Re: [dpdk-dev] [PATCH v2 41/44] net/virtio: move Vhost-kernel data to its backend

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

Hi Maxime,

> -----Original Message-----
> From: Maxime Coquelin <maxime.coquelin@redhat.com>
> Sent: Wednesday, January 20, 2021 5:25 AM
> To: dev@dpdk.org; Xia, Chenbo <chenbo.xia@intel.com>; olivier.matz@6wind.com;
> amorenoz@redhat.com; david.marchand@redhat.com
> Cc: Maxime Coquelin <maxime.coquelin@redhat.com>
> Subject: [PATCH v2 41/44] net/virtio: move Vhost-kernel data to its backend
> 
> As done earlier for Vhost-user, this patch moves the
> Vhost-Kernel specific data to its backend file.
> 
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
>  drivers/net/virtio/virtio_user/vhost_kernel.c | 106 +++++++++++++++---
>  .../net/virtio/virtio_user/virtio_user_dev.c  |  43 ++-----
>  .../net/virtio/virtio_user/virtio_user_dev.h  |   7 +-
>  3 files changed, 98 insertions(+), 58 deletions(-)
> 
> diff --git a/drivers/net/virtio/virtio_user/vhost_kernel.c
> b/drivers/net/virtio/virtio_user/vhost_kernel.c
> index aa1f9ece5e..bc4b3461e1 100644
> --- a/drivers/net/virtio/virtio_user/vhost_kernel.c
> +++ b/drivers/net/virtio/virtio_user/vhost_kernel.c
> @@ -14,6 +14,11 @@
>  #include "virtio_user_dev.h"
>  #include "vhost_kernel_tap.h"
> 
> +struct vhost_kernel_data {
> +	int *vhostfds;
> +	int *tapfds;
> +};
> +
>  struct vhost_memory_kernel {
>  	uint32_t nregions;
>  	uint32_t padding;
> @@ -96,7 +101,9 @@ vhost_kernel_ioctl(int fd, uint64_t request, void *arg)
>  static int
>  vhost_kernel_set_owner(struct virtio_user_dev *dev)
>  {
> -	return vhost_kernel_ioctl(dev->vhostfds[0], VHOST_SET_OWNER, NULL);
> +	struct vhost_kernel_data *data = dev->backend_data;
> +
> +	return vhost_kernel_ioctl(data->vhostfds[0], VHOST_SET_OWNER, NULL);
>  }
> 
>  static int
> @@ -104,8 +111,9 @@ vhost_kernel_get_features(struct virtio_user_dev *dev,
> uint64_t *features)
>  {
>  	int ret;
>  	unsigned int tap_features;
> +	struct vhost_kernel_data *data = dev->backend_data;
> 
> -	ret = vhost_kernel_ioctl(dev->vhostfds[0], VHOST_GET_FEATURES, features);
> +	ret = vhost_kernel_ioctl(data->vhostfds[0], VHOST_GET_FEATURES,
> features);
>  	if (ret < 0) {
>  		PMD_DRV_LOG(ERR, "Failed to get features");
>  		return -1;
> @@ -138,6 +146,8 @@ vhost_kernel_get_features(struct virtio_user_dev *dev,
> uint64_t *features)
>  static int
>  vhost_kernel_set_features(struct virtio_user_dev *dev, uint64_t features)
>  {
> +	struct vhost_kernel_data *data = dev->backend_data;
> +
>  	/* We don't need memory protection here */
>  	features &= ~(1ULL << VIRTIO_F_IOMMU_PLATFORM);
>  	/* VHOST kernel does not know about below flags */
> @@ -145,7 +155,7 @@ vhost_kernel_set_features(struct virtio_user_dev *dev,
> uint64_t features)
>  	features &= ~VHOST_KERNEL_HOST_OFFLOADS_MASK;
>  	features &= ~(1ULL << VIRTIO_NET_F_MQ);
> 
> -	return vhost_kernel_ioctl(dev->vhostfds[0], VHOST_SET_FEATURES,
> &features);
> +	return vhost_kernel_ioctl(data->vhostfds[0], VHOST_SET_FEATURES,
> &features);
>  }
> 
>  static int
> @@ -185,6 +195,7 @@ add_memseg_list(const struct rte_memseg_list *msl, void
> *arg)
>  static int
>  vhost_kernel_set_memory_table(struct virtio_user_dev *dev)
>  {
> +	struct vhost_kernel_data *data = dev->backend_data;
>  	struct vhost_memory_kernel *vm;
>  	int ret;
> 
> @@ -205,7 +216,7 @@ vhost_kernel_set_memory_table(struct virtio_user_dev *dev)
>  	if (ret < 0)
>  		goto err_free;
> 
> -	ret = vhost_kernel_ioctl(dev->vhostfds[0], VHOST_SET_MEM_TABLE, vm);
> +	ret = vhost_kernel_ioctl(data->vhostfds[0], VHOST_SET_MEM_TABLE, vm);
>  	if (ret < 0)
>  		goto err_free;
> 
> @@ -224,9 +235,10 @@ vhost_kernel_set_vring(struct virtio_user_dev *dev,
> uint64_t req, struct vhost_v
>  {
>  	int ret, fd;
>  	unsigned int index = state->index;
> +	struct vhost_kernel_data *data = dev->backend_data;
> 
>  	/* Convert from queue index to queue-pair & offset */
> -	fd = dev->vhostfds[state->index / 2];
> +	fd = data->vhostfds[state->index / 2];
>  	state->index %= 2;
> 
>  	ret = vhost_kernel_ioctl(fd, req, state);
> @@ -265,9 +277,10 @@ vhost_kernel_set_vring_file(struct virtio_user_dev *dev,
> uint64_t req,
>  {
>  	int ret, fd;
>  	unsigned int index = file->index;
> +	struct vhost_kernel_data *data = dev->backend_data;
> 
>  	/* Convert from queue index to queue-pair & offset */
> -	fd = dev->vhostfds[file->index / 2];
> +	fd = data->vhostfds[file->index / 2];
>  	file->index %= 2;
> 
>  	ret = vhost_kernel_ioctl(fd, req, file);
> @@ -299,9 +312,10 @@ vhost_kernel_set_vring_addr(struct virtio_user_dev *dev,
> struct vhost_vring_addr
>  {
>  	int ret, fd;
>  	unsigned int index = addr->index;
> +	struct vhost_kernel_data *data = dev->backend_data;
> 
>  	/* Convert from queue index to queue-pair & offset */
> -	fd = dev->vhostfds[addr->index / 2];
> +	fd = data->vhostfds[addr->index / 2];
>  	addr->index %= 2;
> 
>  	ret = vhost_kernel_ioctl(fd, VHOST_SET_VRING_ADDR, addr);
> @@ -339,27 +353,82 @@ static int
>  vhost_kernel_setup(struct virtio_user_dev *dev)
>  {
>  	int vhostfd;
> -	uint32_t i;
> +	uint32_t q, i;
> +	struct vhost_kernel_data *data;
> +
> +	data = malloc(sizeof(*data));
> +	if (!data) {
> +		PMD_INIT_LOG(ERR, "(%s) Failed to allocate Vhost-kernel data",
> dev->path);
> +		return -1;
> +	}
> +
> +	data->vhostfds = malloc(dev->max_queue_pairs * sizeof(int));
> +	if (!data->vhostfds) {
> +		PMD_INIT_LOG(ERR, "(%s) Failed to allocate Vhost FDs", dev->path);
> +		goto err_data;
> +	}
> +	data->tapfds = malloc(dev->max_queue_pairs * sizeof(int));
> +	if (!data->tapfds) {
> +		PMD_INIT_LOG(ERR, "(%s) Failed to allocate FDs", dev->path);

'allocate tap FDs'?

With this fixed:

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

> +		goto err_vhostfds;
> +	}
> +
> +	for (q = 0; q < dev->max_queue_pairs; ++q) {
> +		data->vhostfds[q] = -1;
> +		data->tapfds[q] = -1;
> +	}
> 
>  	get_vhost_kernel_max_regions();
> 
>  	for (i = 0; i < dev->max_queue_pairs; ++i) {
>  		vhostfd = open(dev->path, O_RDWR);
>  		if (vhostfd < 0) {
> -			PMD_DRV_LOG(ERR, "fail to open %s, %s",
> -				    dev->path, strerror(errno));
> -			return -1;
> +			PMD_DRV_LOG(ERR, "fail to open %s, %s", dev->path,
> strerror(errno));
> +			goto err_tapfds;
>  		}
> 
> -		dev->vhostfds[i] = vhostfd;
> +		data->vhostfds[i] = vhostfd;
>  	}
> 
> +	dev->backend_data = data;
> +
>  	return 0;
> +
> +err_tapfds:
> +	for (i = 0; i < dev->max_queue_pairs; i++)
> +		if (data->vhostfds[i] >= 0)
> +			close(data->vhostfds[i]);
> +
> +	free(data->tapfds);
> +err_vhostfds:
> +	free(data->vhostfds);
> +err_data:
> +	free(data);
> +
> +	return -1;
>  }
> 
>  static int
> -vhost_kernel_destroy(struct virtio_user_dev *dev __rte_unused)
> +vhost_kernel_destroy(struct virtio_user_dev *dev)
>  {
> +	struct vhost_kernel_data *data = dev->backend_data;
> +	uint32_t i;
> +
> +	if (!data)
> +		return 0;
> +
> +	for (i = 0; i < dev->max_queue_pairs; ++i) {
> +		if (data->vhostfds[i] >= 0)
> +			close(data->vhostfds[i]);
> +		if (data->tapfds[i] >= 0)
> +			close(data->tapfds[i]);
> +	}
> +
> +	free(data->vhostfds);
> +	free(data->tapfds);
> +	free(data);
> +	dev->backend_data = NULL;
> +
>  	return 0;
>  }
> 
> @@ -395,14 +464,15 @@ vhost_kernel_enable_queue_pair(struct virtio_user_dev
> *dev,
>  	int vhostfd;
>  	int tapfd;
>  	int req_mq = (dev->max_queue_pairs > 1);
> +	struct vhost_kernel_data *data = dev->backend_data;
> 
> -	vhostfd = dev->vhostfds[pair_idx];
> +	vhostfd = data->vhostfds[pair_idx];
> 
>  	if (dev->qp_enabled[pair_idx] == enable)
>  		return 0;
> 
>  	if (!enable) {
> -		tapfd = dev->tapfds[pair_idx];
> +		tapfd = data->tapfds[pair_idx];
>  		if (vhost_kernel_set_backend(vhostfd, -1) < 0) {
>  			PMD_DRV_LOG(ERR, "fail to set backend for vhost kernel");
>  			return -1;
> @@ -415,8 +485,8 @@ vhost_kernel_enable_queue_pair(struct virtio_user_dev *dev,
>  		return 0;
>  	}
> 
> -	if (dev->tapfds[pair_idx] >= 0) {
> -		tapfd = dev->tapfds[pair_idx];
> +	if (data->tapfds[pair_idx] >= 0) {
> +		tapfd = data->tapfds[pair_idx];
>  		if (vhost_kernel_tap_set_offload(tapfd, dev->features) == -1)
>  			return -1;
>  		if (req_mq && vhost_kernel_tap_set_queue(tapfd, true) < 0) {
> @@ -439,7 +509,7 @@ vhost_kernel_enable_queue_pair(struct virtio_user_dev *dev,
>  		return -1;
>  	}
> 
> -	dev->tapfds[pair_idx] = tapfd;
> +	data->tapfds[pair_idx] = tapfd;
> 
>  set_backend:
>  	if (vhost_kernel_set_backend(vhostfd, tapfd) < 0) {
> diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c
> b/drivers/net/virtio/virtio_user/virtio_user_dev.c
> index 7128457e32..a1e32158bb 100644
> --- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
> +++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
> @@ -398,11 +398,6 @@ virtio_user_mem_event_cb(enum rte_mem_event type
> __rte_unused,
>  static int
>  virtio_user_dev_setup(struct virtio_user_dev *dev)
>  {
> -	uint32_t q;
> -
> -	dev->vhostfds = NULL;
> -	dev->tapfds = NULL;
> -
>  	if (dev->is_server) {
>  		if (dev->backend_type != VIRTIO_USER_BACKEND_VHOST_USER) {
>  			PMD_DRV_LOG(ERR, "Server mode only supports vhost-user!");
> @@ -410,34 +405,21 @@ virtio_user_dev_setup(struct virtio_user_dev *dev)
>  		}
>  	}
> 
> -	if (dev->backend_type == VIRTIO_USER_BACKEND_VHOST_USER) {
> +	switch (dev->backend_type) {
> +	case VIRTIO_USER_BACKEND_VHOST_USER:
>  		dev->ops = &virtio_ops_user;
> -	} else if (dev->backend_type ==
> -			VIRTIO_USER_BACKEND_VHOST_KERNEL) {
> +		break;
> +	case VIRTIO_USER_BACKEND_VHOST_KERNEL:
>  		dev->ops = &virtio_ops_kernel;
> -
> -		dev->vhostfds = malloc(dev->max_queue_pairs *
> -				sizeof(int));
> -		dev->tapfds = malloc(dev->max_queue_pairs *
> -				sizeof(int));
> -		if (!dev->vhostfds || !dev->tapfds) {
> -			PMD_INIT_LOG(ERR, "(%s) Failed to allocate FDs", dev->path);
> -			return -1;
> -		}
> -
> -		for (q = 0; q < dev->max_queue_pairs; ++q) {
> -			dev->vhostfds[q] = -1;
> -			dev->tapfds[q] = -1;
> -		}
> -	} else if (dev->backend_type ==
> -			VIRTIO_USER_BACKEND_VHOST_VDPA) {
> +		break;
> +	case VIRTIO_USER_BACKEND_VHOST_VDPA:
>  		dev->ops = &virtio_ops_vdpa;
> -	} else {
> +		break;
> +	default:
>  		PMD_DRV_LOG(ERR, "(%s) Unknown backend type", dev->path);
>  		return -1;
>  	}
> 
> -
>  	if (dev->ops->setup(dev) < 0) {
>  		PMD_INIT_LOG(ERR, "(%s) Failed to setup backend\n", dev->path);
>  		return -1;
> @@ -593,15 +575,6 @@ virtio_user_dev_uninit(struct virtio_user_dev *dev)
>  		close(dev->callfds[i]);
>  		close(dev->kickfds[i]);
>  	}
> -	if (dev->vhostfds) {
> -		for (i = 0; i < dev->max_queue_pairs; ++i) {
> -			close(dev->vhostfds[i]);
> -			if (dev->tapfds[i] >= 0)
> -				close(dev->tapfds[i]);
> -		}
> -		free(dev->vhostfds);
> -		free(dev->tapfds);
> -	}
> 
>  	free(dev->ifname);
> 
> diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.h
> b/drivers/net/virtio/virtio_user/virtio_user_dev.h
> index 36d2410546..36a9cadcad 100644
> --- a/drivers/net/virtio/virtio_user/virtio_user_dev.h
> +++ b/drivers/net/virtio/virtio_user/virtio_user_dev.h
> @@ -32,11 +32,6 @@ struct virtio_user_dev {
>  	/* for vhost_vdpa backend */
>  	int		vhostfd;
> 
> -	/* for vhost_kernel backend */
> -	char		*ifname;
> -	int		*vhostfds;
> -	int		*tapfds;
> -
>  	/* for both vhost_user and vhost_kernel */
>  	int		callfds[VIRTIO_MAX_VIRTQUEUES];
>  	int		kickfds[VIRTIO_MAX_VIRTQUEUES];
> @@ -56,6 +51,8 @@ struct virtio_user_dev {
>  	uint16_t	port_id;
>  	uint8_t		mac_addr[RTE_ETHER_ADDR_LEN];
>  	char		path[PATH_MAX];
> +	char		*ifname;
> +
>  	union {
>  		struct vring		vrings[VIRTIO_MAX_VIRTQUEUES];
>  		struct vring_packed	packed_vrings[VIRTIO_MAX_VIRTQUEUES];
> --
> 2.29.2