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 December 30, 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. 48The following platforms are supported: 49.Bl -bullet -compat 50.It 51amd64: An Intel CPU with VT-x/EPT or AMD CPU with SVM support is required. 52.It 53arm64: The boot CPU must start in EL2 and the system must have a GICv3 interrupt 54controller. 55VHE support will be used if available. 56.It 57riscv: The CPUs must implement the H (hypervisor) RISC-V ISA extension. 58.El 59.Pp 60PCI device passthrough to a virtual machine requires 61hardware with VT-d support and is available only on amd64. 62.Sh PCI PASSTHROUGH 63On amd64 where the hardware supports VT-d, 64PCI devices can be reserved for use by the hypervisor. 65Entries consisting of the PCI 66.Ar bus Ns / Ns Ar slot Ns / Ns Ar function 67are added to the 68.Va pptdevs 69.Xr loader.conf 5 70variable. 71Additional entries are separated by spaces. 72Host PCI devices that match an entry will be assigned to the hypervisor 73and will not be probed by 74.Fx 75device drivers. 76See the 77.Sx EXAMPLES 78section below for sample usage. 79.Pp 80Note that 81.Nm vmm 82must be given first the right of refusal to all 83.Xr pci 4 84devices it may need to claim. 85As a result, the 86.Nm vmm 87kernel module almost certainly needs to be loaded from 88.Xr loader.conf 5 89rather than by adding it to 90.Va kld_list in 91.Xr rc.conf 5 . 92.Pp 93A large number of PCI device entries may require a string longer than the 94128-character limit of 95.Xr loader.conf 5 96variables. 97The 98.Va pptdevs2 99and 100.Va pptdevs3 101variables can be used for additional entries. 102.Sh LOADER TUNABLES 103Tunables can be set at the 104.Xr loader 8 105prompt before booting the kernel or stored in 106.Xr loader.conf 5 . 107.Bl -tag -width indent 108.It Va hw.vmm.maxcpu 109Maximum number of virtual CPUs. 110The default is the number of physical CPUs in the system. 111.El 112.Sh EXAMPLES 113Reserve three PCI devices for use by the hypervisor: bus 10 slot 0 function 0, 114bus 6 slot 5 function 0, and bus 6 slot 5 function 1. 115.Bd -literal -offset indent 116pptdevs="10/0/0 6/5/0 6/5/1" 117.Ed 118.Pp 119It is possible to detach 120.Va ppt 121from a PCI device without rebooting the host machine and then attach a host 122driver, using the 123.Xr devctl 8 124utility. 125Suppose 126.Va ppt 127is currently attached to 128.Va pci0:0:1:0 129and we want the host's 130.Xr xhci 4 131driver to be attached instead: 132.Bd -literal -offset indent 133# devctl set driver -f pci0:0:1:0 xhci 134.Ed 135.Pp 136The same can be applied to attach 137.Va ppt 138back: 139.Bd -literal -offset indent 140# devctl set driver -f pci0:0:1:0 ppt 141.Ed 142.Sh SEE ALSO 143.Xr bhyve 4 , 144.Xr loader.conf 5 , 145.Xr bhyve 8 , 146.Xr bhyveload 8 , 147.Xr devctl 8 , 148.Xr kldload 8 149.Sh HISTORY 150.Nm vmm.ko 151first appeared in 152.Fx 10.0 . 153arm64 and riscv support first appeared in 154.Fx 15.0 . 155.Sh AUTHORS 156.An Neel Natu Aq neel@freebsd.org 157.An Peter Grehan Aq grehan@freebsd.org 158