Si-Wei Liu
2022-May-02 23:47 UTC
[PATCH v3 1/2] vdpa: Add support for querying vendor statistics
On 5/2/2022 3:22 AM, Eli Cohen wrote:> Allows to read vendor statistics of a vdpa device. The specific > statistics data are received from the upstream driver in the form of an > (attribute name, attribute value) pairs. > > An example of statistics for mlx5_vdpa device are: > > received_desc - number of descriptors received by the virtqueue > completed_desc - number of descriptors completed by the virtqueue > > A descriptor using indirect buffers is still counted as 1. In addition, > N chained descriptors are counted correctly N times as one would expect. > > A new callback was added to vdpa_config_ops which provides the means for > the vdpa driver to return statistics results. > > The interface allows for reading all the supported virtqueues, including > the control virtqueue if it exists. > > Below are some examples taken from mlx5_vdpa which are introduced in the > following patch: > > 1. Read statistics for the virtqueue at index 1 > > $ vdpa dev vstats show vdpa-a qidx 1 > vdpa-a: > queue_type tx queue_index 1 received_desc 3844836 completed_desc 3844836 > > 2. Read statistics for the virtqueue at index 32 > $ vdpa dev vstats show vdpa-a qidx 32 > vdpa-a: > queue_type control_vq queue_index 32 received_desc 62 completed_desc 62 > > 3. Read statisitics for the virtqueue at index 0 with json output > $ vdpa -j dev vstats show vdpa-a qidx 0 > {"vstats":{"vdpa-a":{ > "queue_type":"rx","queue_index":0,"name":"received_desc","value":417776,\ > "name":"completed_desc","value":417548}}} > > 4. Read statistics for the virtqueue at index 0 with preety json output > $ vdpa -jp dev vstats show vdpa-a qidx 0 > { > "vstats": { > "vdpa-a": { > > "queue_type": "rx", > "queue_index": 0, > "name": "received_desc", > "value": 417776, > "name": "completed_desc", > "value": 417548 > } > } > } > > Signed-off-by: Eli Cohen <elic at nvidia.com> > --- > drivers/vdpa/vdpa.c | 129 ++++++++++++++++++++++++++++++++++++++ > include/linux/vdpa.h | 5 ++ > include/uapi/linux/vdpa.h | 6 ++ > 3 files changed, 140 insertions(+) > > diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c > index 2b75c00b1005..933466f61ca8 100644 > --- a/drivers/vdpa/vdpa.c > +++ b/drivers/vdpa/vdpa.c > @@ -909,6 +909,74 @@ vdpa_dev_config_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 portid, > return err; > } > > +static int vdpa_fill_stats_rec(struct vdpa_device *vdev, struct sk_buff *msg, > + struct genl_info *info, u32 index) > +{ > + int err; > + > + err = vdev->config->get_vendor_vq_stats(vdev, index, msg, info->extack); > + if (err) > + return err; > + > + if (nla_put_u32(msg, VDPA_ATTR_DEV_QUEUE_INDEX, index)) > + return -EMSGSIZE; > + > + return 0; > +} > + > +static int vendor_stats_fill(struct vdpa_device *vdev, struct sk_buff *msg, > + struct genl_info *info, u32 index) > +{ > + int err; > + > + if (!vdev->config->get_vendor_vq_stats) > + return -EOPNOTSUPP; > + > + err = vdpa_fill_stats_rec(vdev, msg, info, index); > + if (err) > + return err; > + > + return 0; > +} > + > +static int vdpa_dev_vendor_stats_fill(struct vdpa_device *vdev, > + struct sk_buff *msg, > + struct genl_info *info, u32 index) > +{ > + u32 device_id; > + void *hdr; > + int err; > + u32 portid = info->snd_portid; > + u32 seq = info->snd_seq; > + u32 flags = 0; > + > + hdr = genlmsg_put(msg, portid, seq, &vdpa_nl_family, flags, > + VDPA_CMD_DEV_VSTATS_GET); > + if (!hdr) > + return -EMSGSIZE; > + > + if (nla_put_string(msg, VDPA_ATTR_DEV_NAME, dev_name(&vdev->dev))) { > + err = -EMSGSIZE; > + goto undo_msg; > + } > + > + device_id = vdev->config->get_device_id(vdev); > + if (nla_put_u32(msg, VDPA_ATTR_DEV_ID, device_id)) { > + err = -EMSGSIZE; > + goto undo_msg; > + } > +You seem to miss VDPA_ATTR_DEV_NEGOTIATED_FEATURES from this function, otherwise I can't image how you can ensure the atomicity to infer queue_type for control vq. And should we make sure VIRTIO_CONFIG_S_FEATURES_OK is set before call into vendor_stats_fill()?> + err = vendor_stats_fill(vdev, msg, info, index); > + > + genlmsg_end(msg, hdr); > + > + return err; > + > +undo_msg: > + genlmsg_cancel(msg, hdr); > + return err; > +} > + > static int vdpa_nl_cmd_dev_config_get_doit(struct sk_buff *skb, struct genl_info *info) > { > struct vdpa_device *vdev; > @@ -990,6 +1058,60 @@ vdpa_nl_cmd_dev_config_get_dumpit(struct sk_buff *msg, struct netlink_callback * > return msg->len; > } > > +static int vdpa_nl_cmd_dev_stats_get_doit(struct sk_buff *skb, > + struct genl_info *info) > +{ > + struct vdpa_device *vdev; > + struct sk_buff *msg; > + const char *devname; > + struct device *dev; > + u32 index; > + int err; > + > + if (!info->attrs[VDPA_ATTR_DEV_NAME]) > + return -EINVAL; > + > + if (!info->attrs[VDPA_ATTR_DEV_QUEUE_INDEX]) > + return -EINVAL; > + > + devname = nla_data(info->attrs[VDPA_ATTR_DEV_NAME]); > + msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); > + if (!msg) > + return -ENOMEM; > + > + index = nla_get_u32(info->attrs[VDPA_ATTR_DEV_QUEUE_INDEX]); > + mutex_lock(&vdpa_dev_mutex);Given that stats_get() is a read-only operation that might happen quite often from time to time, I wonder if it is now a good timing to convert vdpa_dev_mutex to a semaphore?> + dev = bus_find_device(&vdpa_bus, NULL, devname, vdpa_name_match); > + if (!dev) { > + NL_SET_ERR_MSG_MOD(info->extack, "device not found"); > + err = -ENODEV; > + goto dev_err;Missing nlmsg_free().> + } > + vdev = container_of(dev, struct vdpa_device, dev); > + if (!vdev->mdev) { > + NL_SET_ERR_MSG_MOD(info->extack, "unmanaged vdpa device"); > + err = -EINVAL; > + goto mdev_err;Missing nlmsg_free(). Otherwise looks fine. Acked-by: Si-Wei Liu <si-wei.liu at oracle.com> -Siwei> + } > + err = vdpa_dev_vendor_stats_fill(vdev, msg, info, index); > + if (!err) > + err = genlmsg_reply(msg, info); > + > + put_device(dev); > + mutex_unlock(&vdpa_dev_mutex); > + > + if (err) > + nlmsg_free(msg); > + > + return err; > + > +mdev_err: > + put_device(dev); > +dev_err: > + mutex_unlock(&vdpa_dev_mutex); > + return err; > +} > + > static const struct nla_policy vdpa_nl_policy[VDPA_ATTR_MAX + 1] = { > [VDPA_ATTR_MGMTDEV_BUS_NAME] = { .type = NLA_NUL_STRING }, > [VDPA_ATTR_MGMTDEV_DEV_NAME] = { .type = NLA_STRING }, > @@ -997,6 +1119,7 @@ static const struct nla_policy vdpa_nl_policy[VDPA_ATTR_MAX + 1] = { > [VDPA_ATTR_DEV_NET_CFG_MACADDR] = NLA_POLICY_ETH_ADDR, > /* virtio spec 1.1 section 5.1.4.1 for valid MTU range */ > [VDPA_ATTR_DEV_NET_CFG_MTU] = NLA_POLICY_MIN(NLA_U16, 68), > + [VDPA_ATTR_DEV_QUEUE_INDEX] = NLA_POLICY_RANGE(NLA_U32, 0, 65535), > }; > > static const struct genl_ops vdpa_nl_ops[] = { > @@ -1030,6 +1153,12 @@ static const struct genl_ops vdpa_nl_ops[] = { > .doit = vdpa_nl_cmd_dev_config_get_doit, > .dumpit = vdpa_nl_cmd_dev_config_get_dumpit, > }, > + { > + .cmd = VDPA_CMD_DEV_VSTATS_GET, > + .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, > + .doit = vdpa_nl_cmd_dev_stats_get_doit, > + .flags = GENL_ADMIN_PERM, > + }, > }; > > static struct genl_family vdpa_nl_family __ro_after_init = { > diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h > index 8943a209202e..48ed1fc00830 100644 > --- a/include/linux/vdpa.h > +++ b/include/linux/vdpa.h > @@ -276,6 +276,9 @@ struct vdpa_config_ops { > const struct vdpa_vq_state *state); > int (*get_vq_state)(struct vdpa_device *vdev, u16 idx, > struct vdpa_vq_state *state); > + int (*get_vendor_vq_stats)(struct vdpa_device *vdev, u16 idx, > + struct sk_buff *msg, > + struct netlink_ext_ack *extack); > struct vdpa_notification_area > (*get_vq_notification)(struct vdpa_device *vdev, u16 idx); > /* vq irq is not expected to be changed once DRIVER_OK is set */ > @@ -473,4 +476,6 @@ struct vdpa_mgmt_dev { > int vdpa_mgmtdev_register(struct vdpa_mgmt_dev *mdev); > void vdpa_mgmtdev_unregister(struct vdpa_mgmt_dev *mdev); > > +#define VDPA_INVAL_QUEUE_INDEX 0xffff > + > #endif /* _LINUX_VDPA_H */ > diff --git a/include/uapi/linux/vdpa.h b/include/uapi/linux/vdpa.h > index 1061d8d2d09d..25c55cab3d7c 100644 > --- a/include/uapi/linux/vdpa.h > +++ b/include/uapi/linux/vdpa.h > @@ -18,6 +18,7 @@ enum vdpa_command { > VDPA_CMD_DEV_DEL, > VDPA_CMD_DEV_GET, /* can dump */ > VDPA_CMD_DEV_CONFIG_GET, /* can dump */ > + VDPA_CMD_DEV_VSTATS_GET, > }; > > enum vdpa_attr { > @@ -46,6 +47,11 @@ enum vdpa_attr { > VDPA_ATTR_DEV_NEGOTIATED_FEATURES, /* u64 */ > VDPA_ATTR_DEV_MGMTDEV_MAX_VQS, /* u32 */ > VDPA_ATTR_DEV_SUPPORTED_FEATURES, /* u64 */ > + > + VDPA_ATTR_DEV_QUEUE_INDEX, /* u32 */ > + VDPA_ATTR_DEV_VENDOR_ATTR_NAME, /* string */ > + VDPA_ATTR_DEV_VENDOR_ATTR_VALUE, /* u64 */ > + > /* new attributes must be added above here */ > VDPA_ATTR_MAX, > };