Re: [PATCH] VFIO driver: Non-privileged user level PCI drivers

[Avi Kivity]

On 05/30/2010 03:49 PM, Michael S. Tsirkin wrote:
> On Sun, May 30, 2010 at 03:27:05PM +0300, Avi Kivity wrote:
>    
> > On 05/30/2010 03:19 PM, Michael S. Tsirkin wrote:
> >      
> > > On Fri, May 28, 2010 at 04:07:38PM -0700, Tom Lyon wrote:
> > >
> > >        
> > > > The VFIO "driver" is used to allow privileged AND non-privileged processes to
> > > > implement user-level device drivers for any well-behaved PCI, PCI-X, and PCIe
> > > > devices.
> > > > 	Signed-off-by: Tom Lyon<pugs@xxxxxxxxx>
> > > > ---
> > > > This patch is the evolution of code which was first proposed as a patch to
> > > > uio/uio_pci_generic, then as a more generic uio patch. Now it is taken entirely
> > > > out of the uio framework, and things seem much cleaner. Of course, there is
> > > > a lot of functional overlap with uio, but the previous version just seemed
> > > > like a giant mode switch in the uio code that did not lead to clarity for
> > > > either the new or old code.
> > > >
> > > >          
> > > IMO this was because this driver does two things: programming iommu and
> > > handling interrupts. uio does interrupt handling.
> > > We could have moved iommu / DMA programming to
> > > a separate driver, and have uio work with it.
> > > This would solve limitation of the current driver
> > > that is needs an iommu domain per device.
> > >
> > >        
> > How do we enforce security then?  We need to ensure that unprivileged
> > users can only use the device with an iommu.
> >      
> Force assigning to iommu before we allow any other operation?
>    

That means the driver must be aware of the iommu.

--
error compiling committee.c: too many arguments to function

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