Devices greyed out - qvm-pci gives "failed"

Dear zithro,
I saw your answers to similar problems here and here

Tried to run exactly what you propose:

sudo xl pci-assignable-list

is empty. Therefore, I try:

sudo xl pci-assignable-add 0000:00:1f.3

which works, as xl pci-assignable-list reports back this device.

Then I try to assign:

sudo xl pci-attach 8 0000:00:1f.3

but this gives me an error message that I do not understand:

libxl: error: libxl_pci.c:1489:libxl__device_pci_reset: The kernel doesn't support reset from sysfs for PCI device 0000:00:1f.3
libxl: error: libxl_pci.c:1444:pci_add_dm_done: Domain 8:xc_assign_device failed: Operation not supported
libxl: error: libxl_pci.c:1774:device_pci_add_done: Domain 8:libxl__device_pci_add  failed for PCI device 0:0:1f.3 (rc -3)
libxl: error: libxl_device.c:1450:device_addrm_aocomplete: unable to add device

I guess the first line tells the kernel cannot reset, but how can I fix this now?
Appreciate your help,
Raspyvotan