On Fri, 7 Oct 2022 11:04:38 -0300 Jason Gunthorpe <jgg@xxxxxxxxxx> wrote: > Testing has shown that virtnodedevd will leave the group FD open for long > periods, even after all the cdevs have been destroyed. This blocks > destruction of the VFIO device and is undesirable. > > That approach was selected to accomodate SPAPR which has an broken > lifecyle model for the iommu_group. However, we can accomodate SPAPR by > realizing that it doesn't use the iommu core at all, so rules about > iommu_group lifetime do not apply to it. > > Giving the KVM code its own kref on the iommu_group allows the VFIO core > code to release its iommu_group reference earlier and we can remove the > sleep that only existed for SPAPR. > > v2: > - Use vfio_file_is_group() istead of open coding > - Do not delete vfio_group_detach_container() from > vfio_group_fops_release() > v1: https://lore.kernel.org/r/0-v1-90bf0950c42c+39-vfio_group_disassociate_jgg@xxxxxxxxxx > > Jason Gunthorpe (3): > vfio: Add vfio_file_is_group() > vfio: Hold a reference to the iommu_group in kvm for SPAPR > vfio: Make the group FD disassociate from the iommu_group > > drivers/vfio/pci/vfio_pci_core.c | 2 +- > drivers/vfio/vfio.h | 1 - > drivers/vfio/vfio_main.c | 85 +++++++++++++++++++++++--------- > include/linux/vfio.h | 1 + > virt/kvm/vfio.c | 45 ++++++++++++----- > 5 files changed, 95 insertions(+), 39 deletions(-) Applied to vfio next branch for v6.1, along with my trivial follow-up. Thanks for the group effort on this one! Alex
