Re: [PATCH 28/28] vhost: Add VDUSE device stop

[Maxime Coquelin <maxime.coquelin@redhat.com>]

Sorry, something went wrong when sending the series.
I'm sending a v3 as the series is broken in two in patchwork because of
this leftover patch.

On 5/25/23 18:15, Maxime Coquelin wrote:
> This patch adds VDUSE device stop and cleanup of its
> virtqueues.
> 
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
>   doc/guides/rel_notes/release_23_07.rst |  6 +++
>   lib/vhost/vduse.c                      | 72 +++++++++++++++++++++++---
>   2 files changed, 70 insertions(+), 8 deletions(-)
> 
> diff --git a/doc/guides/rel_notes/release_23_07.rst b/doc/guides/rel_notes/release_23_07.rst
> index fa889a5ee7..66ba9e25dd 100644
> --- a/doc/guides/rel_notes/release_23_07.rst
> +++ b/doc/guides/rel_notes/release_23_07.rst
> @@ -60,6 +60,12 @@ New Features
>     Introduced ``rte_vhost_driver_set_max_queue_num()`` to be able to limit the
>     maximum number of supported queue pairs, required for VDUSE support.
>   
> +* **Added VDUSE support into Vhost library
> +
> +  VDUSE aims at implementing vDPA devices in userspace. It can be used as an
> +  alternative to Vhost-user when using Vhost-vDPA, but also enable providing a
> +  virtio-net netdev to the host when using Virtio-vDPA driver.
> +
>   
>   Removed Items
>   -------------
> diff --git a/lib/vhost/vduse.c b/lib/vhost/vduse.c
> index 699cfed9e3..f421b1cf4c 100644
> --- a/lib/vhost/vduse.c
> +++ b/lib/vhost/vduse.c
> @@ -252,6 +252,44 @@ vduse_vring_setup(struct virtio_net *dev, unsigned int index)
>   	}
>   }
>   
> +static void
> +vduse_vring_cleanup(struct virtio_net *dev, unsigned int index)
> +{
> +	struct vhost_virtqueue *vq = dev->virtqueue[index];
> +	struct vduse_vq_eventfd vq_efd;
> +	int ret;
> +
> +	if (vq == dev->cvq && vq->kickfd >= 0) {
> +		fdset_del(&vduse.fdset, vq->kickfd);
> +		fdset_pipe_notify(&vduse.fdset);
> +	}
> +
> +	vq_efd.index = index;
> +	vq_efd.fd = VDUSE_EVENTFD_DEASSIGN;
> +
> +	ret = ioctl(dev->vduse_dev_fd, VDUSE_VQ_SETUP_KICKFD, &vq_efd);
> +	if (ret)
> +		VHOST_LOG_CONFIG(dev->ifname, ERR, "Failed to cleanup kickfd for VQ %u: %s\n",
> +				index, strerror(errno));
> +
> +	close(vq->kickfd);
> +	vq->kickfd = VIRTIO_UNINITIALIZED_EVENTFD;
> +
> +	vring_invalidate(dev, vq);
> +
> +	rte_free(vq->batch_copy_elems);
> +	vq->batch_copy_elems = NULL;
> +
> +	rte_free(vq->shadow_used_split);
> +	vq->shadow_used_split = NULL;
> +
> +	vq->enabled = false;
> +	vq->ready = false;
> +	vq->size = 0;
> +	vq->last_used_idx = 0;
> +	vq->last_avail_idx = 0;
> +}
> +
>   static void
>   vduse_device_start(struct virtio_net *dev)
>   {
> @@ -304,6 +342,23 @@ vduse_device_start(struct virtio_net *dev)
>   	}
>   }
>   
> +static void
> +vduse_device_stop(struct virtio_net *dev)
> +{
> +	unsigned int i;
> +
> +	VHOST_LOG_CONFIG(dev->ifname, INFO, "Stopping device...\n");
> +
> +	vhost_destroy_device_notify(dev);
> +
> +	dev->flags &= ~VIRTIO_DEV_READY;
> +
> +	for (i = 0; i < dev->nr_vring; i++)
> +		vduse_vring_cleanup(dev, i);
> +
> +	vhost_user_iotlb_flush_all(dev);
> +}
> +
>   static void
>   vduse_events_handler(int fd, void *arg, int *remove __rte_unused)
>   {
> @@ -311,6 +366,7 @@ vduse_events_handler(int fd, void *arg, int *remove __rte_unused)
>   	struct vduse_dev_request req;
>   	struct vduse_dev_response resp;
>   	struct vhost_virtqueue *vq;
> +	uint8_t old_status;
>   	int ret;
>   
>   	memset(&resp, 0, sizeof(resp));
> @@ -339,10 +395,15 @@ vduse_events_handler(int fd, void *arg, int *remove __rte_unused)
>   	case VDUSE_SET_STATUS:
>   		VHOST_LOG_CONFIG(dev->ifname, INFO, "\tnew status: 0x%08x\n",
>   				req.s.status);
> +		old_status = dev->status;
>   		dev->status = req.s.status;
>   
> -		if (dev->status & VIRTIO_DEVICE_STATUS_DRIVER_OK)
> -			vduse_device_start(dev);
> +		if ((old_status ^ dev->status) & VIRTIO_DEVICE_STATUS_DRIVER_OK) {
> +			if (dev->status & VIRTIO_DEVICE_STATUS_DRIVER_OK)
> +				vduse_device_start(dev);
> +			else
> +				vduse_device_stop(dev);
> +		}
>   
>   		resp.result = VDUSE_REQ_RESULT_OK;
>   		break;
> @@ -560,12 +621,7 @@ vduse_device_destroy(const char *path)
>   	if (vid == RTE_MAX_VHOST_DEVICE)
>   		return -1;
>   
> -	if (dev->cvq && dev->cvq->kickfd >= 0) {
> -		fdset_del(&vduse.fdset, dev->cvq->kickfd);
> -		fdset_pipe_notify(&vduse.fdset);
> -		close(dev->cvq->kickfd);
> -		dev->cvq->kickfd = VIRTIO_UNINITIALIZED_EVENTFD;
> -	}
> +	vduse_device_stop(dev);
>   
>   	fdset_del(&vduse.fdset, dev->vduse_dev_fd);
>   	fdset_pipe_notify(&vduse.fdset);