path: root/drivers/iommu
diff options
authorJean-Philippe Brucker <>2021-04-22 11:42:19 +0200
committerJoerg Roedel <>2021-05-18 11:18:39 +0200
commitd6177a6556f853785867e2ec6d5b7f4906f0d809 (patch)
tree6b0ecf35dc715124138af2022dfc6f2535f76f61 /drivers/iommu
parentd07f6ca923ea0927a1024dfccafc5b53b61cfecc (diff)
iommu/amd: Clear DMA ops when switching domain
Since commit 08a27c1c3ecf ("iommu: Add support to change default domain of an iommu group") a user can switch a device between IOMMU and direct DMA through sysfs. This doesn't work for AMD IOMMU at the moment because dev->dma_ops is not cleared when switching from a DMA to an identity IOMMU domain. The DMA layer thus attempts to use the dma-iommu ops on an identity domain, causing an oops: # echo 0000:00:05.0 > /sys/sys/bus/pci/drivers/e1000e/unbind # echo identity > /sys/bus/pci/devices/0000:00:05.0/iommu_group/type # echo 0000:00:05.0 > /sys/sys/bus/pci/drivers/e1000e/bind ... BUG: kernel NULL pointer dereference, address: 0000000000000028 ... Call Trace: iommu_dma_alloc e1000e_setup_tx_resources e1000e_open Since iommu_change_dev_def_domain() calls probe_finalize() again, clear the dma_ops there like Vt-d does. Fixes: 08a27c1c3ecf ("iommu: Add support to change default domain of an iommu group") Signed-off-by: Jean-Philippe Brucker <> Link: Signed-off-by: Joerg Roedel <>
Diffstat (limited to 'drivers/iommu')
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 80e8e1916dd1..67da96d5b3c2 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -1714,6 +1714,8 @@ static void amd_iommu_probe_finalize(struct device *dev)
domain = iommu_get_domain_for_dev(dev);
if (domain->type == IOMMU_DOMAIN_DMA)
iommu_setup_dma_ops(dev, IOVA_START_PFN << PAGE_SHIFT, 0);
+ else
+ set_dma_ops(dev, NULL);
static void amd_iommu_release_device(struct device *dev)