RFC PATCH 1/5] uapi/linux/if_tun.h: Added new ioctl for tun/tap.

Added TUNGETSUPPORTEDOFFLOADS that should allow
to get bits of supported offloads.
Added 2 additional offlloads for USO(IPv4 & IPv6).
Separate offloads are required for Windows VM guests,
g.e. Windows may set USO rx only for IPv4.

Signed-off-by: Andrew Melnychenko <andrew at daynix.com>
---
 include/uapi/linux/if_tun.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/include/uapi/linux/if_tun.h b/include/uapi/linux/if_tun.h
index 454ae31b93c7..07680fae6e18 100644
--- a/include/uapi/linux/if_tun.h
+++ b/include/uapi/linux/if_tun.h
@@ -61,6 +61,7 @@
 #define TUNSETFILTEREBPF _IOR('T', 225, int)
 #define TUNSETCARRIER _IOW('T', 226, int)
 #define TUNGETDEVNETNS _IO('T', 227)
+#define TUNGETSUPPORTEDOFFLOADS _IOR('T', 228, unsigned int)
 
 /* TUNSETIFF ifr flags */
 #define IFF_TUN		0x0001
@@ -88,6 +89,8 @@
 #define TUN_F_TSO6	0x04	/* I can handle TSO for IPv6 packets */
 #define TUN_F_TSO_ECN	0x08	/* I can handle TSO with ECN bits. */
 #define TUN_F_UFO	0x10	/* I can handle UFO packets */
+#define TUN_F_USO4	0x20	/* I can handle USO for IPv4 packets */
+#define TUN_F_USO6	0x40	/* I can handle USO for IPv6 packets */
 
 /* Protocol info prepended to the packets (when IFF_NO_PI is not set) */
 #define TUN_PKT_STRIP	0x0001
-- 
2.34.1

Andrew Melnychenko

2022-Jan-25 08:46 UTC

head link

[RFC PATCH 2/5] driver/net/tun: Added features for USO.

Added support for USO4 and USO6, also added code for new ioctl
TUNGETSUPPORTEDOFFLOADS.
For now, to "enable" USO, it's required to set both USO4 and USO6
simultaneously.
USO enables NETIF_F_GSO_UDP_L4.

Signed-off-by: Andrew Melnychenko <andrew at daynix.com>
---
 drivers/net/tap.c | 18 ++++++++++++++++--
 drivers/net/tun.c | 15 ++++++++++++++-
 2 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/drivers/net/tap.c b/drivers/net/tap.c
index 8e3a28ba6b28..82d742ba78b1 100644
--- a/drivers/net/tap.c
+++ b/drivers/net/tap.c
@@ -940,6 +940,10 @@ static int set_offload(struct tap_queue *q, unsigned long
arg)
 			if (arg & TUN_F_TSO6)
 				feature_mask |= NETIF_F_TSO6;
 		}
+
+		/* TODO: for now USO4 and USO6 should work simultaneously */
+		if (arg & (TUN_F_USO4 | TUN_F_USO6) == (TUN_F_USO4 | TUN_F_USO6))
+			features |= NETIF_F_GSO_UDP_L4;
 	}
 
 	/* tun/tap driver inverts the usage for TSO offloads, where
@@ -950,7 +954,8 @@ static int set_offload(struct tap_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) ||
+	    feature_mask & (TUN_F_USO4 | TUN_F_USO6) == (TUN_F_USO4 | TUN_F_USO6))
 		features |= RX_OFFLOADS;
 	else
 		features &= ~RX_OFFLOADS;
@@ -979,6 +984,7 @@ static long tap_ioctl(struct file *file, unsigned int cmd,
 	unsigned short u;
 	int __user *sp = argp;
 	struct sockaddr sa;
+	unsigned int supported_offloads;
 	int s;
 	int ret;
 
@@ -1074,7 +1080,8 @@ static long tap_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_UFO))
+			    TUN_F_TSO_ECN | TUN_F_UFO |
+			    TUN_F_USO4 | TUN_F_USO6))
 			return -EINVAL;
 
 		rtnl_lock();
@@ -1082,6 +1089,13 @@ static long tap_ioctl(struct file *file, unsigned int
cmd,
 		rtnl_unlock();
 		return ret;
 
+	case TUNGETSUPPORTEDOFFLOADS:
+		supported_offloads = TUN_F_CSUM | TUN_F_TSO4 | TUN_F_TSO6 |
+						TUN_F_TSO_ECN | TUN_F_UFO | TUN_F_USO4 | TUN_F_USO6;
+		if (copy_to_user(&arg, &supported_offloads,
sizeof(supported_offloads)))
+			return -EFAULT;
+		return 0;
+
 	case SIOCGIFHWADDR:
 		rtnl_lock();
 		tap = tap_get_tap_dev(q);
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index fed85447701a..4f2105d1e6f1 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -185,7 +185,7 @@ 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_GSO_UDP_L4)
 
 	int			align;
 	int			vnet_hdr_sz;
@@ -2821,6 +2821,12 @@ static int set_offload(struct tun_struct *tun, unsigned
long arg)
 		}
 
 		arg &= ~TUN_F_UFO;
+
+		/* TODO: for now USO4 and USO6 should work simultaneously */
+		if (arg & TUN_F_USO4 && arg & TUN_F_USO6) {
+			features |= NETIF_F_GSO_UDP_L4;
+			arg &= ~(TUN_F_USO4 | TUN_F_USO6);
+		}
 	}
 
 	/* This gives the user a way to test for new features in future by
@@ -2991,6 +2997,7 @@ static long __tun_chr_ioctl(struct file *file, unsigned
int cmd,
 	int sndbuf;
 	int vnet_hdr_sz;
 	int le;
+	unsigned int supported_offloads;
 	int ret;
 	bool do_notify = false;
 
@@ -3154,6 +3161,12 @@ static long __tun_chr_ioctl(struct file *file, unsigned
int cmd,
 	case TUNSETOFFLOAD:
 		ret = set_offload(tun, arg);
 		break;
+	case TUNGETSUPPORTEDOFFLOADS:
+		supported_offloads = TUN_F_CSUM | TUN_F_TSO4 | TUN_F_TSO6 |
+				TUN_F_TSO_ECN | TUN_F_UFO | TUN_F_USO4 | TUN_F_USO6;
+		if (copy_to_user(&arg, &supported_offloads,
sizeof(supported_offloads)))
+			ret = -EFAULT;
+		break;
 
 	case TUNSETTXFILTER:
 		/* Can be set only for TAPs */
-- 
2.34.1

Andrew Melnychenko

2022-Jan-25 08:47 UTC

head link

[RFC PATCH 3/5] uapi/linux/virtio_net.h: Added USO types.

Added new GSO type for USO: VIRTIO_NET_HDR_GSO_UDP_L4.
Feature VIRTIO_NET_F_HOST_USO allows to enable NETIF_F_GSO_UDP_L4.
Separated VIRTIO_NET_F_GUEST_USO4 & VIRTIO_NET_F_GUEST_USO6 features
required for Windows guests.

Signed-off-by: Andrew Melnychenko <andrew at daynix.com>
---
 include/uapi/linux/virtio_net.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
index 3f55a4215f11..620addc5767b 100644
--- a/include/uapi/linux/virtio_net.h
+++ b/include/uapi/linux/virtio_net.h
@@ -56,6 +56,9 @@
 #define VIRTIO_NET_F_MQ	22	/* Device supports Receive Flow
 					 * Steering */
 #define VIRTIO_NET_F_CTRL_MAC_ADDR 23	/* Set MAC address */
+#define VIRTIO_NET_F_GUEST_USO4	54	/* Guest can handle USOv4 in. */
+#define VIRTIO_NET_F_GUEST_USO6	55	/* Guest can handle USOv6 in. */
+#define VIRTIO_NET_F_HOST_USO	56	/* Host can handle USO in. */
 
 #define VIRTIO_NET_F_HASH_REPORT  57	/* Supports hash report */
 #define VIRTIO_NET_F_RSS	  60	/* Supports RSS RX steering */
@@ -130,6 +133,7 @@ struct virtio_net_hdr_v1 {
 #define VIRTIO_NET_HDR_GSO_TCPV4	1	/* GSO frame, IPv4 TCP (TSO) */
 #define VIRTIO_NET_HDR_GSO_UDP		3	/* GSO frame, IPv4 UDP (UFO) */
 #define VIRTIO_NET_HDR_GSO_TCPV6	4	/* GSO frame, IPv6 TCP */
+#define VIRTIO_NET_HDR_GSO_UDP_L4	5	/* GSO frame, IPv4 & IPv6 UDP (USO) */
 #define VIRTIO_NET_HDR_GSO_ECN		0x80	/* TCP has ECN set */
 	__u8 gso_type;
 	__virtio16 hdr_len;	/* Ethernet + IP + tcp/udp hdrs */
-- 
2.34.1

Andrew Melnychenko

2022-Jan-25 08:47 UTC

head link

[RFC PATCH 4/5] linux/virtio_net.h: Added Support for GSO_UDP_L4 offload.

Now, it's possible to convert vnet packets from/to skb.

Signed-off-by: Andrew Melnychenko <andrew at daynix.com>
---
 include/linux/virtio_net.h | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h
index a960de68ac69..9311d41d0a81 100644
--- a/include/linux/virtio_net.h
+++ b/include/linux/virtio_net.h
@@ -17,6 +17,9 @@ static inline bool virtio_net_hdr_match_proto(__be16 protocol,
__u8 gso_type)
 	case VIRTIO_NET_HDR_GSO_UDP:
 		return protocol == cpu_to_be16(ETH_P_IP) ||
 		       protocol == cpu_to_be16(ETH_P_IPV6);
+	case VIRTIO_NET_HDR_GSO_UDP_L4:
+		return protocol == cpu_to_be16(ETH_P_IP) ||
+		       protocol == cpu_to_be16(ETH_P_IPV6);
 	default:
 		return false;
 	}
@@ -31,6 +34,7 @@ static inline int virtio_net_hdr_set_proto(struct sk_buff
*skb,
 	switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
 	case VIRTIO_NET_HDR_GSO_TCPV4:
 	case VIRTIO_NET_HDR_GSO_UDP:
+	case VIRTIO_NET_HDR_GSO_UDP_L4:
 		skb->protocol = cpu_to_be16(ETH_P_IP);
 		break;
 	case VIRTIO_NET_HDR_GSO_TCPV6:
@@ -69,6 +73,11 @@ static inline int virtio_net_hdr_to_skb(struct sk_buff *skb,
 			ip_proto = IPPROTO_UDP;
 			thlen = sizeof(struct udphdr);
 			break;
+		case VIRTIO_NET_HDR_GSO_UDP_L4:
+			gso_type = SKB_GSO_UDP_L4;
+			ip_proto = IPPROTO_UDP;
+			thlen = sizeof(struct udphdr);
+			break;
 		default:
 			return -EINVAL;
 		}
@@ -182,6 +191,8 @@ static inline int virtio_net_hdr_from_skb(const struct
sk_buff *skb,
 			hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
 		else if (sinfo->gso_type & SKB_GSO_TCPV6)
 			hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
+		else if (sinfo->gso_type & SKB_GSO_UDP_L4)
+			hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP_L4;
 		else
 			return -EINVAL;
 		if (sinfo->gso_type & SKB_GSO_TCP_ECN)
-- 
2.34.1

Andrew Melnychenko

2022-Jan-25 08:47 UTC

head link

[RFC PATCH 5/5] drivers/net/virtio_net.c: Added USO support.

Now, it possible to enable GSO_UDP_L4("tx-udp-segmentation") for
VirtioNet.

Signed-off-by: Andrew Melnychenko <andrew at daynix.com>
---
 drivers/net/virtio_net.c | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index a801ea40908f..a45eee022be4 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -60,13 +60,17 @@ static const unsigned long guest_offloads[] = {
 	VIRTIO_NET_F_GUEST_TSO6,
 	VIRTIO_NET_F_GUEST_ECN,
 	VIRTIO_NET_F_GUEST_UFO,
-	VIRTIO_NET_F_GUEST_CSUM
+	VIRTIO_NET_F_GUEST_CSUM,
+	VIRTIO_NET_F_GUEST_USO4,
+	VIRTIO_NET_F_GUEST_USO6
 };
 
 #define GUEST_OFFLOAD_GRO_HW_MASK ((1ULL << VIRTIO_NET_F_GUEST_TSO4) | \
 				(1ULL << VIRTIO_NET_F_GUEST_TSO6) | \
 				(1ULL << VIRTIO_NET_F_GUEST_ECN)  | \
-				(1ULL << VIRTIO_NET_F_GUEST_UFO))
+				(1ULL << VIRTIO_NET_F_GUEST_UFO)  | \
+				(1ULL << VIRTIO_NET_F_GUEST_USO4) | \
+				(1ULL << VIRTIO_NET_F_GUEST_USO6))
 
 struct virtnet_stat_desc {
 	char desc[ETH_GSTRING_LEN];
@@ -2530,7 +2534,9 @@ static int virtnet_xdp_set(struct net_device *dev, struct
bpf_prog *prog,
 	        virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6) ||
 	        virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) ||
 		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO) ||
-		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM))) {
+		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM) ||
+		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_USO4) ||
+		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_USO6))) {
 		NL_SET_ERR_MSG_MOD(extack, "Can't set XDP while host is implementing
GRO_HW/CSUM, disable GRO_HW/CSUM first");
 		return -EOPNOTSUPP;
 	}
@@ -3155,6 +3161,8 @@ static int virtnet_probe(struct virtio_device *vdev)
 			dev->hw_features |= NETIF_F_TSO6;
 		if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
 			dev->hw_features |= NETIF_F_TSO_ECN;
+		if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_USO))
+			dev->hw_features |= NETIF_F_GSO_UDP_L4;
 
 		dev->features |= NETIF_F_GSO_ROBUST;
 
@@ -3169,6 +3177,9 @@ static int virtnet_probe(struct virtio_device *vdev)
 		dev->features |= NETIF_F_GRO_HW;
 	if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS))
 		dev->hw_features |= NETIF_F_GRO_HW;
+	if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_USO4) ||
+	    virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_USO6))
+		dev->hw_features |= NETIF_F_LRO;
 
 	dev->vlan_features = dev->features;
 
@@ -3200,7 +3211,9 @@ static int virtnet_probe(struct virtio_device *vdev)
 	if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
 	    virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
 	    virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN) ||
-	    virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_UFO))
+	    virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_UFO) ||
+	    virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_USO4) ||
+	    virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_USO6))
 		vi->big_packets = true;
 
 	if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
@@ -3400,6 +3413,7 @@ static struct virtio_device_id id_table[] = {
 	VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, \
 	VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, \
 	VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, \
+	VIRTIO_NET_F_HOST_USO, VIRTIO_NET_F_GUEST_USO4, VIRTIO_NET_F_GUEST_USO6, \
 	VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, \
 	VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, \
 	VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, \
-- 
2.34.1

Xuan Zhuo

2022-Jan-26 07:52 UTC

head link

[RFC PATCH 0/5] TUN/VirtioNet USO features support.

On Tue, 25 Jan 2022 10:46:57 +0200, Andrew Melnychenko <andrew at
daynix.com> wrote:> Added new offloads for TUN devices TUN_F_USO4 and TUN_F_USO6.
> Technically they enable NETIF_F_GSO_UDP_L4
> (and only if USO4 & USO6 are set simultaneously).
> It allows to transmission of large UDP packets.
>
> Different features USO4 and USO6 are required for qemu where Windows guests
can
> enable disable USO receives for IPv4 and IPv6 separately.
> On the other side, Linux can't really differentiate USO4 and USO6, for
now.
> For now, to enable USO for TUN it requires enabling USO4 and USO6 together.
> In the future, there would be a mechanism to control UDP_L4 GSO separately.
>
> Test it WIP Qemu https://github.com/daynix/qemu/tree/Dev_USOv2
>
> New types for VirtioNet already on mailing:
> https://lists.oasis-open.org/archives/virtio-comment/202110/msg00010.html
Seems like this hasn't been upvoted yet.

	https://github.com/oasis-tcs/virtio-spec#use-of-github-issues

Thanks.
>
> Also, there is a known issue with transmitting packages between two guests.
> Without hacks with skb's GSO - packages are still segmented on the
host's postrouting.
>
> Andrew Melnychenko (5):
>   uapi/linux/if_tun.h: Added new ioctl for tun/tap.
>   driver/net/tun: Added features for USO.
>   uapi/linux/virtio_net.h: Added USO types.
>   linux/virtio_net.h: Added Support for GSO_UDP_L4 offload.
>   drivers/net/virtio_net.c: Added USO support.
>
>  drivers/net/tap.c               | 18 ++++++++++++++++--
>  drivers/net/tun.c               | 15 ++++++++++++++-
>  drivers/net/virtio_net.c        | 22 ++++++++++++++++++----
>  include/linux/virtio_net.h      | 11 +++++++++++
>  include/uapi/linux/if_tun.h     |  3 +++
>  include/uapi/linux/virtio_net.h |  4 ++++
>  6 files changed, 66 insertions(+), 7 deletions(-)
>
> --
> 2.34.1
>
> _______________________________________________
> Virtualization mailing list
> Virtualization at lists.linux-foundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/virtualization

Jason Wang

2022-Feb-09 04:39 UTC

head link

[RFC PATCH 2/5] driver/net/tun: Added features for USO.

? 2022/1/25 ??4:46, Andrew Melnychenko ??:> Added support for USO4 and USO6, also added code for new ioctl
TUNGETSUPPORTEDOFFLOADS.
> For now, to "enable" USO, it's required to set both USO4 and
USO6 simultaneously.
> USO enables NETIF_F_GSO_UDP_L4.
>
> Signed-off-by: Andrew Melnychenko <andrew at daynix.com>
> ---
>   drivers/net/tap.c | 18 ++++++++++++++++--
>   drivers/net/tun.c | 15 ++++++++++++++-
>   2 files changed, 30 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/tap.c b/drivers/net/tap.c
> index 8e3a28ba6b28..82d742ba78b1 100644
> --- a/drivers/net/tap.c
> +++ b/drivers/net/tap.c
> @@ -940,6 +940,10 @@ static int set_offload(struct tap_queue *q, unsigned
long arg)
>   			if (arg & TUN_F_TSO6)
>   				feature_mask |= NETIF_F_TSO6;
>   		}
> +
> +		/* TODO: for now USO4 and USO6 should work simultaneously */
> +		if (arg & (TUN_F_USO4 | TUN_F_USO6) == (TUN_F_USO4 | TUN_F_USO6))
> +			features |= NETIF_F_GSO_UDP_L4;

If kernel doesn't want to split the GSO_UDP features, I wonder how much 
value to keep separated features for TUN and virtio.

Thanks

>   	}
>   
>   	/* tun/tap driver inverts the usage for TSO offloads, where
> @@ -950,7 +954,8 @@ static int set_offload(struct tap_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) ||
> +	    feature_mask & (TUN_F_USO4 | TUN_F_USO6) == (TUN_F_USO4 |
TUN_F_USO6))
>   		features |= RX_OFFLOADS;
>   	else
>   		features &= ~RX_OFFLOADS;
> @@ -979,6 +984,7 @@ static long tap_ioctl(struct file *file, unsigned int
cmd,
>   	unsigned short u;
>   	int __user *sp = argp;
>   	struct sockaddr sa;
> +	unsigned int supported_offloads;
>   	int s;
>   	int ret;
>   
> @@ -1074,7 +1080,8 @@ static long tap_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_UFO))
> +			    TUN_F_TSO_ECN | TUN_F_UFO |
> +			    TUN_F_USO4 | TUN_F_USO6))
>   			return -EINVAL;
>   
>   		rtnl_lock();
> @@ -1082,6 +1089,13 @@ static long tap_ioctl(struct file *file, unsigned
int cmd,
>   		rtnl_unlock();
>   		return ret;
>   
> +	case TUNGETSUPPORTEDOFFLOADS:
> +		supported_offloads = TUN_F_CSUM | TUN_F_TSO4 | TUN_F_TSO6 |
> +						TUN_F_TSO_ECN | TUN_F_UFO | TUN_F_USO4 | TUN_F_USO6;
> +		if (copy_to_user(&arg, &supported_offloads,
sizeof(supported_offloads)))
> +			return -EFAULT;
> +		return 0;
> +
>   	case SIOCGIFHWADDR:
>   		rtnl_lock();
>   		tap = tap_get_tap_dev(q);
> diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> index fed85447701a..4f2105d1e6f1 100644
> --- a/drivers/net/tun.c
> +++ b/drivers/net/tun.c
> @@ -185,7 +185,7 @@ 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_GSO_UDP_L4)
>   
>   	int			align;
>   	int			vnet_hdr_sz;
> @@ -2821,6 +2821,12 @@ static int set_offload(struct tun_struct *tun,
unsigned long arg)
>   		}
>   
>   		arg &= ~TUN_F_UFO;
> +
> +		/* TODO: for now USO4 and USO6 should work simultaneously */
> +		if (arg & TUN_F_USO4 && arg & TUN_F_USO6) {
> +			features |= NETIF_F_GSO_UDP_L4;
> +			arg &= ~(TUN_F_USO4 | TUN_F_USO6);
> +		}
>   	}
>   
>   	/* This gives the user a way to test for new features in future by
> @@ -2991,6 +2997,7 @@ static long __tun_chr_ioctl(struct file *file,
unsigned int cmd,
>   	int sndbuf;
>   	int vnet_hdr_sz;
>   	int le;
> +	unsigned int supported_offloads;
>   	int ret;
>   	bool do_notify = false;
>   
> @@ -3154,6 +3161,12 @@ static long __tun_chr_ioctl(struct file *file,
unsigned int cmd,
>   	case TUNSETOFFLOAD:
>   		ret = set_offload(tun, arg);
>   		break;
> +	case TUNGETSUPPORTEDOFFLOADS:
> +		supported_offloads = TUN_F_CSUM | TUN_F_TSO4 | TUN_F_TSO6 |
> +				TUN_F_TSO_ECN | TUN_F_UFO | TUN_F_USO4 | TUN_F_USO6;
> +		if (copy_to_user(&arg, &supported_offloads,
sizeof(supported_offloads)))
> +			ret = -EFAULT;
> +		break;
>   
>   	case TUNSETTXFILTER:
>   		/* Can be set only for TAPs */

Jason Wang

2022-Feb-09 04:41 UTC

head link

[RFC PATCH 3/5] uapi/linux/virtio_net.h: Added USO types.

? 2022/1/25 ??4:47, Andrew Melnychenko ??:> Added new GSO type for USO: VIRTIO_NET_HDR_GSO_UDP_L4.
> Feature VIRTIO_NET_F_HOST_USO allows to enable NETIF_F_GSO_UDP_L4.
> Separated VIRTIO_NET_F_GUEST_USO4 & VIRTIO_NET_F_GUEST_USO6 features
> required for Windows guests.
>
> Signed-off-by: Andrew Melnychenko <andrew at daynix.com>
> ---
>   include/uapi/linux/virtio_net.h | 4 ++++
>   1 file changed, 4 insertions(+)
>
> diff --git a/include/uapi/linux/virtio_net.h
b/include/uapi/linux/virtio_net.h
> index 3f55a4215f11..620addc5767b 100644
> --- a/include/uapi/linux/virtio_net.h
> +++ b/include/uapi/linux/virtio_net.h
> @@ -56,6 +56,9 @@
>   #define VIRTIO_NET_F_MQ	22	/* Device supports Receive Flow
>   					 * Steering */
>   #define VIRTIO_NET_F_CTRL_MAC_ADDR 23	/* Set MAC address */
> +#define VIRTIO_NET_F_GUEST_USO4	54	/* Guest can handle USOv4 in. */
> +#define VIRTIO_NET_F_GUEST_USO6	55	/* Guest can handle USOv6 in. */
> +#define VIRTIO_NET_F_HOST_USO	56	/* Host can handle USO in. */

I think it's better to be consistent here. Either we split in both guest 
and host or not.

Thanks

>   
>   #define VIRTIO_NET_F_HASH_REPORT  57	/* Supports hash report */
>   #define VIRTIO_NET_F_RSS	  60	/* Supports RSS RX steering */
> @@ -130,6 +133,7 @@ struct virtio_net_hdr_v1 {
>   #define VIRTIO_NET_HDR_GSO_TCPV4	1	/* GSO frame, IPv4 TCP (TSO) */
>   #define VIRTIO_NET_HDR_GSO_UDP		3	/* GSO frame, IPv4 UDP (UFO) */
>   #define VIRTIO_NET_HDR_GSO_TCPV6	4	/* GSO frame, IPv6 TCP */
> +#define VIRTIO_NET_HDR_GSO_UDP_L4	5	/* GSO frame, IPv4 & IPv6 UDP
(USO) */
>   #define VIRTIO_NET_HDR_GSO_ECN		0x80	/* TCP has ECN set */
>   	__u8 gso_type;
>   	__virtio16 hdr_len;	/* Ethernet + IP + tcp/udp hdrs */

Jason Wang

2022-Feb-09 04:42 UTC

head link

[RFC PATCH 4/5] linux/virtio_net.h: Added Support for GSO_UDP_L4 offload.

? 2022/1/25 ??4:47, Andrew Melnychenko ??:> Now, it's possible to convert vnet packets from/to skb.

I suggest to change the title to "net: support XXX offload in vnet
header"

Thanks

>
> Signed-off-by: Andrew Melnychenko <andrew at daynix.com>
> ---
>   include/linux/virtio_net.h | 11 +++++++++++
>   1 file changed, 11 insertions(+)
>
> diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h
> index a960de68ac69..9311d41d0a81 100644
> --- a/include/linux/virtio_net.h
> +++ b/include/linux/virtio_net.h
> @@ -17,6 +17,9 @@ static inline bool virtio_net_hdr_match_proto(__be16
protocol, __u8 gso_type)
>   	case VIRTIO_NET_HDR_GSO_UDP:
>   		return protocol == cpu_to_be16(ETH_P_IP) ||
>   		       protocol == cpu_to_be16(ETH_P_IPV6);
> +	case VIRTIO_NET_HDR_GSO_UDP_L4:
> +		return protocol == cpu_to_be16(ETH_P_IP) ||
> +		       protocol == cpu_to_be16(ETH_P_IPV6);
>   	default:
>   		return false;
>   	}
> @@ -31,6 +34,7 @@ static inline int virtio_net_hdr_set_proto(struct sk_buff
*skb,
>   	switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
>   	case VIRTIO_NET_HDR_GSO_TCPV4:
>   	case VIRTIO_NET_HDR_GSO_UDP:
> +	case VIRTIO_NET_HDR_GSO_UDP_L4:
>   		skb->protocol = cpu_to_be16(ETH_P_IP);
>   		break;
>   	case VIRTIO_NET_HDR_GSO_TCPV6:
> @@ -69,6 +73,11 @@ static inline int virtio_net_hdr_to_skb(struct sk_buff
*skb,
>   			ip_proto = IPPROTO_UDP;
>   			thlen = sizeof(struct udphdr);
>   			break;
> +		case VIRTIO_NET_HDR_GSO_UDP_L4:
> +			gso_type = SKB_GSO_UDP_L4;
> +			ip_proto = IPPROTO_UDP;
> +			thlen = sizeof(struct udphdr);
> +			break;
>   		default:
>   			return -EINVAL;
>   		}
> @@ -182,6 +191,8 @@ static inline int virtio_net_hdr_from_skb(const struct
sk_buff *skb,
>   			hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
>   		else if (sinfo->gso_type & SKB_GSO_TCPV6)
>   			hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
> +		else if (sinfo->gso_type & SKB_GSO_UDP_L4)
> +			hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP_L4;
>   		else
>   			return -EINVAL;
>   		if (sinfo->gso_type & SKB_GSO_TCP_ECN)

Jason Wang

2022-Feb-09 04:44 UTC

head link

[RFC PATCH 5/5] drivers/net/virtio_net.c: Added USO support.

? 2022/1/25 ??4:47, Andrew Melnychenko ??:> Now, it possible to enable GSO_UDP_L4("tx-udp-segmentation") for
VirtioNet.
>
> Signed-off-by: Andrew Melnychenko <andrew at daynix.com>
> ---
>   drivers/net/virtio_net.c | 22 ++++++++++++++++++----
>   1 file changed, 18 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index a801ea40908f..a45eee022be4 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -60,13 +60,17 @@ static const unsigned long guest_offloads[] = {
>   	VIRTIO_NET_F_GUEST_TSO6,
>   	VIRTIO_NET_F_GUEST_ECN,
>   	VIRTIO_NET_F_GUEST_UFO,
> -	VIRTIO_NET_F_GUEST_CSUM
> +	VIRTIO_NET_F_GUEST_CSUM,
> +	VIRTIO_NET_F_GUEST_USO4,
> +	VIRTIO_NET_F_GUEST_USO6
>   };
>   
>   #define GUEST_OFFLOAD_GRO_HW_MASK ((1ULL <<
VIRTIO_NET_F_GUEST_TSO4) | \
>   				(1ULL << VIRTIO_NET_F_GUEST_TSO6) | \
>   				(1ULL << VIRTIO_NET_F_GUEST_ECN)  | \
> -				(1ULL << VIRTIO_NET_F_GUEST_UFO))
> +				(1ULL << VIRTIO_NET_F_GUEST_UFO)  | \
> +				(1ULL << VIRTIO_NET_F_GUEST_USO4) | \
> +				(1ULL << VIRTIO_NET_F_GUEST_USO6))
>   
>   struct virtnet_stat_desc {
>   	char desc[ETH_GSTRING_LEN];
> @@ -2530,7 +2534,9 @@ static int virtnet_xdp_set(struct net_device *dev,
struct bpf_prog *prog,
>   	        virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6) ||
>   	        virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) ||
>   		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO) ||
> -		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM))) {
> +		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM) ||
> +		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_USO4) ||
> +		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_USO6))) {
>   		NL_SET_ERR_MSG_MOD(extack, "Can't set XDP while host is
implementing GRO_HW/CSUM, disable GRO_HW/CSUM first");
>   		return -EOPNOTSUPP;
>   	}
> @@ -3155,6 +3161,8 @@ static int virtnet_probe(struct virtio_device *vdev)
>   			dev->hw_features |= NETIF_F_TSO6;
>   		if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
>   			dev->hw_features |= NETIF_F_TSO_ECN;
> +		if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_USO))
> +			dev->hw_features |= NETIF_F_GSO_UDP_L4;
>   
>   		dev->features |= NETIF_F_GSO_ROBUST;
>   
> @@ -3169,6 +3177,9 @@ static int virtnet_probe(struct virtio_device *vdev)
>   		dev->features |= NETIF_F_GRO_HW;
>   	if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS))
>   		dev->hw_features |= NETIF_F_GRO_HW;
> +	if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_USO4) ||
> +	    virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_USO6))
> +		dev->hw_features |= NETIF_F_LRO;

I think we need to use GRO_HW, see dbcf24d153884 ("virtio-net: use 
NETIF_F_GRO_HW instead of NETIF_F_LRO"

Thanks

>   
>   	dev->vlan_features = dev->features;
>   
> @@ -3200,7 +3211,9 @@ static int virtnet_probe(struct virtio_device *vdev)
>   	if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
>   	    virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6) ||
>   	    virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN) ||
> -	    virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_UFO))
> +	    virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_UFO) ||
> +	    virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_USO4) ||
> +	    virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_USO6))
>   		vi->big_packets = true;
>   
>   	if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
> @@ -3400,6 +3413,7 @@ static struct virtio_device_id id_table[] = {
>   	VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6, \
>   	VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
\
>   	VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_UFO, \
> +	VIRTIO_NET_F_HOST_USO, VIRTIO_NET_F_GUEST_USO4, VIRTIO_NET_F_GUEST_USO6,
\
>   	VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ, \
>   	VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN, \
>   	VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, \

Virtualization - Feb 2022 - [RFC PATCH 3/5] uapi/linux/virtio_net.h: Added USO types.

[RFC PATCH 0/5] TUN/VirtioNet USO features support.

[RFC PATCH 1/5] uapi/linux/if_tun.h: Added new ioctl for tun/tap.

[RFC PATCH 2/5] driver/net/tun: Added features for USO.

[RFC PATCH 3/5] uapi/linux/virtio_net.h: Added USO types.

[RFC PATCH 4/5] linux/virtio_net.h: Added Support for GSO_UDP_L4 offload.

[RFC PATCH 5/5] drivers/net/virtio_net.c: Added USO support.

[RFC PATCH 0/5] TUN/VirtioNet USO features support.

[RFC PATCH 2/5] driver/net/tun: Added features for USO.

[RFC PATCH 3/5] uapi/linux/virtio_net.h: Added USO types.

[RFC PATCH 4/5] linux/virtio_net.h: Added Support for GSO_UDP_L4 offload.

[RFC PATCH 5/5] drivers/net/virtio_net.c: Added USO support.