1.\" Copyright (c) 2013 Peter Grehan 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE 17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" 25.Dd September 27, 2024 26.Dt VMM 4 27.Os 28.Sh NAME 29.Nm vmm.ko 30.Nd "bhyve virtual machine monitor" 31.Sh SYNOPSIS 32To load the driver as a module at boot, add this line to 33.Xr loader.conf 5 : 34.Bd -literal -offset indent 35.Cd vmm_load="YES" 36.Ed 37.Pp 38The module can also be loaded manually with 39.Xr kldload 8 : 40.Bd -literal -offset indent 41kldload vmm 42.Ed 43.Sh DESCRIPTION 44.Nm 45provides the kernel portion of the 46.Xr bhyve 4 47hypervisor. 48.Pp 49An Intel CPU with VT-x/EPT or AMD CPU with SVM support is required. 50.Pp 51PCI device passthrough to a virtual machine requires 52hardware with VT-d support. 53.Sh PCI PASSTHROUGH 54When the hardware supports VT-d, and 55.Nm 56has been loaded at boot time, 57PCI devices can be reserved for use by the hypervisor. 58Entries consisting of the PCI 59.Ar bus Ns / Ns Ar slot Ns / Ns Ar function 60are added to the 61.Va pptdevs 62.Xr loader.conf 5 63variable. 64Additional entries are separated by spaces. 65Host PCI devices that match an entry will be assigned to the hypervisor 66and will not be probed by 67.Fx 68device drivers. 69See the 70.Sx EXAMPLES 71section below for sample usage. 72.Pp 73Note that 74.Nm vmm 75must be given first the right of refusal to all 76.Xr pci 4 77devices it may need to claim. 78As a result, the 79.Nm vmm 80kernel module almost certainly needs to be loaded from 81.Xr loader.conf 5 82rather than by adding it to 83.Va kld_list in 84.Xr rc.conf 5 . 85.Pp 86A large number of PCI device entries may require a string longer than the 87128-character limit of 88.Xr loader.conf 5 89variables. 90The 91.Va pptdevs2 92and 93.Va pptdevs3 94variables can be used for additional entries. 95.Sh LOADER TUNABLES 96Tunables can be set at the 97.Xr loader 8 98prompt before booting the kernel or stored in 99.Xr loader.conf 5 . 100.Bl -tag -width indent 101.It Va hw.vmm.maxcpu 102Maximum number of virtual CPUs. 103The default is the number of physical CPUs in the system. 104.El 105.Sh EXAMPLES 106Reserve three PCI devices for use by the hypervisor: bus 10 slot 0 function 0, 107bus 6 slot 5 function 0, and bus 6 slot 5 function 1. 108.Bd -literal -offset indent 109pptdevs="10/0/0 6/5/0 6/5/1" 110.Ed 111.Pp 112It is possible to detach 113.Va ppt 114from a PCI device without rebooting the host machine and then attach a host 115driver, using the 116.Xr devctl 8 117utility. 118Suppose 119.Va ppt 120is currently attached to 121.Va pci0:0:1:0 122and we want the host's 123.Xr xhci 4 124driver to be attached instead: 125.Bd -literal -offset indent 126# devctl set driver -f pci0:0:1:0 xhci 127.Ed 128.Pp 129The same can be applied to attach 130.Va ppt 131back: 132.Bd -literal -offset indent 133# devctl set driver -f pci0:0:1:0 ppt 134.Ed 135.Sh SEE ALSO 136.Xr bhyve 4 , 137.Xr loader.conf 5 , 138.Xr bhyve 8 , 139.Xr bhyveload 8 , 140.Xr devctl 8 , 141.Xr kldload 8 142.Sh HISTORY 143.Nm vmm.ko 144first appeared in 145.Fx 10.0 . 146.Sh AUTHORS 147.An Neel Natu Aq neel@freebsd.org 148.An Peter Grehan Aq grehan@freebsd.org 149