Re: [dpdk-dev] [PATCH v2 39/44] net/virtio: introduce backend data

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

> -----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 39/44] net/virtio: introduce backend data
> 
> The goal of this patch is to introduce backend-specific
> data in order to better isolate what is backend-specific
> from what is generic to Virtio-user.
> 
> For now, only Vhost-user protocol features are moved to
> Vhost-user backend data.
> 
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
>  drivers/net/virtio/virtio_user/vhost.h        |  1 +
>  drivers/net/virtio/virtio_user/vhost_kernel.c |  7 +++
>  drivers/net/virtio/virtio_user/vhost_user.c   | 62 +++++++++++++++----
>  drivers/net/virtio/virtio_user/vhost_vdpa.c   |  7 +++
>  .../net/virtio/virtio_user/virtio_user_dev.c  |  2 +
>  .../net/virtio/virtio_user/virtio_user_dev.h  |  2 +
>  6 files changed, 68 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/net/virtio/virtio_user/vhost.h
> b/drivers/net/virtio/virtio_user/vhost.h
> index dfa2735a20..fc4f059c02 100644
> --- a/drivers/net/virtio/virtio_user/vhost.h
> +++ b/drivers/net/virtio/virtio_user/vhost.h
> @@ -65,6 +65,7 @@ struct virtio_user_dev;
> 
>  struct virtio_user_backend_ops {
>  	int (*setup)(struct virtio_user_dev *dev);
> +	int (*destroy)(struct virtio_user_dev *dev);
>  	int (*get_backend_features)(uint64_t *features);
>  	int (*set_owner)(struct virtio_user_dev *dev);
>  	int (*get_features)(struct virtio_user_dev *dev, uint64_t *features);
> diff --git a/drivers/net/virtio/virtio_user/vhost_kernel.c
> b/drivers/net/virtio/virtio_user/vhost_kernel.c
> index 5477eb7015..47fb4427be 100644
> --- a/drivers/net/virtio/virtio_user/vhost_kernel.c
> +++ b/drivers/net/virtio/virtio_user/vhost_kernel.c
> @@ -357,6 +357,12 @@ vhost_kernel_setup(struct virtio_user_dev *dev)
>  	return 0;
>  }
> 
> +static int
> +vhost_kernel_destroy(struct virtio_user_dev *dev __rte_unused)
> +{
> +	return 0;
> +}
> +
>  static int
>  vhost_kernel_set_backend(int vhostfd, int tapfd)
>  {
> @@ -455,6 +461,7 @@ vhost_kernel_get_backend_features(uint64_t *features)
> 
>  struct virtio_user_backend_ops virtio_ops_kernel = {
>  	.setup = vhost_kernel_setup,
> +	.destroy = vhost_kernel_destroy,
>  	.get_backend_features = vhost_kernel_get_backend_features,
>  	.set_owner = vhost_kernel_set_owner,
>  	.get_features = vhost_kernel_get_features,
> diff --git a/drivers/net/virtio/virtio_user/vhost_user.c
> b/drivers/net/virtio/virtio_user/vhost_user.c
> index 986d8ac1ac..0147b6d963 100644
> --- a/drivers/net/virtio/virtio_user/vhost_user.c
> +++ b/drivers/net/virtio/virtio_user/vhost_user.c
> @@ -17,6 +17,9 @@
>  #include "vhost.h"
>  #include "virtio_user_dev.h"
> 
> +struct vhost_user_data {
> +	uint64_t protocol_features;
> +};
> 
>  #ifndef VHOST_USER_F_PROTOCOL_FEATURES
>  #define VHOST_USER_F_PROTOCOL_FEATURES 30
> @@ -287,6 +290,7 @@ static int
>  vhost_user_get_features(struct virtio_user_dev *dev, uint64_t *features)
>  {
>  	int ret;
> +	struct vhost_user_data *data = dev->backend_data;
>  	struct vhost_user_msg msg = {
>  		.request = VHOST_USER_GET_FEATURES,
>  		.flags = VHOST_USER_VERSION,
> @@ -316,17 +320,17 @@ vhost_user_get_features(struct virtio_user_dev *dev,
> uint64_t *features)
>  		return 0;
> 
>  	/* Negotiate protocol features */
> -	ret = vhost_user_get_protocol_features(dev, &dev->protocol_features);
> +	ret = vhost_user_get_protocol_features(dev, &data->protocol_features);
>  	if (ret < 0)
>  		goto err;
> 
> -	dev->protocol_features &= VHOST_USER_SUPPORTED_PROTOCOL_FEATURES;
> +	data->protocol_features &= VHOST_USER_SUPPORTED_PROTOCOL_FEATURES;
> 
> -	ret = vhost_user_set_protocol_features(dev, dev->protocol_features);
> +	ret = vhost_user_set_protocol_features(dev, data->protocol_features);
>  	if (ret < 0)
>  		goto err;
> 
> -	if (!(dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_MQ)))
> +	if (!(data->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_MQ)))
>  		dev->unsupported_features |= (1ull << VIRTIO_NET_F_MQ);
> 
>  	return 0;
> @@ -444,12 +448,13 @@ vhost_user_set_memory_table(struct virtio_user_dev *dev)
>  	struct walk_arg wa;
>  	int fds[VHOST_MEMORY_MAX_NREGIONS];
>  	int ret, fd_num;
> +	struct vhost_user_data *data = dev->backend_data;
>  	struct vhost_user_msg msg = {
>  		.request = VHOST_USER_SET_MEM_TABLE,
>  		.flags = VHOST_USER_VERSION,
>  	};
> 
> -	if (dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_REPLY_ACK))
> +	if (data->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_REPLY_ACK))
>  		msg.flags |= VHOST_USER_NEED_REPLY_MASK;
> 
>  	wa.region_nr = 0;
> @@ -628,6 +633,7 @@ static int
>  vhost_user_get_status(struct virtio_user_dev *dev, uint8_t *status)
>  {
>  	int ret;
> +	struct vhost_user_data *data = dev->backend_data;
>  	struct vhost_user_msg msg = {
>  		.request = VHOST_USER_GET_STATUS,
>  		.flags = VHOST_USER_VERSION,
> @@ -644,7 +650,7 @@ vhost_user_get_status(struct virtio_user_dev *dev, uint8_t
> *status)
>  	if (!(dev->device_features & (1ULL << VHOST_USER_F_PROTOCOL_FEATURES)))
>  		return -ENOTSUP;
> 
> -	if (!(dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_STATUS)))
> +	if (!(data->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_STATUS)))
>  		return -ENOTSUP;
> 
>  	ret = vhost_user_write(dev->vhostfd, &msg, NULL, 0);
> @@ -681,6 +687,7 @@ static int
>  vhost_user_set_status(struct virtio_user_dev *dev, uint8_t status)
>  {
>  	int ret;
> +	struct vhost_user_data *data = dev->backend_data;
>  	struct vhost_user_msg msg = {
>  		.request = VHOST_USER_SET_STATUS,
>  		.flags = VHOST_USER_VERSION,
> @@ -699,10 +706,10 @@ vhost_user_set_status(struct virtio_user_dev *dev,
> uint8_t status)
>  	if (!(dev->device_features & (1ULL << VHOST_USER_F_PROTOCOL_FEATURES)))
>  		return -ENOTSUP;
> 
> -	if (!(dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_STATUS)))
> +	if (!(data->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_STATUS)))
>  		return -ENOTSUP;
> 
> -	if (dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_REPLY_ACK))
> +	if (data->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_REPLY_ACK))
>  		msg.flags |= VHOST_USER_NEED_REPLY_MASK;
> 
>  	ret = vhost_user_write(dev->vhostfd, &msg, NULL, 0);
> @@ -762,11 +769,22 @@ vhost_user_setup(struct virtio_user_dev *dev)
>  	int fd;
>  	int flag;
>  	struct sockaddr_un un;
> +	struct vhost_user_data *data;
> +
> +	data = malloc(sizeof(*data));
> +	if (!data) {
> +		PMD_DRV_LOG(ERR, "(%s) Failed to allocate Vhost-user data\n", dev-
> >path);
> +		return -1;
> +	}
> +
> +	memset(data, 0, sizeof(*data));
> +
> +	dev->backend_data = data;
> 
>  	fd = socket(AF_UNIX, SOCK_STREAM, 0);
>  	if (fd < 0) {
>  		PMD_DRV_LOG(ERR, "socket() error, %s", strerror(errno));
> -		return -1;
> +		goto err_data;
>  	}
> 
>  	flag = fcntl(fd, F_GETFD);
> @@ -781,18 +799,35 @@ vhost_user_setup(struct virtio_user_dev *dev)
>  		dev->listenfd = fd;
>  		if (virtio_user_start_server(dev, &un) < 0) {
>  			PMD_DRV_LOG(ERR, "virtio-user startup fails in server mode");
> -			close(fd);
> -			return -1;
> +			goto err_socket;
>  		}
>  	} else {
>  		if (connect(fd, (struct sockaddr *)&un, sizeof(un)) < 0) {
>  			PMD_DRV_LOG(ERR, "connect error, %s", strerror(errno));
> -			close(fd);
> -			return -1;
> +			goto err_socket;
>  		}
>  		dev->vhostfd = fd;
>  	}
> 
> +	return 0;
> +
> +err_socket:
> +	close(fd);
> +err_data:
> +	free(data);
> +	dev->backend_data = NULL;
> +
> +	return -1;
> +}
> +
> +static int
> +vhost_user_destroy(struct virtio_user_dev *dev)
> +{
> +	if (dev->backend_data) {
> +		free(dev->backend_data);
> +		dev->backend_data = NULL;
> +	}
> +
>  	return 0;
>  }
> 
> @@ -830,6 +865,7 @@ vhost_user_get_backend_features(uint64_t *features)
> 
>  struct virtio_user_backend_ops virtio_ops_user = {
>  	.setup = vhost_user_setup,
> +	.destroy = vhost_user_destroy,
>  	.get_backend_features = vhost_user_get_backend_features,
>  	.set_owner = vhost_user_set_owner,
>  	.get_features = vhost_user_get_features,
> diff --git a/drivers/net/virtio/virtio_user/vhost_vdpa.c
> b/drivers/net/virtio/virtio_user/vhost_vdpa.c
> index 8d354b298e..f5a8943993 100644
> --- a/drivers/net/virtio/virtio_user/vhost_vdpa.c
> +++ b/drivers/net/virtio/virtio_user/vhost_vdpa.c
> @@ -432,6 +432,12 @@ vhost_vdpa_setup(struct virtio_user_dev *dev)
>  	return 0;
>  }
> 
> +static int
> +vhost_vdpa_destroy(struct virtio_user_dev *dev __rte_unused)
> +{
> +	return 0;
> +}
> +
>  static int
>  vhost_vdpa_enable_queue_pair(struct virtio_user_dev *dev,
>  			       uint16_t pair_idx,
> @@ -467,6 +473,7 @@ vhost_vdpa_get_backend_features(uint64_t *features)
> 
>  struct virtio_user_backend_ops virtio_ops_vdpa = {
>  	.setup = vhost_vdpa_setup,
> +	.destroy = vhost_vdpa_destroy,
>  	.get_backend_features = vhost_vdpa_get_backend_features,
>  	.set_owner = vhost_vdpa_set_owner,
>  	.get_features = vhost_vdpa_get_features,
> diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c
> b/drivers/net/virtio/virtio_user/virtio_user_dev.c
> index 2614bcb349..215819d46d 100644
> --- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
> +++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
> @@ -621,6 +621,8 @@ virtio_user_dev_uninit(struct virtio_user_dev *dev)
> 
>  	if (dev->is_server)
>  		unlink(dev->path);
> +
> +	dev->ops->destroy(dev);
>  }
> 
>  uint8_t
> diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.h
> b/drivers/net/virtio/virtio_user/virtio_user_dev.h
> index ab62463a5b..7650097b6d 100644
> --- a/drivers/net/virtio/virtio_user/virtio_user_dev.h
> +++ b/drivers/net/virtio/virtio_user/virtio_user_dev.h
> @@ -66,6 +66,8 @@ struct virtio_user_dev {
>  	struct virtio_user_backend_ops *ops;
>  	pthread_mutex_t	mutex;
>  	bool		started;
> +
> +	void *backend_data;
>  };
> 
>  int virtio_user_dev_set_features(struct virtio_user_dev *dev);
> --
> 2.29.2

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