From: Vasant Hegde <vasant.hegde@amd.com>
To: <iommu@lists.linux.dev>, <joro@8bytes.org>
Cc: <suravee.suthikulpanit@amd.com>, <alexander.deucher@amd.com>,
Vasant Hegde <vasant.hegde@amd.com>,
Eric Wagner <ewagner12@gmail.com>,
Robin Murphy <robin.murphy@arm.com>,
Jason Gunthorpe <jgg@ziepe.ca>, <stable@kernel.org>
Subject: [PATCH] iommu/amd: Enhance def_domain_type to handle untrusted device
Date: Fri, 19 Apr 2024 11:47:15 +0000 [thread overview]
Message-ID: <20240419114715.6028-1-vasant.hegde@amd.com> (raw)
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
sstate.
This patch adds untrusted check in AMD IOMMU driver code. So that it
lets eGPUs behind Thunderbolt work again.
Fine tuning amd_iommu_def_domain_type() will be done later.
Reported-by: Eric Wagner <ewagner12@gmail.com>
Link: https://lore.kernel.org/linux-iommu/CAHudX3zLH6CsRmLE-yb+gRjhh-v4bU5_1jW_xCcxOo_oUUZKYg@mail.gmail.com
Fixes: 59ddce4418da ("iommu: Reorganize iommu_get_default_domain_type() to respect def_domain_type()")
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: stable@kernel.org # v6.7+
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
---
@Eric,
Can you please test this patch?
-Vasant
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 e692217fcb28..e405714640b0 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -2754,6 +2754,10 @@ static int amd_iommu_def_domain_type(struct device *dev)
if (!dev_data)
return 0;
+ /* Always use DMA domain for untrusted device */
+ if (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
--
2.31.1
next reply other threads:[~2024-04-19 11:47 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-19 11:47 Vasant Hegde [this message]
2024-04-19 12:12 ` [PATCH] iommu/amd: Enhance def_domain_type to handle untrusted device Jason Gunthorpe
2024-04-19 15:24 ` Deucher, Alexander
2024-04-23 10:11 ` Vasant Hegde
2024-04-19 18:14 ` Eric Wagner
2024-04-21 1:45 ` Baolu Lu
2024-04-23 10:10 ` Vasant Hegde
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