vdpa/mlx5: prepare virtio queues

The HW virtq object represents an emulated context for a VIRTIO_NET
virtqueue which was created and managed by a VIRTIO_NET driver as
defined in VIRTIO Specification.

Add support to prepare and release all the basic HW resources needed
the user virtqs emulation according to the rte_vhost configurations.

This patch prepares the basic configurations needed by DevX commands to
create a virtq.

Add new file mlx5_vdpa_virtq.c to manage virtq operations.

Signed-off-by: Matan Azrad <matan@mellanox.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>

drivers/vdpa/mlx5/Makefile

@@ -10,6 +10,7 @@ LIB = librte_pmd_mlx5_vdpa.a
 SRCS-$(CONFIG_RTE_LIBRTE_MLX5_VDPA_PMD) += mlx5_vdpa.c
 SRCS-$(CONFIG_RTE_LIBRTE_MLX5_VDPA_PMD) += mlx5_vdpa_mem.c
 SRCS-$(CONFIG_RTE_LIBRTE_MLX5_VDPA_PMD) += mlx5_vdpa_event.c
+SRCS-$(CONFIG_RTE_LIBRTE_MLX5_VDPA_PMD) += mlx5_vdpa_virtq.c
 
 # Basic CFLAGS.
 CFLAGS += -O3

drivers/vdpa/mlx5/meson.build

@@ -14,6 +14,7 @@ sources = files(
 	'mlx5_vdpa.c',
 	'mlx5_vdpa_mem.c',
 	'mlx5_vdpa_event.c',
+	'mlx5_vdpa_virtq.c',
 )
 cflags_options = [
 	'-std=c11',

drivers/vdpa/mlx5/mlx5_vdpa.c

@@ -230,6 +230,7 @@ mlx5_vdpa_pci_probe(struct rte_pci_driver *pci_drv __rte_unused,
 		goto error;
 	}
 	SLIST_INIT(&priv->mr_list);
+	SLIST_INIT(&priv->virtq_list);
 	pthread_mutex_lock(&priv_list_lock);
 	TAILQ_INSERT_TAIL(&priv_list, priv, next);
 	pthread_mutex_unlock(&priv_list_lock);

drivers/vdpa/mlx5/mlx5_vdpa.h

@@ -59,6 +59,19 @@ struct mlx5_vdpa_query_mr {
 	int is_indirect;
 };
 
+struct mlx5_vdpa_virtq {
+	SLIST_ENTRY(mlx5_vdpa_virtq) next;
+	uint16_t index;
+	uint16_t vq_size;
+	struct mlx5_devx_obj *virtq;
+	struct mlx5_vdpa_event_qp eqp;
+	struct {
+		struct mlx5dv_devx_umem *obj;
+		void *buf;
+		uint32_t size;
+	} umems[3];
+};
+
 struct mlx5_vdpa_priv {
 	TAILQ_ENTRY(mlx5_vdpa_priv) next;
 	int id; /* vDPA device id. */
@@ -75,6 +88,10 @@ struct mlx5_vdpa_priv {
 	struct mlx5dv_devx_event_channel *eventc;
 	struct mlx5dv_devx_uar *uar;
 	struct rte_intr_handle intr_handle;
+	struct mlx5_devx_obj *td;
+	struct mlx5_devx_obj *tis;
+	uint16_t nr_virtqs;
+	SLIST_HEAD(virtq_list, mlx5_vdpa_virtq) virtq_list;
 	SLIST_HEAD(mr_list, mlx5_vdpa_query_mr) mr_list;
 };
 
@@ -152,4 +169,23 @@ int mlx5_vdpa_cqe_event_setup(struct mlx5_vdpa_priv *priv);
  */
 void mlx5_vdpa_cqe_event_unset(struct mlx5_vdpa_priv *priv);
 
+/**
+ * Release a virtq and all its related resources.
+ *
+ * @param[in] priv
+ *   The vdpa driver private structure.
+ */
+void mlx5_vdpa_virtqs_release(struct mlx5_vdpa_priv *priv);
+
+/**
+ * Create all the HW virtqs resources and all their related resources.
+ *
+ * @param[in] priv
+ *   The vdpa driver private structure.
+ *
+ * @return
+ *   0 on success, a negative errno value otherwise and rte_errno is set.
+ */
+int mlx5_vdpa_virtqs_prepare(struct mlx5_vdpa_priv *priv);
+
 #endif /* RTE_PMD_MLX5_VDPA_H_ */

drivers/vdpa/mlx5/mlx5_vdpa_virtq.c

@@ -0,0 +1,212 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright 2019 Mellanox Technologies, Ltd
+ */
+#include <string.h>
+
+#include <rte_malloc.h>
+#include <rte_errno.h>
+
+#include <mlx5_common.h>
+
+#include "mlx5_vdpa_utils.h"
+#include "mlx5_vdpa.h"
+
+
+static int
+mlx5_vdpa_virtq_unset(struct mlx5_vdpa_virtq *virtq)
+{
+	int i;
+
+	if (virtq->virtq) {
+		claim_zero(mlx5_devx_cmd_destroy(virtq->virtq));
+		virtq->virtq = NULL;
+	}
+	for (i = 0; i < 3; ++i) {
+		if (virtq->umems[i].obj)
+			claim_zero(mlx5_glue->devx_umem_dereg
+							 (virtq->umems[i].obj));
+		if (virtq->umems[i].buf)
+			rte_free(virtq->umems[i].buf);
+	}
+	memset(&virtq->umems, 0, sizeof(virtq->umems));
+	if (virtq->eqp.fw_qp)
+		mlx5_vdpa_event_qp_destroy(&virtq->eqp);
+	return 0;
+}
+
+void
+mlx5_vdpa_virtqs_release(struct mlx5_vdpa_priv *priv)
+{
+	struct mlx5_vdpa_virtq *entry;
+	struct mlx5_vdpa_virtq *next;
+
+	entry = SLIST_FIRST(&priv->virtq_list);
+	while (entry) {
+		next = SLIST_NEXT(entry, next);
+		mlx5_vdpa_virtq_unset(entry);
+		SLIST_REMOVE(&priv->virtq_list, entry, mlx5_vdpa_virtq, next);
+		rte_free(entry);
+		entry = next;
+	}
+	SLIST_INIT(&priv->virtq_list);
+	if (priv->tis) {
+		claim_zero(mlx5_devx_cmd_destroy(priv->tis));
+		priv->tis = NULL;
+	}
+	if (priv->td) {
+		claim_zero(mlx5_devx_cmd_destroy(priv->td));
+		priv->td = NULL;
+	}
+}
+
+static uint64_t
+mlx5_vdpa_hva_to_gpa(struct rte_vhost_memory *mem, uint64_t hva)
+{
+	struct rte_vhost_mem_region *reg;
+	uint32_t i;
+	uint64_t gpa = 0;
+
+	for (i = 0; i < mem->nregions; i++) {
+		reg = &mem->regions[i];
+		if (hva >= reg->host_user_addr &&
+		    hva < reg->host_user_addr + reg->size) {
+			gpa = hva - reg->host_user_addr + reg->guest_phys_addr;
+			break;
+		}
+	}
+	return gpa;
+}
+
+static int
+mlx5_vdpa_virtq_setup(struct mlx5_vdpa_priv *priv,
+		      struct mlx5_vdpa_virtq *virtq, int index)
+{
+	struct rte_vhost_vring vq;
+	struct mlx5_devx_virtq_attr attr = {0};
+	uint64_t gpa;
+	int ret;
+	int i;
+	uint16_t last_avail_idx;
+	uint16_t last_used_idx;
+
+	ret = rte_vhost_get_vhost_vring(priv->vid, index, &vq);
+	if (ret)
+		return -1;
+	virtq->index = index;
+	virtq->vq_size = vq.size;
+	/*
+	 * No need event QPs creation when the guest in poll mode or when the
+	 * capability allows it.
+	 */
+	attr.event_mode = vq.callfd != -1 || !(priv->caps.event_mode & (1 <<
+					       MLX5_VIRTQ_EVENT_MODE_NO_MSIX)) ?
+						      MLX5_VIRTQ_EVENT_MODE_QP :
+						  MLX5_VIRTQ_EVENT_MODE_NO_MSIX;
+	if (attr.event_mode == MLX5_VIRTQ_EVENT_MODE_QP) {
+		ret = mlx5_vdpa_event_qp_create(priv, vq.size, vq.callfd,
+						&virtq->eqp);
+		if (ret) {
+			DRV_LOG(ERR, "Failed to create event QPs for virtq %d.",
+				index);
+			return -1;
+		}
+		attr.qp_id = virtq->eqp.fw_qp->id;
+	} else {
+		DRV_LOG(INFO, "Virtq %d is, for sure, working by poll mode, no"
+			" need event QPs and event mechanism.", index);
+	}
+	/* Setup 3 UMEMs for each virtq. */
+	for (i = 0; i < 3; ++i) {
+		virtq->umems[i].size = priv->caps.umems[i].a * vq.size +
+							  priv->caps.umems[i].b;
+		virtq->umems[i].buf = rte_zmalloc(__func__,
+						  virtq->umems[i].size, 4096);
+		if (!virtq->umems[i].buf) {
+			DRV_LOG(ERR, "Cannot allocate umem %d memory for virtq"
+				" %u.", i, index);
+			goto error;
+		}
+		virtq->umems[i].obj = mlx5_glue->devx_umem_reg(priv->ctx,
+							virtq->umems[i].buf,
+							virtq->umems[i].size,
+							IBV_ACCESS_LOCAL_WRITE);
+		if (!virtq->umems[i].obj) {
+			DRV_LOG(ERR, "Failed to register umem %d for virtq %u.",
+				i, index);
+			goto error;
+		}
+		attr.umems[i].id = virtq->umems[i].obj->umem_id;
+		attr.umems[i].offset = 0;
+		attr.umems[i].size = virtq->umems[i].size;
+	}
+	gpa = mlx5_vdpa_hva_to_gpa(priv->vmem, (uint64_t)(uintptr_t)vq.desc);
+	if (!gpa) {
+		DRV_LOG(ERR, "Fail to get GPA for descriptor ring.");
+		goto error;
+	}
+	attr.desc_addr = gpa;
+	gpa = mlx5_vdpa_hva_to_gpa(priv->vmem, (uint64_t)(uintptr_t)vq.used);
+	if (!gpa) {
+		DRV_LOG(ERR, "Fail to get GPA for used ring.");
+		goto error;
+	}
+	attr.used_addr = gpa;
+	gpa = mlx5_vdpa_hva_to_gpa(priv->vmem, (uint64_t)(uintptr_t)vq.avail);
+	if (!gpa) {
+		DRV_LOG(ERR, "Fail to get GPA for available ring.");
+		goto error;
+	}
+	attr.available_addr = gpa;
+	rte_vhost_get_vring_base(priv->vid, index, &last_avail_idx,
+				 &last_used_idx);
+	DRV_LOG(INFO, "vid %d: Init last_avail_idx=%d, last_used_idx=%d for "
+		"virtq %d.", priv->vid, last_avail_idx, last_used_idx, index);
+	attr.hw_available_index = last_avail_idx;
+	attr.hw_used_index = last_used_idx;
+	attr.q_size = vq.size;
+	attr.mkey = priv->gpa_mkey_index;
+	attr.tis_id = priv->tis->id;
+	attr.queue_index = index;
+	virtq->virtq = mlx5_devx_cmd_create_virtq(priv->ctx, &attr);
+	if (!virtq->virtq)
+		goto error;
+	return 0;
+error:
+	mlx5_vdpa_virtq_unset(virtq);
+	return -1;
+}
+
+int
+mlx5_vdpa_virtqs_prepare(struct mlx5_vdpa_priv *priv)
+{
+	struct mlx5_devx_tis_attr tis_attr = {0};
+	struct mlx5_vdpa_virtq *virtq;
+	uint32_t i;
+	uint16_t nr_vring = rte_vhost_get_vring_num(priv->vid);
+
+	priv->td = mlx5_devx_cmd_create_td(priv->ctx);
+	if (!priv->td) {
+		DRV_LOG(ERR, "Failed to create transport domain.");
+		return -rte_errno;
+	}
+	tis_attr.transport_domain = priv->td->id;
+	priv->tis = mlx5_devx_cmd_create_tis(priv->ctx, &tis_attr);
+	if (!priv->tis) {
+		DRV_LOG(ERR, "Failed to create TIS.");
+		goto error;
+	}
+	for (i = 0; i < nr_vring; i++) {
+		virtq = rte_zmalloc(__func__, sizeof(*virtq), 0);
+		if (!virtq || mlx5_vdpa_virtq_setup(priv, virtq, i)) {
+			if (virtq)
+				rte_free(virtq);
+			goto error;
+		}
+		SLIST_INSERT_HEAD(&priv->virtq_list, virtq, next);
+	}
+	priv->nr_virtqs = nr_vring;
+	return 0;
+error:
+	mlx5_vdpa_virtqs_release(priv);
+	return -1;
+}