Description of problem:
When using virt-install to perform remote installation of VM using disk of a type block device (virt-install --connect=qemu+ssh://hostname/system --disk=/dev/mapper/mpatha,bus=virtio,cache=none ...) it will define a VM disk as a "file" instead of "block" type device, and will define "source" as "file" instead of "dev".

Example, it will create a disk like this:
    <disk type='file' device='disk'>
      <driver name='qemu' type='raw' cache='none' io='native'/>
      <source file='/dev/mapper/mpatha'/>
      <backingStore/>
      <target dev='vda' bus='virtio'/>
      <alias name='virtio-disk0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
    </disk>

When it should be:
    <disk type='block' device='disk'>
      <driver name='qemu' type='raw' cache='none' io='native'/>
      <source dev='/dev/mapper/mpatha'/>
      <backingStore/>
      <target dev='vda' bus='virtio'/>
      <alias name='virtio-disk0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
    </disk>

If using virt-install on local hypervisor, it will define disk just fine. We are using multipath devices (NetApp LUNs) that we are serving to VM as a disk.


Version-Release number of selected component (if applicable):
Tested on virt-install 1.5.0 and virt-install 2.1.0

How reproducible:
Every time it creates a VM on a remote hypervisor using virt-install --connect option

Steps to Reproduce:
1. virt-install --connect=qemu+ssh://hostname/system --name=test --hvm --graphics vnc --disk path=/dev/mapper/mpatha,bus=virtio,cache=none --vcpus=2 --memory=2048 --cdrom=/ISO/CentOS-7-x86_64-Minimal-1810.iso --boot hd,cdrom,menu=on --os-type=linux --os-variant=rhel7 --network bridge=br7,model=virtio --noreboot

Actual results:
It will create a disk defined in XML like this:
    <disk type='file' device='disk'>
      <driver name='qemu' type='raw' cache='none' io='native'/>
      <source file='/dev/mapper/mpatha'/>
      <backingStore/>
      <target dev='vda' bus='virtio'/>
      <alias name='virtio-disk0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
    </disk>

Expected results:
It should create a disk defined in XML like this:
    <disk type='block' device='disk'>
      <driver name='qemu' type='raw' cache='none' io='native'/>
      <source dev='/dev/mapper/mpatha'/>
      <backingStore/>
      <target dev='vda' bus='virtio'/>
      <alias name='virtio-disk0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
    </disk>

Additional info:
VM will seem to work fine but not sure if there could be any issues because disk is improperly defined.
And also cannot be migrated using virsh migrate without using --unsafe. If i edit XML and define it as "block", migrate works as expected.