NAME
pciback —
Xen backend paravirtualized
PCI pass-through driver
SYNOPSIS
pciback* at pci?
DESCRIPTION
The
pciback driver is the backend part of the PCI pass-through
functionality that can be used by the Xen dom0 to export
pci(4) devices to a guest domain.
To export a PCI device to a guest domain, the device has to be attached to
pciback in the dom0.
When the guest domain is
NetBSD, the device attached to
the
pciback driver will attach to a
xpci(4) bus inside the guest
domain.
EXAMPLES
To attach a device to the
pciback driver, follow these steps:
- look for the device PCI ID,
via pcictl(8).
- edit
boot.cfg(5) and add the
PCI ID to the list of PCI IDs that you want to attach to
pciback, in bus:device.function notation. The list is
passed to dom0 module via the pciback.hide parameter:
pciback.hide=(bus:dev.fun)(bus:dev.func)(...)
See also boot(8).
- reboot dom0.
- add the PCI ID to the list of
PCI devices in the domain configuration file:
pci = ['bus:dev.fun', '...']
- start the guest domain.
SEE ALSO
pci(4),
xpci(4),
boot(8),
pcictl(8)
HISTORY
The
pciback driver first appeared in
NetBSD
5.1.
AUTHORS
The
pciback driver was written by
Manuel
Bouyer
<
bouyer@NetBSD.org>.
CAVEATS
Currently, to attach a device to the
pciback backend, this
procedure has to be performed at
boot(8) time. In the future, it
will be possible to do it without requiring a dom0 reboot.
SECURITY CONSIDERATIONS
As PCI passthrough offers the possibility for guest domains to send arbitrary
PCI commands to a physical device, this has direct impact on the overall
stability and security of the system. For example, in case of erroneous or
malicious commands, the device could overwrite physical memory portions, via
DMA.