RDMA/rxe: Protext kernel index from user space

In order to prevent user space from modifying the index that belongs to
the kernel for shared queues let the kernel use a local copy of the index
and copy any new values of that index to the shared rxe_queue_bus struct.

This adds more switch statements which decreases the performance of the
queue API. Move the type into the parameter list for these functions so
that the compiler can optimize out the switch statements when the explicit
type is known. Modify all the calls in the driver on performance paths to
pass in the explicit queue type.

Link: https://lore.kernel.org/r/20210527194748.662636-4-rpearsonhpe@gmail.com
Link: https://lore.kernel.org/linux-rdma/20210526165239.GP1002214@@nvidia.com/Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/sw/rxe/rxe_comp.c

@@ -141,7 +141,10 @@ static inline enum comp_state get_wqe(struct rxe_qp *qp,
 	/* we come here whether or not we found a response packet to see if
 	 * there are any posted WQEs
 	 */
-	wqe = queue_head(qp->sq.queue);
+	if (qp->is_user)
+		wqe = queue_head(qp->sq.queue, QUEUE_TYPE_FROM_USER);
+	else
+		wqe = queue_head(qp->sq.queue, QUEUE_TYPE_KERNEL);
 	*wqe_p = wqe;
 
 	/* no WQE or requester has not started it yet */
@@ -414,16 +417,23 @@ static void do_complete(struct rxe_qp *qp, struct rxe_send_wqe *wqe)
 {
 	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
 	struct rxe_cqe cqe;
+	bool post;
 
-	if ((qp->sq_sig_type == IB_SIGNAL_ALL_WR) ||
+	/* do we need to post a completion */
+	post = ((qp->sq_sig_type == IB_SIGNAL_ALL_WR) ||
 			(wqe->wr.send_flags & IB_SEND_SIGNALED) ||
-	    wqe->status != IB_WC_SUCCESS) {
+			wqe->status != IB_WC_SUCCESS);
+
+	if (post)
 		make_send_cqe(qp, wqe, &cqe);
-		advance_consumer(qp->sq.queue);
+
+	if (qp->is_user)
+		advance_consumer(qp->sq.queue, QUEUE_TYPE_FROM_USER);
+	else
+		advance_consumer(qp->sq.queue, QUEUE_TYPE_KERNEL);
+
+	if (post)
 		rxe_cq_post(qp->scq, &cqe, 0);
-	} else {
-		advance_consumer(qp->sq.queue);
-	}
 
 	if (wqe->wr.opcode == IB_WR_SEND ||
 	    wqe->wr.opcode == IB_WR_SEND_WITH_IMM ||
@@ -511,6 +521,7 @@ static void rxe_drain_resp_pkts(struct rxe_qp *qp, bool notify)
 {
 	struct sk_buff *skb;
 	struct rxe_send_wqe *wqe;
+	struct rxe_queue *q = qp->sq.queue;
 
 	while ((skb = skb_dequeue(&qp->resp_pkts))) {
 		rxe_drop_ref(qp);
@@ -518,12 +529,12 @@ static void rxe_drain_resp_pkts(struct rxe_qp *qp, bool notify)
 		ib_device_put(qp->ibqp.device);
 	}
 
-	while ((wqe = queue_head(qp->sq.queue))) {
+	while ((wqe = queue_head(q, q->type))) {
 		if (notify) {
 			wqe->status = IB_WC_WR_FLUSH_ERR;
 			do_complete(qp, wqe);
 		} else {
-			advance_consumer(qp->sq.queue);
+			advance_consumer(q, q->type);
 		}
 	}
 }

drivers/infiniband/sw/rxe/rxe_cq.c

@@ -25,7 +25,11 @@ int rxe_cq_chk_attr(struct rxe_dev *rxe, struct rxe_cq *cq,
 	}
 
 	if (cq) {
-		count = queue_count(cq->queue);
+		if (cq->is_user)
+			count = queue_count(cq->queue, QUEUE_TYPE_TO_USER);
+		else
+			count = queue_count(cq->queue, QUEUE_TYPE_KERNEL);
+
 		if (cqe < count) {
 			pr_warn("cqe(%d) < current # elements in queue (%d)",
 				cqe, count);
@@ -108,10 +112,17 @@ int rxe_cq_post(struct rxe_cq *cq, struct rxe_cqe *cqe, int solicited)
 {
 	struct ib_event ev;
 	unsigned long flags;
+	int full;
+	void *addr;
 
 	spin_lock_irqsave(&cq->cq_lock, flags);
 
-	if (unlikely(queue_full(cq->queue))) {
+	if (cq->is_user)
+		full = queue_full(cq->queue, QUEUE_TYPE_TO_USER);
+	else
+		full = queue_full(cq->queue, QUEUE_TYPE_KERNEL);
+
+	if (unlikely(full)) {
 		spin_unlock_irqrestore(&cq->cq_lock, flags);
 		if (cq->ibcq.event_handler) {
 			ev.device = cq->ibcq.device;
@@ -123,9 +134,18 @@ int rxe_cq_post(struct rxe_cq *cq, struct rxe_cqe *cqe, int solicited)
 		return -EBUSY;
 	}
 
-	memcpy(producer_addr(cq->queue), cqe, sizeof(*cqe));
+	if (cq->is_user)
+		addr = producer_addr(cq->queue, QUEUE_TYPE_TO_USER);
+	else
+		addr = producer_addr(cq->queue, QUEUE_TYPE_KERNEL);
+
+	memcpy(addr, cqe, sizeof(*cqe));
+
+	if (cq->is_user)
+		advance_producer(cq->queue, QUEUE_TYPE_TO_USER);
+	else
+		advance_producer(cq->queue, QUEUE_TYPE_KERNEL);
 
-	advance_producer(cq->queue);
 	spin_unlock_irqrestore(&cq->cq_lock, flags);
 
 	if ((cq->notify == IB_CQ_NEXT_COMP) ||

drivers/infiniband/sw/rxe/rxe_qp.c

@@ -248,7 +248,13 @@ static int rxe_qp_init_req(struct rxe_dev *rxe, struct rxe_qp *qp,
 		return err;
 	}
 
-	qp->req.wqe_index	= producer_index(qp->sq.queue);
+	if (qp->is_user)
+		qp->req.wqe_index = producer_index(qp->sq.queue,
+						QUEUE_TYPE_FROM_USER);
+	else
+		qp->req.wqe_index = producer_index(qp->sq.queue,
+						QUEUE_TYPE_KERNEL);
+
 	qp->req.state		= QP_STATE_RESET;
 	qp->req.opcode		= -1;
 	qp->comp.opcode		= -1;
@@ -306,6 +312,8 @@ static int rxe_qp_init_resp(struct rxe_dev *rxe, struct rxe_qp *qp,
 	spin_lock_init(&qp->rq.producer_lock);
 	spin_lock_init(&qp->rq.consumer_lock);
 
+	qp->rq.is_user = qp->is_user;
+
 	skb_queue_head_init(&qp->resp_pkts);
 
 	rxe_init_task(rxe, &qp->resp.task, qp,

drivers/infiniband/sw/rxe/rxe_queue.c

@@ -111,14 +111,15 @@ struct rxe_queue *rxe_queue_init(struct rxe_dev *rxe, int *num_elem,
 static int resize_finish(struct rxe_queue *q, struct rxe_queue *new_q,
 			 unsigned int num_elem)
 {
-	if (!queue_empty(q) && (num_elem < queue_count(q)))
+	if (!queue_empty(q, q->type) && (num_elem < queue_count(q, q->type)))
 		return -EINVAL;
 
-	while (!queue_empty(q)) {
-		memcpy(producer_addr(new_q), consumer_addr(q),
+	while (!queue_empty(q, q->type)) {
+		memcpy(producer_addr(new_q, new_q->type),
+					consumer_addr(q, q->type),
 					new_q->elem_size);
-		advance_producer(new_q);
-		advance_consumer(q);
+		advance_producer(new_q, new_q->type);
+		advance_consumer(q, q->type);
 	}
 
 	swap(*q, *new_q);

drivers/infiniband/sw/rxe/rxe_queue.h

@@ -17,6 +17,20 @@
  * up to a power of 2. Since the queue is empty when the
  * producer and consumer indices match the maximum capacity
  * of the queue is one less than the number of element slots
+ *
+ * Notes:
+ *   - Kernel space indices are always masked off to q->index_mask
+ *   before storing so do not need to be checked on reads.
+ *   - User space indices may be out of range and must be
+ *   masked before use when read.
+ *   - The kernel indices for shared queues must not be written
+ *   by user space so a local copy is used and a shared copy is
+ *   stored when the local copy changes.
+ *   - By passing the type in the parameter list separate from q
+ *   the compiler can eliminate the switch statement when the
+ *   actual queue type is known when the function is called.
+ *   In the performance path this is done. In less critical
+ *   paths just q->type is passed.
  */
 
 /* type of queue */
@@ -35,6 +49,12 @@ struct rxe_queue {
 	unsigned int		log2_elem_size;
 	u32			index_mask;
 	enum queue_type		type;
+	/* private copy of index for shared queues between
+	 * kernel space and user space. Kernel reads and writes
+	 * this copy and then replicates to rxe_queue_buf
+	 * for read access by user space.
+	 */
+	u32			index;
 };
 
 int do_mmap_info(struct rxe_dev *rxe, struct mminfo __user *outbuf,
@@ -61,19 +81,19 @@ static inline int next_index(struct rxe_queue *q, int index)
 	return (index + 1) & q->buf->index_mask;
 }
 
-static inline int queue_empty(struct rxe_queue *q)
+static inline int queue_empty(struct rxe_queue *q, enum queue_type type)
 {
 	u32 prod;
 	u32 cons;
 
-	switch (q->type) {
+	switch (type) {
 	case QUEUE_TYPE_FROM_USER:
 		/* protect user space index */
 		prod = smp_load_acquire(&q->buf->producer_index);
-		cons = q->buf->consumer_index;
+		cons = q->index;
 		break;
 	case QUEUE_TYPE_TO_USER:
-		prod = q->buf->producer_index;
+		prod = q->index;
 		/* protect user space index */
 		cons = smp_load_acquire(&q->buf->consumer_index);
 		break;
@@ -86,19 +106,19 @@ static inline int queue_empty(struct rxe_queue *q)
 	return ((prod - cons) & q->index_mask) == 0;
 }
 
-static inline int queue_full(struct rxe_queue *q)
+static inline int queue_full(struct rxe_queue *q, enum queue_type type)
 {
 	u32 prod;
 	u32 cons;
 
-	switch (q->type) {
+	switch (type) {
 	case QUEUE_TYPE_FROM_USER:
 		/* protect user space index */
 		prod = smp_load_acquire(&q->buf->producer_index);
-		cons = q->buf->consumer_index;
+		cons = q->index;
 		break;
 	case QUEUE_TYPE_TO_USER:
-		prod = q->buf->producer_index;
+		prod = q->index;
 		/* protect user space index */
 		cons = smp_load_acquire(&q->buf->consumer_index);
 		break;
@@ -111,19 +131,20 @@ static inline int queue_full(struct rxe_queue *q)
 	return ((prod + 1 - cons) & q->index_mask) == 0;
 }
 
-static inline unsigned int queue_count(const struct rxe_queue *q)
+static inline unsigned int queue_count(const struct rxe_queue *q,
+					enum queue_type type)
 {
 	u32 prod;
 	u32 cons;
 
-	switch (q->type) {
+	switch (type) {
 	case QUEUE_TYPE_FROM_USER:
 		/* protect user space index */
 		prod = smp_load_acquire(&q->buf->producer_index);
-		cons = q->buf->consumer_index;
+		cons = q->index;
 		break;
 	case QUEUE_TYPE_TO_USER:
-		prod = q->buf->producer_index;
+		prod = q->index;
 		/* protect user space index */
 		cons = smp_load_acquire(&q->buf->consumer_index);
 		break;
@@ -136,90 +157,138 @@ static inline unsigned int queue_count(const struct rxe_queue *q)
 	return (prod - cons) & q->index_mask;
 }
 
-static inline void advance_producer(struct rxe_queue *q)
+static inline void advance_producer(struct rxe_queue *q, enum queue_type type)
 {
 	u32 prod;
 
-	if (q->type == QUEUE_TYPE_FROM_USER) {
+	switch (type) {
+	case QUEUE_TYPE_FROM_USER:
+		pr_warn_once("Normally kernel should not write user space index\n");
 		/* protect user space index */
 		prod = smp_load_acquire(&q->buf->producer_index);
 		prod = (prod + 1) & q->index_mask;
 		/* same */
 		smp_store_release(&q->buf->producer_index, prod);
-	} else {
+		break;
+	case QUEUE_TYPE_TO_USER:
+		prod = q->index;
+		q->index = (prod + 1) & q->index_mask;
+		q->buf->producer_index = q->index;
+		break;
+	case QUEUE_TYPE_KERNEL:
 		prod = q->buf->producer_index;
 		q->buf->producer_index = (prod + 1) & q->index_mask;
+		break;
 	}
 }
 
-static inline void advance_consumer(struct rxe_queue *q)
+static inline void advance_consumer(struct rxe_queue *q, enum queue_type type)
 {
 	u32 cons;
 
-	if (q->type == QUEUE_TYPE_TO_USER) {
+	switch (type) {
+	case QUEUE_TYPE_FROM_USER:
+		cons = q->index;
+		q->index = (cons + 1) & q->index_mask;
+		q->buf->consumer_index = q->index;
+		break;
+	case QUEUE_TYPE_TO_USER:
+		pr_warn_once("Normally kernel should not write user space index\n");
 		/* protect user space index */
 		cons = smp_load_acquire(&q->buf->consumer_index);
 		cons = (cons + 1) & q->index_mask;
 		/* same */
 		smp_store_release(&q->buf->consumer_index, cons);
-	} else {
+		break;
+	case QUEUE_TYPE_KERNEL:
 		cons = q->buf->consumer_index;
 		q->buf->consumer_index = (cons + 1) & q->index_mask;
+		break;
 	}
 }
 
-static inline void *producer_addr(struct rxe_queue *q)
+static inline void *producer_addr(struct rxe_queue *q, enum queue_type type)
 {
 	u32 prod;
 
-	if (q->type == QUEUE_TYPE_FROM_USER)
+	switch (type) {
+	case QUEUE_TYPE_FROM_USER:
 		/* protect user space index */
 		prod = smp_load_acquire(&q->buf->producer_index);
-	else
+		prod &= q->index_mask;
+		break;
+	case QUEUE_TYPE_TO_USER:
+		prod = q->index;
+		break;
+	case QUEUE_TYPE_KERNEL:
 		prod = q->buf->producer_index;
+		break;
+	}
 
-	return q->buf->data + ((prod & q->index_mask) << q->log2_elem_size);
+	return q->buf->data + (prod << q->log2_elem_size);
 }
 
-static inline void *consumer_addr(struct rxe_queue *q)
+static inline void *consumer_addr(struct rxe_queue *q, enum queue_type type)
 {
 	u32 cons;
 
-	if (q->type == QUEUE_TYPE_TO_USER)
+	switch (type) {
+	case QUEUE_TYPE_FROM_USER:
+		cons = q->index;
+		break;
+	case QUEUE_TYPE_TO_USER:
 		/* protect user space index */
 		cons = smp_load_acquire(&q->buf->consumer_index);
-	else
+		cons &= q->index_mask;
+		break;
+	case QUEUE_TYPE_KERNEL:
 		cons = q->buf->consumer_index;
+		break;
+	}
 
-	return q->buf->data + ((cons & q->index_mask) << q->log2_elem_size);
+	return q->buf->data + (cons << q->log2_elem_size);
 }
 
-static inline unsigned int producer_index(struct rxe_queue *q)
+static inline unsigned int producer_index(struct rxe_queue *q,
+						enum queue_type type)
 {
 	u32 prod;
 
-	if (q->type == QUEUE_TYPE_FROM_USER)
+	switch (type) {
+	case QUEUE_TYPE_FROM_USER:
 		/* protect user space index */
 		prod = smp_load_acquire(&q->buf->producer_index);
-	else
-		prod = q->buf->producer_index;
-
 		prod &= q->index_mask;
+		break;
+	case QUEUE_TYPE_TO_USER:
+		prod = q->index;
+		break;
+	case QUEUE_TYPE_KERNEL:
+		prod = q->buf->producer_index;
+		break;
+	}
 
 	return prod;
 }
 
-static inline unsigned int consumer_index(struct rxe_queue *q)
+static inline unsigned int consumer_index(struct rxe_queue *q,
+						enum queue_type type)
 {
 	u32 cons;
 
-	if (q->type == QUEUE_TYPE_TO_USER)
+	switch (type) {
+	case QUEUE_TYPE_FROM_USER:
+		cons = q->index;
+		break;
+	case QUEUE_TYPE_TO_USER:
 		/* protect user space index */
 		cons = smp_load_acquire(&q->buf->consumer_index);
-	else
-		cons = q->buf->consumer_index;
-
 		cons &= q->index_mask;
+		break;
+	case QUEUE_TYPE_KERNEL:
+		cons = q->buf->consumer_index;
+		break;
+	}
 
 	return cons;
 }
@@ -238,9 +307,9 @@ static inline unsigned int index_from_addr(const struct rxe_queue *q,
 				& q->index_mask;
 }
 
-static inline void *queue_head(struct rxe_queue *q)
+static inline void *queue_head(struct rxe_queue *q, enum queue_type type)
 {
-	return queue_empty(q) ? NULL : consumer_addr(q);
+	return queue_empty(q, type) ? NULL : consumer_addr(q, type);
 }
 
 #endif /* RXE_QUEUE_H */

drivers/infiniband/sw/rxe/rxe_req.c

@@ -45,14 +45,24 @@ static void req_retry(struct rxe_qp *qp)
 	unsigned int mask;
 	int npsn;
 	int first = 1;
+	struct rxe_queue *q = qp->sq.queue;
+	unsigned int cons;
+	unsigned int prod;
 
-	qp->req.wqe_index	= consumer_index(qp->sq.queue);
+	if (qp->is_user) {
+		cons = consumer_index(q, QUEUE_TYPE_FROM_USER);
+		prod = producer_index(q, QUEUE_TYPE_FROM_USER);
+	} else {
+		cons = consumer_index(q, QUEUE_TYPE_KERNEL);
+		prod = producer_index(q, QUEUE_TYPE_KERNEL);
+	}
+
+	qp->req.wqe_index	= cons;
 	qp->req.psn		= qp->comp.psn;
 	qp->req.opcode		= -1;
 
-	for (wqe_index = consumer_index(qp->sq.queue);
-		wqe_index != producer_index(qp->sq.queue);
-		wqe_index = next_index(qp->sq.queue, wqe_index)) {
+	for (wqe_index = cons; wqe_index != prod;
+			wqe_index = next_index(q, wqe_index)) {
 		wqe = addr_from_index(qp->sq.queue, wqe_index);
 		mask = wr_opcode_mask(wqe->wr.opcode, qp);
 
@@ -104,8 +114,22 @@ void rnr_nak_timer(struct timer_list *t)
 
 static struct rxe_send_wqe *req_next_wqe(struct rxe_qp *qp)
 {
-	struct rxe_send_wqe *wqe = queue_head(qp->sq.queue);
+	struct rxe_send_wqe *wqe;
 	unsigned long flags;
+	struct rxe_queue *q = qp->sq.queue;
+	unsigned int index = qp->req.wqe_index;
+	unsigned int cons;
+	unsigned int prod;
+
+	if (qp->is_user) {
+		wqe = queue_head(q, QUEUE_TYPE_FROM_USER);
+		cons = consumer_index(q, QUEUE_TYPE_FROM_USER);
+		prod = producer_index(q, QUEUE_TYPE_FROM_USER);
+	} else {
+		wqe = queue_head(q, QUEUE_TYPE_KERNEL);
+		cons = consumer_index(q, QUEUE_TYPE_KERNEL);
+		prod = producer_index(q, QUEUE_TYPE_KERNEL);
+	}
 
 	if (unlikely(qp->req.state == QP_STATE_DRAIN)) {
 		/* check to see if we are drained;
@@ -120,8 +144,7 @@ static struct rxe_send_wqe *req_next_wqe(struct rxe_qp *qp)
 				break;
 			}
 
-			if (wqe && ((qp->req.wqe_index !=
-				consumer_index(qp->sq.queue)) ||
+			if (wqe && ((index != cons) ||
 				(wqe->state != wqe_state_posted))) {
 				/* comp not done yet */
 				spin_unlock_irqrestore(&qp->state_lock,
@@ -144,10 +167,10 @@ static struct rxe_send_wqe *req_next_wqe(struct rxe_qp *qp)
 		} while (0);
 	}
 
-	if (qp->req.wqe_index == producer_index(qp->sq.queue))
+	if (index == prod)
 		return NULL;
 
-	wqe = addr_from_index(qp->sq.queue, qp->req.wqe_index);
+	wqe = addr_from_index(q, index);
 
 	if (unlikely((qp->req.state == QP_STATE_DRAIN ||
 		      qp->req.state == QP_STATE_DRAINED) &&
@@ -155,7 +178,7 @@ static struct rxe_send_wqe *req_next_wqe(struct rxe_qp *qp)
 		return NULL;
 
 	if (unlikely((wqe->wr.send_flags & IB_SEND_FENCE) &&
-		     (qp->req.wqe_index != consumer_index(qp->sq.queue)))) {
+						     (index != cons))) {
 		qp->req.wait_fence = 1;
 		return NULL;
 	}
@@ -568,6 +591,7 @@ int rxe_requester(void *arg)
 	int ret;
 	struct rxe_send_wqe rollback_wqe;
 	u32 rollback_psn;
+	struct rxe_queue *q = qp->sq.queue;
 
 	rxe_add_ref(qp);
 
@@ -576,7 +600,7 @@ int rxe_requester(void *arg)
 		goto exit;
 
 	if (unlikely(qp->req.state == QP_STATE_RESET)) {
-		qp->req.wqe_index = consumer_index(qp->sq.queue);
+		qp->req.wqe_index = consumer_index(q, q->type);
 		qp->req.opcode = -1;
 		qp->req.need_rd_atomic = 0;
 		qp->req.wait_psn = 0;

drivers/infiniband/sw/rxe/rxe_resp.c

@@ -293,13 +293,17 @@ static enum resp_states get_srq_wqe(struct rxe_qp *qp)
 	struct rxe_queue *q = srq->rq.queue;
 	struct rxe_recv_wqe *wqe;
 	struct ib_event ev;
+	unsigned int count;
 
 	if (srq->error)
 		return RESPST_ERR_RNR;
 
 	spin_lock_bh(&srq->rq.consumer_lock);
 
-	wqe = queue_head(q);
+	if (qp->is_user)
+		wqe = queue_head(q, QUEUE_TYPE_FROM_USER);
+	else
+		wqe = queue_head(q, QUEUE_TYPE_KERNEL);
 	if (!wqe) {
 		spin_unlock_bh(&srq->rq.consumer_lock);
 		return RESPST_ERR_RNR;
@@ -309,10 +313,15 @@ static enum resp_states get_srq_wqe(struct rxe_qp *qp)
 	memcpy(&qp->resp.srq_wqe, wqe, sizeof(qp->resp.srq_wqe));
 
 	qp->resp.wqe = &qp->resp.srq_wqe.wqe;
-	advance_consumer(q);
+	if (qp->is_user) {
+		advance_consumer(q, QUEUE_TYPE_FROM_USER);
+		count = queue_count(q, QUEUE_TYPE_FROM_USER);
+	} else {
+		advance_consumer(q, QUEUE_TYPE_KERNEL);
+		count = queue_count(q, QUEUE_TYPE_KERNEL);
+	}
 
-	if (srq->limit && srq->ibsrq.event_handler &&
-	    (queue_count(q) < srq->limit)) {
+	if (srq->limit && srq->ibsrq.event_handler && (count < srq->limit)) {
 		srq->limit = 0;
 		goto event;
 	}
@@ -339,7 +348,12 @@ static enum resp_states check_resource(struct rxe_qp *qp,
 			qp->resp.status = IB_WC_WR_FLUSH_ERR;
 			return RESPST_COMPLETE;
 		} else if (!srq) {
-			qp->resp.wqe = queue_head(qp->rq.queue);
+			if (qp->is_user)
+				qp->resp.wqe = queue_head(qp->rq.queue,
+						QUEUE_TYPE_FROM_USER);
+			else
+				qp->resp.wqe = queue_head(qp->rq.queue,
+						QUEUE_TYPE_KERNEL);
 			if (qp->resp.wqe) {
 				qp->resp.status = IB_WC_WR_FLUSH_ERR;
 				return RESPST_COMPLETE;
@@ -366,7 +380,12 @@ static enum resp_states check_resource(struct rxe_qp *qp,
 		if (srq)
 			return get_srq_wqe(qp);
 
-		qp->resp.wqe = queue_head(qp->rq.queue);
+		if (qp->is_user)
+			qp->resp.wqe = queue_head(qp->rq.queue,
+					QUEUE_TYPE_FROM_USER);
+		else
+			qp->resp.wqe = queue_head(qp->rq.queue,
+					QUEUE_TYPE_KERNEL);
 		return (qp->resp.wqe) ? RESPST_CHK_LENGTH : RESPST_ERR_RNR;
 	}
 
@@ -909,8 +928,12 @@ static enum resp_states do_complete(struct rxe_qp *qp,
 	}
 
 	/* have copy for srq and reference for !srq */
-	if (!qp->srq)
-		advance_consumer(qp->rq.queue);
+	if (!qp->srq) {
+		if (qp->is_user)
+			advance_consumer(qp->rq.queue, QUEUE_TYPE_FROM_USER);
+		else
+			advance_consumer(qp->rq.queue, QUEUE_TYPE_KERNEL);
+	}
 
 	qp->resp.wqe = NULL;
 
@@ -1176,6 +1199,7 @@ static enum resp_states do_class_d1e_error(struct rxe_qp *qp)
 static void rxe_drain_req_pkts(struct rxe_qp *qp, bool notify)
 {
 	struct sk_buff *skb;
+	struct rxe_queue *q = qp->rq.queue;
 
 	while ((skb = skb_dequeue(&qp->req_pkts))) {
 		rxe_drop_ref(qp);
@@ -1186,8 +1210,8 @@ static void rxe_drain_req_pkts(struct rxe_qp *qp, bool notify)
 	if (notify)
 		return;
 
-	while (!qp->srq && qp->rq.queue && queue_head(qp->rq.queue))
-		advance_consumer(qp->rq.queue);
+	while (!qp->srq && q && queue_head(q, q->type))
+		advance_consumer(q, q->type);
 }
 
 int rxe_responder(void *arg)

drivers/infiniband/sw/rxe/rxe_srq.c

@@ -86,6 +86,7 @@ int rxe_srq_from_init(struct rxe_dev *rxe, struct rxe_srq *srq,
 	srq->srq_num		= srq->pelem.index;
 	srq->rq.max_wr		= init->attr.max_wr;
 	srq->rq.max_sge		= init->attr.max_sge;
+	srq->rq.is_user		= srq->is_user;
 
 	srq_wqe_size		= rcv_wqe_size(srq->rq.max_sge);
 

drivers/infiniband/sw/rxe/rxe_verbs.c

@@ -216,8 +216,14 @@ static int post_one_recv(struct rxe_rq *rq, const struct ib_recv_wr *ibwr)
 	u32 length;
 	struct rxe_recv_wqe *recv_wqe;
 	int num_sge = ibwr->num_sge;
+	int full;
 
-	if (unlikely(queue_full(rq->queue))) {
+	if (rq->is_user)
+		full = queue_full(rq->queue, QUEUE_TYPE_FROM_USER);
+	else
+		full = queue_full(rq->queue, QUEUE_TYPE_KERNEL);
+
+	if (unlikely(full)) {
 		err = -ENOMEM;
 		goto err1;
 	}
@@ -231,7 +237,11 @@ static int post_one_recv(struct rxe_rq *rq, const struct ib_recv_wr *ibwr)
 	for (i = 0; i < num_sge; i++)
 		length += ibwr->sg_list[i].length;
 
-	recv_wqe = producer_addr(rq->queue);
+	if (rq->is_user)
+		recv_wqe = producer_addr(rq->queue, QUEUE_TYPE_FROM_USER);
+	else
+		recv_wqe = producer_addr(rq->queue, QUEUE_TYPE_KERNEL);
+
 	recv_wqe->wr_id = ibwr->wr_id;
 	recv_wqe->num_sge = num_sge;
 
@@ -244,7 +254,11 @@ static int post_one_recv(struct rxe_rq *rq, const struct ib_recv_wr *ibwr)
 	recv_wqe->dma.cur_sge		= 0;
 	recv_wqe->dma.sge_offset	= 0;
 
-	advance_producer(rq->queue);
+	if (rq->is_user)
+		advance_producer(rq->queue, QUEUE_TYPE_FROM_USER);
+	else
+		advance_producer(rq->queue, QUEUE_TYPE_KERNEL);
+
 	return 0;
 
 err1:
@@ -267,6 +281,9 @@ static int rxe_create_srq(struct ib_srq *ibsrq, struct ib_srq_init_attr *init,
 		if (udata->outlen < sizeof(*uresp))
 			return -EINVAL;
 		uresp = udata->outbuf;
+		srq->is_user = true;
+	} else {
+		srq->is_user = false;
 	}
 
 	err = rxe_srq_chk_attr(rxe, NULL, &init->attr, IB_SRQ_INIT_MASK);
@@ -408,7 +425,9 @@ static struct ib_qp *rxe_create_qp(struct ib_pd *ibpd,
 			err = -EINVAL;
 			goto err2;
 		}
-		qp->is_user = 1;
+		qp->is_user = true;
+	} else {
+		qp->is_user = false;
 	}
 
 	rxe_add_index(qp);
@@ -613,6 +632,7 @@ static int post_one_send(struct rxe_qp *qp, const struct ib_send_wr *ibwr,
 	struct rxe_sq *sq = &qp->sq;
 	struct rxe_send_wqe *send_wqe;
 	unsigned long flags;
+	int full;
 
 	err = validate_send_wr(qp, ibwr, mask, length);
 	if (err)
@@ -620,22 +640,31 @@ static int post_one_send(struct rxe_qp *qp, const struct ib_send_wr *ibwr,
 
 	spin_lock_irqsave(&qp->sq.sq_lock, flags);
 
-	if (unlikely(queue_full(sq->queue))) {
-		err = -ENOMEM;
-		goto err1;
+	if (qp->is_user)
+		full = queue_full(sq->queue, QUEUE_TYPE_FROM_USER);
+	else
+		full = queue_full(sq->queue, QUEUE_TYPE_KERNEL);
+
+	if (unlikely(full)) {
+		spin_unlock_irqrestore(&qp->sq.sq_lock, flags);
+		return -ENOMEM;
 	}
 
-	send_wqe = producer_addr(sq->queue);
+	if (qp->is_user)
+		send_wqe = producer_addr(sq->queue, QUEUE_TYPE_FROM_USER);
+	else
+		send_wqe = producer_addr(sq->queue, QUEUE_TYPE_KERNEL);
+
 	init_send_wqe(qp, ibwr, mask, length, send_wqe);
 
-	advance_producer(sq->queue);
+	if (qp->is_user)
+		advance_producer(sq->queue, QUEUE_TYPE_FROM_USER);
+	else
+		advance_producer(sq->queue, QUEUE_TYPE_KERNEL);
+
 	spin_unlock_irqrestore(&qp->sq.sq_lock, flags);
 
 	return 0;
-
-err1:
-	spin_unlock_irqrestore(&qp->sq.sq_lock, flags);
-	return err;
 }
 
 static int rxe_post_send_kernel(struct rxe_qp *qp, const struct ib_send_wr *wr,
@@ -823,12 +852,18 @@ static int rxe_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *wc)
 
 	spin_lock_irqsave(&cq->cq_lock, flags);
 	for (i = 0; i < num_entries; i++) {
-		cqe = queue_head(cq->queue);
+		if (cq->is_user)
+			cqe = queue_head(cq->queue, QUEUE_TYPE_TO_USER);
+		else
+			cqe = queue_head(cq->queue, QUEUE_TYPE_KERNEL);
 		if (!cqe)
 			break;
 
 		memcpy(wc++, &cqe->ibwc, sizeof(*wc));
-		advance_consumer(cq->queue);
+		if (cq->is_user)
+			advance_consumer(cq->queue, QUEUE_TYPE_TO_USER);
+		else
+			advance_consumer(cq->queue, QUEUE_TYPE_KERNEL);
 	}
 	spin_unlock_irqrestore(&cq->cq_lock, flags);
 
@@ -838,7 +873,12 @@ static int rxe_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *wc)
 static int rxe_peek_cq(struct ib_cq *ibcq, int wc_cnt)
 {
 	struct rxe_cq *cq = to_rcq(ibcq);
-	int count = queue_count(cq->queue);
+	int count;
+
+	if (cq->is_user)
+		count = queue_count(cq->queue, QUEUE_TYPE_TO_USER);
+	else
+		count = queue_count(cq->queue, QUEUE_TYPE_KERNEL);
 
 	return (count > wc_cnt) ? wc_cnt : count;
 }
@@ -848,12 +888,18 @@ static int rxe_req_notify_cq(struct ib_cq *ibcq, enum ib_cq_notify_flags flags)
 	struct rxe_cq *cq = to_rcq(ibcq);
 	unsigned long irq_flags;
 	int ret = 0;
+	int empty;
 
 	spin_lock_irqsave(&cq->cq_lock, irq_flags);
 	if (cq->notify != IB_CQ_NEXT_COMP)
 		cq->notify = flags & IB_CQ_SOLICITED_MASK;
 
-	if ((flags & IB_CQ_REPORT_MISSED_EVENTS) && !queue_empty(cq->queue))
+	if (cq->is_user)
+		empty = queue_empty(cq->queue, QUEUE_TYPE_TO_USER);
+	else
+		empty = queue_empty(cq->queue, QUEUE_TYPE_KERNEL);
+
+	if ((flags & IB_CQ_REPORT_MISSED_EVENTS) && !empty)
 		ret = 1;
 
 	spin_unlock_irqrestore(&cq->cq_lock, irq_flags);

drivers/infiniband/sw/rxe/rxe_verbs.h

@@ -77,6 +77,7 @@ enum wqe_state {
 };
 
 struct rxe_sq {
+	bool			is_user;
 	int			max_wr;
 	int			max_sge;
 	int			max_inline;
@@ -85,6 +86,7 @@ struct rxe_sq {
 };
 
 struct rxe_rq {
+	bool			is_user;
 	int			max_wr;
 	int			max_sge;
 	spinlock_t		producer_lock; /* guard queue producer */
@@ -98,6 +100,7 @@ struct rxe_srq {
 	struct rxe_pd		*pd;
 	struct rxe_rq		rq;
 	u32			srq_num;
+	bool			is_user;
 
 	int			limit;
 	int			error;
@@ -211,7 +214,7 @@ struct rxe_qp {
 	struct ib_qp_attr	attr;
 	unsigned int		valid;
 	unsigned int		mtu;
-	int			is_user;
+	bool			is_user;
 
 	struct rxe_pd		*pd;
 	struct rxe_srq		*srq;