diff mbox series

[v6,net-next,11/14] virtio_net: Accurate ECN flag in virtio_net_hdr

Message ID 20241227191211.12485-12-chia-yu.chang@nokia-bell-labs.com (mailing list archive)
State Deferred
Delegated to: Netdev Maintainers
Headers show
Series AccECN protocol preparation patch series | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next, async
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1 this patch: 1
netdev/build_tools success Errors and warnings before: 0 (+23) this patch: 0 (+23)
netdev/cc_maintainers warning 1 maintainers not CCed: shannon.nelson@amd.com
netdev/build_clang success Errors and warnings before: 38 this patch: 38
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 4 this patch: 4
netdev/checkpatch warning WARNING: line length of 81 exceeds 80 columns WARNING: line length of 82 exceeds 80 columns
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Chia-Yu Chang (Nokia) Dec. 27, 2024, 7:12 p.m. UTC 
From: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com>

Unlike RFC 3168 ECN, accurate ECN uses the CWR flag as part of the ACE
field to count new packets with CE mark; however, it will be corrupted
by the RFC 3168 ECN-aware TSO. Therefore, fallback shall be applied by
seting NETIF_F_GSO_ACCECN to ensure that the CWR flag should not be
changed within a super-skb.

To apply the aforementieond new AccECN GSO for virtio, new featue bits
for host and guest are added for feature negotiation between driver and
device. And the translation of Accurate ECN GSO flag between
virtio_net_hdr and skb header for NETIF_F_GSO_ACCECN is also added to
avoid CWR flag corruption due to RFC3168 ECN TSO.

Signed-off-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com>
---
 drivers/net/virtio_net.c        | 14 +++++++++++---
 drivers/vdpa/pds/debugfs.c      |  6 ++++++
 include/linux/virtio_net.h      | 16 ++++++++++------
 include/uapi/linux/virtio_net.h |  5 +++++
 4 files changed, 32 insertions(+), 9 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 7646ddd9bef7..470c70fa6868 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -58,6 +58,7 @@  static const unsigned long guest_offloads[] = {
 	VIRTIO_NET_F_GUEST_TSO4,
 	VIRTIO_NET_F_GUEST_TSO6,
 	VIRTIO_NET_F_GUEST_ECN,
+	VIRTIO_NET_F_GUEST_ACCECN,
 	VIRTIO_NET_F_GUEST_UFO,
 	VIRTIO_NET_F_GUEST_CSUM,
 	VIRTIO_NET_F_GUEST_USO4,
@@ -68,6 +69,7 @@  static const unsigned long guest_offloads[] = {
 #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_ACCECN) | \
 				(1ULL << VIRTIO_NET_F_GUEST_UFO)  | \
 				(1ULL << VIRTIO_NET_F_GUEST_USO4) | \
 				(1ULL << VIRTIO_NET_F_GUEST_USO6))
@@ -5886,6 +5888,7 @@  static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
 	    && (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) ||
 	        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_ACCECN) ||
 		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_USO4) ||
@@ -6549,6 +6552,7 @@  static bool virtnet_check_guest_gso(const struct virtnet_info *vi)
 	return virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) ||
 		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_ACCECN) ||
 		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO) ||
 		(virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_USO4) &&
 		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_USO6));
@@ -6663,6 +6667,8 @@  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_ACCECN))
+			dev->hw_features |= NETIF_F_GSO_ACCECN;
 		if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_USO))
 			dev->hw_features |= NETIF_F_GSO_UDP_L4;
 
@@ -7061,9 +7067,11 @@  static struct virtio_device_id id_table[] = {
 	VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, \
 	VIRTIO_NET_F_MAC, \
 	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_HOST_ECN, VIRTIO_NET_F_HOST_ACCECN, \
+	VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, \
+	VIRTIO_NET_F_GUEST_ECN, VIRTIO_NET_F_GUEST_ACCECN, \
+	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, \
diff --git a/drivers/vdpa/pds/debugfs.c b/drivers/vdpa/pds/debugfs.c
index c328e694f6e7..90bd95db0245 100644
--- a/drivers/vdpa/pds/debugfs.c
+++ b/drivers/vdpa/pds/debugfs.c
@@ -78,6 +78,9 @@  static void print_feature_bits_all(struct seq_file *seq, u64 features)
 		case BIT_ULL(VIRTIO_NET_F_GUEST_ECN):
 			seq_puts(seq, " VIRTIO_NET_F_GUEST_ECN");
 			break;
+		case BIT_ULL(VIRTIO_NET_F_GUEST_ACCECN):
+			seq_puts(seq, " VIRTIO_NET_F_GUEST_ACCECN");
+			break;
 		case BIT_ULL(VIRTIO_NET_F_GUEST_UFO):
 			seq_puts(seq, " VIRTIO_NET_F_GUEST_UFO");
 			break;
@@ -90,6 +93,9 @@  static void print_feature_bits_all(struct seq_file *seq, u64 features)
 		case BIT_ULL(VIRTIO_NET_F_HOST_ECN):
 			seq_puts(seq, " VIRTIO_NET_F_HOST_ECN");
 			break;
+		case BIT_ULL(VIRTIO_NET_F_HOST_ACCECN):
+			seq_puts(seq, " VIRTIO_NET_F_HOST_ACCECN");
+			break;
 		case BIT_ULL(VIRTIO_NET_F_HOST_UFO):
 			seq_puts(seq, " VIRTIO_NET_F_HOST_UFO");
 			break;
diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h
index 02a9f4dc594d..3b71465f0ddb 100644
--- a/include/linux/virtio_net.h
+++ b/include/linux/virtio_net.h
@@ -11,7 +11,7 @@ 
 
 static inline bool virtio_net_hdr_match_proto(__be16 protocol, __u8 gso_type)
 {
-	switch (gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
+	switch (gso_type & ~VIRTIO_NET_HDR_GSO_ECN_FLAGS) {
 	case VIRTIO_NET_HDR_GSO_TCPV4:
 		return protocol == cpu_to_be16(ETH_P_IP);
 	case VIRTIO_NET_HDR_GSO_TCPV6:
@@ -31,7 +31,7 @@  static inline int virtio_net_hdr_set_proto(struct sk_buff *skb,
 	if (skb->protocol)
 		return 0;
 
-	switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
+	switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN_FLAGS) {
 	case VIRTIO_NET_HDR_GSO_TCPV4:
 	case VIRTIO_NET_HDR_GSO_UDP:
 	case VIRTIO_NET_HDR_GSO_UDP_L4:
@@ -58,7 +58,7 @@  static inline int virtio_net_hdr_to_skb(struct sk_buff *skb,
 	unsigned int ip_proto;
 
 	if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
-		switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
+		switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN_FLAGS) {
 		case VIRTIO_NET_HDR_GSO_TCPV4:
 			gso_type = SKB_GSO_TCPV4;
 			ip_proto = IPPROTO_TCP;
@@ -84,7 +84,9 @@  static inline int virtio_net_hdr_to_skb(struct sk_buff *skb,
 			return -EINVAL;
 		}
 
-		if (hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN)
+		if (hdr->gso_type & VIRTIO_NET_HDR_GSO_ACCECN)
+			gso_type |= SKB_GSO_TCP_ACCECN;
+		else if (hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN)
 			gso_type |= SKB_GSO_TCP_ECN;
 
 		if (hdr->gso_size == 0)
@@ -158,7 +160,7 @@  static inline int virtio_net_hdr_to_skb(struct sk_buff *skb,
 		unsigned int nh_off = p_off;
 		struct skb_shared_info *shinfo = skb_shinfo(skb);
 
-		switch (gso_type & ~SKB_GSO_TCP_ECN) {
+		switch (gso_type & ~(SKB_GSO_TCP_ECN | SKB_GSO_TCP_ACCECN)) {
 		case SKB_GSO_UDP:
 			/* UFO may not include transport header in gso_size. */
 			nh_off -= thlen;
@@ -223,7 +225,9 @@  static inline int virtio_net_hdr_from_skb(const struct sk_buff *skb,
 			hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP_L4;
 		else
 			return -EINVAL;
-		if (sinfo->gso_type & SKB_GSO_TCP_ECN)
+		if (sinfo->gso_type & SKB_GSO_TCP_ACCECN)
+			hdr->gso_type |= VIRTIO_NET_HDR_GSO_ACCECN;
+		else if (sinfo->gso_type & SKB_GSO_TCP_ECN)
 			hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
 	} else
 		hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
index ac9174717ef1..65a13b7d4eed 100644
--- a/include/uapi/linux/virtio_net.h
+++ b/include/uapi/linux/virtio_net.h
@@ -56,6 +56,8 @@ 
 #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_HOST_ACCECN 25	/* Host can handle GSO of Accurate ECN */
+#define VIRTIO_NET_F_GUEST_ACCECN 26	/* Guest can handle GSO of Accurate ECN */
 #define VIRTIO_NET_F_DEVICE_STATS 50	/* Device can provide device-level statistics. */
 #define VIRTIO_NET_F_VQ_NOTF_COAL 52	/* Device supports virtqueue notification coalescing */
 #define VIRTIO_NET_F_NOTF_COAL	53	/* Device supports notifications coalescing */
@@ -137,7 +139,10 @@  struct virtio_net_hdr_v1 {
 #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_ACCECN	0x40	/* TCP AccECN segmentation */
 #define VIRTIO_NET_HDR_GSO_ECN		0x80	/* TCP has ECN set */
+#define VIRTIO_NET_HDR_GSO_ECN_FLAGS	(VIRTIO_NET_HDR_GSO_ECN | \
+					 VIRTIO_NET_HDR_GSO_ACCECN)
 	__u8 gso_type;
 	__virtio16 hdr_len;	/* Ethernet + IP + tcp/udp hdrs */
 	__virtio16 gso_size;	/* Bytes to append to hdr_len per frame */