[dpdk-dev] Query : Does Binding with vfio-pci is supported inside qemu-kvm guest/vm instance.?

[Bruce Richardson]

On Tue, Mar 12, 2019 at 05:54:39PM +0800, Jason Wang wrote:
> 
> On 2019/3/12 下午5:42, Thanneeru Srinivasulu wrote:
> > Thanks Bruce..
> > 
> > On Tue, Mar 12, 2019 at 3:08 PM Bruce Richardson
> > <bruce.richardson at intel.com> wrote:
> > > On Tue, Mar 12, 2019 at 10:57:55AM +0530, Thanneeru Srinivasulu wrote:
> > > > Hi Everyone.
> > > > 
> > > > I did attached pice  to Guest VM using vfio-pci with qemu command, and then
> > > > tried binding the pcie bdf with vfio-pci, observing binding failure with
> > > > vfio-pci.
> > > > 
> > > > Where as when tryied with igb_uio, everything works fine.
> > > > 
> > > > Does Binding with vfio-pci is supported inside VM/guest?
> > > > 
> > > vfio support requires the presence of an IOMMU, and you generally don't
> > > have an IOMMU available in a VM.
> > > 
> > > /Bruce
> 
> 
> Actually, Qemu support vIOMMU + VFIO in guest[1], all you need is to add a
> intel IOMMU and enabling caching mode.
> 
> Thanks
> 
> 
> [1]
> 
> https://www.lfasiallc.com/wp-content/uploads/2017/11/Device-Assignment-with-Nested-Guests-and-DPDK_Peter-Xu.pdf
> 
Thanks for the info.

/Bruce