vDPA: report virtio-block write zeroes configuration to user space

This commits reports write zeroes configuration of
virtio-block devices to user space, includes:
1)maximum write zeroes sectors size
2)maximum write zeroes segment number
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Message-Id: <20240218185606.13509-9-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/vdpa/vdpa.c

@@ -1064,6 +1064,26 @@ static int vdpa_dev_blk_discard_config_fill(struct sk_buff *msg, u64 features,
 	return 0;
 }
 
+static int
+vdpa_dev_blk_write_zeroes_config_fill(struct sk_buff *msg, u64 features,
+				     const struct virtio_blk_config *config)
+{
+	u32 val_u32;
+
+	if ((features & BIT_ULL(VIRTIO_BLK_F_WRITE_ZEROES)) == 0)
+		return 0;
+
+	val_u32 = __virtio32_to_cpu(true, config->max_write_zeroes_sectors);
+	if (nla_put_u32(msg, VDPA_ATTR_DEV_BLK_CFG_MAX_WRITE_ZEROES_SEC, val_u32))
+		return -EMSGSIZE;
+
+	val_u32 = __virtio32_to_cpu(true, config->max_write_zeroes_seg);
+	if (nla_put_u32(msg, VDPA_ATTR_DEV_BLK_CFG_MAX_WRITE_ZEROES_SEG, val_u32))
+		return -EMSGSIZE;
+
+	return 0;
+}
+
 static int vdpa_dev_blk_config_fill(struct vdpa_device *vdev,
 				    struct sk_buff *msg)
 {
@@ -1099,6 +1119,9 @@ static int vdpa_dev_blk_config_fill(struct vdpa_device *vdev,
 	if (vdpa_dev_blk_discard_config_fill(msg, features_device, &config))
 		return -EMSGSIZE;
 
+	if (vdpa_dev_blk_write_zeroes_config_fill(msg, features_device, &config))
+		return -EMSGSIZE;
+
 	return 0;
 }
 

include/uapi/linux/vdpa.h

@@ -68,6 +68,8 @@ enum vdpa_attr {
 	VDPA_ATTR_DEV_BLK_CFG_MAX_DISCARD_SEC,	/* u32 */
 	VDPA_ATTR_DEV_BLK_CFG_MAX_DISCARD_SEG,	/* u32 */
 	VDPA_ATTR_DEV_BLK_CFG_DISCARD_SEC_ALIGN,/* u32 */
+	VDPA_ATTR_DEV_BLK_CFG_MAX_WRITE_ZEROES_SEC,	/* u32 */
+	VDPA_ATTR_DEV_BLK_CFG_MAX_WRITE_ZEROES_SEG,	/* u32 */
 
 	/* new attributes must be added above here */
 	VDPA_ATTR_MAX,