Pass through wireless adapter from host to KVM VM

[kingslavcho]

Hello guys, I have a problem with my KVM virtual machine because it does not have internet connection and i like my connection to be made directly with the wireless adapter which will be connected directly with the wireless router. I am new into KVM and don't know much but from reading i understood that there is an option called passthrough in KVM which can help guest to directly use the wireless adapter.

The host is connected with lan cable and i do not need the wireless adapter on the host but on the guest VM.

This is the output of the host ifconfig:

enp7s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.1.201 netmask 255.255.255.0 broadcast 192.168.1.255
inet6 fe80::3e7c:3fff:fe27:6476 prefixlen 64 scopeid 0x20<link>
ether 3c:7c:3f:27:64:76 txqueuelen 1000 (Ethernet)
RX packets 6114698 bytes 6211114275 (6.2 GB)
RX errors 0 dropped 11 overruns 0 frame 0
TX packets 6022861 bytes 1304250533 (1.3 GB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 3266146 bytes 1699931157 (1.6 GB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 3266146 bytes 1699931157 (1.6 GB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

macvtap0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet6 fe80::5054:ff:fef7:48fe prefixlen 64 scopeid 0x20<link>
ether 52:54:00:f7:48:fe txqueuelen 500 (Ethernet)
RX packets 189 bytes 30948 (30.9 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 2094 bytes 338491 (338.4 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

virbr0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
inet 192.168.122.1 netmask 255.255.255.0 broadcast 192.168.122.255
ether 52:54:00:40:80:51 txqueuelen 1000 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

wlxd03745ed8e3c: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.1.247 netmask 255.255.255.0 broadcast 192.168.1.255
inet6 fe80::325a:43fd:82d9:ec8e prefixlen 64 scopeid 0x20<link>
ether d0:37:45:ed:8e:3c txqueuelen 1000 (Ethernet)
RX packets 6448 bytes 384777 (384.7 KB)
RX errors 0 dropped 175 overruns 0 frame 0
TX packets 2402 bytes 436312 (436.3 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

Also tried to install with virt-manager but i get error: device or resource busy and the wireless adapter is not connected..

How can i make this wlxd03745ed8e3c adapter to be used directly from my KVM VM? Thank you

[TheFu]

Passthru requires that the device be exclusive to the single VM.

If it is a USB device, it is relatively easy. If it is a PCIe card, then you'll need to figure out how to pass-through that PCIe slot, card, to the VM using VT-d and IOMMU. Good luck with that.

It is much easier to setup wired NIC passthru or just setup a bridge for the VMs to use.

[kingslavcho]

It is a USB device (wireless adapter) and the host is not disconnecting it fully.. How can i do that? I don't really know how to use KVM but for my needs it is the most suitable virtualization software. Thank you

[TheFu]

It is a USB device (wireless adapter) and the host is not disconnecting it fully.. How can i do that? I don't really know how to use KVM but for my needs it is the most suitable virtualization software. Thank you

You blacklist the driver on the KVM host. Look in /etc/modprobe.d/ for examples.

The only reasons I know to pass a wifi adapter into a VM is for using it in penetrations or penetration testing. OTOH, wired NIC passthru has lots of good security reasons, like running a router inside a VM.