[RFC PATCH net-next 0/6] net/smc: serveral features's implementation for smc v2.1

[RFC PATCH net-next 0/6] net/smc: serveral features's implementation for smc v2.1

[Guangguan Wang]

This patch set implement serveral new features in SMC v2.1(https://
www.ibm.com/support/pages/node/7009315), including vendor unique
experimental options, max connections per lgr negotiation, max links
per lgr negotiation.

Guangguan Wang (6):
  net/smc: support smc release version negotiation in clc handshake
  net/smc: add vendor unique experimental options area in clc handshake
  net/smc: support smc v2.x features validate
  net/smc: support max connections per lgr negotiation
  net/smc: support max links per lgr negotiation in clc handshake
  net/smc: Extend SMCR v2 linkgroup netlink attribute

 include/uapi/linux/smc.h |   2 +
 net/smc/af_smc.c         |  87 +++++++++++++++++------
 net/smc/smc.h            |   5 +-
 net/smc/smc_clc.c        | 147 ++++++++++++++++++++++++++++++++-------
 net/smc/smc_clc.h        |  53 ++++++++++++--
 net/smc/smc_core.c       |  13 +++-
 net/smc/smc_core.h       |  10 +++
 net/smc/smc_llc.c        |  21 ++++--
 8 files changed, 284 insertions(+), 54 deletions(-)

-- 
2.24.3 (Apple Git-128)

[RFC PATCH net-next 1/6] net/smc: support smc release version negotiation in clc handshake

[Guangguan Wang]

Support smc release version negotiation in clc handshake. And set
the latest smc release version to 2.1.

Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>
Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
---
 net/smc/af_smc.c   | 22 ++++++++++++++++++++--
 net/smc/smc.h      |  5 ++++-
 net/smc/smc_clc.c  | 12 ++++++------
 net/smc/smc_clc.h  | 23 ++++++++++++++++++++++-
 net/smc/smc_core.h |  1 +
 5 files changed, 53 insertions(+), 10 deletions(-)

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index a7f887d91d89..bac73eb0542d 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -1187,6 +1187,11 @@ static int smc_connect_rdma_v2_prepare(struct smc_sock *smc,
 			return SMC_CLC_DECL_NOINDIRECT;
 		}
 	}
+
+	if (fce->release > SMC_RELEASE)
+		return SMC_CLC_DECL_VERSMISMAT;
+	ini->release_ver = fce->release;
+
 	return 0;
 }
 
@@ -1355,6 +1360,15 @@ static int smc_connect_ism(struct smc_sock *smc,
 		struct smc_clc_msg_accept_confirm_v2 *aclc_v2 =
 			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
 
+		if (ini->first_contact_peer) {
+			struct smc_clc_first_contact_ext *fce =
+				smc_get_clc_first_contact_ext(aclc_v2, true);
+
+			if (fce->release > SMC_RELEASE)
+				return SMC_CLC_DECL_VERSMISMAT;
+			ini->release_ver = fce->release;
+		}
+
 		rc = smc_v2_determine_accepted_chid(aclc_v2, ini);
 		if (rc)
 			return rc;
@@ -1389,7 +1403,7 @@ static int smc_connect_ism(struct smc_sock *smc,
 	}
 
 	rc = smc_clc_send_confirm(smc, ini->first_contact_local,
-				  aclc->hdr.version, eid, NULL);
+				  aclc->hdr.version, eid, ini);
 	if (rc)
 		goto connect_abort;
 	mutex_unlock(&smc_server_lgr_pending);
@@ -1965,6 +1979,10 @@ static int smc_listen_v2_check(struct smc_sock *new_smc,
 		}
 	}
 
+	ini->release_ver = pclc_v2_ext->hdr.flag.release;
+	if (pclc_v2_ext->hdr.flag.release > SMC_RELEASE)
+		ini->release_ver = SMC_RELEASE;
+
 out:
 	if (!ini->smcd_version && !ini->smcr_version)
 		return rc;
@@ -2412,7 +2430,7 @@ static void smc_listen_work(struct work_struct *work)
 	/* send SMC Accept CLC message */
 	accept_version = ini->is_smcd ? ini->smcd_version : ini->smcr_version;
 	rc = smc_clc_send_accept(new_smc, ini->first_contact_local,
-				 accept_version, ini->negotiated_eid);
+				 accept_version, ini->negotiated_eid, ini);
 	if (rc)
 		goto out_unlock;
 
diff --git a/net/smc/smc.h b/net/smc/smc.h
index 2eeea4cdc718..9cce1a41e011 100644
--- a/net/smc/smc.h
+++ b/net/smc/smc.h
@@ -21,7 +21,10 @@
 
 #define SMC_V1		1		/* SMC version V1 */
 #define SMC_V2		2		/* SMC version V2 */
-#define SMC_RELEASE	0
+
+#define SMC_RELEASE_0 0
+#define SMC_RELEASE_1 1
+#define SMC_RELEASE	SMC_RELEASE_1 /* the latest release version */
 
 #define SMCPROTO_SMC		0	/* SMC protocol, IPv4 */
 #define SMCPROTO_SMC6		1	/* SMC protocol, IPv6 */
diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
index b9b8b07aa702..b838ad0749b4 100644
--- a/net/smc/smc_clc.c
+++ b/net/smc/smc_clc.c
@@ -420,11 +420,11 @@ smc_clc_msg_decl_valid(struct smc_clc_msg_decline *dclc)
 	return true;
 }
 
-static void smc_clc_fill_fce(struct smc_clc_first_contact_ext *fce, int *len)
+static void smc_clc_fill_fce(struct smc_clc_first_contact_ext *fce, int *len, int release_ver)
 {
 	memset(fce, 0, sizeof(*fce));
 	fce->os_type = SMC_CLC_OS_LINUX;
-	fce->release = SMC_RELEASE;
+	fce->release = release_ver;
 	memcpy(fce->hostname, smc_hostname, sizeof(smc_hostname));
 	(*len) += sizeof(*fce);
 }
@@ -1019,7 +1019,7 @@ static int smc_clc_send_confirm_accept(struct smc_sock *smc,
 				memcpy(clc_v2->d1.eid, eid, SMC_MAX_EID_LEN);
 			len = SMCD_CLC_ACCEPT_CONFIRM_LEN_V2;
 			if (first_contact)
-				smc_clc_fill_fce(&fce, &len);
+				smc_clc_fill_fce(&fce, &len, ini->release_ver);
 			clc_v2->hdr.length = htons(len);
 		}
 		memcpy(trl.eyecatcher, SMCD_EYECATCHER,
@@ -1063,7 +1063,7 @@ static int smc_clc_send_confirm_accept(struct smc_sock *smc,
 				memcpy(clc_v2->r1.eid, eid, SMC_MAX_EID_LEN);
 			len = SMCR_CLC_ACCEPT_CONFIRM_LEN_V2;
 			if (first_contact) {
-				smc_clc_fill_fce(&fce, &len);
+				smc_clc_fill_fce(&fce, &len, ini->release_ver);
 				fce.v2_direct = !link->lgr->uses_gateway;
 				memset(&gle, 0, sizeof(gle));
 				if (ini && clc->hdr.type == SMC_CLC_CONFIRM) {
@@ -1141,7 +1141,7 @@ int smc_clc_send_confirm(struct smc_sock *smc, bool clnt_first_contact,
 
 /* send CLC ACCEPT message across internal TCP socket */
 int smc_clc_send_accept(struct smc_sock *new_smc, bool srv_first_contact,
-			u8 version, u8 *negotiated_eid)
+			u8 version, u8 *negotiated_eid, struct smc_init_info *ini)
 {
 	struct smc_clc_msg_accept_confirm_v2 aclc_v2;
 	int len;
@@ -1149,7 +1149,7 @@ int smc_clc_send_accept(struct smc_sock *new_smc, bool srv_first_contact,
 	memset(&aclc_v2, 0, sizeof(aclc_v2));
 	aclc_v2.hdr.type = SMC_CLC_ACCEPT;
 	len = smc_clc_send_confirm_accept(new_smc, &aclc_v2, srv_first_contact,
-					  version, negotiated_eid, NULL);
+					  version, negotiated_eid, ini);
 	if (len < ntohs(aclc_v2.hdr.length))
 		len = len >= 0 ? -EPROTO : -new_smc->clcsock->sk->sk_err;
 
diff --git a/net/smc/smc_clc.h b/net/smc/smc_clc.h
index 5fee545c9a10..b923e89acafb 100644
--- a/net/smc/smc_clc.h
+++ b/net/smc/smc_clc.h
@@ -370,6 +370,27 @@ smc_get_clc_smcd_v2_ext(struct smc_clc_v2_extension *prop_v2ext)
 		 ntohs(prop_v2ext->hdr.smcd_v2_ext_offset));
 }
 
+static inline struct smc_clc_first_contact_ext *
+smc_get_clc_first_contact_ext(struct smc_clc_msg_accept_confirm_v2 *clc_v2,
+			      bool is_smcd)
+{
+	int clc_v2_len;
+
+	if (clc_v2->hdr.version == SMC_V1 ||
+	    !(clc_v2->hdr.typev2 & SMC_FIRST_CONTACT_MASK))
+		return NULL;
+
+	if (is_smcd)
+		clc_v2_len =
+			offsetofend(struct smc_clc_msg_accept_confirm_v2, d1);
+	else
+		clc_v2_len =
+			offsetofend(struct smc_clc_msg_accept_confirm_v2, r1);
+
+	return (struct smc_clc_first_contact_ext *)(((u8 *)clc_v2) +
+						    clc_v2_len);
+}
+
 struct smcd_dev;
 struct smc_init_info;
 
@@ -382,7 +403,7 @@ int smc_clc_send_proposal(struct smc_sock *smc, struct smc_init_info *ini);
 int smc_clc_send_confirm(struct smc_sock *smc, bool clnt_first_contact,
 			 u8 version, u8 *eid, struct smc_init_info *ini);
 int smc_clc_send_accept(struct smc_sock *smc, bool srv_first_contact,
-			u8 version, u8 *negotiated_eid);
+			u8 version, u8 *negotiated_eid, struct smc_init_info *ini);
 void smc_clc_init(void) __init;
 void smc_clc_exit(void);
 void smc_clc_get_hostname(u8 **host);
diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h
index 3c1b31bfa1cf..1a97fef39127 100644
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h
@@ -374,6 +374,7 @@ struct smc_init_info {
 	u8			is_smcd;
 	u8			smc_type_v1;
 	u8			smc_type_v2;
+	u8			release_ver;
 	u8			first_contact_peer;
 	u8			first_contact_local;
 	unsigned short		vlan_id;
-- 
2.24.3 (Apple Git-128)

[RFC PATCH net-next 2/6] net/smc: add vendor unique experimental options area in clc handshake

[Guangguan Wang]

Add vendor unique experimental options area in clc handshake. In clc
accept and confirm msg, vendor unique experimental options use the
16-Bytes reserved field, which defined in struct smc_clc_fce_gid_ext
in previous version. Because of the struct smc_clc_first_contact_ext
is widely used and limit the scope of modification, this patch moves
the 16-Bytes reserved field out of struct smc_clc_fce_gid_ext, and
followed with the struct smc_clc_first_contact_ext in a new struct
names struct smc_clc_first_contact_ext_v2x.

For SMC-R first connection, in previous version, the struct smc_clc_
first_contact_ext and the 16-Bytes reserved field has already been
included in clc accept and confirm msg. Thus, this patch use struct
smc_clc_first_contact_ext_v2x instead of the struct smc_clc_first_
contact_ext and the 16-Bytes reserved field in SMC-R clc accept and
confirm msg is compatible with previous version.

For SMC-D first connection, in previous version, only the struct smc_
clc_first_contact_ext is included in clc accept and confirm msg, and
the 16-Bytes reserved field is not included. Thus, when the negotiated
smc release version is the version before v2.1, we still use struct
smc_clc_first_contact_ext for compatible consideration. If the negotiated
smc release version is v2.1 or later, use struct smc_clc_first_contact_
ext_v2x instead.

Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>
Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
---
 net/smc/af_smc.c  |  2 +-
 net/smc/smc_clc.c | 44 +++++++++++++++++++++++---------------------
 net/smc/smc_clc.h | 15 +++++++++++++--
 3 files changed, 37 insertions(+), 24 deletions(-)

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index bac73eb0542d..52279bdc100a 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -1113,7 +1113,7 @@ static int smc_connect_ism_vlan_cleanup(struct smc_sock *smc,
 
 #define SMC_CLC_MAX_ACCEPT_LEN \
 	(sizeof(struct smc_clc_msg_accept_confirm_v2) + \
-	 sizeof(struct smc_clc_first_contact_ext) + \
+	 sizeof(struct smc_clc_first_contact_ext_v2x) + \
 	 sizeof(struct smc_clc_msg_trail))
 
 /* CLC handshake during connect */
diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
index b838ad0749b4..df8d17491a25 100644
--- a/net/smc/smc_clc.c
+++ b/net/smc/smc_clc.c
@@ -391,9 +391,7 @@ smc_clc_msg_acc_conf_valid(struct smc_clc_msg_accept_confirm_v2 *clc_v2)
 			return false;
 	} else {
 		if (hdr->typev1 == SMC_TYPE_D &&
-		    ntohs(hdr->length) != SMCD_CLC_ACCEPT_CONFIRM_LEN_V2 &&
-		    (ntohs(hdr->length) != SMCD_CLC_ACCEPT_CONFIRM_LEN_V2 +
-				sizeof(struct smc_clc_first_contact_ext)))
+		    ntohs(hdr->length) < SMCD_CLC_ACCEPT_CONFIRM_LEN_V2)
 			return false;
 		if (hdr->typev1 == SMC_TYPE_R &&
 		    ntohs(hdr->length) < SMCR_CLC_ACCEPT_CONFIRM_LEN_V2)
@@ -420,13 +418,19 @@ smc_clc_msg_decl_valid(struct smc_clc_msg_decline *dclc)
 	return true;
 }
 
-static void smc_clc_fill_fce(struct smc_clc_first_contact_ext *fce, int *len, int release_ver)
+static int smc_clc_fill_fce(struct smc_clc_first_contact_ext_v2x *fce,
+			    struct smc_init_info *ini)
 {
+	int ret = sizeof(*fce);
+
 	memset(fce, 0, sizeof(*fce));
-	fce->os_type = SMC_CLC_OS_LINUX;
-	fce->release = release_ver;
-	memcpy(fce->hostname, smc_hostname, sizeof(smc_hostname));
-	(*len) += sizeof(*fce);
+	fce->fce_v20.os_type = SMC_CLC_OS_LINUX;
+	fce->fce_v20.release = ini->release_ver;
+	memcpy(fce->fce_v20.hostname, smc_hostname, sizeof(smc_hostname));
+	if (ini->is_smcd && ini->release_ver < SMC_RELEASE_1)
+		ret = sizeof(struct smc_clc_first_contact_ext);
+
+	return ret;
 }
 
 /* check if received message has a correct header length and contains valid
@@ -987,12 +991,12 @@ static int smc_clc_send_confirm_accept(struct smc_sock *smc,
 {
 	struct smc_connection *conn = &smc->conn;
 	struct smc_clc_msg_accept_confirm *clc;
-	struct smc_clc_first_contact_ext fce;
+	struct smc_clc_first_contact_ext_v2x fce;
 	struct smc_clc_fce_gid_ext gle;
 	struct smc_clc_msg_trail trl;
 	struct kvec vec[5];
 	struct msghdr msg;
-	int i, len;
+	int i, len, fce_len;
 
 	/* send SMC Confirm CLC msg */
 	clc = (struct smc_clc_msg_accept_confirm *)clc_v2;
@@ -1018,8 +1022,10 @@ static int smc_clc_send_confirm_accept(struct smc_sock *smc,
 			if (eid && eid[0])
 				memcpy(clc_v2->d1.eid, eid, SMC_MAX_EID_LEN);
 			len = SMCD_CLC_ACCEPT_CONFIRM_LEN_V2;
-			if (first_contact)
-				smc_clc_fill_fce(&fce, &len, ini->release_ver);
+			if (first_contact) {
+				fce_len = smc_clc_fill_fce(&fce, ini);
+				len += fce_len;
+			}
 			clc_v2->hdr.length = htons(len);
 		}
 		memcpy(trl.eyecatcher, SMCD_EYECATCHER,
@@ -1063,15 +1069,14 @@ static int smc_clc_send_confirm_accept(struct smc_sock *smc,
 				memcpy(clc_v2->r1.eid, eid, SMC_MAX_EID_LEN);
 			len = SMCR_CLC_ACCEPT_CONFIRM_LEN_V2;
 			if (first_contact) {
-				smc_clc_fill_fce(&fce, &len, ini->release_ver);
-				fce.v2_direct = !link->lgr->uses_gateway;
-				memset(&gle, 0, sizeof(gle));
+				fce_len = smc_clc_fill_fce(&fce, ini);
+				len += fce_len;
+				fce.fce_v20.v2_direct = !link->lgr->uses_gateway;
 				if (ini && clc->hdr.type == SMC_CLC_CONFIRM) {
+					memset(&gle, 0, sizeof(gle));
 					gle.gid_cnt = ini->smcrv2.gidlist.len;
 					len += sizeof(gle);
 					len += gle.gid_cnt * sizeof(gle.gid[0]);
-				} else {
-					len += sizeof(gle.reserved);
 				}
 			}
 			clc_v2->hdr.length = htons(len);
@@ -1094,7 +1099,7 @@ static int smc_clc_send_confirm_accept(struct smc_sock *smc,
 				   sizeof(trl);
 	if (version > SMC_V1 && first_contact) {
 		vec[i].iov_base = &fce;
-		vec[i++].iov_len = sizeof(fce);
+		vec[i++].iov_len = fce_len;
 		if (!conn->lgr->is_smcd) {
 			if (clc->hdr.type == SMC_CLC_CONFIRM) {
 				vec[i].iov_base = &gle;
@@ -1102,9 +1107,6 @@ static int smc_clc_send_confirm_accept(struct smc_sock *smc,
 				vec[i].iov_base = &ini->smcrv2.gidlist.list;
 				vec[i++].iov_len = gle.gid_cnt *
 						   sizeof(gle.gid[0]);
-			} else {
-				vec[i].iov_base = &gle.reserved;
-				vec[i++].iov_len = sizeof(gle.reserved);
 			}
 		}
 	}
diff --git a/net/smc/smc_clc.h b/net/smc/smc_clc.h
index b923e89acafb..6133276a8839 100644
--- a/net/smc/smc_clc.h
+++ b/net/smc/smc_clc.h
@@ -147,7 +147,9 @@ struct smc_clc_msg_proposal_prefix {	/* prefix part of clc proposal message*/
 struct smc_clc_msg_smcd {	/* SMC-D GID information */
 	struct smc_clc_smcd_gid_chid ism; /* ISM native GID+CHID of requestor */
 	__be16 v2_ext_offset;	/* SMC Version 2 Extension Offset */
-	u8 reserved[28];
+	u8 vendor_oui[3];
+	u8 vendor_exp_options[5];
+	u8 reserved[20];
 };
 
 struct smc_clc_smcd_v2_extension {
@@ -231,8 +233,17 @@ struct smc_clc_first_contact_ext {
 	u8 hostname[SMC_MAX_HOSTNAME_LEN];
 };
 
+struct smc_clc_first_contact_ext_v2x {
+	struct smc_clc_first_contact_ext fce_v20;
+	u8 reserved3[4];
+	__be32 vendor_exp_options;
+	u8 reserved4[8];
+} __packed;		/* format defined in
+			 * IBM Shared Memory Communications Version 2 (Third Edition)
+			 * (https://www.ibm.com/support/pages/node/7009315)
+			 */
+
 struct smc_clc_fce_gid_ext {
-	u8 reserved[16];
 	u8 gid_cnt;
 	u8 reserved2[3];
 	u8 gid[][SMC_GID_SIZE];
-- 
2.24.3 (Apple Git-128)

[RFC PATCH net-next 3/6] net/smc: support smc v2.x features validate

[Guangguan Wang]

Support smc v2.x features validate for smc v2.1.

Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>
Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
---
 net/smc/af_smc.c  | 18 ++++++++++++++++++
 net/smc/smc_clc.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 net/smc/smc_clc.h |  7 +++++++
 3 files changed, 71 insertions(+)

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 52279bdc100a..fd58e25beddf 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -1169,6 +1169,7 @@ static int smc_connect_rdma_v2_prepare(struct smc_sock *smc,
 	struct smc_clc_first_contact_ext *fce =
 		(struct smc_clc_first_contact_ext *)
 			(((u8 *)clc_v2) + sizeof(*clc_v2));
+	int rc;
 
 	if (!ini->first_contact_peer || aclc->hdr.version == SMC_V1)
 		return 0;
@@ -1191,6 +1192,9 @@ static int smc_connect_rdma_v2_prepare(struct smc_sock *smc,
 	if (fce->release > SMC_RELEASE)
 		return SMC_CLC_DECL_VERSMISMAT;
 	ini->release_ver = fce->release;
+	rc = smc_clc_cli_v2x_features_validate(fce, ini);
+	if (rc)
+		return rc;
 
 	return 0;
 }
@@ -1367,6 +1371,9 @@ static int smc_connect_ism(struct smc_sock *smc,
 			if (fce->release > SMC_RELEASE)
 				return SMC_CLC_DECL_VERSMISMAT;
 			ini->release_ver = fce->release;
+			rc = smc_clc_cli_v2x_features_validate(fce, ini);
+			if (rc)
+				return rc;
 		}
 
 		rc = smc_v2_determine_accepted_chid(aclc_v2, ini);
@@ -2417,6 +2424,10 @@ static void smc_listen_work(struct work_struct *work)
 	if (rc)
 		goto out_decl;
 
+	rc = smc_clc_srv_v2x_features_validate(pclc, ini);
+	if (rc)
+		goto out_decl;
+
 	mutex_lock(&smc_server_lgr_pending);
 	smc_close_init(new_smc);
 	smc_rx_init(new_smc);
@@ -2449,6 +2460,13 @@ static void smc_listen_work(struct work_struct *work)
 		goto out_decl;
 	}
 
+	rc = smc_clc_v2x_features_confirm_check(cclc, ini);
+	if (rc) {
+		if (!ini->is_smcd)
+			goto out_unlock;
+		goto out_decl;
+	}
+
 	/* finish worker */
 	if (!ini->is_smcd) {
 		rc = smc_listen_rdma_finish(new_smc, cclc,
diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
index df8d17491a25..b25a72f1c9ac 100644
--- a/net/smc/smc_clc.c
+++ b/net/smc/smc_clc.c
@@ -1158,6 +1158,52 @@ int smc_clc_send_accept(struct smc_sock *new_smc, bool srv_first_contact,
 	return len > 0 ? 0 : len;
 }
 
+int smc_clc_srv_v2x_features_validate(struct smc_clc_msg_proposal *pclc,
+				      struct smc_init_info *ini)
+{
+	struct smc_clc_v2_extension *pclc_v2_ext;
+
+	if ((!(ini->smcd_version & SMC_V2) && !(ini->smcr_version & SMC_V2)) ||
+	    ini->release_ver < SMC_RELEASE_1)
+		return 0;
+
+	pclc_v2_ext = smc_get_clc_v2_ext(pclc);
+	if (!pclc_v2_ext)
+		return SMC_CLC_DECL_NOV2EXT;
+
+	return 0;
+}
+
+int smc_clc_cli_v2x_features_validate(struct smc_clc_first_contact_ext *fce,
+				      struct smc_init_info *ini)
+{
+	if (ini->release_ver < SMC_RELEASE_1)
+		return 0;
+
+	return 0;
+}
+
+int smc_clc_v2x_features_confirm_check(struct smc_clc_msg_accept_confirm *cclc,
+				       struct smc_init_info *ini)
+{
+	struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
+		(struct smc_clc_msg_accept_confirm_v2 *)cclc;
+	struct smc_clc_first_contact_ext *fce =
+		smc_get_clc_first_contact_ext(clc_v2, ini->is_smcd);
+
+	if (cclc->hdr.version == SMC_V1 ||
+	    !(cclc->hdr.typev2 & SMC_FIRST_CONTACT_MASK))
+		return 0;
+
+	if (ini->release_ver != fce->release)
+		return SMC_CLC_DECL_RELEASEERR;
+
+	if (fce->release < SMC_RELEASE_1)
+		return 0;
+
+	return 0;
+}
+
 void smc_clc_get_hostname(u8 **host)
 {
 	*host = &smc_hostname[0];
diff --git a/net/smc/smc_clc.h b/net/smc/smc_clc.h
index 6133276a8839..66932bfdc6d0 100644
--- a/net/smc/smc_clc.h
+++ b/net/smc/smc_clc.h
@@ -45,6 +45,7 @@
 #define SMC_CLC_DECL_NOSEID	0x03030006  /* peer sent no SEID	      */
 #define SMC_CLC_DECL_NOSMCD2DEV	0x03030007  /* no SMC-Dv2 device found	      */
 #define SMC_CLC_DECL_NOUEID	0x03030008  /* peer sent no UEID	      */
+#define SMC_CLC_DECL_RELEASEERR	0x03030009  /* release version negotiate failed */
 #define SMC_CLC_DECL_MODEUNSUPP	0x03040000  /* smc modes do not match (R or D)*/
 #define SMC_CLC_DECL_RMBE_EC	0x03050000  /* peer has eyecatcher in RMBE    */
 #define SMC_CLC_DECL_OPTUNSUPP	0x03060000  /* fastopen sockopt not supported */
@@ -415,6 +416,12 @@ int smc_clc_send_confirm(struct smc_sock *smc, bool clnt_first_contact,
 			 u8 version, u8 *eid, struct smc_init_info *ini);
 int smc_clc_send_accept(struct smc_sock *smc, bool srv_first_contact,
 			u8 version, u8 *negotiated_eid, struct smc_init_info *ini);
+int smc_clc_srv_v2x_features_validate(struct smc_clc_msg_proposal *pclc,
+				      struct smc_init_info *ini);
+int smc_clc_cli_v2x_features_validate(struct smc_clc_first_contact_ext *fce,
+				      struct smc_init_info *ini);
+int smc_clc_v2x_features_confirm_check(struct smc_clc_msg_accept_confirm *cclc,
+				       struct smc_init_info *ini);
 void smc_clc_init(void) __init;
 void smc_clc_exit(void);
 void smc_clc_get_hostname(u8 **host);
-- 
2.24.3 (Apple Git-128)

[RFC PATCH net-next 4/6] net/smc: support max connections per lgr negotiation

[Guangguan Wang]

Support max connections per lgr negotiation for SMCR v2.1,
which is one of smc v2.1 features.

Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>
Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
---
 net/smc/af_smc.c   |  1 +
 net/smc/smc_clc.c  | 41 +++++++++++++++++++++++++++++++++++++++--
 net/smc/smc_clc.h  |  7 +++++--
 net/smc/smc_core.c |  4 +++-
 net/smc/smc_core.h |  4 ++++
 net/smc/smc_llc.c  |  6 +++++-
 6 files changed, 57 insertions(+), 6 deletions(-)

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index fd58e25beddf..b95d3fd48c28 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -1214,6 +1214,7 @@ static int smc_connect_rdma(struct smc_sock *smc,
 	memcpy(ini->peer_systemid, aclc->r0.lcl.id_for_peer, SMC_SYSTEMID_LEN);
 	memcpy(ini->peer_gid, aclc->r0.lcl.gid, SMC_GID_SIZE);
 	memcpy(ini->peer_mac, aclc->r0.lcl.mac, ETH_ALEN);
+	ini->max_conns = SMC_RMBS_PER_LGR_MAX;
 
 	reason_code = smc_connect_rdma_v2_prepare(smc, aclc, ini);
 	if (reason_code)
diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
index b25a72f1c9ac..5e90234df189 100644
--- a/net/smc/smc_clc.c
+++ b/net/smc/smc_clc.c
@@ -427,9 +427,17 @@ static int smc_clc_fill_fce(struct smc_clc_first_contact_ext_v2x *fce,
 	fce->fce_v20.os_type = SMC_CLC_OS_LINUX;
 	fce->fce_v20.release = ini->release_ver;
 	memcpy(fce->fce_v20.hostname, smc_hostname, sizeof(smc_hostname));
-	if (ini->is_smcd && ini->release_ver < SMC_RELEASE_1)
+	if (ini->is_smcd && ini->release_ver < SMC_RELEASE_1) {
 		ret = sizeof(struct smc_clc_first_contact_ext);
+		goto out;
+	}
+
+	if (ini->release_ver >= SMC_RELEASE_1) {
+		if (!ini->is_smcd)
+			fce->max_conns = ini->max_conns;
+	}
 
+out:
 	return ret;
 }
 
@@ -931,8 +939,10 @@ int smc_clc_send_proposal(struct smc_sock *smc, struct smc_init_info *ini)
 				sizeof(struct smc_clc_smcd_gid_chid);
 		}
 	}
-	if (smcr_indicated(ini->smc_type_v2))
+	if (smcr_indicated(ini->smc_type_v2)) {
 		memcpy(v2_ext->roce, ini->smcrv2.ib_gid_v2, SMC_GID_SIZE);
+		v2_ext->max_conns = SMC_CONN_PER_LGR_MAX;
+	}
 
 	pclc_base->hdr.length = htons(plen);
 	memcpy(trl->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
@@ -1163,6 +1173,11 @@ int smc_clc_srv_v2x_features_validate(struct smc_clc_msg_proposal *pclc,
 {
 	struct smc_clc_v2_extension *pclc_v2_ext;
 
+	/* default max conn is SMC_RMBS_PER_LGR_MAX(255),
+	 * which is the default value in smc v1 and v2.0.
+	 */
+	ini->max_conns = SMC_RMBS_PER_LGR_MAX;
+
 	if ((!(ini->smcd_version & SMC_V2) && !(ini->smcr_version & SMC_V2)) ||
 	    ini->release_ver < SMC_RELEASE_1)
 		return 0;
@@ -1171,15 +1186,30 @@ int smc_clc_srv_v2x_features_validate(struct smc_clc_msg_proposal *pclc,
 	if (!pclc_v2_ext)
 		return SMC_CLC_DECL_NOV2EXT;
 
+	if (ini->smcr_version & SMC_V2) {
+		ini->max_conns = min_t(u8, pclc_v2_ext->max_conns, SMC_CONN_PER_LGR_MAX);
+		if (!ini->max_conns)
+			return SMC_CLC_DECL_MAXCONNERR;
+	}
+
 	return 0;
 }
 
 int smc_clc_cli_v2x_features_validate(struct smc_clc_first_contact_ext *fce,
 				      struct smc_init_info *ini)
 {
+	struct smc_clc_first_contact_ext_v2x *fce_v2x =
+		(struct smc_clc_first_contact_ext_v2x *)fce;
+
 	if (ini->release_ver < SMC_RELEASE_1)
 		return 0;
 
+	if (!ini->is_smcd) {
+		if (fce_v2x->max_conns > SMC_CONN_PER_LGR_MAX)
+			return SMC_CLC_DECL_MAXCONNERR;
+		ini->max_conns = fce_v2x->max_conns;
+	}
+
 	return 0;
 }
 
@@ -1190,6 +1220,8 @@ int smc_clc_v2x_features_confirm_check(struct smc_clc_msg_accept_confirm *cclc,
 		(struct smc_clc_msg_accept_confirm_v2 *)cclc;
 	struct smc_clc_first_contact_ext *fce =
 		smc_get_clc_first_contact_ext(clc_v2, ini->is_smcd);
+	struct smc_clc_first_contact_ext_v2x *fce_v2x =
+		(struct smc_clc_first_contact_ext_v2x *)fce;
 
 	if (cclc->hdr.version == SMC_V1 ||
 	    !(cclc->hdr.typev2 & SMC_FIRST_CONTACT_MASK))
@@ -1201,6 +1233,11 @@ int smc_clc_v2x_features_confirm_check(struct smc_clc_msg_accept_confirm *cclc,
 	if (fce->release < SMC_RELEASE_1)
 		return 0;
 
+	if (!ini->is_smcd) {
+		if (fce_v2x->max_conns != ini->max_conns)
+			return SMC_CLC_DECL_MAXCONNERR;
+	}
+
 	return 0;
 }
 
diff --git a/net/smc/smc_clc.h b/net/smc/smc_clc.h
index 66932bfdc6d0..54077e50c368 100644
--- a/net/smc/smc_clc.h
+++ b/net/smc/smc_clc.h
@@ -46,6 +46,7 @@
 #define SMC_CLC_DECL_NOSMCD2DEV	0x03030007  /* no SMC-Dv2 device found	      */
 #define SMC_CLC_DECL_NOUEID	0x03030008  /* peer sent no UEID	      */
 #define SMC_CLC_DECL_RELEASEERR	0x03030009  /* release version negotiate failed */
+#define SMC_CLC_DECL_MAXCONNERR	0x0303000a  /* max connections negotiate failed */
 #define SMC_CLC_DECL_MODEUNSUPP	0x03040000  /* smc modes do not match (R or D)*/
 #define SMC_CLC_DECL_RMBE_EC	0x03050000  /* peer has eyecatcher in RMBE    */
 #define SMC_CLC_DECL_OPTUNSUPP	0x03060000  /* fastopen sockopt not supported */
@@ -134,7 +135,8 @@ struct smc_clc_smcd_gid_chid {
 struct smc_clc_v2_extension {
 	struct smc_clnt_opts_area_hdr hdr;
 	u8 roce[16];		/* RoCEv2 GID */
-	u8 reserved[16];
+	u8 max_conns;
+	u8 reserved[15];
 	u8 user_eids[][SMC_MAX_EID_LEN];
 };
 
@@ -236,7 +238,8 @@ struct smc_clc_first_contact_ext {
 
 struct smc_clc_first_contact_ext_v2x {
 	struct smc_clc_first_contact_ext fce_v20;
-	u8 reserved3[4];
+	u8 max_conns; /* for SMC-R only */
+	u8 reserved3[3];
 	__be32 vendor_exp_options;
 	u8 reserved4[8];
 } __packed;		/* format defined in
diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index 6aa3db47a956..5de1fbaa6e28 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -895,9 +895,11 @@ static int smc_lgr_create(struct smc_sock *smc, struct smc_init_info *ini)
 			lgr->uses_gateway = ini->smcrv2.uses_gateway;
 			memcpy(lgr->nexthop_mac, ini->smcrv2.nexthop_mac,
 			       ETH_ALEN);
+			lgr->max_conns = ini->max_conns;
 		} else {
 			ibdev = ini->ib_dev;
 			ibport = ini->ib_port;
+			lgr->max_conns = SMC_RMBS_PER_LGR_MAX;
 		}
 		memcpy(lgr->pnet_id, ibdev->pnetid[ibport - 1],
 		       SMC_MAX_PNETID_LEN);
@@ -1890,7 +1892,7 @@ int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini)
 		    (ini->smcd_version == SMC_V2 ||
 		     lgr->vlan_id == ini->vlan_id) &&
 		    (role == SMC_CLNT || ini->is_smcd ||
-		    (lgr->conns_num < SMC_RMBS_PER_LGR_MAX &&
+		    (lgr->conns_num < lgr->max_conns &&
 		      !bitmap_full(lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX)))) {
 			/* link group found */
 			ini->first_contact_local = 0;
diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h
index 1a97fef39127..065369dc6584 100644
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h
@@ -22,6 +22,7 @@
 #include "smc_ib.h"
 
 #define SMC_RMBS_PER_LGR_MAX	255	/* max. # of RMBs per link group */
+#define SMC_CONN_PER_LGR_MAX	255	/* max. # of connections per link group */
 
 struct smc_lgr_list {			/* list of link group definition */
 	struct list_head	list;
@@ -331,6 +332,8 @@ struct smc_link_group {
 			__be32			saddr;
 						/* net namespace */
 			struct net		*net;
+			u8			max_conns;
+						/* max conn can be assigned to lgr */
 		};
 		struct { /* SMC-D */
 			u64			peer_gid;
@@ -375,6 +378,7 @@ struct smc_init_info {
 	u8			smc_type_v1;
 	u8			smc_type_v2;
 	u8			release_ver;
+	u8			max_conns;
 	u8			first_contact_peer;
 	u8			first_contact_local;
 	unsigned short		vlan_id;
diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c
index 90f0b60b196a..5347b62f1518 100644
--- a/net/smc/smc_llc.c
+++ b/net/smc/smc_llc.c
@@ -52,7 +52,8 @@ struct smc_llc_msg_confirm_link {	/* type 0x01 */
 	u8 link_num;
 	u8 link_uid[SMC_LGR_ID_SIZE];
 	u8 max_links;
-	u8 reserved[9];
+	u8 max_conns;
+	u8 reserved[8];
 };
 
 #define SMC_LLC_FLAG_ADD_LNK_REJ	0x40
@@ -472,6 +473,9 @@ int smc_llc_send_confirm_link(struct smc_link *link,
 	confllc->link_num = link->link_id;
 	memcpy(confllc->link_uid, link->link_uid, SMC_LGR_ID_SIZE);
 	confllc->max_links = SMC_LLC_ADD_LNK_MAX_LINKS;
+	if (link->lgr->smc_version == SMC_V2 &&
+	    link->lgr->peer_smc_release >= SMC_RELEASE_1)
+		confllc->max_conns = link->lgr->max_conns;
 	/* send llc message */
 	rc = smc_wr_tx_send(link, pend);
 put_out:
-- 
2.24.3 (Apple Git-128)

[RFC PATCH net-next 5/6] net/smc: support max links per lgr negotiation in clc handshake

[Guangguan Wang]

Support max links per lgr negotiation in clc handshake for SMCR v2.1,
which is one of smc v2.1 features.

Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>
Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
---
 net/smc/af_smc.c   | 44 +++++++++++++++++++++++++++-----------------
 net/smc/smc_clc.c  | 16 +++++++++++++++-
 net/smc/smc_clc.h  |  7 +++++--
 net/smc/smc_core.c |  5 +++++
 net/smc/smc_core.h |  5 +++++
 net/smc/smc_llc.c  | 17 +++++++++++++----
 6 files changed, 70 insertions(+), 24 deletions(-)

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index b95d3fd48c28..23384d08d3f2 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -610,20 +610,22 @@ static int smcr_clnt_conf_first_link(struct smc_sock *smc)
 	smc_llc_link_active(link);
 	smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE);
 
-	/* optional 2nd link, receive ADD LINK request from server */
-	qentry = smc_llc_wait(link->lgr, NULL, SMC_LLC_WAIT_TIME,
-			      SMC_LLC_ADD_LINK);
-	if (!qentry) {
-		struct smc_clc_msg_decline dclc;
-
-		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
-				      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
-		if (rc == -EAGAIN)
-			rc = 0; /* no DECLINE received, go with one link */
-		return rc;
+	if (link->lgr->max_links > 1) {
+		/* optional 2nd link, receive ADD LINK request from server */
+		qentry = smc_llc_wait(link->lgr, NULL, SMC_LLC_WAIT_TIME,
+				      SMC_LLC_ADD_LINK);
+		if (!qentry) {
+			struct smc_clc_msg_decline dclc;
+
+			rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
+					      SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
+			if (rc == -EAGAIN)
+				rc = 0; /* no DECLINE received, go with one link */
+			return rc;
+		}
+		smc_llc_flow_qentry_clr(&link->lgr->llc_flow_lcl);
+		smc_llc_cli_add_link(link, qentry);
 	}
-	smc_llc_flow_qentry_clr(&link->lgr->llc_flow_lcl);
-	smc_llc_cli_add_link(link, qentry);
 	return 0;
 }
 
@@ -1215,6 +1217,7 @@ static int smc_connect_rdma(struct smc_sock *smc,
 	memcpy(ini->peer_gid, aclc->r0.lcl.gid, SMC_GID_SIZE);
 	memcpy(ini->peer_mac, aclc->r0.lcl.mac, ETH_ALEN);
 	ini->max_conns = SMC_RMBS_PER_LGR_MAX;
+	ini->max_links = SMC_LINKS_ADD_LNK_MAX;
 
 	reason_code = smc_connect_rdma_v2_prepare(smc, aclc, ini);
 	if (reason_code)
@@ -1861,10 +1864,12 @@ static int smcr_serv_conf_first_link(struct smc_sock *smc)
 	smc_llc_link_active(link);
 	smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE);
 
-	down_write(&link->lgr->llc_conf_mutex);
-	/* initial contact - try to establish second link */
-	smc_llc_srv_add_link(link, NULL);
-	up_write(&link->lgr->llc_conf_mutex);
+	if (link->lgr->max_links > 1) {
+		down_write(&link->lgr->llc_conf_mutex);
+		/* initial contact - try to establish second link */
+		smc_llc_srv_add_link(link, NULL);
+		up_write(&link->lgr->llc_conf_mutex);
+	}
 	return 0;
 }
 
@@ -2468,6 +2473,11 @@ static void smc_listen_work(struct work_struct *work)
 		goto out_decl;
 	}
 
+	/* fce smc release version is needed in smc_listen_rdma_finish,
+	 * so save fce info here.
+	 */
+	smc_conn_save_peer_info_fce(new_smc, cclc);
+
 	/* finish worker */
 	if (!ini->is_smcd) {
 		rc = smc_listen_rdma_finish(new_smc, cclc,
diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
index 5e90234df189..66b6d2dc98a8 100644
--- a/net/smc/smc_clc.c
+++ b/net/smc/smc_clc.c
@@ -433,8 +433,10 @@ static int smc_clc_fill_fce(struct smc_clc_first_contact_ext_v2x *fce,
 	}
 
 	if (ini->release_ver >= SMC_RELEASE_1) {
-		if (!ini->is_smcd)
+		if (!ini->is_smcd) {
 			fce->max_conns = ini->max_conns;
+			fce->max_links = ini->max_links;
+		}
 	}
 
 out:
@@ -942,6 +944,7 @@ int smc_clc_send_proposal(struct smc_sock *smc, struct smc_init_info *ini)
 	if (smcr_indicated(ini->smc_type_v2)) {
 		memcpy(v2_ext->roce, ini->smcrv2.ib_gid_v2, SMC_GID_SIZE);
 		v2_ext->max_conns = SMC_CONN_PER_LGR_MAX;
+		v2_ext->max_links = SMC_LINKS_PER_LGR_MAX_PREFER;
 	}
 
 	pclc_base->hdr.length = htons(plen);
@@ -1177,6 +1180,7 @@ int smc_clc_srv_v2x_features_validate(struct smc_clc_msg_proposal *pclc,
 	 * which is the default value in smc v1 and v2.0.
 	 */
 	ini->max_conns = SMC_RMBS_PER_LGR_MAX;
+	ini->max_links = SMC_LINKS_ADD_LNK_MAX;
 
 	if ((!(ini->smcd_version & SMC_V2) && !(ini->smcr_version & SMC_V2)) ||
 	    ini->release_ver < SMC_RELEASE_1)
@@ -1190,6 +1194,10 @@ int smc_clc_srv_v2x_features_validate(struct smc_clc_msg_proposal *pclc,
 		ini->max_conns = min_t(u8, pclc_v2_ext->max_conns, SMC_CONN_PER_LGR_MAX);
 		if (!ini->max_conns)
 			return SMC_CLC_DECL_MAXCONNERR;
+
+		ini->max_links = min_t(u8, pclc_v2_ext->max_links, SMC_LINKS_PER_LGR_MAX_PREFER);
+		if (!ini->max_links)
+			return SMC_CLC_DECL_MAXLINKERR;
 	}
 
 	return 0;
@@ -1208,6 +1216,10 @@ int smc_clc_cli_v2x_features_validate(struct smc_clc_first_contact_ext *fce,
 		if (fce_v2x->max_conns > SMC_CONN_PER_LGR_MAX)
 			return SMC_CLC_DECL_MAXCONNERR;
 		ini->max_conns = fce_v2x->max_conns;
+
+		if (fce_v2x->max_links > SMC_LINKS_ADD_LNK_MAX)
+			return SMC_CLC_DECL_MAXLINKERR;
+		ini->max_links = fce_v2x->max_links;
 	}
 
 	return 0;
@@ -1236,6 +1248,8 @@ int smc_clc_v2x_features_confirm_check(struct smc_clc_msg_accept_confirm *cclc,
 	if (!ini->is_smcd) {
 		if (fce_v2x->max_conns != ini->max_conns)
 			return SMC_CLC_DECL_MAXCONNERR;
+		if (fce_v2x->max_links != ini->max_links)
+			return SMC_CLC_DECL_MAXLINKERR;
 	}
 
 	return 0;
diff --git a/net/smc/smc_clc.h b/net/smc/smc_clc.h
index 54077e50c368..53fb20d7c14d 100644
--- a/net/smc/smc_clc.h
+++ b/net/smc/smc_clc.h
@@ -47,6 +47,7 @@
 #define SMC_CLC_DECL_NOUEID	0x03030008  /* peer sent no UEID	      */
 #define SMC_CLC_DECL_RELEASEERR	0x03030009  /* release version negotiate failed */
 #define SMC_CLC_DECL_MAXCONNERR	0x0303000a  /* max connections negotiate failed */
+#define SMC_CLC_DECL_MAXLINKERR	0x0303000b  /* max links negotiate failed */
 #define SMC_CLC_DECL_MODEUNSUPP	0x03040000  /* smc modes do not match (R or D)*/
 #define SMC_CLC_DECL_RMBE_EC	0x03050000  /* peer has eyecatcher in RMBE    */
 #define SMC_CLC_DECL_OPTUNSUPP	0x03060000  /* fastopen sockopt not supported */
@@ -136,7 +137,8 @@ struct smc_clc_v2_extension {
 	struct smc_clnt_opts_area_hdr hdr;
 	u8 roce[16];		/* RoCEv2 GID */
 	u8 max_conns;
-	u8 reserved[15];
+	u8 max_links;
+	u8 reserved[14];
 	u8 user_eids[][SMC_MAX_EID_LEN];
 };
 
@@ -239,7 +241,8 @@ struct smc_clc_first_contact_ext {
 struct smc_clc_first_contact_ext_v2x {
 	struct smc_clc_first_contact_ext fce_v20;
 	u8 max_conns; /* for SMC-R only */
-	u8 reserved3[3];
+	u8 max_links; /* for SMC-R only */
+	u8 reserved3[2];
 	__be32 vendor_exp_options;
 	u8 reserved4[8];
 } __packed;		/* format defined in
diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index 5de1fbaa6e28..d5967826bcdf 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -896,10 +896,12 @@ static int smc_lgr_create(struct smc_sock *smc, struct smc_init_info *ini)
 			memcpy(lgr->nexthop_mac, ini->smcrv2.nexthop_mac,
 			       ETH_ALEN);
 			lgr->max_conns = ini->max_conns;
+			lgr->max_links = ini->max_links;
 		} else {
 			ibdev = ini->ib_dev;
 			ibport = ini->ib_port;
 			lgr->max_conns = SMC_RMBS_PER_LGR_MAX;
+			lgr->max_links = SMC_LINKS_ADD_LNK_MAX;
 		}
 		memcpy(lgr->pnet_id, ibdev->pnetid[ibport - 1],
 		       SMC_MAX_PNETID_LEN);
@@ -1667,6 +1669,9 @@ void smcr_port_add(struct smc_ib_device *smcibdev, u8 ibport)
 		    !rdma_dev_access_netns(smcibdev->ibdev, lgr->net))
 			continue;
 
+		if (lgr->type == SMC_LGR_SINGLE && lgr->max_links <= 1)
+			continue;
+
 		/* trigger local add link processing */
 		link = smc_llc_usable_link(lgr);
 		if (link)
diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h
index 065369dc6584..60820b71c1c7 100644
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h
@@ -165,6 +165,8 @@ struct smc_link {
  */
 #define SMC_LINKS_PER_LGR_MAX	3
 #define SMC_SINGLE_LINK		0
+#define SMC_LINKS_PER_LGR_MAX_PREFER	2	/* prefer 2 links max per lgr */
+#define SMC_LINKS_ADD_LNK_MAX	2
 
 /* tx/rx buffer list element for sndbufs list and rmbs list of a lgr */
 struct smc_buf_desc {
@@ -334,6 +336,8 @@ struct smc_link_group {
 			struct net		*net;
 			u8			max_conns;
 						/* max conn can be assigned to lgr */
+			u8			max_links;
+						/* max links can be added in lgr */
 		};
 		struct { /* SMC-D */
 			u64			peer_gid;
@@ -379,6 +383,7 @@ struct smc_init_info {
 	u8			smc_type_v2;
 	u8			release_ver;
 	u8			max_conns;
+	u8			max_links;
 	u8			first_contact_peer;
 	u8			first_contact_local;
 	unsigned short		vlan_id;
diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c
index 5347b62f1518..41e5e149edf3 100644
--- a/net/smc/smc_llc.c
+++ b/net/smc/smc_llc.c
@@ -59,8 +59,6 @@ struct smc_llc_msg_confirm_link {	/* type 0x01 */
 #define SMC_LLC_FLAG_ADD_LNK_REJ	0x40
 #define SMC_LLC_REJ_RSN_NO_ALT_PATH	1
 
-#define SMC_LLC_ADD_LNK_MAX_LINKS	2
-
 struct smc_llc_msg_add_link {		/* type 0x02 */
 	struct smc_llc_hdr hd;
 	u8 sender_mac[ETH_ALEN];
@@ -472,10 +470,12 @@ int smc_llc_send_confirm_link(struct smc_link *link,
 	hton24(confllc->sender_qp_num, link->roce_qp->qp_num);
 	confllc->link_num = link->link_id;
 	memcpy(confllc->link_uid, link->link_uid, SMC_LGR_ID_SIZE);
-	confllc->max_links = SMC_LLC_ADD_LNK_MAX_LINKS;
+	confllc->max_links = SMC_LINKS_ADD_LNK_MAX;
 	if (link->lgr->smc_version == SMC_V2 &&
-	    link->lgr->peer_smc_release >= SMC_RELEASE_1)
+	    link->lgr->peer_smc_release >= SMC_RELEASE_1) {
 		confllc->max_conns = link->lgr->max_conns;
+		confllc->max_links = link->lgr->max_links;
+	}
 	/* send llc message */
 	rc = smc_wr_tx_send(link, pend);
 put_out:
@@ -1045,6 +1045,9 @@ int smc_llc_cli_add_link(struct smc_link *link, struct smc_llc_qentry *qentry)
 		goto out_reject;
 	}
 
+	if (lgr->type == SMC_LGR_SINGLE && lgr->max_links <= 1)
+		goto out_reject;
+
 	ini->vlan_id = lgr->vlan_id;
 	if (lgr->smc_version == SMC_V2) {
 		ini->check_smcrv2 = true;
@@ -1169,6 +1172,9 @@ static void smc_llc_cli_add_link_invite(struct smc_link *link,
 	    lgr->type == SMC_LGR_ASYMMETRIC_PEER)
 		goto out;
 
+	if (lgr->type == SMC_LGR_SINGLE && lgr->max_links <= 1)
+		goto out;
+
 	ini = kzalloc(sizeof(*ini), GFP_KERNEL);
 	if (!ini)
 		goto out;
@@ -1414,6 +1420,9 @@ int smc_llc_srv_add_link(struct smc_link *link,
 		goto out;
 	}
 
+	if (lgr->type == SMC_LGR_SINGLE && lgr->max_links <= 1)
+		goto out;
+
 	/* ignore client add link recommendation, start new flow */
 	ini->vlan_id = lgr->vlan_id;
 	if (lgr->smc_version == SMC_V2) {
-- 
2.24.3 (Apple Git-128)

[RFC PATCH net-next 6/6] net/smc: Extend SMCR v2 linkgroup netlink attribute

[Guangguan Wang]

Add SMC_NLA_LGR_R_V2_MAX_CONNS and SMC_NLA_LGR_R_V2_MAX_LINKS
to SMCR v2 linkgroup netlink attribute SMC_NLA_LGR_R_V2 for
linkgroup's detail info showing.

Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>
---
 include/uapi/linux/smc.h | 2 ++
 net/smc/smc_core.c       | 4 ++++
 2 files changed, 6 insertions(+)

diff --git a/include/uapi/linux/smc.h b/include/uapi/linux/smc.h
index bb4dacca31e7..837fcd4b0abc 100644
--- a/include/uapi/linux/smc.h
+++ b/include/uapi/linux/smc.h
@@ -107,6 +107,8 @@ enum {
 enum {
 	SMC_NLA_LGR_R_V2_UNSPEC,
 	SMC_NLA_LGR_R_V2_DIRECT,	/* u8 */
+	SMC_NLA_LGR_R_V2_MAX_CONNS,	/* u8 */
+	SMC_NLA_LGR_R_V2_MAX_LINKS,	/* u8 */
 	__SMC_NLA_LGR_R_V2_MAX,
 	SMC_NLA_LGR_R_V2_MAX = __SMC_NLA_LGR_R_V2_MAX - 1
 };
diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index d5967826bcdf..182ac69d25c8 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -319,6 +319,10 @@ static int smc_nl_fill_smcr_lgr_v2(struct smc_link_group *lgr,
 		goto errattr;
 	if (nla_put_u8(skb, SMC_NLA_LGR_R_V2_DIRECT, !lgr->uses_gateway))
 		goto errv2attr;
+	if (nla_put_u8(skb, SMC_NLA_LGR_R_V2_MAX_CONNS, lgr->max_conns))
+		goto errv2attr;
+	if (nla_put_u8(skb, SMC_NLA_LGR_R_V2_MAX_LINKS, lgr->max_links))
+		goto errv2attr;
 
 	nla_nest_end(skb, v2_attrs);
 	return 0;
-- 
2.24.3 (Apple Git-128)

Re: [RFC PATCH net-next 1/6] net/smc: support smc release version negotiation in clc handshake

[Simon Horman]

On Thu, Aug 03, 2023 at 09:24:17PM +0800, Guangguan Wang wrote:

...

Hi Guangguan Wang,

> @@ -1063,7 +1063,7 @@ static int smc_clc_send_confirm_accept(struct smc_sock *smc,
>  				memcpy(clc_v2->r1.eid, eid, SMC_MAX_EID_LEN);
>  			len = SMCR_CLC_ACCEPT_CONFIRM_LEN_V2;
>  			if (first_contact) {
> -				smc_clc_fill_fce(&fce, &len);
> +				smc_clc_fill_fce(&fce, &len, ini->release_ver);

Here ini is dereferenced...


>  				fce.v2_direct = !link->lgr->uses_gateway;
>  				memset(&gle, 0, sizeof(gle));
>  				if (ini && clc->hdr.type == SMC_CLC_CONFIRM) {

... but here it is assumed that ini may be NULL.

This seems inconsistent.

As flagged by Smatch.

...

-- 
pw-bot: changes-requested

Re: [RFC PATCH net-next 2/6] net/smc: add vendor unique experimental options area in clc handshake

[Simon Horman]

On Thu, Aug 03, 2023 at 09:24:18PM +0800, Guangguan Wang wrote:

...

Hi Guangguan Wang,

> @@ -987,12 +991,12 @@ static int smc_clc_send_confirm_accept(struct smc_sock *smc,
>  {
>  	struct smc_connection *conn = &smc->conn;
>  	struct smc_clc_msg_accept_confirm *clc;
> -	struct smc_clc_first_contact_ext fce;
> +	struct smc_clc_first_contact_ext_v2x fce;
>  	struct smc_clc_fce_gid_ext gle;
>  	struct smc_clc_msg_trail trl;
>  	struct kvec vec[5];
>  	struct msghdr msg;
> -	int i, len;
> +	int i, len, fce_len;

Please preserve reverse xmas tree - longest line to shortest -
for local variable declarations: this is Networking code.

https://github.com/ecree-solarflare/xmastree is your friend here.

...

Re: [RFC PATCH net-next 4/6] net/smc: support max connections per lgr negotiation

[Simon Horman]

On Thu, Aug 03, 2023 at 09:24:20PM +0800, Guangguan Wang wrote:
> Support max connections per lgr negotiation for SMCR v2.1,
> which is one of smc v2.1 features.
> 
> Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>
> Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>

...

Hi Guangguan Wang,

>  int smc_clc_cli_v2x_features_validate(struct smc_clc_first_contact_ext *fce,
>  				      struct smc_init_info *ini)
>  {
> +	struct smc_clc_first_contact_ext_v2x *fce_v2x =
> +		(struct smc_clc_first_contact_ext_v2x *)fce;
> +
>  	if (ini->release_ver < SMC_RELEASE_1)
>  		return 0;
>  
> +	if (!ini->is_smcd) {
> +		if (fce_v2x->max_conns > SMC_CONN_PER_LGR_MAX)

The type of the max_cons field is u8.
The value of SMC_CONN_PER_LGR_MAX is 255 (in another patch of this series),
the maximum value that the max_cons field can be assigned.
So it seems that this condition cannot ever be true.

As flagged by Smatch.

> +			return SMC_CLC_DECL_MAXCONNERR;
> +		ini->max_conns = fce_v2x->max_conns;
> +	}
> +
>  	return 0;
>  }

...

> diff --git a/net/smc/smc_clc.h b/net/smc/smc_clc.h

...

> @@ -236,7 +238,8 @@ struct smc_clc_first_contact_ext {
>  
>  struct smc_clc_first_contact_ext_v2x {
>  	struct smc_clc_first_contact_ext fce_v20;
> -	u8 reserved3[4];
> +	u8 max_conns; /* for SMC-R only */
> +	u8 reserved3[3];
>  	__be32 vendor_exp_options;
>  	u8 reserved4[8];
>  } __packed;		/* format defined in

...

> diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h
> index 1a97fef39127..065369dc6584 100644
> --- a/net/smc/smc_core.h
> +++ b/net/smc/smc_core.h
> @@ -22,6 +22,7 @@
>  #include "smc_ib.h"
>  
>  #define SMC_RMBS_PER_LGR_MAX	255	/* max. # of RMBs per link group */
> +#define SMC_CONN_PER_LGR_MAX	255	/* max. # of connections per link group */
>  
>  struct smc_lgr_list {			/* list of link group definition */
>  	struct list_head	list;

Re: [RFC PATCH net-next 1/6] net/smc: support smc release version negotiation in clc handshake

[Guangguan Wang]

Hi Simon,

Thanks for the review.

Before this patch set, the ini pointer is NULL when sending accept clc msg. This patch set
has changed the ini pointer to non-NULL value both when sending accept clc msg and when
sending confirm clc msg. And the ini pointer in smc_clc_send_confirm_accept will not be NULL
any more.

I will remove the ini NULL check in the next version.
if (ini && clc->hdr.type == SMC_CLC_CONFIRM) => if (clc->hdr.type == SMC_CLC_CONFIRM)

Thanks,
Guangguan Wang

On 2023/8/4 01:42, Simon Horman wrote:
> On Thu, Aug 03, 2023 at 09:24:17PM +0800, Guangguan Wang wrote:
> 
> ...
> 
> Hi Guangguan Wang,
> 
>> @@ -1063,7 +1063,7 @@ static int smc_clc_send_confirm_accept(struct smc_sock *smc,
>>  				memcpy(clc_v2->r1.eid, eid, SMC_MAX_EID_LEN);
>>  			len = SMCR_CLC_ACCEPT_CONFIRM_LEN_V2;
>>  			if (first_contact) {
>> -				smc_clc_fill_fce(&fce, &len);
>> +				smc_clc_fill_fce(&fce, &len, ini->release_ver);
> 
> Here ini is dereferenced...
> 
> 
>>  				fce.v2_direct = !link->lgr->uses_gateway;
>>  				memset(&gle, 0, sizeof(gle));
>>  				if (ini && clc->hdr.type == SMC_CLC_CONFIRM) {
> 
> ... but here it is assumed that ini may be NULL.
> 
> This seems inconsistent.
> 
> As flagged by Smatch.
> 
> ...
> 

Re: [RFC PATCH net-next 2/6] net/smc: add vendor unique experimental options area in clc handshake

[Guangguan Wang]

I will fix it in the next version.

Thanks, 
Guangguan Wang

On 2023/8/4 01:45, Simon Horman wrote:
> On Thu, Aug 03, 2023 at 09:24:18PM +0800, Guangguan Wang wrote:
> 
> ...
> 
> Hi Guangguan Wang,
> 
>> @@ -987,12 +991,12 @@ static int smc_clc_send_confirm_accept(struct smc_sock *smc,
>>  {
>>  	struct smc_connection *conn = &smc->conn;
>>  	struct smc_clc_msg_accept_confirm *clc;
>> -	struct smc_clc_first_contact_ext fce;
>> +	struct smc_clc_first_contact_ext_v2x fce;
>>  	struct smc_clc_fce_gid_ext gle;
>>  	struct smc_clc_msg_trail trl;
>>  	struct kvec vec[5];
>>  	struct msghdr msg;
>> -	int i, len;
>> +	int i, len, fce_len;
> 
> Please preserve reverse xmas tree - longest line to shortest -
> for local variable declarations: this is Networking code.
> 
> https://github.com/ecree-solarflare/xmastree is your friend here.
> 
> ...

Re: [RFC PATCH net-next 4/6] net/smc: support max connections per lgr negotiation

[Guangguan Wang]

Got it.
I will remove the check in the next version.

Thanks,
Guangguan Wang

On 2023/8/4 01:55, Simon Horman wrote:
> On Thu, Aug 03, 2023 at 09:24:20PM +0800, Guangguan Wang wrote:
>> Support max connections per lgr negotiation for SMCR v2.1,
>> which is one of smc v2.1 features.
>>
>> Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>
>> Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
> 
> ...
> 
> Hi Guangguan Wang,
> 
>>  int smc_clc_cli_v2x_features_validate(struct smc_clc_first_contact_ext *fce,
>>  				      struct smc_init_info *ini)
>>  {
>> +	struct smc_clc_first_contact_ext_v2x *fce_v2x =
>> +		(struct smc_clc_first_contact_ext_v2x *)fce;
>> +
>>  	if (ini->release_ver < SMC_RELEASE_1)
>>  		return 0;
>>  
>> +	if (!ini->is_smcd) {
>> +		if (fce_v2x->max_conns > SMC_CONN_PER_LGR_MAX)
> 
> The type of the max_cons field is u8.
> The value of SMC_CONN_PER_LGR_MAX is 255 (in another patch of this series),
> the maximum value that the max_cons field can be assigned.
> So it seems that this condition cannot ever be true.
> 
> As flagged by Smatch.
> 
>> +			return SMC_CLC_DECL_MAXCONNERR;
>> +		ini->max_conns = fce_v2x->max_conns;
>> +	}
>> +
>>  	return 0;
>>  }
> 
> ...
> 
>> diff --git a/net/smc/smc_clc.h b/net/smc/smc_clc.h
> 
> ...
> 
>> @@ -236,7 +238,8 @@ struct smc_clc_first_contact_ext {
>>  
>>  struct smc_clc_first_contact_ext_v2x {
>>  	struct smc_clc_first_contact_ext fce_v20;
>> -	u8 reserved3[4];
>> +	u8 max_conns; /* for SMC-R only */
>> +	u8 reserved3[3];
>>  	__be32 vendor_exp_options;
>>  	u8 reserved4[8];
>>  } __packed;		/* format defined in
> 
> ...
> 
>> diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h
>> index 1a97fef39127..065369dc6584 100644
>> --- a/net/smc/smc_core.h
>> +++ b/net/smc/smc_core.h
>> @@ -22,6 +22,7 @@
>>  #include "smc_ib.h"
>>  
>>  #define SMC_RMBS_PER_LGR_MAX	255	/* max. # of RMBs per link group */
>> +#define SMC_CONN_PER_LGR_MAX	255	/* max. # of connections per link group */
>>  
>>  struct smc_lgr_list {			/* list of link group definition */
>>  	struct list_head	list;