On Tue, Nov 03, 2020 at 03:35:32PM +0100, joro@xxxxxxxxxx wrote: > On Tue, Nov 03, 2020 at 10:06:42AM -0400, Jason Gunthorpe wrote: > > The point is that other places beyond VFIO need this > > Which and why? > > > Sure, but sometimes it is necessary, and in those cases the answer > > can't be "rewrite a SVA driver to use vfio" > > This is getting to abstract. Can you come up with an example where > handling this in VFIO or an endpoint device kernel driver does not work? This whole thread was brought up by IDXD which has a SVA driver and now wants to add a vfio-mdev driver too. SVA devices that want to be plugged into VMs are going to be common - this architecture that a SVA driver cannot cover the kvm case seems problematic. Yes, everything can have a SVA driver and a vfio-mdev, it works just fine, but it is not very clean or simple. Jason
