RE: [RFC 27/27] vhost: add multiqueue support to VDUSE

["Xia, Chenbo" <chenbo.xia@intel.com>]

> -----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 27/27] vhost: add multiqueue support to VDUSE
> 
> This patch enables control queue support in order to
> support multiqueue.
> 
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
>  lib/vhost/vduse.c | 69 ++++++++++++++++++++++++++++++++++++++++++-----
>  1 file changed, 63 insertions(+), 6 deletions(-)
> 
> diff --git a/lib/vhost/vduse.c b/lib/vhost/vduse.c
> index 1cd04b4872..135e78fc35 100644
> --- a/lib/vhost/vduse.c
> +++ b/lib/vhost/vduse.c
> @@ -21,6 +21,7 @@
>  #include "iotlb.h"
>  #include "vduse.h"
>  #include "vhost.h"
> +#include "virtio_net_ctrl.h"
> 
>  #define VHOST_VDUSE_API_VERSION 0
>  #define VDUSE_CTRL_PATH "/dev/vduse/control"
> @@ -31,7 +32,9 @@
>  				(1ULL << VIRTIO_RING_F_INDIRECT_DESC) | \
>  				(1ULL << VIRTIO_RING_F_EVENT_IDX) | \
>  				(1ULL << VIRTIO_F_IN_ORDER) | \
> -				(1ULL << VIRTIO_F_IOMMU_PLATFORM))
> +				(1ULL << VIRTIO_F_IOMMU_PLATFORM) | \
> +				(1ULL << VIRTIO_NET_F_CTRL_VQ) | \
> +				(1ULL << VIRTIO_NET_F_MQ))
> 
>  struct vduse {
>  	struct fdset fdset;
> @@ -127,6 +130,25 @@ static struct vhost_backend_ops vduse_backend_ops = {
>  	.inject_irq = vduse_inject_irq,
>  };
> 
> +static void
> +vduse_control_queue_event(int fd, void *arg, int *remove __rte_unused)
> +{
> +	struct virtio_net *dev = arg;
> +	uint64_t buf;
> +	int ret;
> +
> +	ret = read(fd, &buf, sizeof(buf));
> +	if (ret < 0) {
> +		VHOST_LOG_CONFIG(dev->ifname, ERR, "Failed to read control
> queue event: %s\n",
> +				strerror(errno));
> +		return;
> +	}
> +
> +	VHOST_LOG_CONFIG(dev->ifname, DEBUG, "Control queue kicked\n");
> +	if (virtio_net_ctrl_handle(dev))
> +		VHOST_LOG_CONFIG(dev->ifname, ERR, "Failed to handle ctrl
> request\n");
> +}
> +
>  static void
>  vduse_vring_setup(struct virtio_net *dev, unsigned int index)
>  {
> @@ -192,6 +214,18 @@ vduse_vring_setup(struct virtio_net *dev, unsigned
> int index)
>  		vq->kickfd = VIRTIO_UNINITIALIZED_EVENTFD;
>  		return;
>  	}
> +
> +	if (vq == dev->cvq) {
> +		vhost_enable_guest_notification(dev, vq, 1);
> +		ret = fdset_add(&vduse.fdset, vq->kickfd,
> vduse_control_queue_event, NULL, dev);
> +		if (ret) {
> +			VHOST_LOG_CONFIG(dev->ifname, ERR,
> +					"Failed to setup kickfd handler for
> VQ %u: %s\n",
> +					index, strerror(errno));
> +			close(vq->kickfd);
> +			vq->kickfd = VIRTIO_UNINITIALIZED_EVENTFD;
> +		}
> +	}
>  }
> 
>  static void
> @@ -236,6 +270,9 @@ vduse_device_start(struct virtio_net *dev)
>  	for (i = 0; i < dev->nr_vring; i++) {
>  		struct vhost_virtqueue *vq = dev->virtqueue[i];
> 
> +		if (vq == dev->cvq)
> +			continue;
> +
>  		if (dev->notify_ops->vring_state_changed)
>  			dev->notify_ops->vring_state_changed(dev->vid, i, vq-
> >enabled);
>  	}
> @@ -315,8 +352,9 @@ vduse_device_create(const char *path)
>  {
>  	int control_fd, dev_fd, vid, ret;
>  	pthread_t fdset_tid;
> -	uint32_t i;
> +	uint32_t i, max_queue_pairs;
>  	struct virtio_net *dev;
> +	struct virtio_net_config vnet_config = { 0 };
>  	uint64_t ver = VHOST_VDUSE_API_VERSION;
>  	struct vduse_dev_config *dev_config = NULL;
>  	const char *name = path + strlen("/dev/vduse/");
> @@ -357,22 +395,33 @@ vduse_device_create(const char *path)
>  		goto out_ctrl_close;
>  	}
> 
> -	dev_config = malloc(offsetof(struct vduse_dev_config, config));
> +	dev_config = malloc(offsetof(struct vduse_dev_config, config) +
> +			sizeof(vnet_config));
>  	if (!dev_config) {
>  		VHOST_LOG_CONFIG(name, ERR, "Failed to allocate VDUSE
> config\n");
>  		ret = -1;
>  		goto out_ctrl_close;
>  	}
> 
> +	ret = rte_vhost_driver_get_queue_num(path, &max_queue_pairs);
> +	if (ret < 0) {
> +		VHOST_LOG_CONFIG(name, ERR, "Failed to get max queue pairs\n");
> +		goto out_free;
> +	}
> +
> +	VHOST_LOG_CONFIG(path, INFO, "VDUSE max queue pairs: %u\n",
> max_queue_pairs);
> +
> +	vnet_config.max_virtqueue_pairs = max_queue_pairs;
>  	memset(dev_config, 0, sizeof(struct vduse_dev_config));
> 
>  	strncpy(dev_config->name, name, VDUSE_NAME_MAX - 1);
>  	dev_config->device_id = VIRTIO_ID_NET;
>  	dev_config->vendor_id = 0;
>  	dev_config->features = VDUSE_NET_SUPPORTED_FEATURES;
> -	dev_config->vq_num = 2;
> +	dev_config->vq_num = max_queue_pairs * 2 + 1; /* Includes ctrl queue
> */
>  	dev_config->vq_align = sysconf(_SC_PAGE_SIZE);
> -	dev_config->config_size = 0;
> +	dev_config->config_size = sizeof(struct virtio_net_config);
> +	memcpy(dev_config->config, &vnet_config, sizeof(vnet_config));
> 
>  	ret = ioctl(control_fd, VDUSE_CREATE_DEV, dev_config);
>  	if (ret < 0) {
> @@ -407,7 +456,7 @@ vduse_device_create(const char *path)
>  	dev->vduse_dev_fd = dev_fd;
>  	vhost_setup_virtio_net(dev->vid, true, true, true, true);
> 
> -	for (i = 0; i < 2; i++) {
> +	for (i = 0; i < max_queue_pairs * 2 + 1; i++) {
>  		struct vduse_vq_config vq_cfg = { 0 };
> 
>  		ret = alloc_vring_queue(dev, i);
> @@ -426,6 +475,8 @@ vduse_device_create(const char *path)
>  		}
>  	}
> 
> +	dev->cvq = dev->virtqueue[max_queue_pairs * 2];
> +
>  	ret = fdset_add(&vduse.fdset, dev->vduse_dev_fd,
> vduse_events_handler, NULL, dev);
>  	if (ret) {
>  		VHOST_LOG_CONFIG(name, ERR, "Failed to add fd %d to vduse
> fdset\n",
> @@ -471,6 +522,12 @@ 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);
> +		close(dev->cvq->kickfd);
> +		dev->cvq->kickfd = VIRTIO_UNINITIALIZED_EVENTFD;
> +	}
> +
>  	fdset_del(&vduse.fdset, dev->vduse_dev_fd);
> 
>  	if (dev->vduse_dev_fd >= 0) {
> --
> 2.39.2

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