Yes, I have booted my kernel with the intel_iommu=on. (I don't remember how to check that now though ^^)
[ 0.000000] ACPI: DMAR 00000000bf79e0c0 00118 (v01 AMI OEMDMAR 00000001 MSFT 00000097)
[ 0.000000] Intel-IOMMU: enabled
[ 0.039149] dmar: IOMMU 0: reg_base_addr fbffe000 ver 1:0 cap c90780106f0462 ecap f020f6
[ 0.550126] IOMMU 0 0xfbffe000: using Queued invalidation
[ 0.550131] IOMMU: Setting RMRR:
[ 0.550149] IOMMU: Setting identity map for device 0000:00:1a.0 [0xbf7ec000 - 0xbf7fffff]
[ 0.550184] IOMMU: Setting identity map for device 0000:00:1a.1 [0xbf7ec000 - 0xbf7fffff]
[ 0.550211] IOMMU: Setting identity map for device 0000:00:1a.2 [0xbf7ec000 - 0xbf7fffff]
[ 0.550241] IOMMU: Setting identity map for device 0000:00:1a.7 [0xbf7ec000 - 0xbf7fffff]
[ 0.550272] IOMMU: Setting identity map for device 0000:00:1d.0 [0xbf7ec000 - 0xbf7fffff]
[ 0.550302] IOMMU: Setting identity map for device 0000:00:1d.1 [0xbf7ec000 - 0xbf7fffff]
[ 0.550329] IOMMU: Setting identity map for device 0000:00:1d.2 [0xbf7ec000 - 0xbf7fffff]
[ 0.550358] IOMMU: Setting identity map for device 0000:00:1d.7 [0xbf7ec000 - 0xbf7fffff]
[ 0.550375] IOMMU: Setting identity map for device 0000:00:1a.0 [0xec000 - 0xeffff]
[ 0.550387] IOMMU: Setting identity map for device 0000:00:1a.1 [0xec000 - 0xeffff]
[ 0.550399] IOMMU: Setting identity map for device 0000:00:1a.2 [0xec000 - 0xeffff]
[ 0.550410] IOMMU: Setting identity map for device 0000:00:1a.7 [0xec000 - 0xeffff]
[ 0.550421] IOMMU: Setting identity map for device 0000:00:1d.0 [0xec000 - 0xeffff]
[ 0.550433] IOMMU: Setting identity map for device 0000:00:1d.1 [0xec000 - 0xeffff]
[ 0.550444] IOMMU: Setting identity map for device 0000:00:1d.2 [0xec000 - 0xeffff]
[ 0.550458] IOMMU: Setting identity map for device 0000:00:1d.7 [0xec000 - 0xeffff]
[ 0.550471] IOMMU: Prepare 0-16MiB unity mapping for LPC
[ 0.550483] IOMMU: Setting identity map for device 0000:00:1f.0 [0x0 - 0xffffff]