On Mon, 3 Apr 2023 09:25:06 +0000 "Liu, Yi L" <yi.l.liu@xxxxxxxxx> wrote: > > From: Liu, Yi L <yi.l.liu@xxxxxxxxx> > > Sent: Saturday, April 1, 2023 10:44 PM > > > @@ -791,7 +813,21 @@ static int vfio_pci_fill_devs(struct pci_dev *pdev, void *data) > > if (!iommu_group) > > return -EPERM; /* Cannot reset non-isolated devices */ > > Hi Alex, > > Is disabling iommu a sane way to test vfio noiommu mode? Yes > I added intel_iommu=off to disable intel iommu and bind a device to vfio-pci. > I can see the /dev/vfio/noiommu-0 and /dev/vfio/devices/noiommu-vfio0. Bind > iommufd==-1 can succeed, but failed to get hot reset info due to the above > group check. Reason is that this happens to have some affected devices, and > these devices have no valid iommu_group (because they are not bound to vfio-pci > hence nobody allocates noiommu group for them). So when hot reset info loops > such devices, it failed with -EPERM. Is this expected? Hmm, I didn't recall that we put in such a limitation, but given the minimally intrusive approach to no-iommu and the fact that we never defined an invalid group ID to return to the user, it makes sense that we just blocked the ioctl for no-iommu use. I guess we can do the same for no-iommu cdev. BTW, what does this series apply on? I'm assuming[1], but I don't see a branch from Jason yet. Thanks, Alex [1]https://lore.kernel.org/all/20230327093351.44505-1-yi.l.liu@xxxxxxxxx/
