[PATCH net-next v7 04/10] net/smc: support SMCv2.x supplemental features negotiation

Wen Gu
2023-12-19T08:45:56Z

This patch adds SMCv2.x supplemental features negotiation. Supported
SMCv2.x supplemental features are represented by feature_mask in FCE
field. The negotiation process is as follows.

Server Client
Proposal(features(c-mask bits))
<-----------------------------------------
Accept(features(s-mask bits))
----------------------------------------->
Confirm(features(s&c-mask bits))
<-----------------------------------------

Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-and-tested-by: Wenjia Zhang <wenjia@linux.ibm.com>
---
net/smc/smc.h | 4 ++++
net/smc/smc_clc.c | 7 +++++++
net/smc/smc_clc.h | 14 ++++++++++----
net/smc/smc_core.h | 1 +
4 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/net/smc/smc.h b/net/smc/smc.h
index cd51261b7d9e..95f56c712b0a 100644
--- a/net/smc/smc.h
+++ b/net/smc/smc.h
@@ -58,6 +58,10 @@ enum smc_state { /* possible states of an SMC socket */
SMC_PROCESSABORT = 27,
};

+#define SMC_FEATURE_MASK 0 /* bitmask of
+ * supported supplemental features
+ */
+
struct smc_link_group;

struct smc_wr_rx_hdr { /* common prefix part of LLC and CDC to demultiplex */
diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
index 64733335b6ca..900d307c17a9 100644
--- a/net/smc/smc_clc.c
+++ b/net/smc/smc_clc.c
@@ -438,6 +438,7 @@ static int smc_clc_fill_fce_v2x(struct smc_clc_first_contact_ext_v2x *fce_v2x,
fce_v2x->max_conns = ini->max_conns;
fce_v2x->max_links = ini->max_links;
}
+ fce_v2x->feature_mask = htons(ini->feature_mask);
}

out:
@@ -907,6 +908,7 @@ int smc_clc_send_proposal(struct smc_sock *smc, struct smc_init_info *ini)
pclc_smcd->v2_ext_offset = htons(v2_ext_offset);
plen += sizeof(*v2_ext);

+ v2_ext->feature_mask = htons(SMC_FEATURE_MASK);
read_lock(&smc_clc_eid_table.lock);
v2_ext->hdr.eid_cnt = smc_clc_eid_table.ueid_cnt;
plen += smc_clc_eid_table.ueid_cnt * SMC_MAX_EID_LEN;
@@ -1208,6 +1210,7 @@ int smc_clc_srv_v2x_features_validate(struct smc_sock *smc,

ini->max_conns = SMC_CONN_PER_LGR_MAX;
ini->max_links = SMC_LINKS_ADD_LNK_MAX;
+ ini->feature_mask = SMC_FEATURE_MASK;

if ((!(ini->smcd_version & SMC_V2) && !(ini->smcr_version & SMC_V2)) ||
ini->release_nr < SMC_RELEASE_1)
@@ -1251,6 +1254,8 @@ int smc_clc_clnt_v2x_features_validate(struct smc_clc_first_contact_ext *fce,
return SMC_CLC_DECL_MAXLINKERR;
ini->max_links = fce_v2x->max_links;
}
+ /* common supplemental features of server and client */
+ ini->feature_mask = ntohs(fce_v2x->feature_mask) & SMC_FEATURE_MASK;

return 0;
}
@@ -1279,6 +1284,8 @@ int smc_clc_v2x_features_confirm_check(struct smc_clc_msg_accept_confirm *cclc,
if (fce_v2x->max_links != ini->max_links)
return SMC_CLC_DECL_MAXLINKERR;
}
+ /* common supplemental features returned by client */
+ ini->feature_mask = ntohs(fce_v2x->feature_mask);

return 0;
}
diff --git a/net/smc/smc_clc.h b/net/smc/smc_clc.h
index 03f9ccea8c5e..c187d5f09d02 100644
--- a/net/smc/smc_clc.h
+++ b/net/smc/smc_clc.h
@@ -138,7 +138,8 @@ struct smc_clc_v2_extension {
u8 roce[16]; /* RoCEv2 GID */
u8 max_conns;
u8 max_links;
- u8 reserved[14];
+ __be16 feature_mask;
+ u8 reserved[12];
u8 user_eids[][SMC_MAX_EID_LEN];
};

@@ -240,9 +241,14 @@ struct smc_clc_first_contact_ext {

struct smc_clc_first_contact_ext_v2x {
struct smc_clc_first_contact_ext fce_v2_base;
- u8 max_conns; /* for SMC-R only */
- u8 max_links; /* for SMC-R only */
- u8 reserved3[2];
+ union {
+ struct {
+ u8 max_conns; /* for SMC-R only */
+ u8 max_links; /* for SMC-R only */
+ };
+ u8 reserved3[2]; /* for SMC-D only */
+ };
+ __be16 feature_mask;
__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 120027d40469..9f656780d46c 100644
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h
@@ -401,6 +401,7 @@ struct smc_init_info {
u8 max_links;
u8 first_contact_peer;
u8 first_contact_local;
+ u16 feature_mask;
unsigned short vlan_id;
u32 rc;
u8 negotiated_eid[SMC_MAX_EID_LEN];
--
2.32.0.3.g01195cf9f