Re: [Qemu-discuss] IOMMU in kernel command line, still getting "No IOMMU found. Unable to assign device "(null)"I

[Kevin Wilson]

Hi,
Following your mail I tried using "-device vfio-pci,host=04:02.0" as a
parameter to qemu-system-x86_64 instead of , and I get:
...
qemu-system-x86_64: -device vfio-pci,host=04:02.0: vfio error:
0000:04:02.0: no iommu_group found: No such file or directory

Any ideas what this means ?

Kevin
...

On Thu, Jan 12, 2017 at 4:43 AM, Fam Zheng <address@hidden> wrote:
> On Wed, 01/11 20:04, Kevin Wilson wrote:
>> Hello,
>> I have IOMMU in the kernel command line on a server which supports Virt-d:
>>
>> cat /proc/cmdline | grep -i iommu
>> BOOT_IMAGE=...intel_iommu=on iommu=pt
>>
>> Now when I try to start a KVM VM with qemu-system-x86_64 without any
>> PCI device assignment it starts ok, and I can work with this VM just
>> fine.
>>
>> But when I try to add PCI device assignment to a VF (of a nic) in the
>> qemu command line and launch an image, it failed with this message:
>>
>> qemu-system-x86_64: -device pci-assign,host=05:00.0:  No IOMMU found.
>> Unable to assign device "(null)"
>
> Have you tried "-device vfio-pci"?
>
> Fam