On device shutdown, make vfio_pci_core_close_device() call vfio_pci_dma_buf_cleanup() before the function is disabled via vfio_pci_core_disable(). This ensures that any access to DMABUFs is revoked (and importers act on move_notify()) before the function's BARs become inaccessible.
This fixes an issue where, if the function is disabled first, a tiny window exists in which the function's MSE is cleared and yet BARs could still be accessed via the DMABUF. Worse, the resources would also be free/up for grabs by a different driver.
Fixes: 5d74781ebc86c ("vfio/pci: Add dma-buf export support for MMIO regions") Signed-off-by: Matt Evans mattev@meta.com --- drivers/vfio/pci/vfio_pci_core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c index 3a11e6f450f7..8d0e3605fbc7 100644 --- a/drivers/vfio/pci/vfio_pci_core.c +++ b/drivers/vfio/pci/vfio_pci_core.c @@ -726,10 +726,10 @@ void vfio_pci_core_close_device(struct vfio_device *core_vdev) #if IS_ENABLED(CONFIG_EEH) eeh_dev_release(vdev->pdev); #endif - vfio_pci_core_disable(vdev); - vfio_pci_dma_buf_cleanup(vdev);
+ vfio_pci_core_disable(vdev); + mutex_lock(&vdev->igate); vfio_pci_eventfd_replace_locked(vdev, &vdev->err_trigger, NULL); vfio_pci_eventfd_replace_locked(vdev, &vdev->req_trigger, NULL);