[PATCH 01/10] vDPA: report virtio-block capacity to user space

[Zhu Lingshan <lingshan.zhu@xxxxxxxxx>]

This commit allows userspace to query capacity of
a virtio-block device.

Signed-off-by: Zhu Lingshan <lingshan.zhu@xxxxxxxxx>
---
 drivers/vdpa/vdpa.c       | 35 +++++++++++++++++++++++++++++++++++
 include/linux/vdpa.h      |  1 +
 include/uapi/linux/vdpa.h |  2 ++
 3 files changed, 38 insertions(+)

diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
index d0695680b282..d5ccb618de2b 100644
--- a/drivers/vdpa/vdpa.c
+++ b/drivers/vdpa/vdpa.c
@@ -944,6 +944,38 @@ static int vdpa_dev_net_config_fill(struct vdpa_device *vdev, struct sk_buff *ms
 	return vdpa_dev_net_mq_config_fill(msg, features_device, &config);
 }
 
+static int
+vdpa_dev_blk_capacity_config_fill(struct sk_buff *msg,
+				  const struct virtio_blk_config *config)
+{
+	u64 val_u64;
+
+	val_u64 = __virtio64_to_cpu(true, config->capacity);
+
+	return nla_put_u64_64bit(msg, VDPA_ATTR_DEV_BLK_CFG_CAPACITY,
+				 val_u64, VDPA_ATTR_PAD);
+}
+
+static int vdpa_dev_blk_config_fill(struct vdpa_device *vdev,
+				    struct sk_buff *msg)
+{
+	struct virtio_blk_config config = {};
+	u64 features_device;
+
+	vdev->config->get_config(vdev, 0, &config, sizeof(config));
+
+	features_device = vdev->config->get_device_features(vdev);
+
+	if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_FEATURES, features_device,
+			      VDPA_ATTR_PAD))
+		return -EMSGSIZE;
+
+	if (vdpa_dev_blk_capacity_config_fill(msg, &config))
+		return -EMSGSIZE;
+
+	return 0;
+}
+
 static int
 vdpa_dev_config_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 portid, u32 seq,
 		     int flags, struct netlink_ext_ack *extack)
@@ -988,6 +1020,9 @@ vdpa_dev_config_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 portid,
 	case VIRTIO_ID_NET:
 		err = vdpa_dev_net_config_fill(vdev, msg);
 		break;
+	case VIRTIO_ID_BLOCK:
+		err = vdpa_dev_blk_config_fill(vdev, msg);
+		break;
 	default:
 		err = -EOPNOTSUPP;
 		break;
diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
index db15ac07f8a6..a184aa6538cb 100644
--- a/include/linux/vdpa.h
+++ b/include/linux/vdpa.h
@@ -7,6 +7,7 @@
 #include <linux/interrupt.h>
 #include <linux/vhost_iotlb.h>
 #include <linux/virtio_net.h>
+#include <linux/virtio_blk.h>
 #include <linux/if_ether.h>
 
 /**
diff --git a/include/uapi/linux/vdpa.h b/include/uapi/linux/vdpa.h
index 54b649ab0f22..1bf69226cb96 100644
--- a/include/uapi/linux/vdpa.h
+++ b/include/uapi/linux/vdpa.h
@@ -56,6 +56,8 @@ enum vdpa_attr {
 	/* virtio features that are provisioned to the vDPA device */
 	VDPA_ATTR_DEV_FEATURES,                 /* u64 */
 
+	VDPA_ATTR_DEV_BLK_CFG_CAPACITY,		/* u64 */
+
 	/* new attributes must be added above here */
 	VDPA_ATTR_MAX,
 };
-- 
2.39.3