Re: [Qemu-devel] [PATCH v1 0/3] intel_iommu: support scalable mode

[Yi Sun <yi.y.sun@linux.intel.com>]

On 19-03-05 13:36:12, Peter Xu wrote:
> On Tue, Mar 05, 2019 at 01:15:53PM +0800, Yi Sun wrote:
> 
> [...]
> 
> > > > w/o passthr
> > > >     -device intel-iommu \
> > > >     -netdev tap,id=net1,vhost=off|on \
> > > >     -device virtio-net-pci,netdev=net1 \
> > > 
> > > Virtio devices require explicit enabling of DMAR:
> > > 
> > > https://wiki.qemu.org/Features/VT-d#With_Virtio_Devices
> > > 
> > > Otherwise it could probably still be bypassing the translation unit.
> > > 
> > > If you retest any, please feel free to skip some of the tests like
> > > kernel build.  Quick netperf should work, which can save you time.
> > > 
> > Thanks! Just made a quick test. It works well. Please check below
> > command.
> > 
> >     -device intel-iommu,intremap=on,device-iotlb=on \
> >     -netdev tap,id=net1,vhost=off \
> >     -device ioh3420,id=pcie.1,chassis=1 \
> >     -device
> > virtio-net-pci,bus=pcie.1,netdev=net1,disable-legacy=on,disable-modern=off,iommu_platform=on,ats=on
> > \
> 
> Please also consider to try vhost=on with/without iommu=pt.
> 
Just tested vhost=on/off with/without iommu=pt for legacy mode. All pass.

> Regards,
> 
> -- 
> Peter Xu