nvme-rdma: add metadata/T10-PI support

For capable HCAs (e.g. ConnectX-5/ConnectX-6) this will allow end-to-end
protection information passthrough and validation for NVMe over RDMA
transport. Metadata offload support was implemented over the new RDMA
signature verbs API and it is enabled for capable controllers.
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/nvme/host/rdma.c

@@ -34,6 +34,11 @@
 
 #define NVME_RDMA_MAX_INLINE_SEGMENTS	4
 
+#define NVME_RDMA_DATA_SGL_SIZE \
+	(sizeof(struct scatterlist) * NVME_INLINE_SG_CNT)
+#define NVME_RDMA_METADATA_SGL_SIZE \
+	(sizeof(struct scatterlist) * NVME_INLINE_METADATA_SG_CNT)
+
 struct nvme_rdma_device {
 	struct ib_device	*dev;
 	struct ib_pd		*pd;
@@ -67,6 +72,8 @@ struct nvme_rdma_request {
 	struct ib_cqe		reg_cqe;
 	struct nvme_rdma_queue  *queue;
 	struct nvme_rdma_sgl	data_sgl;
+	struct nvme_rdma_sgl	*metadata_sgl;
+	bool			use_sig_mr;
 };
 
 enum nvme_rdma_queue_flags {
@@ -88,6 +95,7 @@ struct nvme_rdma_queue {
 	struct rdma_cm_id	*cm_id;
 	int			cm_error;
 	struct completion	cm_done;
+	bool			pi_support;
 };
 
 struct nvme_rdma_ctrl {
@@ -264,6 +272,8 @@ static int nvme_rdma_create_qp(struct nvme_rdma_queue *queue, const int factor)
 	init_attr.qp_type = IB_QPT_RC;
 	init_attr.send_cq = queue->ib_cq;
 	init_attr.recv_cq = queue->ib_cq;
+	if (queue->pi_support)
+		init_attr.create_flags |= IB_QP_CREATE_INTEGRITY_EN;
 
 	ret = rdma_create_qp(queue->cm_id, dev->pd, &init_attr);
 
@@ -293,6 +303,12 @@ static int nvme_rdma_init_request(struct blk_mq_tag_set *set,
 	if (!req->sqe.data)
 		return -ENOMEM;
 
+	/* metadata nvme_rdma_sgl struct is located after command's data SGL */
+	if (queue->pi_support)
+		req->metadata_sgl = (void *)nvme_req(rq) +
+			sizeof(struct nvme_rdma_request) +
+			NVME_RDMA_DATA_SGL_SIZE;
+
 	req->queue = queue;
 
 	return 0;
@@ -403,6 +419,8 @@ static void nvme_rdma_destroy_queue_ib(struct nvme_rdma_queue *queue)
 	dev = queue->device;
 	ibdev = dev->dev;
 
+	if (queue->pi_support)
+		ib_mr_pool_destroy(queue->qp, &queue->qp->sig_mrs);
 	ib_mr_pool_destroy(queue->qp, &queue->qp->rdma_mrs);
 
 	/*
@@ -419,10 +437,16 @@ static void nvme_rdma_destroy_queue_ib(struct nvme_rdma_queue *queue)
 	nvme_rdma_dev_put(dev);
 }
 
-static int nvme_rdma_get_max_fr_pages(struct ib_device *ibdev)
+static int nvme_rdma_get_max_fr_pages(struct ib_device *ibdev, bool pi_support)
 {
-	return min_t(u32, NVME_RDMA_MAX_SEGMENTS,
-		     ibdev->attrs.max_fast_reg_page_list_len - 1);
+	u32 max_page_list_len;
+
+	if (pi_support)
+		max_page_list_len = ibdev->attrs.max_pi_fast_reg_page_list_len;
+	else
+		max_page_list_len = ibdev->attrs.max_fast_reg_page_list_len;
+
+	return min_t(u32, NVME_RDMA_MAX_SEGMENTS, max_page_list_len - 1);
 }
 
 static int nvme_rdma_create_queue_ib(struct nvme_rdma_queue *queue)
@@ -479,7 +503,7 @@ static int nvme_rdma_create_queue_ib(struct nvme_rdma_queue *queue)
 	 * misaligned we'll end up using two entries for a single data page,
 	 * so one additional entry is required.
 	 */
-	pages_per_mr = nvme_rdma_get_max_fr_pages(ibdev) + 1;
+	pages_per_mr = nvme_rdma_get_max_fr_pages(ibdev, queue->pi_support) + 1;
 	ret = ib_mr_pool_init(queue->qp, &queue->qp->rdma_mrs,
 			      queue->queue_size,
 			      IB_MR_TYPE_MEM_REG,
@@ -491,10 +515,24 @@ static int nvme_rdma_create_queue_ib(struct nvme_rdma_queue *queue)
 		goto out_destroy_ring;
 	}
 
+	if (queue->pi_support) {
+		ret = ib_mr_pool_init(queue->qp, &queue->qp->sig_mrs,
+				      queue->queue_size, IB_MR_TYPE_INTEGRITY,
+				      pages_per_mr, pages_per_mr);
+		if (ret) {
+			dev_err(queue->ctrl->ctrl.device,
+				"failed to initialize PI MR pool sized %d for QID %d\n",
+				queue->queue_size, idx);
+			goto out_destroy_mr_pool;
+		}
+	}
+
 	set_bit(NVME_RDMA_Q_TR_READY, &queue->flags);
 
 	return 0;
 
+out_destroy_mr_pool:
+	ib_mr_pool_destroy(queue->qp, &queue->qp->rdma_mrs);
 out_destroy_ring:
 	nvme_rdma_free_ring(ibdev, queue->rsp_ring, queue->queue_size,
 			    sizeof(struct nvme_completion), DMA_FROM_DEVICE);
@@ -516,6 +554,10 @@ static int nvme_rdma_alloc_queue(struct nvme_rdma_ctrl *ctrl,
 
 	queue = &ctrl->queues[idx];
 	queue->ctrl = ctrl;
+	if (idx && ctrl->ctrl.max_integrity_segments)
+		queue->pi_support = true;
+	else
+		queue->pi_support = false;
 	init_completion(&queue->cm_done);
 
 	if (idx > 0)
@@ -726,7 +768,7 @@ static struct blk_mq_tag_set *nvme_rdma_alloc_tagset(struct nvme_ctrl *nctrl,
 		set->reserved_tags = 2; /* connect + keep-alive */
 		set->numa_node = nctrl->numa_node;
 		set->cmd_size = sizeof(struct nvme_rdma_request) +
-			NVME_INLINE_SG_CNT * sizeof(struct scatterlist);
+				NVME_RDMA_DATA_SGL_SIZE;
 		set->driver_data = ctrl;
 		set->nr_hw_queues = 1;
 		set->timeout = ADMIN_TIMEOUT;
@@ -740,7 +782,10 @@ static struct blk_mq_tag_set *nvme_rdma_alloc_tagset(struct nvme_ctrl *nctrl,
 		set->numa_node = nctrl->numa_node;
 		set->flags = BLK_MQ_F_SHOULD_MERGE;
 		set->cmd_size = sizeof(struct nvme_rdma_request) +
-			NVME_INLINE_SG_CNT * sizeof(struct scatterlist);
+				NVME_RDMA_DATA_SGL_SIZE;
+		if (nctrl->max_integrity_segments)
+			set->cmd_size += sizeof(struct nvme_rdma_sgl) +
+					 NVME_RDMA_METADATA_SGL_SIZE;
 		set->driver_data = ctrl;
 		set->nr_hw_queues = nctrl->queue_count - 1;
 		set->timeout = NVME_IO_TIMEOUT;
@@ -773,6 +818,7 @@ static void nvme_rdma_destroy_admin_queue(struct nvme_rdma_ctrl *ctrl,
 static int nvme_rdma_configure_admin_queue(struct nvme_rdma_ctrl *ctrl,
 		bool new)
 {
+	bool pi_capable = false;
 	int error;
 
 	error = nvme_rdma_alloc_queue(ctrl, 0, NVME_AQ_DEPTH);
@@ -782,7 +828,13 @@ static int nvme_rdma_configure_admin_queue(struct nvme_rdma_ctrl *ctrl,
 	ctrl->device = ctrl->queues[0].device;
 	ctrl->ctrl.numa_node = dev_to_node(ctrl->device->dev->dma_device);
 
-	ctrl->max_fr_pages = nvme_rdma_get_max_fr_pages(ctrl->device->dev);
+	/* T10-PI support */
+	if (ctrl->device->dev->attrs.device_cap_flags &
+	    IB_DEVICE_INTEGRITY_HANDOVER)
+		pi_capable = true;
+
+	ctrl->max_fr_pages = nvme_rdma_get_max_fr_pages(ctrl->device->dev,
+							pi_capable);
 
 	/*
 	 * Bind the async event SQE DMA mapping to the admin queue lifetime.
@@ -824,6 +876,10 @@ static int nvme_rdma_configure_admin_queue(struct nvme_rdma_ctrl *ctrl,
 
 	ctrl->ctrl.max_segments = ctrl->max_fr_pages;
 	ctrl->ctrl.max_hw_sectors = ctrl->max_fr_pages << (ilog2(SZ_4K) - 9);
+	if (pi_capable)
+		ctrl->ctrl.max_integrity_segments = ctrl->max_fr_pages;
+	else
+		ctrl->ctrl.max_integrity_segments = 0;
 
 	blk_mq_unquiesce_queue(ctrl->ctrl.admin_q);
 
@@ -1152,12 +1208,23 @@ static void nvme_rdma_unmap_data(struct nvme_rdma_queue *queue,
 	struct nvme_rdma_request *req = blk_mq_rq_to_pdu(rq);
 	struct nvme_rdma_device *dev = queue->device;
 	struct ib_device *ibdev = dev->dev;
+	struct list_head *pool = &queue->qp->rdma_mrs;
 
 	if (!blk_rq_nr_phys_segments(rq))
 		return;
 
+	if (blk_integrity_rq(rq)) {
+		ib_dma_unmap_sg(ibdev, req->metadata_sgl->sg_table.sgl,
+				req->metadata_sgl->nents, rq_dma_dir(rq));
+		sg_free_table_chained(&req->metadata_sgl->sg_table,
+				      NVME_INLINE_METADATA_SG_CNT);
+	}
+
+	if (req->use_sig_mr)
+		pool = &queue->qp->sig_mrs;
+
 	if (req->mr) {
-		ib_mr_pool_put(queue->qp, &queue->qp->rdma_mrs, req->mr);
+		ib_mr_pool_put(queue->qp, pool, req->mr);
 		req->mr = NULL;
 	}
 
@@ -1261,12 +1328,125 @@ static int nvme_rdma_map_sg_fr(struct nvme_rdma_queue *queue,
 	return 0;
 }
 
+static void nvme_rdma_set_sig_domain(struct blk_integrity *bi,
+		struct nvme_command *cmd, struct ib_sig_domain *domain,
+		u16 control, u8 pi_type)
+{
+	domain->sig_type = IB_SIG_TYPE_T10_DIF;
+	domain->sig.dif.bg_type = IB_T10DIF_CRC;
+	domain->sig.dif.pi_interval = 1 << bi->interval_exp;
+	domain->sig.dif.ref_tag = le32_to_cpu(cmd->rw.reftag);
+	if (control & NVME_RW_PRINFO_PRCHK_REF)
+		domain->sig.dif.ref_remap = true;
+
+	domain->sig.dif.app_tag = le16_to_cpu(cmd->rw.apptag);
+	domain->sig.dif.apptag_check_mask = le16_to_cpu(cmd->rw.appmask);
+	domain->sig.dif.app_escape = true;
+	if (pi_type == NVME_NS_DPS_PI_TYPE3)
+		domain->sig.dif.ref_escape = true;
+}
+
+static void nvme_rdma_set_sig_attrs(struct blk_integrity *bi,
+		struct nvme_command *cmd, struct ib_sig_attrs *sig_attrs,
+		u8 pi_type)
+{
+	u16 control = le16_to_cpu(cmd->rw.control);
+
+	memset(sig_attrs, 0, sizeof(*sig_attrs));
+	if (control & NVME_RW_PRINFO_PRACT) {
+		/* for WRITE_INSERT/READ_STRIP no memory domain */
+		sig_attrs->mem.sig_type = IB_SIG_TYPE_NONE;
+		nvme_rdma_set_sig_domain(bi, cmd, &sig_attrs->wire, control,
+					 pi_type);
+		/* Clear the PRACT bit since HCA will generate/verify the PI */
+		control &= ~NVME_RW_PRINFO_PRACT;
+		cmd->rw.control = cpu_to_le16(control);
+	} else {
+		/* for WRITE_PASS/READ_PASS both wire/memory domains exist */
+		nvme_rdma_set_sig_domain(bi, cmd, &sig_attrs->wire, control,
+					 pi_type);
+		nvme_rdma_set_sig_domain(bi, cmd, &sig_attrs->mem, control,
+					 pi_type);
+	}
+}
+
+static void nvme_rdma_set_prot_checks(struct nvme_command *cmd, u8 *mask)
+{
+	*mask = 0;
+	if (le16_to_cpu(cmd->rw.control) & NVME_RW_PRINFO_PRCHK_REF)
+		*mask |= IB_SIG_CHECK_REFTAG;
+	if (le16_to_cpu(cmd->rw.control) & NVME_RW_PRINFO_PRCHK_GUARD)
+		*mask |= IB_SIG_CHECK_GUARD;
+}
+
+static void nvme_rdma_sig_done(struct ib_cq *cq, struct ib_wc *wc)
+{
+	if (unlikely(wc->status != IB_WC_SUCCESS))
+		nvme_rdma_wr_error(cq, wc, "SIG");
+}
+
+static int nvme_rdma_map_sg_pi(struct nvme_rdma_queue *queue,
+		struct nvme_rdma_request *req, struct nvme_command *c,
+		int count, int pi_count)
+{
+	struct nvme_rdma_sgl *sgl = &req->data_sgl;
+	struct ib_reg_wr *wr = &req->reg_wr;
+	struct request *rq = blk_mq_rq_from_pdu(req);
+	struct nvme_ns *ns = rq->q->queuedata;
+	struct bio *bio = rq->bio;
+	struct nvme_keyed_sgl_desc *sg = &c->common.dptr.ksgl;
+	int nr;
+
+	req->mr = ib_mr_pool_get(queue->qp, &queue->qp->sig_mrs);
+	if (WARN_ON_ONCE(!req->mr))
+		return -EAGAIN;
+
+	nr = ib_map_mr_sg_pi(req->mr, sgl->sg_table.sgl, count, NULL,
+			     req->metadata_sgl->sg_table.sgl, pi_count, NULL,
+			     SZ_4K);
+	if (unlikely(nr))
+		goto mr_put;
+
+	nvme_rdma_set_sig_attrs(blk_get_integrity(bio->bi_disk), c,
+				req->mr->sig_attrs, ns->pi_type);
+	nvme_rdma_set_prot_checks(c, &req->mr->sig_attrs->check_mask);
+
+	ib_update_fast_reg_key(req->mr, ib_inc_rkey(req->mr->rkey));
+
+	req->reg_cqe.done = nvme_rdma_sig_done;
+	memset(wr, 0, sizeof(*wr));
+	wr->wr.opcode = IB_WR_REG_MR_INTEGRITY;
+	wr->wr.wr_cqe = &req->reg_cqe;
+	wr->wr.num_sge = 0;
+	wr->wr.send_flags = 0;
+	wr->mr = req->mr;
+	wr->key = req->mr->rkey;
+	wr->access = IB_ACCESS_LOCAL_WRITE |
+		     IB_ACCESS_REMOTE_READ |
+		     IB_ACCESS_REMOTE_WRITE;
+
+	sg->addr = cpu_to_le64(req->mr->iova);
+	put_unaligned_le24(req->mr->length, sg->length);
+	put_unaligned_le32(req->mr->rkey, sg->key);
+	sg->type = NVME_KEY_SGL_FMT_DATA_DESC << 4;
+
+	return 0;
+
+mr_put:
+	ib_mr_pool_put(queue->qp, &queue->qp->sig_mrs, req->mr);
+	req->mr = NULL;
+	if (nr < 0)
+		return nr;
+	return -EINVAL;
+}
+
 static int nvme_rdma_map_data(struct nvme_rdma_queue *queue,
 		struct request *rq, struct nvme_command *c)
 {
 	struct nvme_rdma_request *req = blk_mq_rq_to_pdu(rq);
 	struct nvme_rdma_device *dev = queue->device;
 	struct ib_device *ibdev = dev->dev;
+	int pi_count = 0;
 	int count, ret;
 
 	req->num_sge = 1;
@@ -1294,6 +1474,35 @@ static int nvme_rdma_map_data(struct nvme_rdma_queue *queue,
 		goto out_free_table;
 	}
 
+	if (blk_integrity_rq(rq)) {
+		req->metadata_sgl->sg_table.sgl =
+			(struct scatterlist *)(req->metadata_sgl + 1);
+		ret = sg_alloc_table_chained(&req->metadata_sgl->sg_table,
+				blk_rq_count_integrity_sg(rq->q, rq->bio),
+				req->metadata_sgl->sg_table.sgl,
+				NVME_INLINE_METADATA_SG_CNT);
+		if (unlikely(ret)) {
+			ret = -ENOMEM;
+			goto out_unmap_sg;
+		}
+
+		req->metadata_sgl->nents = blk_rq_map_integrity_sg(rq->q,
+				rq->bio, req->metadata_sgl->sg_table.sgl);
+		pi_count = ib_dma_map_sg(ibdev,
+					 req->metadata_sgl->sg_table.sgl,
+					 req->metadata_sgl->nents,
+					 rq_dma_dir(rq));
+		if (unlikely(pi_count <= 0)) {
+			ret = -EIO;
+			goto out_free_pi_table;
+		}
+	}
+
+	if (req->use_sig_mr) {
+		ret = nvme_rdma_map_sg_pi(queue, req, c, count, pi_count);
+		goto out;
+	}
+
 	if (count <= dev->num_inline_segments) {
 		if (rq_data_dir(rq) == WRITE && nvme_rdma_queue_idx(queue) &&
 		    queue->ctrl->use_inline_data &&
@@ -1312,10 +1521,18 @@ static int nvme_rdma_map_data(struct nvme_rdma_queue *queue,
 	ret = nvme_rdma_map_sg_fr(queue, req, c, count);
 out:
 	if (unlikely(ret))
-		goto out_unmap_sg;
+		goto out_unmap_pi_sg;
 
 	return 0;
 
+out_unmap_pi_sg:
+	if (blk_integrity_rq(rq))
+		ib_dma_unmap_sg(ibdev, req->metadata_sgl->sg_table.sgl,
+				req->metadata_sgl->nents, rq_dma_dir(rq));
+out_free_pi_table:
+	if (blk_integrity_rq(rq))
+		sg_free_table_chained(&req->metadata_sgl->sg_table,
+				      NVME_INLINE_METADATA_SG_CNT);
 out_unmap_sg:
 	ib_dma_unmap_sg(ibdev, req->data_sgl.sg_table.sgl, req->data_sgl.nents,
 			rq_dma_dir(rq));
@@ -1768,6 +1985,15 @@ static blk_status_t nvme_rdma_queue_rq(struct blk_mq_hw_ctx *hctx,
 
 	blk_mq_start_request(rq);
 
+	if (IS_ENABLED(CONFIG_BLK_DEV_INTEGRITY) &&
+	    queue->pi_support &&
+	    (c->common.opcode == nvme_cmd_write ||
+	     c->common.opcode == nvme_cmd_read) &&
+	    nvme_ns_has_pi(ns))
+		req->use_sig_mr = true;
+	else
+		req->use_sig_mr = false;
+
 	err = nvme_rdma_map_data(queue, rq, c);
 	if (unlikely(err < 0)) {
 		dev_err(queue->ctrl->ctrl.device,
@@ -1808,12 +2034,46 @@ static int nvme_rdma_poll(struct blk_mq_hw_ctx *hctx)
 	return ib_process_cq_direct(queue->ib_cq, -1);
 }
 
+static void nvme_rdma_check_pi_status(struct nvme_rdma_request *req)
+{
+	struct request *rq = blk_mq_rq_from_pdu(req);
+	struct ib_mr_status mr_status;
+	int ret;
+
+	ret = ib_check_mr_status(req->mr, IB_MR_CHECK_SIG_STATUS, &mr_status);
+	if (ret) {
+		pr_err("ib_check_mr_status failed, ret %d\n", ret);
+		nvme_req(rq)->status = NVME_SC_INVALID_PI;
+		return;
+	}
+
+	if (mr_status.fail_status & IB_MR_CHECK_SIG_STATUS) {
+		switch (mr_status.sig_err.err_type) {
+		case IB_SIG_BAD_GUARD:
+			nvme_req(rq)->status = NVME_SC_GUARD_CHECK;
+			break;
+		case IB_SIG_BAD_REFTAG:
+			nvme_req(rq)->status = NVME_SC_REFTAG_CHECK;
+			break;
+		case IB_SIG_BAD_APPTAG:
+			nvme_req(rq)->status = NVME_SC_APPTAG_CHECK;
+			break;
+		}
+		pr_err("PI error found type %d expected 0x%x vs actual 0x%x\n",
+		       mr_status.sig_err.err_type, mr_status.sig_err.expected,
+		       mr_status.sig_err.actual);
+	}
+}
+
 static void nvme_rdma_complete_rq(struct request *rq)
 {
 	struct nvme_rdma_request *req = blk_mq_rq_to_pdu(rq);
 	struct nvme_rdma_queue *queue = req->queue;
 	struct ib_device *ibdev = queue->device->dev;
 
+	if (req->use_sig_mr)
+		nvme_rdma_check_pi_status(req);
+
 	nvme_rdma_unmap_data(queue, rq);
 	ib_dma_unmap_single(ibdev, req->sqe.dma, sizeof(struct nvme_command),
 			    DMA_TO_DEVICE);
@@ -1933,7 +2193,7 @@ static void nvme_rdma_reset_ctrl_work(struct work_struct *work)
 static const struct nvme_ctrl_ops nvme_rdma_ctrl_ops = {
 	.name			= "rdma",
 	.module			= THIS_MODULE,
-	.flags			= NVME_F_FABRICS,
+	.flags			= NVME_F_FABRICS | NVME_F_METADATA_SUPPORTED,
 	.reg_read32		= nvmf_reg_read32,
 	.reg_read64		= nvmf_reg_read64,
 	.reg_write32		= nvmf_reg_write32,