[RFC,26/27] vhost: add VDUSE device startup

  This patch adds the device and its virtqueues
initialization once the Virtio driver has set the DRIVER_OK
in the Virtio status register.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/vhost/vduse.c | 118 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 118 insertions(+)
  

> -----Original Message-----
> From: Maxime Coquelin <maxime.coquelin@redhat.com>
> Sent: Friday, March 31, 2023 11:43 PM
> To: dev@dpdk.org; david.marchand@redhat.com; Xia, Chenbo
> <chenbo.xia@intel.com>; mkp@redhat.com; fbl@redhat.com;
> jasowang@redhat.com; Liang, Cunming <cunming.liang@intel.com>; Xie, Yongji
> <xieyongji@bytedance.com>; echaudro@redhat.com; eperezma@redhat.com;
> amorenoz@redhat.com
> Cc: Maxime Coquelin <maxime.coquelin@redhat.com>
> Subject: [RFC 26/27] vhost: add VDUSE device startup
> 
> This patch adds the device and its virtqueues
> initialization once the Virtio driver has set the DRIVER_OK
> in the Virtio status register.
> 
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
>  lib/vhost/vduse.c | 118 ++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 118 insertions(+)
> 
> diff --git a/lib/vhost/vduse.c b/lib/vhost/vduse.c
> index b5b9fa2eb1..1cd04b4872 100644
> --- a/lib/vhost/vduse.c
> +++ b/lib/vhost/vduse.c
> @@ -127,6 +127,120 @@ static struct vhost_backend_ops vduse_backend_ops =
> {
>  	.inject_irq = vduse_inject_irq,
>  };
> 
> +static void
> +vduse_vring_setup(struct virtio_net *dev, unsigned int index)
> +{
> +	struct vhost_virtqueue *vq = dev->virtqueue[index];
> +	struct vhost_vring_addr *ra = &vq->ring_addrs;
> +	struct vduse_vq_info vq_info;
> +	struct vduse_vq_eventfd vq_efd;
> +	int ret;
> +
> +	vq_info.index = index;
> +	ret = ioctl(dev->vduse_dev_fd, VDUSE_VQ_GET_INFO, &vq_info);
> +	if (ret) {
> +		VHOST_LOG_CONFIG(dev->ifname, ERR, "Failed to get VQ %u
> info: %s\n",
> +				index, strerror(errno));
> +		return;
> +	}
> +
> +	VHOST_LOG_CONFIG(dev->ifname, INFO, "VQ %u info:\n", index);
> +	VHOST_LOG_CONFIG(dev->ifname, INFO, "\tnum: %u\n", vq_info.num);
> +	VHOST_LOG_CONFIG(dev->ifname, INFO, "\tdesc_addr: %llx\n",
> vq_info.desc_addr);
> +	VHOST_LOG_CONFIG(dev->ifname, INFO, "\tdriver_addr: %llx\n",
> vq_info.driver_addr);
> +	VHOST_LOG_CONFIG(dev->ifname, INFO, "\tdevice_addr: %llx\n",
> vq_info.device_addr);
> +	VHOST_LOG_CONFIG(dev->ifname, INFO, "\tavail_idx: %u\n",
> vq_info.split.avail_index);
> +	VHOST_LOG_CONFIG(dev->ifname, INFO, "\tready: %u\n", vq_info.ready);
> +
> +	vq->last_avail_idx = vq_info.split.avail_index;
> +	vq->size = vq_info.num;
> +	vq->ready = vq_info.ready;
> +	vq->enabled = true;
> +	ra->desc_user_addr = vq_info.desc_addr;
> +	ra->avail_user_addr = vq_info.driver_addr;
> +	ra->used_user_addr = vq_info.device_addr;
> +
> +	vq->shadow_used_split = rte_malloc_socket(NULL,
> +				vq->size * sizeof(struct vring_used_elem),
> +				RTE_CACHE_LINE_SIZE, 0);
> +	vq->batch_copy_elems = rte_malloc_socket(NULL,
> +				vq->size * sizeof(struct batch_copy_elem),
> +				RTE_CACHE_LINE_SIZE, 0);
> +
> +	vhost_user_iotlb_rd_lock(vq);
> +	if (vring_translate(dev, vq))
> +		VHOST_LOG_CONFIG(dev->ifname, ERR, "Failed to translate
> vring %d addresses\n",
> +				index);
> +	vhost_user_iotlb_rd_unlock(vq);
> +
> +	vq->kickfd = eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC);
> +	if (vq->kickfd < 0) {
> +		VHOST_LOG_CONFIG(dev->ifname, ERR, "Failed to init kickfd for
> VQ %u: %s\n",
> +				index, strerror(errno));
> +		vq->kickfd = VIRTIO_INVALID_EVENTFD;
> +		return;
> +	}
> +
> +	vq_efd.index = index;
> +	vq_efd.fd = vq->kickfd;
> +
> +	ret = ioctl(dev->vduse_dev_fd, VDUSE_VQ_SETUP_KICKFD, &vq_efd);
> +	if (ret) {
> +		VHOST_LOG_CONFIG(dev->ifname, ERR, "Failed to setup kickfd for
> VQ %u: %s\n",
> +				index, strerror(errno));
> +		close(vq->kickfd);
> +		vq->kickfd = VIRTIO_UNINITIALIZED_EVENTFD;
> +		return;
> +	}
> +}
> +
> +static void
> +vduse_device_start(struct virtio_net *dev)
> +{
> +	unsigned int i, ret;
> +
> +	dev->notify_ops = vhost_driver_callback_get(dev->ifname);
> +	if (!dev->notify_ops) {
> +		VHOST_LOG_CONFIG(dev->ifname, ERR,
> +				"Failed to get callback ops for driver\n");
> +		return;
> +	}
> +
> +	ret = ioctl(dev->vduse_dev_fd, VDUSE_DEV_GET_FEATURES, &dev-
> >features);
> +	if (ret) {
> +		VHOST_LOG_CONFIG(dev->ifname, ERR, "Failed to get
> features: %s\n",
> +				strerror(errno));
> +		return;
> +	}
> +
> +	VHOST_LOG_CONFIG(dev->ifname, INFO, "negotiated Virtio features:
> 0x%" PRIx64 "\n",
> +		dev->features);
> +
> +	if (dev->features &
> +		((1ULL << VIRTIO_NET_F_MRG_RXBUF) |
> +		 (1ULL << VIRTIO_F_VERSION_1) |
> +		 (1ULL << VIRTIO_F_RING_PACKED))) {
> +		dev->vhost_hlen = sizeof(struct virtio_net_hdr_mrg_rxbuf);
> +	} else {
> +		dev->vhost_hlen = sizeof(struct virtio_net_hdr);
> +	}
> +
> +	for (i = 0; i < dev->nr_vring; i++)
> +		vduse_vring_setup(dev, i);
> +
> +	dev->flags |= VIRTIO_DEV_READY;
> +
> +	if (dev->notify_ops->new_device(dev->vid) == 0)
> +		dev->flags |= VIRTIO_DEV_RUNNING;
> +
> +	for (i = 0; i < dev->nr_vring; i++) {
> +		struct vhost_virtqueue *vq = dev->virtqueue[i];
> +
> +		if (dev->notify_ops->vring_state_changed)
> +			dev->notify_ops->vring_state_changed(dev->vid, i, vq-
> >enabled);
> +	}
> +}
> +
>  static void
>  vduse_events_handler(int fd, void *arg, int *remove __rte_unused)
>  {
> @@ -167,6 +281,10 @@ vduse_events_handler(int fd, void *arg, int *remove
> __rte_unused)
>  		VHOST_LOG_CONFIG(dev->ifname, INFO, "\tnew status: 0x%08x\n",
>  				req.s.status);
>  		dev->status = req.s.status;
> +
> +		if (dev->status & VIRTIO_DEVICE_STATUS_DRIVER_OK)
> +			vduse_device_start(dev);
> +
>  		resp.result = VDUSE_REQ_RESULT_OK;
>  		break;
>  	case VDUSE_UPDATE_IOTLB:
> --
> 2.39.2

Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>