The commit 2ad56efa80db ("powerpc/iommu: Setup a default domain and remove set_platform_dma_ops") refactored the code removing the set_platform_dma_ops(). It missed out the table group release_ownership() call which would have got called otherwise during the guest shutdown via vfio_group_detach_container(). On PPC64, this particular call actually sets up the 32-bit TCE table, and enables the 64-bit DMA bypass etc. Now after guest shutdown, the subsequent host driver (e.g megaraid-sas) probe post unbind from vfio-pci fails like,
megaraid_sas 0031:01:00.0: Warning: IOMMU dma not supported: mask 0x7fffffffffffffff, table unavailable megaraid_sas 0031:01:00.0: Warning: IOMMU dma not supported: mask 0xffffffff, table unavailable megaraid_sas 0031:01:00.0: Failed to set DMA mask megaraid_sas 0031:01:00.0: Failed from megasas_init_fw 6539 The patch brings back the call to table_group release_ownership() call when switching back to PLATFORM domain. Fixes: 2ad56efa80db ("powerpc/iommu: Setup a default domain and remove set_platform_dma_ops") Signed-off-by: Shivaprasad G Bhat <sb...@linux.ibm.com> --- arch/powerpc/kernel/iommu.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c index ebe259bdd462..ac7df43fa7ef 100644 --- a/arch/powerpc/kernel/iommu.c +++ b/arch/powerpc/kernel/iommu.c @@ -1296,9 +1296,19 @@ spapr_tce_platform_iommu_attach_dev(struct iommu_domain *platform_domain, if (!grp) return -ENODEV; - table_group = iommu_group_get_iommudata(grp); - ret = table_group->ops->take_ownership(table_group); - iommu_group_put(grp); + if (platform_domain->type == IOMMU_DOMAIN_PLATFORM) { + ret = 0; + table_group = iommu_group_get_iommudata(grp); + /* + * The domain being set to PLATFORM from earlier + * BLOCKED. The table_group ownership has to be released. + */ + table_group->ops->release_ownership(table_group); + } else if (platform_domain->type == IOMMU_DOMAIN_BLOCKED) { + table_group = iommu_group_get_iommudata(grp); + ret = table_group->ops->take_ownership(table_group); + iommu_group_put(grp); + } return ret; }