How to assign devices with VT-d

http://www.linux-kvm.org/page/How_to_assign_devices_with_VT-d_in_KVM

To support VT-d, both CPU & Motherboard (and BIOS too) need have capability, IE: H67 + i7 2600 still don't support VT-d; but i7 2600 + Q67 should VT-d enabled; Mobile platform like GM45 also VT-d capable.

On a GM45 platform (CPU P8400):

$ dmesg | grep -i iommu
[    0.019293] IOMMU 0: reg_base_addr feb03000 ver 1:0 cap c9008020e30260 ecap 1000
[    0.019569] IOMMU 1: reg_base_addr feb01000 ver 1:0 cap c0000020630260 ecap 1000
[    0.020008] IOMMU 2: reg_base_addr feb00000 ver 1:0 cap c0000020630270 ecap 1000
[    0.020284] IOMMU 3: reg_base_addr feb02000 ver 1:0 cap c9008020630260 ecap 1000
[    0.214461] DMAR: Disabling IOMMU for graphics on this chipset
[    0.409195] IOMMU 2 0xfeb00000: using Register based invalidation
[    0.409306] IOMMU 0 0xfeb03000: using Register based invalidation
[    0.409413] IOMMU 3 0xfeb02000: using Register based invalidation
[    0.409523] IOMMU: Setting RMRR:
[    0.409641] IOMMU: Setting identity map for device 0000:00:1d.0 [0xfc226c00 - 0xfc227400]
[    0.409844] IOMMU: Setting identity map for device 0000:00:1d.1 [0xfc226c00 - 0xfc227400]
[    0.410057] IOMMU: Setting identity map for device 0000:00:1d.2 [0xfc226c00 - 0xfc227400]
[    0.410253] IOMMU: Setting identity map for device 0000:00:1d.7 [0xfc226c00 - 0xfc227400]
[    0.410449] IOMMU: Setting identity map for device 0000:00:1a.0 [0xfc226c00 - 0xfc227400]
[    0.410650] IOMMU: Setting identity map for device 0000:00:1a.1 [0xfc226c00 - 0xfc227400]
[    0.410848] IOMMU: Setting identity map for device 0000:00:1a.2 [0xfc226c00 - 0xfc227400]
[    0.411055] IOMMU: Setting identity map for device 0000:00:1a.7 [0xfc226c00 - 0xfc227400]
[    0.411242] IOMMU: Prepare 0-16MiB unity mapping for LPC
[    0.411366] IOMMU: Setting identity map for device 0000:00:1f.0 [0x0 - 0x1000000]
$

While on H67 (CPU 2600) platform:
$ dmesg | grep -i iommu
$

Looks like only workstation or mobile platform is VT-d enabled; while desktop platform usually don't have VT-d support. Also check the following link for VT-d enabled system: