Re: [dpdk-dev] [PATCH 2/3] net/virtio: add device config support to vDPA

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

Hi Maxime,

> -----Original Message-----
> From: Maxime Coquelin <maxime.coquelin@redhat.com>
> Sent: Tuesday, June 8, 2021 10:14 PM
> To: dev@dpdk.org; Xia, Chenbo <chenbo.xia@intel.com>; amorenoz@redhat.com;
> david.marchand@redhat.com
> Cc: Maxime Coquelin <maxime.coquelin@redhat.com>
> Subject: [PATCH 2/3] net/virtio: add device config support to vDPA
> 
> This patch introduces two virtio-user callbacks to get
> and set device's config, and implements it for vDPA
> backends.
> 
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
>  drivers/net/virtio/virtio_user/vhost.h      |  3 +
>  drivers/net/virtio/virtio_user/vhost_vdpa.c | 69 +++++++++++++++++++++
>  2 files changed, 72 insertions(+)
> 
> diff --git a/drivers/net/virtio/virtio_user/vhost.h
> b/drivers/net/virtio/virtio_user/vhost.h
> index c49e88036d..dfbf6be033 100644
> --- a/drivers/net/virtio/virtio_user/vhost.h
> +++ b/drivers/net/virtio/virtio_user/vhost.h
> @@ -79,6 +79,9 @@ struct virtio_user_backend_ops {
>  	int (*set_vring_addr)(struct virtio_user_dev *dev, struct
> vhost_vring_addr *addr);
>  	int (*get_status)(struct virtio_user_dev *dev, uint8_t *status);
>  	int (*set_status)(struct virtio_user_dev *dev, uint8_t status);
> +	int (*get_config)(struct virtio_user_dev *dev, uint8_t *data, uint32_t
> off, uint32_t len);
> +	int (*set_config)(struct virtio_user_dev *dev, const uint8_t *data,
> uint32_t off,
> +			uint32_t len);
>  	int (*enable_qp)(struct virtio_user_dev *dev, uint16_t pair_idx, int
> enable);
>  	int (*dma_map)(struct virtio_user_dev *dev, void *addr, uint64_t iova,
> size_t len);
>  	int (*dma_unmap)(struct virtio_user_dev *dev, void *addr, uint64_t iova,
> size_t len);
> diff --git a/drivers/net/virtio/virtio_user/vhost_vdpa.c
> b/drivers/net/virtio/virtio_user/vhost_vdpa.c
> index e2d6d3504d..59bc712d48 100644
> --- a/drivers/net/virtio/virtio_user/vhost_vdpa.c
> +++ b/drivers/net/virtio/virtio_user/vhost_vdpa.c
> @@ -41,6 +41,8 @@ struct vhost_vdpa_data {
>  #define VHOST_VDPA_GET_DEVICE_ID _IOR(VHOST_VIRTIO, 0x70, __u32)
>  #define VHOST_VDPA_GET_STATUS _IOR(VHOST_VIRTIO, 0x71, __u8)
>  #define VHOST_VDPA_SET_STATUS _IOW(VHOST_VIRTIO, 0x72, __u8)
> +#define VHOST_VDPA_GET_CONFIG _IOR(VHOST_VIRTIO, 0x73, struct
> vhost_vdpa_config)
> +#define VHOST_VDPA_SET_CONFIG _IOW(VHOST_VIRTIO, 0x74, struct
> vhost_vdpa_config)
>  #define VHOST_VDPA_SET_VRING_ENABLE _IOW(VHOST_VIRTIO, 0x75, struct
> vhost_vring_state)
>  #define VHOST_SET_BACKEND_FEATURES _IOW(VHOST_VIRTIO, 0x25, __u64)
>  #define VHOST_GET_BACKEND_FEATURES _IOR(VHOST_VIRTIO, 0x26, __u64)
> @@ -65,6 +67,12 @@ struct vhost_iotlb_msg {
> 
>  #define VHOST_IOTLB_MSG_V2 0x2
> 
> +struct vhost_vdpa_config {
> +	uint32_t off;
> +	uint32_t len;
> +	uint8_t buf[0];
> +};
> +
>  struct vhost_msg {
>  	uint32_t type;
>  	uint32_t reserved;
> @@ -440,6 +448,65 @@ vhost_vdpa_set_status(struct virtio_user_dev *dev,
> uint8_t status)
>  	return vhost_vdpa_ioctl(data->vhostfd, VHOST_VDPA_SET_STATUS, &status);
>  }
> 
> +static int
> +vhost_vdpa_get_config(struct virtio_user_dev *dev, uint8_t *data, uint32_t
> off, uint32_t len)
> +{
> +	struct vhost_vdpa_data *vdpa_data = dev->backend_data;
> +	struct vhost_vdpa_config *config;
> +	int ret = 0;
> +
> +	config = malloc(sizeof(*config) + len);
> +	if (!config) {
> +		PMD_DRV_LOG(ERR, "Failed to allocate vDPA config data\n");

No need to add '\n'. And same for below three 'PMD_DRV_LOG'

> +		return -1;
> +	}
> +
> +	config->off = off;
> +	config->len = len;
> +
> +	ret = vhost_vdpa_ioctl(vdpa_data->vhostfd, VHOST_VDPA_GET_CONFIG,
> config);
> +	if (ret) {
> +		PMD_DRV_LOG(ERR, "Failed to get vDPA config (offset %x, len %x)\n",

Better add '0x' here as it will be friendly to user 😊

> off, len);
> +		ret = -1;
> +		goto out;
> +	}
> +
> +	memcpy(data, config->buf, len);
> +out:
> +	free(config);
> +
> +	return ret;
> +}
> +
> +static int
> +vhost_vdpa_set_config(struct virtio_user_dev *dev, const uint8_t *data,
> uint32_t off, uint32_t len)
> +{
> +	struct vhost_vdpa_data *vdpa_data = dev->backend_data;
> +	struct vhost_vdpa_config *config;
> +	int ret = 0;
> +
> +	config = malloc(sizeof(*config) + len);
> +	if (!config) {
> +		PMD_DRV_LOG(ERR, "Failed to allocate vDPA config data\n");
> +		return -1;
> +	}
> +
> +	config->off = off;
> +	config->len = len;
> +
> +	memcpy(config->buf, data, len);
> +
> +	ret = vhost_vdpa_ioctl(vdpa_data->vhostfd, VHOST_VDPA_SET_CONFIG,
> config);
> +	if (ret) {
> +		PMD_DRV_LOG(ERR, "Failed to set vDPA config (offset %x, len %x)\n",
> off, len);

Ditto

Thanks,
Chenbo

> +		ret = -1;
> +	}
> +
> +	free(config);
> +
> +	return ret;
> +}
> +
>  /**
>   * Set up environment to talk with a vhost vdpa backend.
>   *
> @@ -559,6 +626,8 @@ struct virtio_user_backend_ops virtio_ops_vdpa = {
>  	.set_vring_addr = vhost_vdpa_set_vring_addr,
>  	.get_status = vhost_vdpa_get_status,
>  	.set_status = vhost_vdpa_set_status,
> +	.get_config = vhost_vdpa_get_config,
> +	.set_config = vhost_vdpa_set_config,
>  	.enable_qp = vhost_vdpa_enable_queue_pair,
>  	.dma_map = vhost_vdpa_dma_map_batch,
>  	.dma_unmap = vhost_vdpa_dma_unmap_batch,
> --
> 2.31.1