it always create sdx device when I configure ide device with hdx name

I have configured 2 ide disks with name starting with hd, but when the vm boots up, it shows disks whose name starting with sd.

1. ide disks in vm xml:

    <disk type='file' device='disk'>
      <driver name='qemu' type='raw'/>
      <source file='/data3_raw.qcow2'/>
      <target dev='hdc' bus='ide'/>
    </disk>
    <disk type='file' device='disk'>
      <driver name='qemu' type='qcow2'/>
      <source file='/data2.qcow2'/>
      <target dev='hdb' bus='ide'/>
    </disk>


2. in VM:

sda            8:0    0    2G  0 disk
sdb            8:16   0    1G  0 disk


3. from vm.log:

le=/data2.qcow2,format=qcow2,if=none,id=drive-ide0-0-1 -device ide-hd,bus=ide.0,unit=1,drive=drive-ide0-0-1,id=ide0-0-1 -drive file=/data3_raw.qcow2,format=raw,if=none,id=drive-ide0-1-0 -device ide-hd,bus=ide.1,unit=0,drive=drive-ide0-1-0,id=ide0-1-0 -netdev t


4. rpm info: (I got the same issue on 2 diff envs)
(1) env1
qemu-kvm-1.5.3-105
libvirt-3.2.0-14.el7
(2) env2
libvirt-5.9.0-1.el8
qemu-4.1.0-1.el8