Arch Linux

boogerlad

Member

Registered: 2013-04-20

Posts: 48

What determines if a module is loaded by default?

Hi, I've been trying to get kvm and qemu working together. So far it's been great. I read the wiki regarding the kvm and it told me that udev should automatically load the necessary modules. So I did a check

# lsmod | grep kvm
kvm_intel             155648  0
kvm                   438272  1 kvm_intel
# lsmod | grep virtio
# modprobe virtio
# lsmod | grep virtio
virtio                 16384  0

I'm running 4.1.10-3-ck haswell. Why are the necessary kvm modules automatically loaded, but virtio is not? I checked the default config with

cat /proc/config.gz | gunzip > running.config

and both kvm and it seems both virtio and kvm are listed as [m]. Here's the config incase I'm an idiot when it comes to interpretation. http://pastebin.com/4SrPr4NL

It's not a huge hassle to have to modprobe is manually each time since I'm going to be running qemu with a script, but I'm just curious.

Thank you for your time.

olive

Member

From: Belgium

Registered: 2008-06-22

Posts: 1,490

Re: What determines if a module is loaded by default?

I cannot answer for qemu bu tthe  virtio module is automatically loaded in VirtualBox. I think that the module itself claim the hardware they support and udev see if it match some present hardware. Hardware are supposed to identify themself. For more detail see https://wiki.archlinux.org/index.php/Modalias. For some reason something don't work in your case.