Messages in this thread | | | From | Eli Cohen <> | Subject | RE: [PATCH v3 1/2] vdpa: Add support for querying vendor statistics | Date | Sun, 8 May 2022 07:44:15 +0000 |
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> -----Original Message----- > From: Si-Wei Liu <si-wei.liu@oracle.com> > Sent: Tuesday, May 3, 2022 2:48 AM > To: Eli Cohen <elic@nvidia.com>; mst@redhat.com; jasowang@redhat.com > Cc: virtualization@lists.linux-foundation.org; linux-kernel@vger.kernel.org > Subject: Re: [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@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?
No sure I follow you. You still need that the process that took the lock will release it. So in that respect we should still use a mutex.
Did you mean use readers/writers lock?
> > > + 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().
Thanks will fix.
> > Otherwise looks fine. > > Acked-by: Si-Wei Liu <si-wei.liu@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, > > };
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