Comment # 6 on bug 109649 from Jan Vesely

I managed to get IOMMU working by passing "amd_iommu=pt
ivrs_ioapic[32]=00:14.0" on the kernel commandline.
Now it's back to square one.
all clover kernels hang the GPU unless I limit VM size to 'vm_size =
min(vm_size, 1ULL << 40);'
otherwise the machine works (including 3d graphics and suspend/resume).