Re: [PATCH v1 3/4] vdpa: Support for configuring max VQ pairs for a device

[Si-Wei Liu <si-wei.liu@oracle.com>]

On 2/10/2022 5:31 AM, Eli Cohen wrote:
> Use VDPA_ATTR_DEV_MGMTDEV_MAX_VQS to specify max number of virtqueue
> pairs to configure for a vdpa device when adding a device.
>
> Examples:
> 1. Create a device with 3 virtqueue pairs:
> $ vdpa dev add name vdpa-a mgmtdev auxiliary/mlx5_core.sf.1 max_vqp 3
>
> 2. Read the configuration of a vdpa device
> $ vdpa dev config show vdpa-a
>    vdpa-a: mac 00:00:00:00:88:88 link up link_announce false max_vq_pairs 3 \
>            mtu 1500
>    negotiated_features CSUM GUEST_CSUM MTU MAC HOST_TSO4 HOST_TSO6 STATUS \
>                        CTRL_VQ MQ CTRL_MAC_ADDR VERSION_1 ACCESS_PLATFORM
>
> Signed-off-by: Eli Cohen <elic@nvidia.com>
> ---
>   vdpa/include/uapi/linux/vdpa.h |  1 +
>   vdpa/vdpa.c                    | 25 ++++++++++++++++++++++++-
>   2 files changed, 25 insertions(+), 1 deletion(-)
>
> diff --git a/vdpa/include/uapi/linux/vdpa.h b/vdpa/include/uapi/linux/vdpa.h
> index 748c350450b2..a3ebf4d4d9b8 100644
> --- a/vdpa/include/uapi/linux/vdpa.h
> +++ b/vdpa/include/uapi/linux/vdpa.h
> @@ -41,6 +41,7 @@ enum vdpa_attr {
>   	VDPA_ATTR_DEV_NET_CFG_MTU,		/* u16 */
>   
>   	VDPA_ATTR_DEV_NEGOTIATED_FEATURES,	/* u64 */
> +	VDPA_ATTR_DEV_MGMTDEV_MAX_VQS,          /* u32 */
>   
>   	/* new attributes must be added above here */
>   	VDPA_ATTR_MAX,
> diff --git a/vdpa/vdpa.c b/vdpa/vdpa.c
> index 7deab710913d..99ee828630cc 100644
> --- a/vdpa/vdpa.c
> +++ b/vdpa/vdpa.c
> @@ -24,6 +24,7 @@
>   #define VDPA_OPT_VDEV_HANDLE		BIT(3)
>   #define VDPA_OPT_VDEV_MAC		BIT(4)
>   #define VDPA_OPT_VDEV_MTU		BIT(5)
> +#define VDPA_OPT_MAX_VQP		BIT(6)
>   
>   struct vdpa_opts {
>   	uint64_t present; /* flags of present items */
> @@ -33,6 +34,7 @@ struct vdpa_opts {
>   	unsigned int device_id;
>   	char mac[ETH_ALEN];
>   	uint16_t mtu;
> +	uint16_t max_vqp;
>   };
>   
>   struct vdpa {
> @@ -80,6 +82,7 @@ static const enum mnl_attr_data_type vdpa_policy[VDPA_ATTR_MAX + 1] = {
>   	[VDPA_ATTR_DEV_MAX_VQS] = MNL_TYPE_U32,
>   	[VDPA_ATTR_DEV_MAX_VQ_SIZE] = MNL_TYPE_U16,
>   	[VDPA_ATTR_DEV_NEGOTIATED_FEATURES] = MNL_TYPE_U64,
> +	[VDPA_ATTR_DEV_MGMTDEV_MAX_VQS] = MNL_TYPE_U32,
>   };
>   
>   static int attr_cb(const struct nlattr *attr, void *data)
> @@ -221,6 +224,8 @@ static void vdpa_opts_put(struct nlmsghdr *nlh, struct vdpa *vdpa)
>   			     sizeof(opts->mac), opts->mac);
>   	if (opts->present & VDPA_OPT_VDEV_MTU)
>   		mnl_attr_put_u16(nlh, VDPA_ATTR_DEV_NET_CFG_MTU, opts->mtu);
> +	if (opts->present & VDPA_OPT_MAX_VQP)
> +		mnl_attr_put_u16(nlh, VDPA_ATTR_DEV_NET_CFG_MAX_VQP, opts->max_vqp);
>   }
>   
>   static int vdpa_argv_parse(struct vdpa *vdpa, int argc, char **argv,
> @@ -289,6 +294,14 @@ static int vdpa_argv_parse(struct vdpa *vdpa, int argc, char **argv,
>   
>   			NEXT_ARG_FWD();
>   			o_found |= VDPA_OPT_VDEV_MTU;
> +		} else if ((matches(*argv, "max_vqp")  == 0) && (o_optional & VDPA_OPT_MAX_VQP)) {
> +			NEXT_ARG_FWD();
> +			err = vdpa_argv_u16(vdpa, argc, argv, &opts->max_vqp);
> +			if (err)
> +				return err;
> +
> +			NEXT_ARG_FWD();
> +			o_found |= VDPA_OPT_MAX_VQP;
It'd be nice to update cmd_dev_help() to include the max_vqp option as well.

Reviewed-by: Si-Wei Liu <si-wei.liu@oracle.com>

>   		} else {
>   			fprintf(stderr, "Unknown option \"%s\"\n", *argv);
>   			return -EINVAL;
> @@ -513,6 +526,15 @@ static void pr_out_mgmtdev_show(struct vdpa *vdpa, const struct nlmsghdr *nlh,
>   		pr_out_array_end(vdpa);
>   	}
>   
> +	if (tb[VDPA_ATTR_DEV_MGMTDEV_MAX_VQS]) {
> +		uint16_t num_vqs;
> +
> +		if (!vdpa->json_output)
> +			printf("\n");
> +		num_vqs = mnl_attr_get_u16(tb[VDPA_ATTR_DEV_MGMTDEV_MAX_VQS]);
> +		print_uint(PRINT_ANY, "max_supported_vqs", "  max_supported_vqs %d", num_vqs);
> +	}
> +
>   	pr_out_handle_end(vdpa);
>   }
>   
> @@ -662,7 +684,8 @@ static int cmd_dev_add(struct vdpa *vdpa, int argc, char **argv)
>   					  NLM_F_REQUEST | NLM_F_ACK);
>   	err = vdpa_argv_parse_put(nlh, vdpa, argc, argv,
>   				  VDPA_OPT_VDEV_MGMTDEV_HANDLE | VDPA_OPT_VDEV_NAME,
> -				  VDPA_OPT_VDEV_MAC | VDPA_OPT_VDEV_MTU);
> +				  VDPA_OPT_VDEV_MAC | VDPA_OPT_VDEV_MTU |
> +				  VDPA_OPT_MAX_VQP);
>   	if (err)
>   		return err;
>