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That's why I'm > pushing back so hard on using phys_addr_t or CPU addresses. > > See the CPU address is only valid temporary because the VF BAR is > only a window into the device memory. I know, generally yes. But there should be no way that a VFIO VF driver in the hypervisor knows what is currently mapped to the VF's BAR. The only way I can make sense of what Xe is doing here is if the VF BAR is a static aperture of the VRAM.. Would be nice to know the details. > What Simona agreed on is exactly what I proposed as well, that you > get a private interface for exactly that use case. A "private" interface to exchange phys_addr_t between at least VFIO/KVM/iommufd - sure no complaint with that. Jason