vdpa: Enable user to query vdpa device info

Enable user to query vdpa device information.

$ vdpa dev add mgmtdev vdpasim_net name foo2

Show the newly created vdpa device by its name:
$ vdpa dev show foo2
foo2: type network mgmtdev vdpasim_net vendor_id 0 max_vqs 2 max_vq_size 256

$ vdpa dev show foo2 -jp
{
    "dev": {
        "foo2": {
            "type": "network",
            "mgmtdev": "vdpasim_net",
            "vendor_id": 0,
            "max_vqs": 2,
            "max_vq_size": 256
        }
    }
}

Signed-off-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Eli Cohen <elic@nvidia.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210105103203.82508-6-parav@nvidia.com
Including a memory leak fix:

Link: https://lore.kernel.org/r/20210217060614.59561-1-parav@nvidia.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
index f122818..da67f07 100644 (file)
--- a/drivers/vdpa/vdpa.c
+++ b/drivers/vdpa/vdpa.c
@@ -478,6 +478,131 @@ dev_err:
        return err;
 }
 
+static int
+vdpa_dev_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 portid, u32 seq,
+             int flags, struct netlink_ext_ack *extack)
+{
+       u16 max_vq_size;
+       u32 device_id;
+       u32 vendor_id;
+       void *hdr;
+       int err;
+
+       hdr = genlmsg_put(msg, portid, seq, &vdpa_nl_family, flags, VDPA_CMD_DEV_NEW);
+       if (!hdr)
+               return -EMSGSIZE;
+
+       err = vdpa_nl_mgmtdev_handle_fill(msg, vdev->mdev);
+       if (err)
+               goto msg_err;
+
+       device_id = vdev->config->get_device_id(vdev);
+       vendor_id = vdev->config->get_vendor_id(vdev);
+       max_vq_size = vdev->config->get_vq_num_max(vdev);
+
+       err = -EMSGSIZE;
+       if (nla_put_string(msg, VDPA_ATTR_DEV_NAME, dev_name(&vdev->dev)))
+               goto msg_err;
+       if (nla_put_u32(msg, VDPA_ATTR_DEV_ID, device_id))
+               goto msg_err;
+       if (nla_put_u32(msg, VDPA_ATTR_DEV_VENDOR_ID, vendor_id))
+               goto msg_err;
+       if (nla_put_u32(msg, VDPA_ATTR_DEV_MAX_VQS, vdev->nvqs))
+               goto msg_err;
+       if (nla_put_u16(msg, VDPA_ATTR_DEV_MAX_VQ_SIZE, max_vq_size))
+               goto msg_err;
+
+       genlmsg_end(msg, hdr);
+       return 0;
+
+msg_err:
+       genlmsg_cancel(msg, hdr);
+       return err;
+}
+
+static int vdpa_nl_cmd_dev_get_doit(struct sk_buff *skb, struct genl_info *info)
+{
+       struct vdpa_device *vdev;
+       struct sk_buff *msg;
+       const char *devname;
+       struct device *dev;
+       int err;
+
+       if (!info->attrs[VDPA_ATTR_DEV_NAME])
+               return -EINVAL;
+       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 err;
+       }
+       vdev = container_of(dev, struct vdpa_device, dev);
+       if (!vdev->mdev) {
+               err = -EINVAL;
+               goto mdev_err;
+       }
+       err = vdpa_dev_fill(vdev, msg, info->snd_portid, info->snd_seq, 0, info->extack);
+       if (!err)
+               err = genlmsg_reply(msg, info);
+mdev_err:
+       put_device(dev);
+err:
+       mutex_unlock(&vdpa_dev_mutex);
+       if (err)
+               nlmsg_free(msg);
+       return err;
+}
+
+struct vdpa_dev_dump_info {
+       struct sk_buff *msg;
+       struct netlink_callback *cb;
+       int start_idx;
+       int idx;
+};
+
+static int vdpa_dev_dump(struct device *dev, void *data)
+{
+       struct vdpa_device *vdev = container_of(dev, struct vdpa_device, dev);
+       struct vdpa_dev_dump_info *info = data;
+       int err;
+
+       if (!vdev->mdev)
+               return 0;
+       if (info->idx < info->start_idx) {
+               info->idx++;
+               return 0;
+       }
+       err = vdpa_dev_fill(vdev, info->msg, NETLINK_CB(info->cb->skb).portid,
+                           info->cb->nlh->nlmsg_seq, NLM_F_MULTI, info->cb->extack);
+       if (err)
+               return err;
+
+       info->idx++;
+       return 0;
+}
+
+static int vdpa_nl_cmd_dev_get_dumpit(struct sk_buff *msg, struct netlink_callback *cb)
+{
+       struct vdpa_dev_dump_info info;
+
+       info.msg = msg;
+       info.cb = cb;
+       info.start_idx = cb->args[0];
+       info.idx = 0;
+
+       mutex_lock(&vdpa_dev_mutex);
+       bus_for_each_dev(&vdpa_bus, NULL, &info, vdpa_dev_dump);
+       mutex_unlock(&vdpa_dev_mutex);
+       cb->args[0] = info.idx;
+       return msg->len;
+}
+
 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 },
@@ -503,6 +628,12 @@ static const struct genl_ops vdpa_nl_ops[] = {
                .doit = vdpa_nl_cmd_dev_del_set_doit,
                .flags = GENL_ADMIN_PERM,
        },
+       {
+               .cmd = VDPA_CMD_DEV_GET,
+               .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+               .doit = vdpa_nl_cmd_dev_get_doit,
+               .dumpit = vdpa_nl_cmd_dev_get_dumpit,
+       },
 };
 
 static struct genl_family vdpa_nl_family __ro_after_init = {

diff --git a/include/uapi/linux/vdpa.h b/include/uapi/linux/vdpa.h
index bb4a1f0..66a41e4 100644 (file)
--- a/include/uapi/linux/vdpa.h
+++ b/include/uapi/linux/vdpa.h
@@ -16,6 +16,7 @@ enum vdpa_command {
        VDPA_CMD_MGMTDEV_GET,           /* can dump */
        VDPA_CMD_DEV_NEW,
        VDPA_CMD_DEV_DEL,
+       VDPA_CMD_DEV_GET,               /* can dump */
 };
 
 enum vdpa_attr {
@@ -27,6 +28,10 @@ enum vdpa_attr {
        VDPA_ATTR_MGMTDEV_SUPPORTED_CLASSES,    /* u64 */
 
        VDPA_ATTR_DEV_NAME,                     /* string */
+       VDPA_ATTR_DEV_ID,                       /* u32 */
+       VDPA_ATTR_DEV_VENDOR_ID,                /* u32 */
+       VDPA_ATTR_DEV_MAX_VQS,                  /* u32 */
+       VDPA_ATTR_DEV_MAX_VQ_SIZE,              /* u16 */
 
        /* new attributes must be added above here */
        VDPA_ATTR_MAX,