From: Jon Derrick jonathan.derrick@intel.com

commit bba9cc2cf82840bd3c9b3f4f7edac2dc8329ci241 upstream

By removing the real DMA indirection in find_domain(), we can allow sub-devices of a real DMA device to have their own valid device_domain_info. The dmar lookup and context entry removal paths have been fixed to account for sub-devices.

Fixes: 2b0140c69637 ("iommu/vt-d: Use pci_real_dma_dev() for mapping") Signed-off-by: Jon Derrick jonathan.derrick@intel.com Acked-by: Lu Baolu baolu.lu@linux.intel.com Link: https://lore.kernel.org/r/20200527165617.297470-4-jonathan.derrick@intel.com Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=207575 Signed-off-by: Joerg Roedel jroedel@suse.de Signed-off-by: Sushma Kalakota sushmax.kalakota@intel.com --- Hi,

Please apply this patch to 5.7 (and 5.6 if it's still being maintained). This patch is part 3 of a 3-patch series, of which [1][2] have been applied to 5.7. This patch is necessary to prevent kernel panics in specific configurations.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... [2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

drivers/iommu/intel-iommu.c | 3 --- 1 file changed, 3 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 11ed871dd255..fde7aba49b74 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -2518,9 +2518,6 @@ struct dmar_domain *find_domain(struct device *dev) if (unlikely(attach_deferred(dev) || iommu_dummy(dev))) return NULL;

- if (dev_is_pci(dev)) - dev = &pci_real_dma_dev(to_pci_dev(dev))->dev; - /* No lock here, assumes no domain exit in normal case */ info = dev->archdata.iommu; if (likely(info))