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[for-next,v3,2/2] IB/hfi1: Adjust pkey entry in index 0

Message ID 20210715160445.142451.47651.stgit@awfm-01.cornelisnetworks.com (mailing list archive)
State Accepted
Delegated to: Jason Gunthorpe
Headers show
Series attempt at two small fixups | expand

Commit Message

Dennis Dalessandro July 15, 2021, 4:04 p.m. UTC 
From: Mike Marciniszyn <mike.marciniszyn@cornelisnetworks.com>

It is possible for the primary IPoIB network device associated with any
RDMA device to fail to join certain multicast groups preventing IPv6
neighbor discovery and possibly other network ULPs from working
correctly. The IPv4 broadcast group is not affected as the IPoIB
network device handles joining that multicast group directly.

This is because the primary IPoIB network device uses the pkey at
ndex 0 in the associated RDMA device's pkey table. Anytime the pkey
value of index 0 changes, the primary IPoIB network device
automatically modifies it's broadcast address
(i.e. /sys/class/net/[ib0]/broadcast), since the broadcast address
includes the pkey value, and then bounces carrier. This includes
initial pkey assignment, such as when the pkey at index 0 transitions
from the opa default of invalid (0x0000) to some value such as the
OPA default pkey for Virtual Fabric 0: 0x8001 or when the fabric manager
is restarted with a configuration change causing the pkey at index 0
to change. Many network ULPs are not sensitive to the carrier bounce
and are not expecting the broadcast address to change including the
linux IPv6 stack.  This problem does not affect IPoIB child network
devices as their pkey value is constant for all time.

To mitigate this issue, change the default pkey in at index 0 to
0x8001 to cover the predominant case and avoid issues as ipoib
comes up and the FM sweeps.

At some point, ipoib multicast support should automatically
fix non-broadcast addresses as it does with the primary broadcast
address.


Fixes: 7724105686e7 ("IB/hfi1: add driver files")
Suggested-by: Josh Collier <josh.d.collier@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@cornelisnetworks.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
---
 drivers/infiniband/hw/hfi1/init.c |    7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)
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Patch

diff --git a/drivers/infiniband/hw/hfi1/init.c b/drivers/infiniband/hw/hfi1/init.c
index 0986aa0..34106e5 100644
--- a/drivers/infiniband/hw/hfi1/init.c
+++ b/drivers/infiniband/hw/hfi1/init.c
@@ -650,12 +650,7 @@  void hfi1_init_pportdata(struct pci_dev *pdev, struct hfi1_pportdata *ppd,
 
 	ppd->pkeys[default_pkey_idx] = DEFAULT_P_KEY;
 	ppd->part_enforce |= HFI1_PART_ENFORCE_IN;
-
-	if (loopback) {
-		dd_dev_err(dd, "Faking data partition 0x8001 in idx %u\n",
-			   !default_pkey_idx);
-		ppd->pkeys[!default_pkey_idx] = 0x8001;
-	}
+	ppd->pkeys[0] = 0x8001;
 
 	INIT_WORK(&ppd->link_vc_work, handle_verify_cap);
 	INIT_WORK(&ppd->link_up_work, handle_link_up);