KVM error with device pass through

Posted by javano on Server Fault See other posts from Server Fault or by javano
Published on 2012-09-19T09:30:16Z Indexed on 2012/09/19 9:40 UTC
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I am running the following command booting a Debian live CD passing a host PCI device to the guest as a test and KVM errors out;

kvm  -m 512 -boot c -net none -hda /media/AA502592502565F3/debian.iso -device pci-assign,host=07:00.0
PCI region 1 at address 0xf7920000 has size 0x80, which is not a multiple of 4K. You might experience some performance hit due to that.
No IOMMU found.  Unable to assign device "(null)"
kvm: -device pci-assign,host=07:00.0: Device 'pci-assign' could not be initialized

lspci | grep 07
07:00.0 Ethernet controller: 3Com Corporation 3c905C-TX/TX-M [Tornado] (rev 74)

I shoved an old spare NIC into my motherboard to test PCI pass through. I have searched the Internet with Goolge and found that errors relating to "No IOMMU found" often mean the PCI device is not supported by KVM.

Does KVM have to support the device being "passed-through"? I though the point was to pass the device through and let the guest worry about it? Ultimately I want to pass-through a PCI random number generator, is this not going to be possible with KVM?

Thank you.

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