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Having a UAPI on the PF to give DMABUFs for arbitary VRAM seems security exciting. I'd probably want to insist the calling process prove to the PF driver that it also has access to the VF. Having the VF create the DMABUF is one way to do that, but I imagine there are other options. But sure, if you can solve, or ignore, the security proof it makes a lot more sense. Jason