Re: [Qemu-devel] [PATCH v2 0/6] Extend vhost-user to support VFIO based accelerators

[Michael S. Tsirkin]

On Wed, Mar 28, 2018 at 08:24:07PM +0800, Tiwei Bie wrote:
> > > Update notes
> > > ============
> > > 
> > > IOMMU feature bit check is removed in this version, because:
> > > 
> > > The IOMMU feature is negotiable, when an accelerator is used and
> > > it doesn't support virtual IOMMU, its driver just won't provide
> > > this feature bit when vhost library querying its features. And if
> > > it supports the virtual IOMMU, its driver can provide this feature
> > > bit. It's not reasonable to add this limitation in this patch set.
> > 
> > Fair enough. Still:
> > Can hardware on intel platforms actually support IOTLB requests?
> > Don't you need to add support for vIOMMU shadowing instead?
> > 
> 
> For the hardware I have, I guess they can't for now.

So VFIO in QEMU has support for vIOMMU shadowing.
Can you use that somehow?

Ability to run dpdk within guest seems important.

-- 
MST