On 12-Mar-19 10:20 AM, Bruce Richardson wrote:
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.richard...@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
One more thing: even without vIOMMU, VFIO has no-IOMMU mode which can be
enabled (for a recent-enough kernel). This will make VFIO work even in
cases where the guest doesn't have IOMMU emulation. See? There's no
reason to use igb_uio, ever! :D
--
Thanks,
Anatoly
