[libvirt] how to know if PCI device has SR-IOV PF capability

Hi, I was looking on the output of virsh nodedev-dumpxml on a PCI to see if it has SR-IOV PF capability. It seem that if the virtual functions are enables the xml look like [1] but if the PCI has no VFs enabled the output is like in [2]. As you can see for PCI which has no VFs the <capability type='virt_functions'> tag doen't exist. Is this by design? I would except that <capability type='virt_functions'/> tag with empty elements will also be include in that case. Thanks, Moshe Levi. [1] root@r-ufm152:~# virsh nodedev-dumpxml pci_0000_03_00_0 <device> <name>pci_0000_03_00_0</name> <path>/sys/devices/pci0000:00/0000:00:02.0/0000:03:00.0</path> <parent>pci_0000_00_02_0</parent> <driver> <name>mlx5_core</name> </driver> <capability type='pci'> <domain>0</domain> <bus>3</bus> <slot>0</slot> <function>0</function> <product id='0x1013'>MT27700 Family [ConnectX-4]</product> <vendor id='0x15b3'>Mellanox Technologies</vendor> <capability type='virt_functions'> <address domain='0x0000' bus='0x03' slot='0x00' function='0x2'/> <address domain='0x0000' bus='0x03' slot='0x00' function='0x3'/> <address domain='0x0000' bus='0x03' slot='0x00' function='0x4'/> <address domain='0x0000' bus='0x03' slot='0x00' function='0x5'/> </capability> <iommuGroup number='15'> <address domain='0x0000' bus='0x03' slot='0x00' function='0x0'/> <address domain='0x0000' bus='0x03' slot='0x00' function='0x1'/> </iommuGroup> <numa node='0'/> <pci-express> <link validity='cap' port='0' speed='8' width='16'/> <link validity='sta' speed='8' width='16'/> </pci-express> </capability> </device> [2] root@r-ufm152:~# virsh nodedev-dumpxml pci_0000_03_00_1 <device> <name>pci_0000_03_00_1</name> <path>/sys/devices/pci0000:00/0000:00:02.0/0000:03:00.1</path> <parent>pci_0000_00_02_0</parent> <driver> <name>mlx5_core</name> </driver> <capability type='pci'> <domain>0</domain> <bus>3</bus> <slot>0</slot> <function>1</function> <product id='0x1013'>MT27700 Family [ConnectX-4]</product> <vendor id='0x15b3'>Mellanox Technologies</vendor> <iommuGroup number='15'> <address domain='0x0000' bus='0x03' slot='0x00' function='0x0'/> <address domain='0x0000' bus='0x03' slot='0x00' function='0x1'/> </iommuGroup> <numa node='0'/> <pci-express> <link validity='cap' port='0' speed='8' width='16'/> <link validity='sta' speed='8' width='16'/> </pci-express> </capability> </device>