IB/hfi1: Add transmit fault injection feature

Add ability to fault packets on transmit by opcode.
Dropping by packet can be achieved by setting the mask to 0.

In order to drop non-verbs traffic we set PbcInsertHrc
to NONE (0x2). The packet will still be delivered to
the receiving node but a KHdrHCRCErr (KDETH packet
with a bad HCRC) will be triggered and the packet will
not be delivered to the correct context.

In order to drop regular verbs traffic we set the
PbcTestEbp flag. The packet will still be delivered
to the receiving node but a 'late ebp error' will
be triggered and will be dropped.

A global toggle (/sys/kernel/debug/hfi1/hfi1_X/fault_suppress_err)
has been added to suppress the error messages on the receive
node when a packet was faulted on the sending node.
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Don Hiatt <don.hiatt@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/hfi1/chip.c

@@ -64,6 +64,7 @@
 #include "platform.h"
 #include "aspm.h"
 #include "affinity.h"
+#include "debugfs.h"
 
 #define NUM_IB_PORTS 1
 
@@ -7898,6 +7899,9 @@ static void handle_dcc_err(struct hfi1_devdata *dd, u32 unused, u64 reg)
 		reg &= ~DCC_ERR_FLG_EN_CSR_ACCESS_BLOCKED_HOST_SMASK;
 	}
 
+	if (unlikely(hfi1_dbg_fault_suppress_err(&dd->verbs_dev)))
+		reg &= ~DCC_ERR_FLG_LATE_EBP_ERR_SMASK;
+
 	/* report any remaining errors */
 	if (reg)
 		dd_dev_info_ratelimited(dd, "DCC Error: %s\n",

drivers/infiniband/hw/hfi1/debugfs.c

@@ -1240,6 +1240,11 @@ static int fault_init_debugfs(struct hfi1_ibdev *ibd)
 	return ret;
 }
 
+bool hfi1_dbg_fault_suppress_err(struct hfi1_ibdev *ibd)
+{
+	return ibd->fault_suppress_err;
+}
+
 bool hfi1_dbg_fault_opcode(struct rvt_qp *qp, u32 opcode, bool rx)
 {
 	bool ret = false;
@@ -1329,6 +1334,9 @@ void hfi1_dbg_ibdev_init(struct hfi1_ibdev *ibd)
 		}
 
 #ifdef CONFIG_FAULT_INJECTION
+	debugfs_create_bool("fault_suppress_err", 0600,
+			    ibd->hfi1_ibdev_dbg,
+			    &ibd->fault_suppress_err);
 	fault_init_debugfs(ibd);
 #endif
 }

drivers/infiniband/hw/hfi1/debugfs.h

@@ -75,6 +75,7 @@ struct fault_packet {
 
 bool hfi1_dbg_fault_opcode(struct rvt_qp *qp, u32 opcode, bool rx);
 bool hfi1_dbg_fault_packet(struct hfi1_packet *packet);
+bool hfi1_dbg_fault_suppress_err(struct hfi1_ibdev *ibd);
 #else
 static inline bool hfi1_dbg_fault_packet(struct hfi1_packet *packet)
 {
@@ -86,6 +87,11 @@ static inline bool hfi1_dbg_fault_opcode(struct rvt_qp *qp,
 {
 	return false;
 }
+
+static inline bool hfi1_dbg_fault_suppress_err(struct hfi1_ibdev *ibd)
+{
+	return false;
+}
 #endif
 
 #else
@@ -115,6 +121,11 @@ static inline bool hfi1_dbg_fault_opcode(struct rvt_qp *qp,
 {
 	return false;
 }
+
+static inline bool hfi1_dbg_fault_suppress_err(struct hfi1_ibdev *ibd)
+{
+	return false;
+}
 #endif
 
 #endif                          /* _HFI1_DEBUGFS_H */

drivers/infiniband/hw/hfi1/driver.c

@@ -1367,6 +1367,11 @@ int process_receive_ib(struct hfi1_packet *packet)
 			  packet->updegr,
 			  rhf_egr_index(packet->rhf));
 
+	if (unlikely(
+		 (hfi1_dbg_fault_suppress_err(&packet->rcd->dd->verbs_dev) &&
+		 (packet->rhf & RHF_DC_ERR))))
+		return RHF_RCV_CONTINUE;
+
 	if (unlikely(rhf_err_flags(packet->rhf))) {
 		handle_eflags(packet);
 		return RHF_RCV_CONTINUE;
@@ -1402,6 +1407,12 @@ int process_receive_bypass(struct hfi1_packet *packet)
 
 int process_receive_error(struct hfi1_packet *packet)
 {
+	/* KHdrHCRCErr -- KDETH packet with a bad HCRC */
+	if (unlikely(
+		 hfi1_dbg_fault_suppress_err(&packet->rcd->dd->verbs_dev) &&
+		 rhf_rcv_type_err(packet->rhf) == 3))
+		return RHF_RCV_CONTINUE;
+
 	handle_eflags(packet);
 
 	if (unlikely(rhf_err_flags(packet->rhf)))

drivers/infiniband/hw/hfi1/verbs.c

@@ -518,6 +518,35 @@ static inline opcode_handler qp_ok(int opcode, struct hfi1_packet *packet)
 	return NULL;
 }
 
+static u64 hfi1_fault_tx(struct rvt_qp *qp, u8 opcode, u64 pbc)
+{
+#ifdef CONFIG_FAULT_INJECTION
+	if ((opcode & IB_OPCODE_MSP) == IB_OPCODE_MSP)
+		/*
+		 * In order to drop non-IB traffic we
+		 * set PbcInsertHrc to NONE (0x2).
+		 * The packet will still be delivered
+		 * to the receiving node but a
+		 * KHdrHCRCErr (KDETH packet with a bad
+		 * HCRC) will be triggered and the
+		 * packet will not be delivered to the
+		 * correct context.
+		 */
+		pbc |= (u64)PBC_IHCRC_NONE << PBC_INSERT_HCRC_SHIFT;
+	else
+		/*
+		 * In order to drop regular verbs
+		 * traffic we set the PbcTestEbp
+		 * flag. The packet will still be
+		 * delivered to the receiving node but
+		 * a 'late ebp error' will be
+		 * triggered and will be dropped.
+		 */
+		pbc |= PBC_TEST_EBP;
+#endif
+	return pbc;
+}
+
 /**
  * hfi1_ib_rcv - process an incoming packet
  * @packet: data packet information
@@ -803,7 +832,6 @@ static int build_verbs_tx_desc(
 		if (ret)
 			goto bail_txadd;
 	}
-
 	/* add the ulp payload - if any. tx->ss can be NULL for acks */
 	if (tx->ss)
 		ret = build_verbs_ulp_payload(sde, length, tx);
@@ -822,7 +850,6 @@ int hfi1_verbs_send_dma(struct rvt_qp *qp, struct hfi1_pkt_state *ps,
 	struct hfi1_ibdev *dev = ps->dev;
 	struct hfi1_pportdata *ppd = ps->ppd;
 	struct verbs_txreq *tx;
-	u64 pbc_flags = 0;
 	u8 sc5 = priv->s_sc;
 
 	int ret;
@@ -831,12 +858,16 @@ int hfi1_verbs_send_dma(struct rvt_qp *qp, struct hfi1_pkt_state *ps,
 	if (!sdma_txreq_built(&tx->txreq)) {
 		if (likely(pbc == 0)) {
 			u32 vl = sc_to_vlt(dd_from_ibdev(qp->ibqp.device), sc5);
+			u8 opcode = get_opcode(&tx->phdr.hdr);
+
 			/* No vl15 here */
 			/* set PBC_DC_INFO bit (aka SC[4]) in pbc_flags */
-			pbc_flags |= (!!(sc5 & 0x10)) << PBC_DC_INFO_SHIFT;
+			pbc |= (!!(sc5 & 0x10)) << PBC_DC_INFO_SHIFT;
 
+			if (unlikely(hfi1_dbg_fault_opcode(qp, opcode, false)))
+				pbc = hfi1_fault_tx(qp, opcode, pbc);
 			pbc = create_pbc(ppd,
-					 pbc_flags,
+					 pbc,
 					 qp->srate_mbps,
 					 vl,
 					 plen);
@@ -939,7 +970,6 @@ int hfi1_verbs_send_pio(struct rvt_qp *qp, struct hfi1_pkt_state *ps,
 	u32 plen = hdrwords + dwords + 2; /* includes pbc */
 	struct hfi1_pportdata *ppd = ps->ppd;
 	u32 *hdr = (u32 *)&ps->s_txreq->phdr.hdr;
-	u64 pbc_flags = 0;
 	u8 sc5;
 	unsigned long flags = 0;
 	struct send_context *sc;
@@ -964,9 +994,14 @@ int hfi1_verbs_send_pio(struct rvt_qp *qp, struct hfi1_pkt_state *ps,
 
 	if (likely(pbc == 0)) {
 		u8 vl = sc_to_vlt(dd_from_ibdev(qp->ibqp.device), sc5);
+		struct verbs_txreq *tx = ps->s_txreq;
+		u8 opcode = get_opcode(&tx->phdr.hdr);
+
 		/* set PBC_DC_INFO bit (aka SC[4]) in pbc_flags */
-		pbc_flags |= (!!(sc5 & 0x10)) << PBC_DC_INFO_SHIFT;
-		pbc = create_pbc(ppd, pbc_flags, qp->srate_mbps, vl, plen);
+		pbc |= (!!(sc5 & 0x10)) << PBC_DC_INFO_SHIFT;
+		if (unlikely(hfi1_dbg_fault_opcode(qp, opcode, false)))
+			pbc = hfi1_fault_tx(qp, opcode, pbc);
+		pbc = create_pbc(ppd, pbc, qp->srate_mbps, vl, plen);
 	}
 	if (cb)
 		iowait_pio_inc(&priv->s_iowait);

drivers/infiniband/hw/hfi1/verbs.h

@@ -198,6 +198,7 @@ struct hfi1_ibdev {
 #ifdef CONFIG_FAULT_INJECTION
 	struct fault_opcode *fault_opcode;
 	struct fault_packet *fault_packet;
+	bool fault_suppress_err;
 #endif
 #endif
 };

include/rdma/ib_pack.h

@@ -80,6 +80,8 @@ enum {
 	IB_OPCODE_UD                                = 0x60,
 	/* per IBTA 1.3 vol 1 Table 38, A10.3.2 */
 	IB_OPCODE_CNP                               = 0x80,
+	/* Manufacturer specific */
+	IB_OPCODE_MSP                               = 0xe0,
 
 	/* operations -- just used to define real constants */
 	IB_OPCODE_SEND_FIRST                        = 0x00,