On Thu, Nov 25, 2021 at 12:56 AM Eli Cohen <elic@xxxxxxxxxx> wrote:
>
> Add support for querying virtqueue statistics. Supported statistics are:
>
> received_desc - number of descriptors received for the virtqueue
> completed_desc - number of descriptors completed for the virtqueue
>
> A descriptors 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, by returning the next queue index to
> query.
>
> Examples:
> 1. Read statisitics for the virtqueue at index 1
> $ vdpa dev vstats show vdpa-a qidx 0
> vdpa-a:
> qidx 0 rx received_desc 256 completed_desc 9
>
> 2. Read statisitics for all the virtqueues
> $ vdpa dev vstats show vdpa-a
> vdpa-a:
> qidx 0 rx received_desc 256 completed_desc 9
> qidx 1 tx received_desc 21 completed_desc 21
> qidx 2 ctrl received_desc 0 completed_desc 0
>
> Signed-off-by: Eli Cohen <elic@xxxxxxxxxx>
> ---
> v0 -> v1:
> Emphasize that we're dealing with vendor specific counters.
> Terminate query loop on error
>
> drivers/vdpa/vdpa.c | 144 ++++++++++++++++++++++++++++++++++++++
> include/linux/vdpa.h | 10 +++
> include/uapi/linux/vdpa.h | 9 +++
> 3 files changed, 163 insertions(+)
>
> diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
> index 7332a74a4b00..da658c80ff2a 100644
> --- a/drivers/vdpa/vdpa.c
> +++ b/drivers/vdpa/vdpa.c
> @@ -781,6 +781,90 @@ 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, u16 *index)
> +{
> + struct vdpa_vq_stats stats;
> + u16 idx = *index;
> + int err;
> +
> + err = vdev->config->get_vq_stats(vdev, index, &stats);
> + if (err)
> + return err;
I wonder what happens if some other vendor adds their specific stats.
Can we then have very large stats but only few of them is necessary
for a specific vendor? If this is ture, is this better to simply pass
the msg to the parent instead of a structure like stats?
> +
> + if (nla_put_u16(msg, VDPA_ATTR_DEV_QUEUE_INDEX, idx))
> + return -EMSGSIZE;
> +
> + if (nla_put_u16(msg, VDPA_ATTR_DEV_QUEUE_CTRL, !!stats.ctrl_vq))
> + return -EMSGSIZE;
> +
> + if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_VENDOR_RECEIVED_DESC, stats.received_desc,
> + VDPA_ATTR_PAD))
> + return -EMSGSIZE;
> +
> + if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_VENDOR_COMPLETED_DESC, stats.completed_desc,
> + VDPA_ATTR_PAD))
> + return -EMSGSIZE;
> +
> + return 0;
> +}
> +
> +static int vdpa_dev_net_stats_fill(struct vdpa_device *vdev, struct sk_buff *msg, u16 index)
> +{
> + int err;
> +
> + if (!vdev->config->get_vq_stats)
> + return -EOPNOTSUPP;
> +
> + if (index != VDPA_INVAL_QUEUE_INDEX) {
> + err = vdpa_fill_stats_rec(vdev, msg, &index);
> + if (err)
> + return err;
> + } else {
> + index = 0;
> + do {
> + err = vdpa_fill_stats_rec(vdev, msg, &index);
> + if (err)
> + return err;
> + } while (index != VDPA_INVAL_QUEUE_INDEX);
> + }
> +
> + return 0;
> +}
> +
> +static int vdpa_dev_stats_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 portid,
> + u32 seq, int flags, u16 index)
> +{
> + u32 device_id;
> + void *hdr;
> + int err;
> +
> + 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;
> + }
> +
> + err = vdpa_dev_net_stats_fill(vdev, msg, 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;
> @@ -862,6 +946,59 @@ 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;
> + u16 index = -1;
> + int err;
> +
> + if (!info->attrs[VDPA_ATTR_DEV_NAME])
> + return -EINVAL;
> +
> + if (info->attrs[VDPA_ATTR_DEV_QUEUE_INDEX])
> + index = nla_get_u16(info->attrs[VDPA_ATTR_DEV_QUEUE_INDEX]);
> +
> + devname = nla_data(info->attrs[VDPA_ATTR_DEV_NAME]);
> + msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
> + if (!msg)
> + return -ENOMEM;
> +
> + mutex_lock(&vdpa_dev_mutex);
> + 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;
> + }
> + 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;
> + }
> + err = vdpa_dev_stats_fill(vdev, msg, info->snd_portid, info->snd_seq, 0, 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 },
> @@ -869,6 +1006,7 @@ 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_U16, 0, 32767),
It looks to me that the virtio spec allows up to 65535 vqs.
> };
>
> static const struct genl_ops vdpa_nl_ops[] = {
> @@ -902,6 +1040,12 @@ 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 c3011ccda430..1df19a87a9cb 100644
> --- a/include/linux/vdpa.h
> +++ b/include/linux/vdpa.h
> @@ -58,6 +58,12 @@ struct vdpa_vq_state {
> };
> };
>
> +struct vdpa_vq_stats {
> + u64 received_desc;
> + u64 completed_desc;
> + bool ctrl_vq;
> +};
> +
> struct vdpa_mgmt_dev;
>
> /**
> @@ -269,6 +275,8 @@ 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_vq_stats)(struct vdpa_device *vdev, u16 *idx,
> + struct vdpa_vq_stats *stats);
I'm fine with this but I wonder if it's better to move this to mgmtdev_ops.
> 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 */
> @@ -443,4 +451,6 @@ 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
This seems a valid index unless I miss something in the spec.
Thanks
> +
> #endif /* _LINUX_VDPA_H */
> diff --git a/include/uapi/linux/vdpa.h b/include/uapi/linux/vdpa.h
> index a252f06f9dfd..b749d312dd9c 100644
> --- a/include/uapi/linux/vdpa.h
> +++ b/include/uapi/linux/vdpa.h
> @@ -18,11 +18,15 @@ 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 {
> VDPA_ATTR_UNSPEC,
>
> + /* Pad attribute for 64b alignment */
> + VDPA_ATTR_PAD = VDPA_ATTR_UNSPEC,
> +
> /* bus name (optional) + dev name together make the parent device handle */
> VDPA_ATTR_MGMTDEV_BUS_NAME, /* string */
> VDPA_ATTR_MGMTDEV_DEV_NAME, /* string */
> @@ -40,6 +44,11 @@ enum vdpa_attr {
> VDPA_ATTR_DEV_NET_CFG_MAX_VQP, /* u16 */
> VDPA_ATTR_DEV_NET_CFG_MTU, /* u16 */
>
> + VDPA_ATTR_DEV_QUEUE_INDEX, /* u16 */
> + VDPA_ATTR_DEV_QUEUE_CTRL, /* u16 */
> + VDPA_ATTR_DEV_VENDOR_RECEIVED_DESC, /* u64 */
> + VDPA_ATTR_DEV_VENDOR_COMPLETED_DESC, /* u64 */
> +
> /* new attributes must be added above here */
> VDPA_ATTR_MAX,
> };
> --
> 2.33.1
>
_______________________________________________
Virtualization mailing list
Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
