.\"	$NetBSD: xpci.4,v 1.3 2014/03/18 18:20:39 riastradh Exp $
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.Dd January 8, 2011
.Dt XPCI 4 xen
.Os
.Sh NAME
.Nm xpci
.Nd Xen frontend paravirtualized PCI pass-through driver
.Sh SYNOPSIS
.Cd "xpci* at xenbus?"
.Cd "pci* at xpci?"
.Sh DESCRIPTION
The
.Nm
driver is the frontend part of the PCI pass-through functionality
that can be used by
.Tn Xen
guest domains to communicate with PCI devices.
.Pp
From a guest point of view,
.Nm
is similar to a
.Xr pci 4
bus, except that the guest talks with the PCI backend driver
instead of the real physical device directly.
.Pp
When the host domain is
.Nx ,
the
.Nm
driver is backed by a
.Xr pciback 4
driver within the dom0.
.Sh SEE ALSO
.Xr pci 4 ,
.Xr pciback 4 ,
.Xr xenbus 4
.Sh HISTORY
The
.Nm
driver first appeared in
.Nx 5.1 .
.Sh AUTHORS
.An -nosplit
The
.Nm
driver was written by
.An Manuel Bouyer Aq Mt bouyer@NetBSD.org .
.Sh 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.