> From: kvm-ow...@vger.kernel.org [kvm-ow...@vger.kernel.org] on behalf of > Chris Wright [chr...@sous-sol.org] > Sent: 21 December 2010 17:12 > To: Prasad Joshi > Cc: Chris Wright; kvm@vger.kernel.org > Subject: Re: Query on IOMMU
>>* Prasad Joshi (p.g.jo...@student.reading.ac.uk) wrote: > > From: Chris Wright [chr...@sous-sol.org] > > >> I have enabled IOMMU in the BIOS, but I am not sure why it is still asking > >> to enabled IOMMU in BIOS. Do I need to worry about this? > > > It's unfortunate wording. It's telling you that the GART is missing, > > which is fine because you have an IOMMU. > > >> Besides I don't see the DMAR message similar to the one mentioned on the > >> link > >> http://www.linux-kvm.org/page/How_to_assign_devices_with_VT-d_in_KVM > > > That wiki page is specific to Intel VT-d. You have an AMD box with IOMMU, > > so all looks fine. > > Yes I am using AMD processor and ASUS motherboard. Both of them have the > IOMMU support, atleast it is mentioned on the Xen VT-d > Looks like we need some additional info in the wiki. Care to create an > account and add the info? Sure I would love to. > > Are you interested in using the IOMMU to do direct PCI device assignment > > to a guest? > > Thanks a lot for your reply. Yes I am interested in working on GPU > pass-through to Virtual Machine. But for now I am trying to pass-through a > network card to VM. > > r...@prasad-kvm:~/VMDisks# qemu-system-x86_64 -hda Ubuntu-10.10-amd64.img -m > 1024M -device pci-assign,host=01:05.0 > Failed to assign device "(null)" : Device or resource busy > *** The driver 'pci-stub' is occupying your device 0000:01:05.0. > *** > *** You can try the following commands to free it: > *** > *** $ echo "8086 1229" > /sys/bus/pci/drivers/pci-stub/new_id > *** $ echo "0000:01:05.0" > /sys/bus/pci/drivers/pci-stub/unbind > *** $ echo "0000:01:05.0" > /sys/bus/pci/drivers/pci-stub/bind > *** $ echo "8086 1229" > /sys/bus/pci/drivers/pci-stub/remove_id > *** > Heh, this error is a little odd. It's telling you the pci-stub > driver already has this device. Then it's telling you to unbind it > from pci-stub, and bind it to pci-stub. That error message is meant to > tell you that the real host driver (in your case e100) has the device, > unbind from it, and bind to pci-stub. > qemu-system-x86_64: -device pci-assign,host=01:05.0: Device 'pci-assign' > could not be initialized > r...@prasad-kvm:~/VMDisks# echo "8086 1229" > > /sys/bus/pci/drivers/pci-stub/new_id > r...@prasad-kvm:~/VMDisks# echo "0000:01:05.0" > > /sys/bus/pci/drivers/pci-stub/unbind > r...@prasad-kvm:~/VMDisks# echo "0000:01:05.0" > > /sys/bus/pci/drivers/pci-stub/bind > r...@prasad-kvm:~/VMDisks# echo "8086 1229" > > /sys/bus/pci/drivers/pci-stub/remove_id > r...@prasad-kvm:~/VMDisks# qemu-system-x86_64 -hda Ubuntu-10.10-amd64.img -m > 1024M -device pci-assign,host=01:05.0 > Failed to assign device "(null)" : Device or resource busy > *** The driver 'pci-stub' is occupying your device 0000:01:05.0. > > > [ 605.015852] e100 0000:01:05.0: BAR 0: can't reserve [mem > 0xf9cff000-0xf9cfffff] > [ 605.015855] kvm_vm_ioctl_assign_device: Could not get access to device > regions > This is what is returning -EBUSY and triggering the error message. > The device was previously owned by e100, now it shows it is owned by > pci_stub. Initially the pci_stub.ko module was not loaded, I had to load it > manually so that these assignment commands would work. > And it looks like it is not working yet. Is that correct? Yes this is still not working. > Can you start fresh (make sure the e100 is loaded and functional), and > do the following: Better I rebooted the machine. > verify it's starting with e100 > # ls -l /sys/bus/pci/devices/0000:01:05.0/driver <-- should show e100 > add device id to pci-stub driver > # modprobe pci-stub > # echo "8086 1229" > /sys/bus/pci/drivers/pci-stub/new_id > unbind e100 from device > # echo "0000:01:05.0" > /sys/bus/pci/drivers/e100/unbind > bind pci-stub to device > # echo "0000:01:05.0" > /sys/bus/pci/drivers/pci-stub/bind > remove the id from pci-stub so that subsequent probing will pick up e100 > # echo "8086 1229" > /sys/bus/pci/drivers/pci-stub/remove_id > verify it worked > # ls -l /sys/bus/pci/devices/0000:01:05.0/driver <-- should show pci-stub > Launch your VM...assigned device should show up in VM now. It still fails with the same error, here is the screen shot. r...@prasad-kvm:/sys# uptime 17:29:11 up 2 min, 3 users, load average: 0.93, 0.52, 0.20 r...@prasad-kvm:/sys# ls -l /sys/bus/pci/devices/0000:01:05.0/driver lrwxrwxrwx 1 root root 0 2010-12-21 17:26 /sys/bus/pci/devices/0000:01:05.0/driver -> ../../../../bus/pci/drivers/e100 r...@prasad-kvm:/sys# lsmod | grep pci_stub r...@prasad-kvm:/sys# modprobe pci_stub r...@prasad-kvm:/sys# lsmod | grep pci_stub pci_stub 1590 0 r...@prasad-kvm:/sys# echo "8086 1229" > /sys/bus/pci/drivers/pci-stub/new_id r...@prasad-kvm:/sys# echo "0000:01:05.0" > /sys/bus/pci/drivers/e100/unbind r...@prasad-kvm:/sys# echo "0000:01:05.0" > /sys/bus/pci/drivers/pci-stub/bind r...@prasad-kvm:/sys# echo "8086 1229" > /sys/bus/pci/drivers/pci-stub/remove_id r...@prasad-kvm:/sys# ls -l /sys/bus/pci/devices/0000:01:05.0/driver lrwxrwxrwx 1 root root 0 2010-12-21 17:31 /sys/bus/pci/devices/0000:01:05.0/driver -> ../../../../bus/pci/drivers/pci-stub r...@prasad-kvm:~/VMDisks# modprobe kvm_amd r...@prasad-kvm:~/VMDisks# lsmod | grep -i kvm kvm_amd 56416 0 kvm 348987 1 kvm_amd r...@prasad-kvm:~/VMDisks# qemu-system-x86_64 -hda Ubuntu-10.10-amd64.img -m 1024M -device pci-assign,host=01:05.0 Failed to assign device "(null)" : Device or resource busy *** The driver 'pci-stub' is occupying your device 0000:01:05.0. *** *** You can try the following commands to free it: *** *** $ echo "8086 1229" > /sys/bus/pci/drivers/pci-stub/new_id *** $ echo "0000:01:05.0" > /sys/bus/pci/drivers/pci-stub/unbind *** $ echo "0000:01:05.0" > /sys/bus/pci/drivers/pci-stub/bind *** $ echo "8086 1229" > /sys/bus/pci/drivers/pci-stub/remove_id *** qemu-system-x86_64: -device pci-assign,host=01:05.0: Device 'pci-assign' could not be initialized r...@prasad-kvm:~/VMDisks# echo $? 1 r...@prasad-kvm:~/VMDisks# The VM does not boot. > thanks, > -chris > ---- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
