Re: [Qemu-devel] VFIO and scheduled SR-IOV cards

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Jun 04, 2013 at 05:50:30PM +0200, Benoît Canet wrote:
> 
> Hello,
> 
> More informations on how the hardware works.
> 
> -Each VF will have its own memory and MMR, etc.
> That means the resources are not shared.
> 
> -Each VF will have its own bus number, function number and device number.
> That means request ID is separated for each VF.
> 
> There is also VF save/restore area for the switch.
> 
> A VF regular memory (not MMR) is still accessible after a switch out.
> 
> But when a function VF1 is scheduled a read to a MRR of VF number 0 could return
> the value of the same MMR in VF number 1 because VF number 1 is switched on and
> the PF processor is busy servicing VF number 1.
> 
> This could confuse the guest VF driver so the unmap and block or a same goal
> achieving technique is required.
> 
> I hope these informations makes the area of the problem to solve narrower.
> 
> Best regards
> 
> Benoît Canet

Confused.
You have one VF accessing BAR of another VF?
Why?

-- 
MST