IB/iser: Support the remote invalidation exception

Declare that we support remote invalidation in case we are:
1. using fastreg method
2. always registering memory

Detect the invalidated rkey from the work completion info so we
won't invalidate it locally. The spec mandates that we must not rely
on the target remote invalidate our rkey so we must check it upon
a receive (scsi response) completion.
Signed-off-by: Jenny Derzhavetz <jennyf@mellanox.com>
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/ulp/iser/iscsi_iser.h

@@ -369,6 +369,7 @@ struct iser_reg_ops {
  *                 cpus and device max completion vectors
  * @comps:         Dinamically allocated array of completion handlers
  * @reg_ops:       Registration ops
+ * @remote_inv_sup: Remote invalidate is supported on this device
  */
 struct iser_device {
 	struct ib_device             *ib_device;
@@ -380,6 +381,7 @@ struct iser_device {
 	int			     comps_used;
 	struct iser_comp	     *comps;
 	const struct iser_reg_ops    *reg_ops;
+	bool                         remote_inv_sup;
 };
 
 #define ISER_CHECK_GUARD	0xc0
@@ -525,6 +527,7 @@ struct iser_conn {
 	u32                          num_rx_descs;
 	unsigned short               scsi_sg_tablesize;
 	unsigned int                 scsi_max_sectors;
+	bool			     snd_w_inv;
 };
 
 /**

drivers/infiniband/ulp/iser/iser_initiator.c

@@ -590,6 +590,57 @@ void iser_login_rsp(struct ib_cq *cq, struct ib_wc *wc)
 	ib_conn->post_recv_buf_count--;
 }
 
+static inline void
+iser_inv_desc(struct iser_fr_desc *desc, u32 rkey)
+{
+	if (likely(rkey == desc->rsc.mr->rkey))
+		desc->rsc.mr_valid = 0;
+	else if (likely(rkey == desc->pi_ctx->sig_mr->rkey))
+		desc->pi_ctx->sig_mr_valid = 0;
+}
+
+static int
+iser_check_remote_inv(struct iser_conn *iser_conn,
+		      struct ib_wc *wc,
+		      struct iscsi_hdr *hdr)
+{
+	if (wc->wc_flags & IB_WC_WITH_INVALIDATE) {
+		struct iscsi_task *task;
+		u32 rkey = wc->ex.invalidate_rkey;
+
+		iser_dbg("conn %p: remote invalidation for rkey %#x\n",
+			 iser_conn, rkey);
+
+		if (unlikely(!iser_conn->snd_w_inv)) {
+			iser_err("conn %p: unexepected remote invalidation, "
+				 "terminating connection\n", iser_conn);
+			return -EPROTO;
+		}
+
+		task = iscsi_itt_to_ctask(iser_conn->iscsi_conn, hdr->itt);
+		if (likely(task)) {
+			struct iscsi_iser_task *iser_task = task->dd_data;
+			struct iser_fr_desc *desc;
+
+			if (iser_task->dir[ISER_DIR_IN]) {
+				desc = iser_task->rdma_reg[ISER_DIR_IN].mem_h;
+				iser_inv_desc(desc, rkey);
+			}
+
+			if (iser_task->dir[ISER_DIR_OUT]) {
+				desc = iser_task->rdma_reg[ISER_DIR_OUT].mem_h;
+				iser_inv_desc(desc, rkey);
+			}
+		} else {
+			iser_err("failed to get task for itt=%d\n", hdr->itt);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+
 void iser_task_rsp(struct ib_cq *cq, struct ib_wc *wc)
 {
 	struct ib_conn *ib_conn = wc->qp->qp_context;
@@ -614,6 +665,12 @@ void iser_task_rsp(struct ib_cq *cq, struct ib_wc *wc)
 	iser_dbg("op 0x%x itt 0x%x dlen %d\n", hdr->opcode,
 		 hdr->itt, length);
 
+	if (iser_check_remote_inv(iser_conn, wc, hdr)) {
+		iscsi_conn_failure(iser_conn->iscsi_conn,
+				   ISCSI_ERR_CONN_FAILED);
+		return;
+	}
+
 	iscsi_iser_recv(iser_conn->iscsi_conn, hdr, desc->data, length);
 
 	ib_dma_sync_single_for_device(ib_conn->device->ib_device,

drivers/infiniband/ulp/iser/iser_memory.c

@@ -84,6 +84,7 @@ int iser_assign_reg_ops(struct iser_device *device)
 	} else if (ib_dev->attrs.device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS) {
 		iser_info("FastReg supported, using FastReg for registration\n");
 		device->reg_ops = &fastreg_ops;
+		device->remote_inv_sup = iser_always_reg;
 	} else {
 		iser_err("IB device does not support FMRs nor FastRegs, can't register memory\n");
 		return -1;

drivers/infiniband/ulp/iser/iser_verbs.c

@@ -812,7 +812,9 @@ static void iser_route_handler(struct rdma_cm_id *cma_id)
 	conn_param.rnr_retry_count     = 6;
 
 	memset(&req_hdr, 0, sizeof(req_hdr));
-	req_hdr.flags = (ISER_ZBVA_NOT_SUP | ISER_SEND_W_INV_NOT_SUP);
+	req_hdr.flags = ISER_ZBVA_NOT_SUP;
+	if (!device->remote_inv_sup)
+		req_hdr.flags |= ISER_SEND_W_INV_NOT_SUP;
 	conn_param.private_data	= (void *)&req_hdr;
 	conn_param.private_data_len = sizeof(struct iser_cm_hdr);
 
@@ -827,7 +829,8 @@ static void iser_route_handler(struct rdma_cm_id *cma_id)
 	iser_connect_error(cma_id);
 }
 
-static void iser_connected_handler(struct rdma_cm_id *cma_id)
+static void iser_connected_handler(struct rdma_cm_id *cma_id,
+				   const void *private_data)
 {
 	struct iser_conn *iser_conn;
 	struct ib_qp_attr attr;
@@ -841,6 +844,15 @@ static void iser_connected_handler(struct rdma_cm_id *cma_id)
 	(void)ib_query_qp(cma_id->qp, &attr, ~0, &init_attr);
 	iser_info("remote qpn:%x my qpn:%x\n", attr.dest_qp_num, cma_id->qp->qp_num);
 
+	if (private_data) {
+		u8 flags = *(u8 *)private_data;
+
+		iser_conn->snd_w_inv = !(flags & ISER_SEND_W_INV_NOT_SUP);
+	}
+
+	iser_info("conn %p: negotiated %s invalidation\n",
+		  iser_conn, iser_conn->snd_w_inv ? "remote" : "local");
+
 	iser_conn->state = ISER_CONN_UP;
 	complete(&iser_conn->up_completion);
 }
@@ -892,7 +904,7 @@ static int iser_cma_handler(struct rdma_cm_id *cma_id, struct rdma_cm_event *eve
 		iser_route_handler(cma_id);
 		break;
 	case RDMA_CM_EVENT_ESTABLISHED:
-		iser_connected_handler(cma_id);
+		iser_connected_handler(cma_id, event->param.conn.private_data);
 		break;
 	case RDMA_CM_EVENT_ADDR_ERROR:
 	case RDMA_CM_EVENT_ROUTE_ERROR: