On Mon, Sep 21, 2026 at 02:08:47PM +0100, Matt Evans wrote: > Not quite; the priv->revoked flag tracks temporary periods of > inaccessibility. An example is VFIO resetting a function; the BAR > mappings as seen by the CPU and DMABUFs made from the BARs are all made > inaccessible before the reset, and made accessible again after the > reset.
>From the importer perspective this is a permanent revoke. The right way to view this flow is VFIO permanently revokes the DMABUF FD. Then instead of forcing a new FD to be obtained it replaces the existing FD with a working one. >From an importer perspective it sees the revoke happen and then that's it, the dmabuf never does anything further. The importer has to unmap and start from scratch, get a FD and map it. That VFIO re-used the FD to make a new live export isn't visible to the importer at all. I think that is where this "temporary revoke" language gets confusing. Call it "VFIO reuses the FD to create a new live mapping" is clearer than calling it "temporarily revoke" which sounds too much like move. Jason
