On Tue, Nov 03, 2020 at 08:14:29PM +0100, joro@xxxxxxxxxx wrote: > On Tue, Nov 03, 2020 at 01:48:51PM -0400, Jason Gunthorpe wrote: > > I think the same PCI driver with a small flag to support the PF or > > VF is not the same as two completely different drivers in different > > subsystems > > There are counter-examples: ixgbe vs. ixgbevf. > > Note that also a single driver can support both, an SVA device and an > mdev device, sharing code for accessing parts of the device like queues > and handling interrupts. Needing a mdev device at all is the larger issue, mdev means the kernel must carry a lot of emulation code depending on how the SVA device is designed. Eg creating queues may require an emulated BAR. Shifting that code to userspace and having a single clean 'SVA' interface from the kernel for the device makes a lot more sense, esepcially from a security perspective. Forcing all vIOMMU stuff to only use VFIO permanently closes this as an option. Jason
