Re: [PATCH v4 3/3] vdpa/mlx5: Add support for reading descriptor statistics
From: Jason Wang
Date: Mon May 09 2022 - 23:01:27 EST
On Mon, May 9, 2022 at 12:33 AM Eli Cohen <elic@xxxxxxxxxx> wrote:
>
> Implement the get_vq_stats calback of vdpa_config_ops to return the
> statistics for a virtqueue.
>
> The statistics are provided as vendor specific statistics where the
> driver provides a pair of attribute name and attribute value.
>
> In addition to the attribute name/attribute value pair, the driver
> returns the negotiated features and max virtqueue pairs for userspace
> can decide for a given queue index whether it is a data or control
> virtqueue.
>
> Currently supported are received descriptors and completed descriptors.
>
> Signed-off-by: Eli Cohen <elic@xxxxxxxxxx>
>
> v3 -> v4:
> Only return statistics if feature negotiation was complete
> ---
> drivers/vdpa/mlx5/core/mlx5_vdpa.h | 2 +
> drivers/vdpa/mlx5/net/mlx5_vnet.c | 171 +++++++++++++++++++++++++++++
> include/linux/mlx5/mlx5_ifc.h | 1 +
> include/linux/mlx5/mlx5_ifc_vdpa.h | 39 +++++++
> 4 files changed, 213 insertions(+)
>
> diff --git a/drivers/vdpa/mlx5/core/mlx5_vdpa.h b/drivers/vdpa/mlx5/core/mlx5_vdpa.h
> index daaf7b503677..44104093163b 100644
> --- a/drivers/vdpa/mlx5/core/mlx5_vdpa.h
> +++ b/drivers/vdpa/mlx5/core/mlx5_vdpa.h
> @@ -61,6 +61,8 @@ struct mlx5_control_vq {
> struct vringh_kiov riov;
> struct vringh_kiov wiov;
> unsigned short head;
> + unsigned int received_desc;
> + unsigned int completed_desc;
> };
>
> struct mlx5_vdpa_wq_ent {
> diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> index 79001301b383..5b1c4304ffc7 100644
> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> @@ -119,6 +119,7 @@ struct mlx5_vdpa_virtqueue {
> struct mlx5_vdpa_umem umem2;
> struct mlx5_vdpa_umem umem3;
>
> + u32 counter_set_id;
> bool initialized;
> int index;
> u32 virtq_id;
> @@ -164,6 +165,8 @@ struct mlx5_vdpa_net {
> struct notifier_block nb;
> struct vdpa_callback config_cb;
> struct mlx5_vdpa_wq_ent cvq_ent;
> + /* sync access to virtqueues statistics */
> + struct mutex numq_lock;
Can we reuse reslock?
> };
>
> static void free_resources(struct mlx5_vdpa_net *ndev);
> @@ -822,6 +825,12 @@ static u16 get_features_12_3(u64 features)
> (!!(features & BIT_ULL(VIRTIO_NET_F_GUEST_CSUM)) << 6);
> }
>
> +static bool counters_supported(const struct mlx5_vdpa_dev *mvdev)
> +{
> + return MLX5_CAP_GEN_64(mvdev->mdev, general_obj_types) &
> + BIT_ULL(MLX5_OBJ_TYPE_VIRTIO_Q_COUNTERS);
> +}
> +
> static int create_virtqueue(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq)
> {
> int inlen = MLX5_ST_SZ_BYTES(create_virtio_net_q_in);
> @@ -876,6 +885,8 @@ static int create_virtqueue(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtque
> MLX5_SET(virtio_q, vq_ctx, umem_3_id, mvq->umem3.id);
> MLX5_SET(virtio_q, vq_ctx, umem_3_size, mvq->umem3.size);
> MLX5_SET(virtio_q, vq_ctx, pd, ndev->mvdev.res.pdn);
> + if (counters_supported(&ndev->mvdev))
> + MLX5_SET(virtio_q, vq_ctx, counter_set_id, mvq->counter_set_id);
>
> err = mlx5_cmd_exec(ndev->mvdev.mdev, in, inlen, out, sizeof(out));
> if (err)
> @@ -1139,6 +1150,47 @@ static int modify_virtqueue(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtque
> return err;
> }
>
> +static int counter_set_alloc(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq)
> +{
> + u32 in[MLX5_ST_SZ_DW(create_virtio_q_counters_in)] = {};
> + u32 out[MLX5_ST_SZ_DW(create_virtio_q_counters_out)] = {};
> + void *cmd_hdr;
> + int err;
> +
> + if (!counters_supported(&ndev->mvdev))
> + return 0;
> +
> + cmd_hdr = MLX5_ADDR_OF(create_virtio_q_counters_in, in, hdr);
> +
> + MLX5_SET(general_obj_in_cmd_hdr, cmd_hdr, opcode, MLX5_CMD_OP_CREATE_GENERAL_OBJECT);
> + MLX5_SET(general_obj_in_cmd_hdr, cmd_hdr, obj_type, MLX5_OBJ_TYPE_VIRTIO_Q_COUNTERS);
> + MLX5_SET(general_obj_in_cmd_hdr, cmd_hdr, uid, ndev->mvdev.res.uid);
> +
> + err = mlx5_cmd_exec(ndev->mvdev.mdev, in, sizeof(in), out, sizeof(out));
> + if (err)
> + return err;
> +
> + mvq->counter_set_id = MLX5_GET(general_obj_out_cmd_hdr, out, obj_id);
> +
> + return 0;
> +}
> +
> +static void counter_set_dealloc(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq)
> +{
> + u32 in[MLX5_ST_SZ_DW(destroy_virtio_q_counters_in)] = {};
> + u32 out[MLX5_ST_SZ_DW(destroy_virtio_q_counters_out)] = {};
> +
> + if (!counters_supported(&ndev->mvdev))
> + return;
> +
> + MLX5_SET(destroy_virtio_q_counters_in, in, hdr.opcode, MLX5_CMD_OP_DESTROY_GENERAL_OBJECT);
> + MLX5_SET(destroy_virtio_q_counters_in, in, hdr.obj_id, mvq->counter_set_id);
> + MLX5_SET(destroy_virtio_q_counters_in, in, hdr.uid, ndev->mvdev.res.uid);
> + MLX5_SET(destroy_virtio_q_counters_in, in, hdr.obj_type, MLX5_OBJ_TYPE_VIRTIO_Q_COUNTERS);
> + if (mlx5_cmd_exec(ndev->mvdev.mdev, in, sizeof(in), out, sizeof(out)))
> + mlx5_vdpa_warn(&ndev->mvdev, "dealloc counter set 0x%x\n", mvq->counter_set_id);
> +}
> +
> static int setup_vq(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq)
> {
> u16 idx = mvq->index;
> @@ -1166,6 +1218,10 @@ static int setup_vq(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq)
> if (err)
> goto err_connect;
>
> + err = counter_set_alloc(ndev, mvq);
> + if (err)
> + goto err_counter;
Does this mean if the counter is not supported, we will fail the
entire device setup?
> +
> err = create_virtqueue(ndev, mvq);
> if (err)
> goto err_connect;
> @@ -1183,6 +1239,8 @@ static int setup_vq(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq)
> return 0;
>
> err_connect:
> + counter_set_dealloc(ndev, mvq);
> +err_counter:
> qp_destroy(ndev, &mvq->vqqp);
> err_vqqp:
> qp_destroy(ndev, &mvq->fwqp);
> @@ -1227,6 +1285,7 @@ static void teardown_vq(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *
>
> suspend_vq(ndev, mvq);
> destroy_virtqueue(ndev, mvq);
> + counter_set_dealloc(ndev, mvq);
> qp_destroy(ndev, &mvq->vqqp);
> qp_destroy(ndev, &mvq->fwqp);
> cq_destroy(ndev, mvq->index);
> @@ -1633,8 +1692,10 @@ static virtio_net_ctrl_ack handle_ctrl_mq(struct mlx5_vdpa_dev *mvdev, u8 cmd)
> break;
> }
>
> + mutex_lock(&ndev->numq_lock);
> if (!change_num_qps(mvdev, newqps))
> status = VIRTIO_NET_OK;
> + mutex_unlock(&ndev->numq_lock);
>
> break;
> default:
> @@ -1681,6 +1742,7 @@ static void mlx5_cvq_kick_handler(struct work_struct *work)
> if (read != sizeof(ctrl))
> break;
>
> + cvq->received_desc++;
> switch (ctrl.class) {
> case VIRTIO_NET_CTRL_MAC:
> status = handle_ctrl_mac(mvdev, ctrl.cmd);
> @@ -1704,6 +1766,7 @@ static void mlx5_cvq_kick_handler(struct work_struct *work)
> if (vringh_need_notify_iotlb(&cvq->vring))
> vringh_notify(&cvq->vring);
>
> + cvq->completed_desc++;
> queue_work(mvdev->wq, &wqent->work);
> break;
> }
> @@ -2323,6 +2386,8 @@ static int mlx5_vdpa_reset(struct vdpa_device *vdev)
> mlx5_vdpa_destroy_mr(&ndev->mvdev);
> ndev->mvdev.status = 0;
> ndev->cur_num_vqs = 0;
> + ndev->mvdev.cvq.received_desc = 0;
> + ndev->mvdev.cvq.completed_desc = 0;
> memset(ndev->event_cbs, 0, sizeof(*ndev->event_cbs) * (mvdev->max_vqs + 1));
> ndev->mvdev.actual_features = 0;
> ++mvdev->generation;
> @@ -2401,6 +2466,7 @@ static void mlx5_vdpa_free(struct vdpa_device *vdev)
> mlx5_mpfs_del_mac(pfmdev, ndev->config.mac);
> }
> mlx5_vdpa_free_resources(&ndev->mvdev);
> + mutex_destroy(&ndev->numq_lock);
> mutex_destroy(&ndev->reslock);
> kfree(ndev->event_cbs);
> kfree(ndev->vqs);
> @@ -2442,6 +2508,108 @@ static u64 mlx5_vdpa_get_driver_features(struct vdpa_device *vdev)
> return mvdev->actual_features;
> }
>
> +static int counter_set_query(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq,
> + u64 *received_desc, u64 *completed_desc)
> +{
> + u32 in[MLX5_ST_SZ_DW(query_virtio_q_counters_in)] = {};
> + u32 out[MLX5_ST_SZ_DW(query_virtio_q_counters_out)] = {};
> + void *cmd_hdr;
> + void *ctx;
> + int err;
> +
> + if (!counters_supported(&ndev->mvdev))
> + return -EOPNOTSUPP;
> +
> + if (mvq->fw_state != MLX5_VIRTIO_NET_Q_OBJECT_STATE_RDY)
> + return -EAGAIN;
> +
> + cmd_hdr = MLX5_ADDR_OF(query_virtio_q_counters_in, in, hdr);
> +
> + MLX5_SET(general_obj_in_cmd_hdr, cmd_hdr, opcode, MLX5_CMD_OP_QUERY_GENERAL_OBJECT);
> + MLX5_SET(general_obj_in_cmd_hdr, cmd_hdr, obj_type, MLX5_OBJ_TYPE_VIRTIO_Q_COUNTERS);
> + MLX5_SET(general_obj_in_cmd_hdr, cmd_hdr, uid, ndev->mvdev.res.uid);
> + MLX5_SET(general_obj_in_cmd_hdr, cmd_hdr, obj_id, mvq->counter_set_id);
> +
> + err = mlx5_cmd_exec(ndev->mvdev.mdev, in, sizeof(in), out, sizeof(out));
> + if (err)
> + return err;
> +
> + ctx = MLX5_ADDR_OF(query_virtio_q_counters_out, out, counters);
> + *received_desc = MLX5_GET64(virtio_q_counters, ctx, received_desc);
> + *completed_desc = MLX5_GET64(virtio_q_counters, ctx, completed_desc);
> + return 0;
> +}
> +
> +static int mlx5_vdpa_get_vendor_vq_stats(struct vdpa_device *vdev, u16 idx,
> + struct sk_buff *msg,
> + struct netlink_ext_ack *extack)
> +{
> + struct mlx5_vdpa_dev *mvdev = to_mvdev(vdev);
> + struct mlx5_vdpa_net *ndev = to_mlx5_vdpa_ndev(mvdev);
> + struct mlx5_vdpa_virtqueue *mvq;
> + struct mlx5_control_vq *cvq;
> + u64 received_desc;
> + u64 completed_desc;
> + int err = 0;
> + u16 max_vqp;
> +
> + mutex_lock(&ndev->numq_lock);
> + if (!(ndev->mvdev.status & VIRTIO_CONFIG_S_FEATURES_OK)) {
> + NL_SET_ERR_MSG_MOD(extack, "feature negotiation not complete");
> + err = -EAGAIN;
> + goto out_err;
> + }
> +
> + if (!is_index_valid(mvdev, idx)) {
> + NL_SET_ERR_MSG_MOD(extack, "virtqueue index is not valid");
> + err = -EINVAL;
> + goto out_err;
> + }
> +
> + if (idx == ctrl_vq_idx(mvdev)) {
> + cvq = &mvdev->cvq;
> + received_desc = cvq->received_desc;
> + completed_desc = cvq->completed_desc;
> + goto out;
> + }
> +
> + mvq = &ndev->vqs[idx];
> + err = counter_set_query(ndev, mvq, &received_desc, &completed_desc);
> + if (err) {
> + NL_SET_ERR_MSG_MOD(extack, "failed to query hardware");
> + goto out_err;
> + }
> +
> +out:
> + err = -EMSGSIZE;
> + if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_NEGOTIATED_FEATURES,
> + mvdev->actual_features, VDPA_ATTR_PAD))
> + goto out_err;
Rethink this, considering we accept vq index, it might make sense to
move this to the caller (general code).
> +
> + max_vqp = mlx5vdpa16_to_cpu(mvdev, ndev->config.max_virtqueue_pairs);
> + if (nla_put_u16(msg, VDPA_ATTR_DEV_NET_CFG_MAX_VQP, max_vqp))
> + goto out_err;
It looks to me like the userspace program doesn't use this attribute?
Thanks
> +
> + if (nla_put_string(msg, VDPA_ATTR_DEV_VENDOR_ATTR_NAME, "received_desc"))
> + goto out_err;
> +
> + if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_VENDOR_ATTR_VALUE, received_desc,
> + VDPA_ATTR_PAD))
> + goto out_err;
> +
> + if (nla_put_string(msg, VDPA_ATTR_DEV_VENDOR_ATTR_NAME, "completed_desc"))
> + goto out_err;
> +
> + if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_VENDOR_ATTR_VALUE, completed_desc,
> + VDPA_ATTR_PAD))
> + goto out_err;
> +
> + err = 0;
> +out_err:
> + mutex_unlock(&ndev->numq_lock);
> + return err;
> +}
> +
> static const struct vdpa_config_ops mlx5_vdpa_ops = {
> .set_vq_address = mlx5_vdpa_set_vq_address,
> .set_vq_num = mlx5_vdpa_set_vq_num,
> @@ -2451,6 +2619,7 @@ static const struct vdpa_config_ops mlx5_vdpa_ops = {
> .get_vq_ready = mlx5_vdpa_get_vq_ready,
> .set_vq_state = mlx5_vdpa_set_vq_state,
> .get_vq_state = mlx5_vdpa_get_vq_state,
> + .get_vendor_vq_stats = mlx5_vdpa_get_vendor_vq_stats,
> .get_vq_notification = mlx5_get_vq_notification,
> .get_vq_irq = mlx5_get_vq_irq,
> .get_vq_align = mlx5_vdpa_get_vq_align,
> @@ -2706,6 +2875,7 @@ static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name,
>
> init_mvqs(ndev);
> mutex_init(&ndev->reslock);
> + mutex_init(&ndev->numq_lock);
> config = &ndev->config;
>
> if (add_config->mask & BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MTU)) {
> @@ -2788,6 +2958,7 @@ static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name,
> if (!is_zero_ether_addr(config->mac))
> mlx5_mpfs_del_mac(pfmdev, config->mac);
> err_mtu:
> + mutex_destroy(&ndev->numq_lock);
> mutex_destroy(&ndev->reslock);
> err_alloc:
> put_device(&mvdev->vdev.dev);
> diff --git a/include/linux/mlx5/mlx5_ifc.h b/include/linux/mlx5/mlx5_ifc.h
> index 49a48d7709ac..1d193d9b6029 100644
> --- a/include/linux/mlx5/mlx5_ifc.h
> +++ b/include/linux/mlx5/mlx5_ifc.h
> @@ -94,6 +94,7 @@ enum {
> enum {
> MLX5_OBJ_TYPE_GENEVE_TLV_OPT = 0x000b,
> MLX5_OBJ_TYPE_VIRTIO_NET_Q = 0x000d,
> + MLX5_OBJ_TYPE_VIRTIO_Q_COUNTERS = 0x001c,
> MLX5_OBJ_TYPE_MATCH_DEFINER = 0x0018,
> MLX5_OBJ_TYPE_MKEY = 0xff01,
> MLX5_OBJ_TYPE_QP = 0xff02,
> diff --git a/include/linux/mlx5/mlx5_ifc_vdpa.h b/include/linux/mlx5/mlx5_ifc_vdpa.h
> index 1a9c9d94cb59..4414ed5b6ed2 100644
> --- a/include/linux/mlx5/mlx5_ifc_vdpa.h
> +++ b/include/linux/mlx5/mlx5_ifc_vdpa.h
> @@ -165,4 +165,43 @@ struct mlx5_ifc_modify_virtio_net_q_out_bits {
> struct mlx5_ifc_general_obj_out_cmd_hdr_bits general_obj_out_cmd_hdr;
> };
>
> +struct mlx5_ifc_virtio_q_counters_bits {
> + u8 modify_field_select[0x40];
> + u8 reserved_at_40[0x40];
> + u8 received_desc[0x40];
> + u8 completed_desc[0x40];
> + u8 error_cqes[0x20];
> + u8 bad_desc_errors[0x20];
> + u8 exceed_max_chain[0x20];
> + u8 invalid_buffer[0x20];
> + u8 reserved_at_180[0x280];
> +};
> +
> +struct mlx5_ifc_create_virtio_q_counters_in_bits {
> + struct mlx5_ifc_general_obj_in_cmd_hdr_bits hdr;
> + struct mlx5_ifc_virtio_q_counters_bits virtio_q_counters;
> +};
> +
> +struct mlx5_ifc_create_virtio_q_counters_out_bits {
> + struct mlx5_ifc_general_obj_in_cmd_hdr_bits hdr;
> + struct mlx5_ifc_virtio_q_counters_bits virtio_q_counters;
> +};
> +
> +struct mlx5_ifc_destroy_virtio_q_counters_in_bits {
> + struct mlx5_ifc_general_obj_in_cmd_hdr_bits hdr;
> +};
> +
> +struct mlx5_ifc_destroy_virtio_q_counters_out_bits {
> + struct mlx5_ifc_general_obj_out_cmd_hdr_bits hdr;
> +};
> +
> +struct mlx5_ifc_query_virtio_q_counters_in_bits {
> + struct mlx5_ifc_general_obj_in_cmd_hdr_bits hdr;
> +};
> +
> +struct mlx5_ifc_query_virtio_q_counters_out_bits {
> + struct mlx5_ifc_general_obj_in_cmd_hdr_bits hdr;
> + struct mlx5_ifc_virtio_q_counters_bits counters;
> +};
> +
> #endif /* __MLX5_IFC_VDPA_H_ */
> --
> 2.35.1
>