[PATCH net-next 07/18] net/smc: disable SEID on non-s390 architecture

Wen Gu
2023-09-19T14:43:05Z

On s390 architecture SMC-Dv2 SEID is generated by ISMv2 device with
partial cpuid. It is predefined and unique to represents the physical
machine (CPC), the maximum communication space of SMC-D.

On non-s390 archs like x86/64 or ARM, there is no similar information
to identify physical machine, especially in virtualization scenarios
like KVM, etc. In such cases, SEID is forcibly disabled and the user-
defined UEID will be used to represent the communicable space.

Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
---
net/smc/smc_clc.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)

diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
index c08e138..be56a7d 100644
--- a/net/smc/smc_clc.c
+++ b/net/smc/smc_clc.c
@@ -155,10 +155,12 @@ static int smc_clc_ueid_remove(char *ueid)
rc = 0;
}
}
+#if IS_ENABLED(CONFIG_S390)
if (!rc && !smc_clc_eid_table.ueid_cnt) {
smc_clc_eid_table.seid_enabled = 1;
rc = -EAGAIN; /* indicate success and enabling of seid */
}
+#endif
write_unlock(&smc_clc_eid_table.lock);
return rc;
}
@@ -273,22 +275,30 @@ int smc_nl_dump_seid(struct sk_buff *skb, struct netlink_callback *cb)

int smc_nl_enable_seid(struct sk_buff *skb, struct genl_info *info)
{
+#if IS_ENABLED(CONFIG_S390)
write_lock(&smc_clc_eid_table.lock);
smc_clc_eid_table.seid_enabled = 1;
write_unlock(&smc_clc_eid_table.lock);
return 0;
+#else
+ return -EOPNOTSUPP;
+#endif
}

int smc_nl_disable_seid(struct sk_buff *skb, struct genl_info *info)
{
int rc = 0;

+#if IS_ENABLED(CONFIG_S390)
write_lock(&smc_clc_eid_table.lock);
if (!smc_clc_eid_table.ueid_cnt)
rc = -ENOENT;
else
smc_clc_eid_table.seid_enabled = 0;
write_unlock(&smc_clc_eid_table.lock);
+#else
+ rc = -EOPNOTSUPP;
+#endif
return rc;
}

@@ -1290,7 +1300,11 @@ void __init smc_clc_init(void)
INIT_LIST_HEAD(&smc_clc_eid_table.list);
rwlock_init(&smc_clc_eid_table.lock);
smc_clc_eid_table.ueid_cnt = 0;
+#if IS_ENABLED(CONFIG_S390)
smc_clc_eid_table.seid_enabled = 1;
+#else
+ smc_clc_eid_table.seid_enabled = 0;
+#endif
}

void smc_clc_exit(void)
--
1.8.3.1