On 2023/4/28 15:00, Tian, Kevin wrote:
From: Liu, Yi L <yi.l.liu@xxxxxxxxx>
Sent: Friday, April 28, 2023 2:21 PM
On 2023/4/28 02:32, Alex Williamson wrote:
On Thu, 27 Apr 2023 06:59:17 +0000
"Liu, Yi L" <yi.l.liu@xxxxxxxxx> wrote:
From: Tian, Kevin <kevin.tian@xxxxxxxxx>
Sent: Thursday, April 27, 2023 2:39 PM
From: Liu, Yi L <yi.l.liu@xxxxxxxxx>
Sent: Wednesday, April 26, 2023 10:54 PM
@@ -121,7 +128,8 @@ static void vfio_emulated_unmap(void *data,
unsigned long iova,
{
struct vfio_device *vdev = data;
- if (vdev->ops->dma_unmap)
+ /* noiommu devices cannot do map/unmap */
+ if (vdev->noiommu && vdev->ops->dma_unmap)
vdev->ops->dma_unmap(vdev, iova, length);
Is it necessary? All mdev devices implementing @dma_unmap won't
set noiommu flag.
Hmmm. Yes, and all the devices set noiommu is not implementing
@dma_unmap
as far as I see. Maybe this noiommu check can be removed.
Not to mention that the polarity of the noiommu test is backwards here!
This also seems to be the only performance path where noiommu is tested
and therefore I believe the only actual justification of the previous
patch.
but this patch needs to use vfio_iommufd_emulated_bind() and
vfio_iommufd_emulated_unbind() for the noiommu devices when binding
to iommufd. So needs to check noiommu in the vfio_iommufd_bind()
and vfio_iommu_unbind() as well.
You can continue to use vfio_device_is_noiommu() in this patch. It's not
big deal to drop it from this series and then add back in cdev series.
yes.:-) patch 01 of this series was added more per the cdev series reviews.
--
Regards,
Yi Liu
