> From: Matt Evans <[email protected]> > Sent: Thursday, July 16, 2026 1:48 AM > > Previously, vfio_pci_zap_bars() (and the wrapper > vfio_pci_zap_and_down_write_memory_lock()) calls were paired with > calls to vfio_pci_dma_buf_move(). > > This commit replaces them with a unified new function, > vfio_pci_revoke_bars() containing both the vfio_pci_dma_buf_move() and > the unmap_mapping_range(), making it harder for callers to omit one. > It adds a wrapper, vfio_pci_lock_revoke_bars(), which takes the write > memory_lock before zapping, and adds a new vfio_pci_unrevoke_bars() > for the re-enable path. > > As of "vfio/pci: Convert BAR mmap() to use a DMABUF", the zap via > unmap_mapping_range() is no longer performed for vfio-pci since the > DMABUFs used for BAR mappings already zap PTEs when the > vfio_pci_dma_buf_move() occurs. > > However, it must be assumed that VFIO drivers which override the .mmap > op could create mappings _not_ backed by DMABUFs. So, the zap is > still performed on revoke if .mmap is overridden, using a new > zap_bars_on_revoke flag. A driver can explicitly opt out; the flag is > cleared by the hisi_acc_vfio_pci driver, since its .mmap just wraps > vfio_pci_core_mmap() and so still uses DMABUFs. > > Signed-off-by: Matt Evans <[email protected]>
Reviewed-by: Kevin Tian <[email protected]>
