1What:           /sys/bus/pci/drivers/pciback/quirks
2Date:           Oct 2011
3KernelVersion:  3.1
4Contact:        xen-devel@lists.xenproject.org
5Description:
6                If the permissive attribute is set, then writing a string in
7                the format of DDDD:BB:DD.F-REG:SIZE:MASK will allow the guest
8                to write and read from the PCI device. That is Domain:Bus:
9                Device.Function-Register:Size:Mask (Domain is optional).
10                For example::
11
12                  #echo 00:19.0-E0:2:FF > /sys/bus/pci/drivers/pciback/quirks
13
14                will allow the guest to read and write to the configuration
15                register 0x0E.
16
17What:           /sys/bus/pci/drivers/pciback/allow_interrupt_control
18Date:           Jan 2020
19KernelVersion:  5.6
20Contact:        xen-devel@lists.xenproject.org
21Description:
22                List of devices which can have interrupt control flag (INTx,
23                MSI, MSI-X) set by a connected guest. It is meant to be set
24                only when the guest is a stubdomain hosting device model (qemu)
25                and the actual device is assigned to a HVM. It is not safe
26                (similar to permissive attribute) to set for a devices assigned
27                to a PV guest. The device is automatically removed from this
28                list when the connected pcifront terminates.
29