From: Pranjal Shrivastava <praan@google•com>
To: iommu@lists•linux.dev, linux-pci@vger•kernel.org,
linux-arm-kernel@lists•infradead.org,
linux-kernel@vger•kernel.org
Cc: Joerg Roedel <joro@8bytes•org>, Will Deacon <will@kernel•org>,
Bjorn Helgaas <bhelgaas@google•com>,
David Woodhouse <dwmw2@infradead•org>,
Lu Baolu <baolu.lu@linux•intel.com>,
Robin Murphy <robin.murphy@arm•com>,
Suravee Suthikulpanit <suravee.suthikulpanit@amd•com>,
Jason Gunthorpe <jgg@ziepe•ca>,
Nicolin Chen <nicolinc@nvidia•com>,
David Matlack <dmatlack@google•com>,
Samiullah Khawaja <skhawaja@google•com>,
Daniel Mentz <danielmentz@google•com>,
Pasha Tatashin <pasha.tatashin@soleen•com>,
Mostafa Saleh <smostafa@google•com>,
Pranjal Shrivastava <praan@google•com>
Subject: [PATCH v6 5/6] iommu/vt-d: Fail probe on ATS configuration failure
Date: Fri, 29 May 2026 11:12:07 +0000 [thread overview]
Message-ID: <20260529111208.387412-6-praan@google.com> (raw)
In-Reply-To: <20260529111208.387412-1-praan@google.com>
Update the Intel VT-d driver to handle ATS configuration and enablement
more strictly. Specifically, update the device probe to fail if
pci_prepare_ats() returns an error. This ensures that any ATS-capable
master reaching the attach phase is guaranteed to have a valid config.
Additionally, update iommu_enable_pci_ats() to WARN() if pci_enable_ats
fails. Since earlier checks in the probe phase preclude config-related
failures, any failure during hardware enablement is considered a kernel
bug.
Signed-off-by: Pranjal Shrivastava <praan@google•com>
---
drivers/iommu/intel/iommu.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 4d0e65bc131d..22308e4911e1 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -873,8 +873,14 @@ static void iommu_enable_pci_ats(struct device_domain_info *info)
if (!pci_ats_page_aligned(pdev))
return;
- if (!pci_enable_ats(pdev, VTD_PAGE_SHIFT))
- info->ats_enabled = 1;
+ /*
+ * pci_enable_ats() should not fail here because earlier checks
+ * have already verified support and configuration.
+ */
+ if (WARN_ON(pci_enable_ats(pdev, VTD_PAGE_SHIFT)))
+ return;
+
+ info->ats_enabled = 1;
}
static void iommu_disable_pci_ats(struct device_domain_info *info)
@@ -3288,7 +3294,10 @@ static struct iommu_device *intel_iommu_probe_device(struct device *dev)
dev_iommu_priv_set(dev, info);
if (pdev && pci_ats_supported(pdev)) {
- pci_prepare_ats(pdev, VTD_PAGE_SHIFT);
+ ret = pci_prepare_ats(pdev, VTD_PAGE_SHIFT);
+ if (ret)
+ goto free;
+
ret = device_rbtree_insert(iommu, info);
if (ret)
goto free;
--
2.54.0.823.g6e5bcc1fc9-goog
next prev parent reply other threads:[~2026-05-29 11:12 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-29 11:12 [PATCH v6 0/6] iommu: Standardize ATS robustness and state tracking Pranjal Shrivastava
2026-05-29 11:12 ` [PATCH v6 1/6] PCI/ATS: Ensure pci_ats_supported() is PF-aware for VFs Pranjal Shrivastava
2026-05-29 11:12 ` [PATCH v6 2/6] PCI/ATS: Validate STU for VFs in pci_prepare_ats() Pranjal Shrivastava
2026-05-29 11:12 ` [PATCH v6 3/6] PCI/ATS: Mandate checking pci_ats_supported() before pci_prepare_ats() Pranjal Shrivastava
2026-05-29 21:56 ` Nicolin Chen
2026-05-31 17:06 ` Pranjal Shrivastava
2026-05-29 11:12 ` [PATCH v6 4/6] iommu/arm-smmu-v3: Standardize ATS enablement failure reporting Pranjal Shrivastava
2026-05-29 21:51 ` Nicolin Chen
2026-05-31 17:13 ` Pranjal Shrivastava
2026-05-29 11:12 ` Pranjal Shrivastava [this message]
2026-05-29 11:12 ` [PATCH v6 6/6] iommu/amd: Fail probe on ATS configuration failure Pranjal Shrivastava
2026-06-01 6:00 ` Ankit Soni
2026-06-01 6:20 ` Pranjal Shrivastava
2026-06-01 8:17 ` Ankit Soni
2026-06-01 10:35 ` Pranjal Shrivastava
2026-06-01 9:28 ` Vasant Hegde
2026-06-01 10:41 ` Pranjal Shrivastava
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