From 3e7b3519b751123ab8ac6894a322456ea2f1138d Mon Sep 17 00:00:00 2001 From: Vasant Hegde Date: Tue, 23 Apr 2024 11:17:25 +0000 Subject: [PATCH] iommu/amd: Enhance def_domain_type to handle untrusted device commit 0f91d0795741c12cee200667648669a91b568735 upstream. Previously, IOMMU core layer was forcing IOMMU_DOMAIN_DMA domain for untrusted device. This always took precedence over driver's def_domain_type(). Commit 59ddce4418da ("iommu: Reorganize iommu_get_default_domain_type() to respect def_domain_type()") changed the behaviour. Current code calls def_domain_type() but if it doesn't return IOMMU_DOMAIN_DMA for untrusted device it throws error. This results in IOMMU group (and potentially IOMMU itself) in undetermined state. This patch adds untrusted check in AMD IOMMU driver code. So that it allows eGPUs behind Thunderbolt work again. Fine tuning amd_iommu_def_domain_type() will be done later. Reported-by: Eric Wagner Link: https://lore.kernel.org/linux-iommu/CAHudX3zLH6CsRmLE-yb+gRjhh-v4bU5_1jW_xCcxOo_oUUZKYg@mail.gmail.com Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3182 Fixes: 59ddce4418da ("iommu: Reorganize iommu_get_default_domain_type() to respect def_domain_type()") Cc: Robin Murphy Cc: Jason Gunthorpe Cc: stable@kernel.org # v6.7+ Signed-off-by: Vasant Hegde Link: https://lore.kernel.org/r/20240423111725.5813-1-vasant.hegde@amd.com Signed-off-by: Joerg Roedel Signed-off-by: Greg Kroah-Hartman --- drivers/iommu/amd/iommu.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c index 4283dd8191f05..f945bf3253ce0 100644 --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -2593,6 +2593,10 @@ static int amd_iommu_def_domain_type(struct device *dev) if (!dev_data) return 0; + /* Always use DMA domain for untrusted device */ + if (dev_is_pci(dev) && to_pci_dev(dev)->untrusted) + return IOMMU_DOMAIN_DMA; + /* * Do not identity map IOMMUv2 capable devices when: * - memory encryption is active, because some of those devices -- 2.47.2