Patch "net/smc: disable SEID on non-s390 archs where virtual ISM may be used" has been added to the 6.7-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    net/smc: disable SEID on non-s390 archs where virtual ISM may be used

to the 6.7-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     net-smc-disable-seid-on-non-s390-archs-where-virtual.patch
and it can be found in the queue-6.7 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 0b1dc89f74a514eafd8145365e42c283db6e22de
Author: Wen Gu <guwen@xxxxxxxxxxxxxxxxx>
Date:   Tue Dec 19 22:26:15 2023 +0800

    net/smc: disable SEID on non-s390 archs where virtual ISM may be used
    
    [ Upstream commit c6b8b8eb49904018e22e4e4b1fa502e57dc747d9 ]
    
    The system EID (SEID) is an internal EID used by SMC-D to represent the
    s390 physical machine that OS is executing on. On s390 architecture, it
    predefined by fixed string and part of cpuid and is enabled regardless
    of whether underlay device is virtual ISM or platform firmware ISM.
    
    However on non-s390 architectures where SMC-D can be used with virtual
    ISM devices, there is no similar information to identify physical
    machines, especially in virtualization scenarios. So 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@xxxxxxxxxxxxxxxxx>
    Reviewed-and-tested-by: Wenjia Zhang <wenjia@xxxxxxxxxxxxx>
    Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
index 72f4d81a3f41..1489a8421d78 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;
 }
 
@@ -1269,7 +1279,11 @@ 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)