text: /*-
   *   BSD LICENSE
   *
   *   Copyright(c) 2010-2016 Intel Corporation. All rights reserved.
   *   All rights reserved.
   *
   *   Redistribution and use in source and binary forms, with or without
   *   modification, are permitted provided that the following conditions
   *   are met:
   *
   *     * Redistributions of source code must retain the above copyright
   *       notice, this list of conditions and the following disclaimer.
   *     * Redistributions in binary form must reproduce the above copyright
   *       notice, this list of conditions and the following disclaimer in
   *       the documentation and/or other materials provided with the
   *       distribution.
   *     * Neither the name of Intel Corporation nor the names of its
   *       contributors may be used to endorse or promote products derived
   *       from this software without specific prior written permission.
   *
   *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include "spdk/stdinc.h"
  
  #include <sys/eventfd.h>
  
  #include <linux/virtio_scsi.h>
  
  #include <rte_config.h>
  #include <rte_malloc.h>
  #include <rte_alarm.h>
  
  #include "virtio_user/vhost.h"
  #include "spdk/string.h"
  #include "spdk/config.h"
  
  #include "spdk_internal/virtio.h"
  
  #define VIRTIO_USER_SUPPORTED_PROTOCOL_FEATURES \
  	((1ULL << VHOST_USER_PROTOCOL_F_MQ) | \
  	(1ULL << VHOST_USER_PROTOCOL_F_CONFIG))
  
  static int
  virtio_user_create_queue(struct virtio_dev *vdev, uint32_t queue_sel)
  {
  	struct virtio_user_dev *dev = vdev->ctx;
  
  	/* Of all per virtqueue MSGs, make sure VHOST_SET_VRING_CALL come
  	 * firstly because vhost depends on this msg to allocate virtqueue
  	 * pair.
  	 */
  	struct vhost_vring_file file;
  
  	file.index = queue_sel;
  	file.fd = dev->callfds[queue_sel];
  	return dev->ops->send_request(dev, VHOST_USER_SET_VRING_CALL, &file);
  }
  
  static int
  virtio_user_set_vring_addr(struct virtio_dev *vdev, uint32_t queue_sel)
  {
  	struct virtio_user_dev *dev = vdev->ctx;
  	struct vring *vring = &dev->vrings[queue_sel];
  	struct vhost_vring_addr addr = {
  		.index = queue_sel,
  		.desc_user_addr = (uint64_t)(uintptr_t)vring->desc,
  		.avail_user_addr = (uint64_t)(uintptr_t)vring->avail,
  		.used_user_addr = (uint64_t)(uintptr_t)vring->used,
  		.log_guest_addr = 0,
  		.flags = 0, /* disable log */
  	};
  
  	return dev->ops->send_request(dev, VHOST_USER_SET_VRING_ADDR, &addr);
  }
  
  static int
  virtio_user_kick_queue(struct virtio_dev *vdev, uint32_t queue_sel)
  {
  	struct virtio_user_dev *dev = vdev->ctx;
  	struct vhost_vring_file file;
  	struct vhost_vring_state state;
  	struct vring *vring = &dev->vrings[queue_sel];
  	int rc;
  
  	state.index = queue_sel;
  	state.num = vring->num;
  	rc = dev->ops->send_request(dev, VHOST_USER_SET_VRING_NUM, &state);
  	if (rc < 0) {
  		return rc;
  	}
  
  	state.index = queue_sel;
  	state.num = 0; /* no reservation */
  	rc = dev->ops->send_request(dev, VHOST_USER_SET_VRING_BASE, &state);
  	if (rc < 0) {
  		return rc;
  	}
  
  	virtio_user_set_vring_addr(vdev, queue_sel);
  
  	/* Of all per virtqueue MSGs, make sure VHOST_USER_SET_VRING_KICK comes
  	 * lastly because vhost depends on this msg to judge if
  	 * virtio is ready.
  	 */
  	file.index = queue_sel;
  	file.fd = dev->kickfds[queue_sel];
  	return dev->ops->send_request(dev, VHOST_USER_SET_VRING_KICK, &file);
  }
  
  static int
  virtio_user_stop_queue(struct virtio_dev *vdev, uint32_t queue_sel)
  {
  	struct virtio_user_dev *dev = vdev->ctx;
  	struct vhost_vring_state state;
  
  	state.index = queue_sel;
  	state.num = 0;
  
  	return dev->ops->send_request(dev, VHOST_USER_GET_VRING_BASE, &state);
  }
  
  static int
  virtio_user_queue_setup(struct virtio_dev *vdev,
  			int (*fn)(struct virtio_dev *, uint32_t))
  {
  	uint32_t i;
  	int rc;
  
  	for (i = 0; i < vdev->max_queues; ++i) {
  		rc = fn(vdev, i);
  		if (rc < 0) {
  			SPDK_ERRLOG("setup tx vq fails: %"PRIu32".\n", i);
  			return rc;
  		}
  	}
  
  	return 0;
  }
  
  static int
  virtio_user_map_notify(void *cb_ctx, struct spdk_mem_map *map,
  		       enum spdk_mem_map_notify_action action,
  		       void *vaddr, size_t size)
  {
  	struct virtio_dev *vdev = cb_ctx;
  	struct virtio_user_dev *dev = vdev->ctx;
  	uint64_t features;
  	int ret;
  
  	/* We have to resend all mappings anyway, so don't bother with any
  	 * page tracking.
  	 */
  	ret = dev->ops->send_request(dev, VHOST_USER_SET_MEM_TABLE, NULL);
  	if (ret < 0) {
  		return ret;
  	}
  
  #ifdef SPDK_CONFIG_VHOST_INTERNAL_LIB
  	/* Our internal rte_vhost lib requires SET_VRING_ADDR to flush a pending
  	 * SET_MEM_TABLE. On the other hand, the upstream rte_vhost will invalidate
  	 * the entire queue upon receiving SET_VRING_ADDR message, so we mustn't
  	 * send it here. Both behaviors are strictly implementation specific, but
  	 * this message isn't needed from the point of the spec, so send it only
  	 * if vhost is compiled with our internal lib.
  	 */
  	ret = virtio_user_queue_setup(vdev, virtio_user_set_vring_addr);
  	if (ret < 0) {
  		return ret;
  	}
  #endif
  
  	/* Since we might want to use that mapping straight away, we have to
  	 * make sure the guest has already processed our SET_MEM_TABLE message.
  	 * F_REPLY_ACK is just a feature and the host is not obliged to
  	 * support it, so we send a simple message that always has a response
  	 * and we wait for that response. Messages are always processed in order.
  	 */
  	return dev->ops->send_request(dev, VHOST_USER_GET_FEATURES, &features);
  }
  
  static int
  virtio_user_register_mem(struct virtio_dev *vdev)
  {
  	struct virtio_user_dev *dev = vdev->ctx;
  	const struct spdk_mem_map_ops virtio_user_map_ops = {
  		.notify_cb = virtio_user_map_notify,
  		.are_contiguous = NULL
  	};
  
  	dev->mem_map = spdk_mem_map_alloc(0, &virtio_user_map_ops, vdev);
  	if (dev->mem_map == NULL) {
  		SPDK_ERRLOG("spdk_mem_map_alloc() failed\n");
  		return -1;
  	}
  
  	return 0;
  }
  
  static void
  virtio_user_unregister_mem(struct virtio_dev *vdev)
  {
  	struct virtio_user_dev *dev = vdev->ctx;
  
  	spdk_mem_map_free(&dev->mem_map);
  }
  
  static int
  virtio_user_start_device(struct virtio_dev *vdev)
  {
  	struct virtio_user_dev *dev = vdev->ctx;
  	uint64_t host_max_queues;
  	int ret;
  
  	if ((dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_MQ)) == 0 &&
  	    vdev->max_queues > 1 + vdev->fixed_queues_num) {
  		SPDK_WARNLOG("%s: requested %"PRIu16" request queues, but the "
  			     "host doesn't support VHOST_USER_PROTOCOL_F_MQ. "
  			     "Only one request queue will be used.\n",
  			     vdev->name, vdev->max_queues - vdev->fixed_queues_num);
  		vdev->max_queues = 1 + vdev->fixed_queues_num;
  	}
  
  	/* negotiate the number of I/O queues. */
  	ret = dev->ops->send_request(dev, VHOST_USER_GET_QUEUE_NUM, &host_max_queues);
  	if (ret < 0) {
  		return ret;
  	}
  
  	if (vdev->max_queues > host_max_queues + vdev->fixed_queues_num) {
  		SPDK_WARNLOG("%s: requested %"PRIu16" request queues"
  			     "but only %"PRIu64" available\n",
  			     vdev->name, vdev->max_queues - vdev->fixed_queues_num,
  			     host_max_queues);
  		vdev->max_queues = host_max_queues;
  	}
  
  	/* tell vhost to create queues */
  	ret = virtio_user_queue_setup(vdev, virtio_user_create_queue);
  	if (ret < 0) {
  		return ret;
  	}
  
  	ret = virtio_user_register_mem(vdev);
  	if (ret < 0) {
  		return ret;
  	}
  
  	return virtio_user_queue_setup(vdev, virtio_user_kick_queue);
  }
  
  static int
  virtio_user_stop_device(struct virtio_dev *vdev)
  {
  	int ret;
  
  	ret = virtio_user_queue_setup(vdev, virtio_user_stop_queue);
  	/* a queue might fail to stop for various reasons, e.g. socket
  	 * connection going down, but this mustn't prevent us from freeing
  	 * the mem map.
  	 */
  	virtio_user_unregister_mem(vdev);
  	return ret;
  }
  
  static int
  virtio_user_dev_setup(struct virtio_dev *vdev)
  {
  	struct virtio_user_dev *dev = vdev->ctx;
  	uint16_t i;
  
  	dev->vhostfd = -1;
  
  	for (i = 0; i < SPDK_VIRTIO_MAX_VIRTQUEUES; ++i) {
  		dev->callfds[i] = -1;
  		dev->kickfds[i] = -1;
  	}
  
  	dev->ops = &ops_user;
  
  	return dev->ops->setup(dev);
  }
  
  static int
  virtio_user_read_dev_config(struct virtio_dev *vdev, size_t offset,
  			    void *dst, int length)
  {
  	struct virtio_user_dev *dev = vdev->ctx;
  	struct vhost_user_config cfg = {0};
  	int rc;
  
  	if ((dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_CONFIG)) == 0) {
  		return -ENOTSUP;
  	}
  
  	cfg.offset = 0;
  	cfg.size = VHOST_USER_MAX_CONFIG_SIZE;
  
  	rc = dev->ops->send_request(dev, VHOST_USER_GET_CONFIG, &cfg);
  	if (rc < 0) {
  		SPDK_ERRLOG("get_config failed: %s\n", spdk_strerror(-rc));
  		return rc;
  	}
  
  	memcpy(dst, cfg.region + offset, length);
  	return 0;
  }
  
  static int
  virtio_user_write_dev_config(struct virtio_dev *vdev, size_t offset,
  			     const void *src, int length)
  {
  	struct virtio_user_dev *dev = vdev->ctx;
  	struct vhost_user_config cfg = {0};
  	int rc;
  
  	if ((dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_CONFIG)) == 0) {
  		return -ENOTSUP;
  	}
  
  	cfg.offset = offset;
  	cfg.size = length;
  	memcpy(cfg.region, src, length);
  
  	rc = dev->ops->send_request(dev, VHOST_USER_SET_CONFIG, &cfg);
  	if (rc < 0) {
  		SPDK_ERRLOG("set_config failed: %s\n", spdk_strerror(-rc));
  		return rc;
  	}
  
  	return 0;
  }
  
  static void
  virtio_user_set_status(struct virtio_dev *vdev, uint8_t status)
  {
  	struct virtio_user_dev *dev = vdev->ctx;
  	int rc = 0;
  
  	if ((dev->status & VIRTIO_CONFIG_S_NEEDS_RESET) &&
  	    status != VIRTIO_CONFIG_S_RESET) {
  		rc = -1;
  	} else if (status & VIRTIO_CONFIG_S_DRIVER_OK) {
  		rc = virtio_user_start_device(vdev);
  	} else if (status == VIRTIO_CONFIG_S_RESET &&
  		   (dev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
  		rc = virtio_user_stop_device(vdev);
  	}
  
  	if (rc != 0) {
  		dev->status |= VIRTIO_CONFIG_S_NEEDS_RESET;
  	} else {
  		dev->status = status;
  	}
  }
  
  static uint8_t
  virtio_user_get_status(struct virtio_dev *vdev)
  {
  	struct virtio_user_dev *dev = vdev->ctx;
  
  	return dev->status;
  }
  
  static uint64_t
  virtio_user_get_features(struct virtio_dev *vdev)
  {
  	struct virtio_user_dev *dev = vdev->ctx;
  	uint64_t features;
  	int rc;
  
  	rc = dev->ops->send_request(dev, VHOST_USER_GET_FEATURES, &features);
  	if (rc < 0) {
  		SPDK_ERRLOG("get_features failed: %s\n", spdk_strerror(-rc));
  		return 0;
  	}
  
  	return features;
  }
  
  static int
  virtio_user_set_features(struct virtio_dev *vdev, uint64_t features)
  {
  	struct virtio_user_dev *dev = vdev->ctx;
  	uint64_t protocol_features;
  	int ret;
  
  	ret = dev->ops->send_request(dev, VHOST_USER_SET_FEATURES, &features);
  	if (ret < 0) {
  		return ret;
  	}
  
  	vdev->negotiated_features = features;
  	vdev->modern = virtio_dev_has_feature(vdev, VIRTIO_F_VERSION_1);
  
  	if (!virtio_dev_has_feature(vdev, VHOST_USER_F_PROTOCOL_FEATURES)) {
  		/* nothing else to do */
  		return 0;
  	}
  
  	ret = dev->ops->send_request(dev, VHOST_USER_GET_PROTOCOL_FEATURES, &protocol_features);
  	if (ret < 0) {
  		return ret;
  	}
  
  	protocol_features &= VIRTIO_USER_SUPPORTED_PROTOCOL_FEATURES;
  	ret = dev->ops->send_request(dev, VHOST_USER_SET_PROTOCOL_FEATURES, &protocol_features);
  	if (ret < 0) {
  		return ret;
  	}
  
  	dev->protocol_features = protocol_features;
  	return 0;
  }
  
  static uint16_t
  virtio_user_get_queue_size(struct virtio_dev *vdev, uint16_t queue_id)
  {
  	struct virtio_user_dev *dev = vdev->ctx;
  
  	/* Currently each queue has same queue size */
  	return dev->queue_size;
  }
  
  static int
  virtio_user_setup_queue(struct virtio_dev *vdev, struct virtqueue *vq)
  {
  	struct virtio_user_dev *dev = vdev->ctx;
  	struct vhost_vring_state state;
  	uint16_t queue_idx = vq->vq_queue_index;
  	void *queue_mem;
  	uint64_t desc_addr, avail_addr, used_addr;
  	int callfd, kickfd, rc;
  
  	if (dev->callfds[queue_idx] != -1 || dev->kickfds[queue_idx] != -1) {
  		SPDK_ERRLOG("queue %"PRIu16" already exists\n", queue_idx);
  		return -EEXIST;
  	}
  
  	/* May use invalid flag, but some backend uses kickfd and
  	 * callfd as criteria to judge if dev is alive. so finally we
  	 * use real event_fd.
  	 */
  	callfd = eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK);
  	if (callfd < 0) {
  		SPDK_ERRLOG("callfd error, %s\n", spdk_strerror(errno));
  		return -errno;
  	}
  
  	kickfd = eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK);
  	if (kickfd < 0) {
  		SPDK_ERRLOG("kickfd error, %s\n", spdk_strerror(errno));
  		close(callfd);
  		return -errno;
  	}
  
  	queue_mem = spdk_zmalloc(vq->vq_ring_size, VIRTIO_PCI_VRING_ALIGN, NULL,
  				 SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
  	if (queue_mem == NULL) {
  		close(kickfd);
  		close(callfd);
  		return -ENOMEM;
  	}
  
  	vq->vq_ring_mem = SPDK_VTOPHYS_ERROR;
  	vq->vq_ring_virt_mem = queue_mem;
  
  	state.index = vq->vq_queue_index;
  	state.num = 0;
  
  	if (virtio_dev_has_feature(vdev, VHOST_USER_F_PROTOCOL_FEATURES)) {
  		rc = dev->ops->send_request(dev, VHOST_USER_SET_VRING_ENABLE, &state);
  		if (rc < 0) {
  			SPDK_ERRLOG("failed to send VHOST_USER_SET_VRING_ENABLE: %s\n",
  				    spdk_strerror(-rc));
  			spdk_free(queue_mem);
  			return -rc;
  		}
  	}
  
  	dev->callfds[queue_idx] = callfd;
  	dev->kickfds[queue_idx] = kickfd;
  
  	desc_addr = (uintptr_t)vq->vq_ring_virt_mem;
  	avail_addr = desc_addr + vq->vq_nentries * sizeof(struct vring_desc);
  	used_addr = RTE_ALIGN_CEIL(avail_addr + offsetof(struct vring_avail,
  				   ring[vq->vq_nentries]),
  				   VIRTIO_PCI_VRING_ALIGN);
  
  	dev->vrings[queue_idx].num = vq->vq_nentries;
  	dev->vrings[queue_idx].desc = (void *)(uintptr_t)desc_addr;
  	dev->vrings[queue_idx].avail = (void *)(uintptr_t)avail_addr;
  	dev->vrings[queue_idx].used = (void *)(uintptr_t)used_addr;
  
  	return 0;
  }
  
  static void
  virtio_user_del_queue(struct virtio_dev *vdev, struct virtqueue *vq)
  {
  	/* For legacy devices, write 0 to VIRTIO_PCI_QUEUE_PFN port, QEMU
  	 * correspondingly stops the ioeventfds, and reset the status of
  	 * the device.
  	 * For modern devices, set queue desc, avail, used in PCI bar to 0,
  	 * not see any more behavior in QEMU.
  	 *
  	 * Here we just care about what information to deliver to vhost-user.
  	 * So we just close ioeventfd for now.
  	 */
  	struct virtio_user_dev *dev = vdev->ctx;
  
  	close(dev->callfds[vq->vq_queue_index]);
  	close(dev->kickfds[vq->vq_queue_index]);
  	dev->callfds[vq->vq_queue_index] = -1;
  	dev->kickfds[vq->vq_queue_index] = -1;
  
  	spdk_free(vq->vq_ring_virt_mem);
  }
  
  static void
  virtio_user_notify_queue(struct virtio_dev *vdev, struct virtqueue *vq)
  {
  	uint64_t buf = 1;
  	struct virtio_user_dev *dev = vdev->ctx;
  
  	if (write(dev->kickfds[vq->vq_queue_index], &buf, sizeof(buf)) < 0) {
  		SPDK_ERRLOG("failed to kick backend: %s.\n", spdk_strerror(errno));
  	}
  }
  
  static void
  virtio_user_destroy(struct virtio_dev *vdev)
  {
  	struct virtio_user_dev *dev = vdev->ctx;
  
  	close(dev->vhostfd);
  	free(dev);
  }
  
  static void
  virtio_user_dump_json_info(struct virtio_dev *vdev, struct spdk_json_write_ctx *w)
  {
  	struct virtio_user_dev *dev = vdev->ctx;
  
  	spdk_json_write_named_string(w, "type", "user");
  	spdk_json_write_named_string(w, "socket", dev->path);
  }
  
  static void
  virtio_user_write_json_config(struct virtio_dev *vdev, struct spdk_json_write_ctx *w)
  {
  	struct virtio_user_dev *dev = vdev->ctx;
  
  	spdk_json_write_named_string(w, "trtype", "user");
  	spdk_json_write_named_string(w, "traddr", dev->path);
  	spdk_json_write_named_uint32(w, "vq_count", vdev->max_queues - vdev->fixed_queues_num);
  	spdk_json_write_named_uint32(w, "vq_size", virtio_dev_backend_ops(vdev)->get_queue_size(vdev, 0));
  }
  
  static const struct virtio_dev_ops virtio_user_ops = {
  	.read_dev_cfg	= virtio_user_read_dev_config,
  	.write_dev_cfg	= virtio_user_write_dev_config,
  	.get_status	= virtio_user_get_status,
  	.set_status	= virtio_user_set_status,
  	.get_features	= virtio_user_get_features,
  	.set_features	= virtio_user_set_features,
  	.destruct_dev	= virtio_user_destroy,
  	.get_queue_size	= virtio_user_get_queue_size,
  	.setup_queue	= virtio_user_setup_queue,
  	.del_queue	= virtio_user_del_queue,
  	.notify_queue	= virtio_user_notify_queue,
  	.dump_json_info = virtio_user_dump_json_info,
  	.write_json_config = virtio_user_write_json_config,
  };
  
  int
  virtio_user_dev_init(struct virtio_dev *vdev, const char *name, const char *path,
  		     uint32_t queue_size)
  {
  	struct virtio_user_dev *dev;
  	int rc;
  
  	if (name == NULL) {
  		SPDK_ERRLOG("No name gived for controller: %s\n", path);
  		return -EINVAL;
  	}
  
  	dev = calloc(1, sizeof(*dev));
  	if (dev == NULL) {
  		return -ENOMEM;
  	}
  
  	rc = virtio_dev_construct(vdev, name, &virtio_user_ops, dev);
  	if (rc != 0) {
  		SPDK_ERRLOG("Failed to init device: %s\n", path);
  		free(dev);
  		return rc;
  	}
  
  	vdev->is_hw = 0;
  
  	snprintf(dev->path, PATH_MAX, "%s", path);
  	dev->queue_size = queue_size;
  
  	rc = virtio_user_dev_setup(vdev);
  	if (rc < 0) {
  		SPDK_ERRLOG("backend set up fails\n");
  		goto err;
  	}
  
  	rc = dev->ops->send_request(dev, VHOST_USER_SET_OWNER, NULL);
  	if (rc < 0) {
  		SPDK_ERRLOG("set_owner fails: %s\n", spdk_strerror(-rc));
  		goto err;
  	}
  
  	return 0;
  
  err:
  	virtio_dev_destruct(vdev);
  	return rc;
  }
  