Copyright (c) 2015 Reyk Floeter <reyk@openbsd.org>
Copyright (c) 2006 Jason McIntyre <jmc@openbsd.org>
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.Dd $Mdocdate: September 15 2016 $ .Dt PVBUS 4 .Os .Sh NAME .Nm pvbus .Nd paravirtual device tree root .Sh SYNOPSIS .Cd "pvbus0 at mainbus0"
p n sys/types.h n sys/ioctl.h n dev/pv/pvvar.h .Sh DESCRIPTION .Nm is used on virtual machines that are running on hypervisors. It provides a pseudo-bus for all paravirtual devices that do not attach to a well-known bus like .Xr pci 4 . The .Nm driver is responsible for detecting the hypervisor interface, checking the capabilities, attaching the paravirtual devices, and providing access to supported information stores. .Ss Supported hypervisors l -tag -width 13n -offset ind -compact t KVM Kernel-based Virtual Machine t Hyper-V Microsoft Hyper-V t OpenBSD .Ox .Xr vmm 4 t VMware VMware vSphere Hypervisor and ESXi t Xen Xen VMM .El
p Note that a hypervisor can attempt to emulate other hypervisors, so multiple hypervisor interfaces may be available on the same host. .Ss VMware paravirtual devices l -tag -width 13n -offset ind -compact t Xr vmt 4 VMware Tools driver and .Dq guestinfo information store .El .Ss Hyper-V paravirtual devices l -tag -width 13n -offset ind -compact t Xr hvn 4 Hyper-V virtual networking interface t Xr hyperv 4 Hyper-V guest nexus device .El .Ss Xen paravirtual devices l -tag -width 13n -offset ind -compact t Xr xen 4 Xen domU nexus device and XenStore information store t Xr xnf 4 Xen Netfront virtual networking interface .El .Sh IOCTL INTERFACE .Nm supports .Xr ioctl 2 commands to exchange information with the hypervisor interface, as implemented in the .Xr hostctl 8 program. Each detected hypervisor interface is available as a character special device file,
a /dev/pvbus1 , etc. All available commands use the same .Fa pvbus_req structure: d -literal struct pvbus_req { size_t pvr_keylen; char *pvr_key; size_t pvr_valuelen; char *pvr_value; }; .Ed
p The caller is responsible for attaching character buffers to the .Fa pvr_key and .Fa pvr_value fields and to set their length in .Fa pvr_keylen and .Fa pvr_valuelen accordingly. All keys and values are nul-terminated strings.
p The following .Xr ioctl 2 commands are available: l -tag -width PVBUSIOC_KVWRITE t Dv PVBUSIOC_KVREAD Read the value from .Fa pvr_key and return it in .Fa pvr_value . t Dv PVBUSIOC_KVTYPE Return the type of the attached hypervisor interface as a string in .Fa pvr_key ; see .Sx Supported Hypervisors . t Dv PVBUSIOC_KVWRITE Write the new value .Fa pvr_value to the key .Fa pvr_key . This command requires write permissions on the device file. .El .Sh FILES l -tag -width "/dev/pvbusX" -compact t /dev/pvbus Ns Ar u .Nm device unit .Ar u file. .El .Sh SEE ALSO .Xr autoconf 4 , .Xr intro 4 , .Xr mainbus 4 , .Xr vmm 4 , .Xr hostctl 8 .Sh HISTORY The .Nm pseudo-bus first appeared in .Ox 5.8 . .Sh AUTHORS The .Nm pseudo-bus was written by .An Reyk Floeter Aq Mt reyk@openbsd.org .