vDPA: report virtio-block topology info to user space

This commit allows vDPA reporting topology information of
virtio-blk devices to user space, includes:
1) the number of logical blocks per physical block
2) offset of first aligned logical block
3) suggested minimum I/O size in blocks
4) optimal (suggested maximum) I/O size in blocks
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Message-Id: <20240218185606.13509-7-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/vdpa/vdpa.c

@@ -1012,6 +1012,35 @@ static int vdpa_dev_blk_mq_config_fill(struct sk_buff *msg, u64 features,
 	return nla_put_u16(msg, VDPA_ATTR_DEV_BLK_CFG_NUM_QUEUES, val_u16);
 }
 
+static int vdpa_dev_blk_topology_config_fill(struct sk_buff *msg, u64 features,
+				       const struct virtio_blk_config *config)
+{
+	u16 min_io_size;
+	u32 opt_io_size;
+
+	if ((features & BIT_ULL(VIRTIO_BLK_F_TOPOLOGY)) == 0)
+		return 0;
+
+	min_io_size = __virtio16_to_cpu(true, config->min_io_size);
+	opt_io_size = __virtio32_to_cpu(true, config->opt_io_size);
+
+	if (nla_put_u8(msg, VDPA_ATTR_DEV_BLK_CFG_PHY_BLK_EXP,
+	    config->physical_block_exp))
+		return -EMSGSIZE;
+
+	if (nla_put_u8(msg, VDPA_ATTR_DEV_BLK_CFG_ALIGN_OFFSET,
+	    config->alignment_offset))
+		return -EMSGSIZE;
+
+	if (nla_put_u16(msg, VDPA_ATTR_DEV_BLK_CFG_MIN_IO_SIZE, min_io_size))
+		return -EMSGSIZE;
+
+	if (nla_put_u32(msg, VDPA_ATTR_DEV_BLK_CFG_OPT_IO_SIZE, opt_io_size))
+		return -EMSGSIZE;
+
+	return 0;
+}
+
 static int vdpa_dev_blk_config_fill(struct vdpa_device *vdev,
 				    struct sk_buff *msg)
 {
@@ -1041,6 +1070,9 @@ static int vdpa_dev_blk_config_fill(struct vdpa_device *vdev,
 	if (vdpa_dev_blk_mq_config_fill(msg, features_device, &config))
 		return -EMSGSIZE;
 
+	if (vdpa_dev_blk_topology_config_fill(msg, features_device, &config))
+		return -EMSGSIZE;
+
 	return 0;
 }
 

include/uapi/linux/vdpa.h

@@ -61,6 +61,10 @@ enum vdpa_attr {
 	VDPA_ATTR_DEV_BLK_CFG_BLK_SIZE,		/* u32 */
 	VDPA_ATTR_DEV_BLK_CFG_SEG_MAX,		/* u32 */
 	VDPA_ATTR_DEV_BLK_CFG_NUM_QUEUES,	/* u16 */
+	VDPA_ATTR_DEV_BLK_CFG_PHY_BLK_EXP,	/* u8 */
+	VDPA_ATTR_DEV_BLK_CFG_ALIGN_OFFSET,	/* u8 */
+	VDPA_ATTR_DEV_BLK_CFG_MIN_IO_SIZE,	/* u16 */
+	VDPA_ATTR_DEV_BLK_CFG_OPT_IO_SIZE,	/* u32 */
 
 	/* new attributes must be added above here */
 	VDPA_ATTR_MAX,