On 31-Jan-18 9:51 PM, Ravi Kerur wrote:
Hi Anatoly,
Thanks. I am following wiki link below which uses vIOMMU with DPDK as a
use-case and instantiate VM as specified with Q35 chipset in Qemu.
https://wiki.qemu.org/Features/VT-d
Qemu-version is 2.11
Host kernel 4.9
Guest kernel 4.4
I can only guess that guest kernel needs an upgrade in my setup to work
correctly, if versions on my setup rings a bell on not having support
kindly let me know.
When 'modprobe vfio enable_unsafe_noiommu_node=Y' is executed on guest I
get following error
...
vfio: unknown parameter 'enable_unsafe_noiommu_node' ignored
...
in guest.
Thanks.
AFAIK kernel 4.4 should have noiommu mode - it was introduced in 3.1x
days. However, in order for that to work, kernel also has to be built
with this mode enabled. My guess is, whoever is the supplier of your
kernel, did not do that. You should double-check the kernel
configuration of your distribution.
However, if you have vIOMMU in QEMU, you shouldn't need noiommu mode -
"regular" vfio should work fine. noiommu mode should only be needed if
you know you don't have IOMMU enabled in your kernel, and even if you
can't enable it, you can still use igb_uio.
--
Thanks,
Anatoly
