[PATCH v5 03/16] vhost: add support for VHOST_USER_GET_CONFIG and VHOST_USER_SET_CONFIG

[Xia, Chenbo]

Hi Andy,

> -----Original Message-----
> From: Pei, Andy <andy.pei at intel.com>
> Sent: Monday, March 28, 2022 3:17 PM
> To: dev at dpdk.org
> Cc: Xia, Chenbo <chenbo.xia at intel.com>; maxime.coquelin at redhat.com; Cao,
> Gang <gang.cao at intel.com>; Liu, Changpeng <changpeng.liu at intel.com>
> Subject: [PATCH v5 03/16] vhost: add support for VHOST_USER_GET_CONFIG and
> VHOST_USER_SET_CONFIG

Let's make the title a bit short...

./devtools/check-git-log.sh will help you find other similar errors for other
patches.

> 
> Add support for VHOST_USER_GET_CONFIG and VHOST_USER_SET_CONFIG.
> VHOST_USER_GET_CONFIG and VHOST_USER_SET_CONFIG message is only
> supported by virtio blk VDPA device.
> 
> Signed-off-by: Andy Pei <andy.pei at intel.com>
> ---
>  lib/vhost/vhost_user.c | 50
> ++++++++++++++++++++++++++++++++++++++++++++++++++
>  lib/vhost/vhost_user.h | 15 +++++++++++++++
>  2 files changed, 65 insertions(+)
> 
> diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c
> index 1d39067..55e8bd0 100644
> --- a/lib/vhost/vhost_user.c
> +++ b/lib/vhost/vhost_user.c
> @@ -80,6 +80,8 @@
>  	[VHOST_USER_NET_SET_MTU]  = "VHOST_USER_NET_SET_MTU",
>  	[VHOST_USER_SET_SLAVE_REQ_FD]  = "VHOST_USER_SET_SLAVE_REQ_FD",
>  	[VHOST_USER_IOTLB_MSG]  = "VHOST_USER_IOTLB_MSG",
> +	[VHOST_USER_GET_CONFIG]  = "VHOST_USER_GET_CONFIG",
> +	[VHOST_USER_SET_CONFIG]  = "VHOST_USER_SET_CONFIG",
>  	[VHOST_USER_CRYPTO_CREATE_SESS] = "VHOST_USER_CRYPTO_CREATE_SESS",
>  	[VHOST_USER_CRYPTO_CLOSE_SESS] = "VHOST_USER_CRYPTO_CLOSE_SESS",
>  	[VHOST_USER_POSTCOPY_ADVISE]  = "VHOST_USER_POSTCOPY_ADVISE",
> @@ -2542,6 +2544,52 @@ static int is_vring_iotlb(struct virtio_net *dev,
>  }
> 
>  static int
> +vhost_user_get_config(struct virtio_net **pdev,
> +			struct vhu_msg_context *ctx,
> +			int main_fd __rte_unused)
> +{
> +	struct virtio_net *dev = *pdev;
> +	struct rte_vdpa_device *vdpa_dev = dev->vdpa_dev;
> +	int ret = 0;
> +
> +	if (vdpa_dev->ops->get_config) {
> +		ret = vdpa_dev->ops->get_config(dev->vid,
> +					   ctx->msg.payload.cfg.region,
> +					   ctx->msg.payload.cfg.size);
> +		if (ret != 0) {
> +			ctx->msg.size = 0;
> +			VHOST_LOG_CONFIG(ERR, "get_config() return error!\n");
> +		}
> +	} else {
> +		VHOST_LOG_CONFIG(ERR, "get_config() not supported!\n");
> +	}
> +
> +	return RTE_VHOST_MSG_RESULT_REPLY;
> +}
> +
> +static int
> +vhost_user_set_config(struct virtio_net **pdev,
> +			struct vhu_msg_context *ctx,
> +			int main_fd __rte_unused)
> +{
> +	struct virtio_net *dev = *pdev;
> +	struct rte_vdpa_device *vdpa_dev = dev->vdpa_dev;
> +	int ret = 0;
> +
> +	if (vdpa_dev->ops->set_config) {
> +		ret = vdpa_dev->ops->set_config(dev->vid,
> +			ctx->msg.payload.cfg.region,
> +			ctx->msg.payload.cfg.offset,
> +			ctx->msg.payload.cfg.size,
> +			ctx->msg.payload.cfg.flags);
> +	} else {
> +		VHOST_LOG_CONFIG(ERR, "set_config() not supported!\n");
> +	}
> +
> +	return ret == 0 ? RTE_VHOST_MSG_RESULT_OK : RTE_VHOST_MSG_RESULT_ERR;

I think when set_config fails in vdpa driver, it should not break message handler by
returning RESULT_ERR here.

All error log above, please print dev->ifname too, which will be user-friendly.

> +}
> +
> +static int
>  vhost_user_iotlb_msg(struct virtio_net **pdev,
>  			struct vhu_msg_context *ctx,
>  			int main_fd __rte_unused)
> @@ -2782,6 +2830,8 @@ typedef int (*vhost_message_handler_t)(struct
> virtio_net **pdev,
>  	[VHOST_USER_NET_SET_MTU] = vhost_user_net_set_mtu,
>  	[VHOST_USER_SET_SLAVE_REQ_FD] = vhost_user_set_req_fd,
>  	[VHOST_USER_IOTLB_MSG] = vhost_user_iotlb_msg,
> +	[VHOST_USER_GET_CONFIG] = vhost_user_get_config,
> +	[VHOST_USER_SET_CONFIG] = vhost_user_set_config,
>  	[VHOST_USER_POSTCOPY_ADVISE] = vhost_user_set_postcopy_advise,
>  	[VHOST_USER_POSTCOPY_LISTEN] = vhost_user_set_postcopy_listen,
>  	[VHOST_USER_POSTCOPY_END] = vhost_user_postcopy_end,
> diff --git a/lib/vhost/vhost_user.h b/lib/vhost/vhost_user.h
> index c946cc2..d3f014e 100644
> --- a/lib/vhost/vhost_user.h
> +++ b/lib/vhost/vhost_user.h
> @@ -50,6 +50,8 @@
>  	VHOST_USER_NET_SET_MTU = 20,
>  	VHOST_USER_SET_SLAVE_REQ_FD = 21,
>  	VHOST_USER_IOTLB_MSG = 22,
> +	VHOST_USER_GET_CONFIG = 24,
> +	VHOST_USER_SET_CONFIG = 25,
>  	VHOST_USER_CRYPTO_CREATE_SESS = 26,
>  	VHOST_USER_CRYPTO_CLOSE_SESS = 27,
>  	VHOST_USER_POSTCOPY_ADVISE = 28,
> @@ -125,6 +127,18 @@
>  	uint16_t queue_size;
>  } VhostUserInflight;
> 
> +#ifndef VHOST_USER_MAX_CONFIG_SIZE
> +#define VHOST_USER_MAX_CONFIG_SIZE		256
> +#endif

For this config size, maybe '+#define VHOST_USER_MAX_CONFIG_SIZE 256' is enough?

> +
> +/** Get/set config msg payload */
> +struct vhost_user_config {
> +	uint32_t offset;
> +	uint32_t size;
> +	uint32_t flags;
> +	uint8_t region[VHOST_USER_MAX_CONFIG_SIZE];
> +};

Since the max size is defined, in the handler, we should check the size in the msg
handler.

Thanks,
Chenbo

> +
>  typedef struct VhostUserMsg {
>  	union {
>  		uint32_t master; /* a VhostUserRequest value */
> @@ -148,6 +162,7 @@
>  		VhostUserCryptoSessionParam crypto_session;
>  		VhostUserVringArea area;
>  		VhostUserInflight inflight;
> +		struct vhost_user_config cfg;
>  	} payload;
>  	/* Nothing should be added after the payload */
>  } __rte_packed VhostUserMsg;
> --
> 1.8.3.1