> From: Chris Wright [chrisw@xxxxxxxxxxxx] > Sent: 21 December 2010 16:15 > To: Prasad Joshi > Cc: kvm@xxxxxxxxxxxxxxx > Subject: Re: Query on IOMMU >> 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 > 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. root@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 root@prasad-kvm:~/VMDisks# echo "8086 1229" > /sys/bus/pci/drivers/pci-stub/new_id root@prasad-kvm:~/VMDisks# echo "0000:01:05.0" > /sys/bus/pci/drivers/pci-stub/unbind root@prasad-kvm:~/VMDisks# echo "0000:01:05.0" > /sys/bus/pci/drivers/pci-stub/bind root@prasad-kvm:~/VMDisks# echo "8086 1229" > /sys/bus/pci/drivers/pci-stub/remove_id root@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 [ 667.410228] e100 0000:01:05.0: PCI INT A disabled [ 700.500278] pci-stub: invalid id string "" [ 707.730636] pci-stub 0000:01:05.0: claimed by stub [ 734.755491] pci-stub 0000:01:05.0: PCI INT A -> GSI 20 (level, low) -> IRQ 20 [ 734.790077] pci-stub 0000:01:05.0: restoring config space at offset 0xf (was 0x38080100, writing 0x3808010b) [ 734.790095] pci-stub 0000:01:05.0: restoring config space at offset 0xc (was 0x0, writing 0xf9ce0000) [ 734.790113] pci-stub 0000:01:05.0: restoring config space at offset 0x6 (was 0x0, writing 0xf9cc0000) [ 734.790123] pci-stub 0000:01:05.0: restoring config space at offset 0x5 (was 0x1, writing 0xac01) [ 734.790132] pci-stub 0000:01:05.0: restoring config space at offset 0x4 (was 0x0, writing 0xf9cff000) [ 734.790142] pci-stub 0000:01:05.0: restoring config space at offset 0x3 (was 0x0, writing 0x4010) [ 734.790153] pci-stub 0000:01:05.0: restoring config space at offset 0x1 (was 0x2900000, writing 0x2900113) [ 735.173647] assign device 0:1:5.0 failed [ 735.173688] pci-stub 0000:01:05.0: PCI INT A disabled [ 768.850519] pci-stub 0000:01:05.0: claimed by stub [ 775.855376] pci-stub 0000:01:05.0: PCI INT A -> GSI 20 (level, low) -> IRQ 20 [ 775.890080] pci-stub 0000:01:05.0: restoring config space at offset 0xf (was 0x38080100, writing 0x3808010b) [ 775.890097] pci-stub 0000:01:05.0: restoring config space at offset 0xc (was 0x0, writing 0xf9ce0000) [ 775.890115] pci-stub 0000:01:05.0: restoring config space at offset 0x6 (was 0x0, writing 0xf9cc0000) [ 775.890126] pci-stub 0000:01:05.0: restoring config space at offset 0x5 (was 0x1, writing 0xac01) [ 775.890135] pci-stub 0000:01:05.0: restoring config space at offset 0x4 (was 0x0, writing 0xf9cff000) [ 775.890144] pci-stub 0000:01:05.0: restoring config space at offset 0x3 (was 0x0, writing 0x4010) [ 775.890155] pci-stub 0000:01:05.0: restoring config space at offset 0x1 (was 0x2900000, writing 0x2900113) [ 776.275188] assign device 0:1:5.0 failed [ 776.275230] pci-stub 0000:01:05.0: PCI INT A disabled 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. > thanks, > -chris -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
