On Fri, Sep 22, 2023 at 09:25:01AM -0300, Jason Gunthorpe wrote: > On Fri, Sep 22, 2023 at 11:02:50AM +0800, Jason Wang wrote: > > On Fri, Sep 22, 2023 at 3:53 AM Jason Gunthorpe <jgg@xxxxxxxxxx> wrote: > > > > > > On Thu, Sep 21, 2023 at 03:34:03PM -0400, Michael S. Tsirkin wrote: > > > > > > > that's easy/practical. If instead VDPA gives the same speed with just > > > > shadow vq then keeping this hack in vfio seems like less of a problem. > > > > Finally if VDPA is faster then maybe you will reconsider using it ;) > > > > > > It is not all about the speed. > > > > > > VDPA presents another large and complex software stack in the > > > hypervisor that can be eliminated by simply using VFIO. > > > > vDPA supports standard virtio devices so how did you define > > complexity? > > As I said, VFIO is already required for other devices in these VMs. So > anything incremental over base-line vfio-pci is complexity to > minimize. > > Everything vdpa does is either redundant or unnecessary compared to > VFIO in these environments. > > Jason Yes but you know. There are all kind of environments. I guess you consider yours the most mainstream and important, and are sure it will always stay like this. But if there's a driver that does what you need then you use that. You really should be explaining what vdpa *does not* do that you need. But anyway, if Alex wants to maintain this it's not too bad, but I would like to see more code move into a library living under the virtio directory. As it is structured now it will make virtio core development harder. -- MST
