linux-kernel - [PATCH RFCv1 2/3] PCI: Allow ATS to be always on for non-CXL NVIDIA GPUs

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <61388f3f7d660994fa03e77bd37aa84b6c5fa3b8.1768624181.git.nicolinc@nvidia.com>
Date: Fri, 16 Jan 2026 20:56:41 -0800
From: Nicolin Chen <nicolinc@...dia.com>
To: <jgg@...dia.com>, <will@...nel.org>, <robin.murphy@....com>,
	<bhelgaas@...gle.com>
CC: <joro@...tes.org>, <praan@...gle.com>, <baolu.lu@...ux.intel.com>,
	<kevin.tian@...el.com>, <miko.lenczewski@....com>,
	<linux-arm-kernel@...ts.infradead.org>, <iommu@...ts.linux.dev>,
	<linux-kernel@...r.kernel.org>, <linux-pci@...r.kernel.org>
Subject: [PATCH RFCv1 2/3] PCI: Allow ATS to be always on for non-CXL NVIDIA GPUs

Some non-CXL NVIDIA GPU devices support non-PASID ATS function when their
RIDs are IOMMU bypassed. This is slightly different than the default ATS
policy which would only enable ATS on demand: when a non-zero PASID line
is enabled in SVA use cases.

Introduce a pci_dev_specific_ats_always_on() quirk function to support a
list of IDs for these device. Then, include it pci_ats_always_on().

Suggested-by: Jason Gunthorpe <jgg@...dia.com>
Signed-off-by: Nicolin Chen <nicolinc@...dia.com>
---
 drivers/pci/pci.h    |  9 +++++++++
 drivers/pci/ats.c    |  3 ++-
 drivers/pci/quirks.c | 23 +++++++++++++++++++++++
 3 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 0e67014aa001..1391df064983 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -1032,6 +1032,15 @@ static inline int pci_dev_specific_reset(struct pci_dev *dev, bool probe)
 }
 #endif
 
+#if defined(CONFIG_PCI_QUIRKS) && defined(CONFIG_PCI_ATS)
+bool pci_dev_specific_ats_always_on(struct pci_dev *dev);
+#else
+static inline bool pci_dev_specific_ats_always_on(struct pci_dev *dev)
+{
+	return false;
+}
+#endif
+
 #if defined(CONFIG_PCI_QUIRKS) && defined(CONFIG_ARM64)
 int acpi_get_rc_resources(struct device *dev, const char *hid, u16 segment,
 			  struct resource *res);
diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
index 1795131f0697..6db45ae2cc8e 100644
--- a/drivers/pci/ats.c
+++ b/drivers/pci/ats.c
@@ -245,7 +245,8 @@ bool pci_ats_always_on(struct pci_dev *pdev)
 	if (pdev->is_virtfn)
 		pdev = pci_physfn(pdev);
 
-	return pci_cxl_ats_always_on(pdev);
+	return pci_cxl_ats_always_on(pdev) ||
+	       pci_dev_specific_ats_always_on(pdev);
 }
 EXPORT_SYMBOL_GPL(pci_ats_always_on);
 
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index b9c252aa6fe0..afc1d2adb13a 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -5654,6 +5654,29 @@ DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x1457, quirk_intel_e2000_no_ats);
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x1459, quirk_intel_e2000_no_ats);
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x145a, quirk_intel_e2000_no_ats);
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x145c, quirk_intel_e2000_no_ats);
+
+static const struct pci_dev_ats_always_on {
+	u16 vendor;
+	u16 device;
+} pci_dev_ats_always_on[] = {
+	{ PCI_VENDOR_ID_NVIDIA, 0x2e12, },
+	{ PCI_VENDOR_ID_NVIDIA, 0x2e2a, },
+	{ PCI_VENDOR_ID_NVIDIA, 0x2e2b, },
+	{ 0 }
+};
+
+/* Some non-CXL devices support ATS on RID when it is IOMMU-bypassed */
+bool pci_dev_specific_ats_always_on(struct pci_dev *pdev)
+{
+	const struct pci_dev_ats_always_on *i;
+
+	for (i = pci_dev_ats_always_on; i->vendor; i++) {
+		if (i->vendor == pdev->vendor && i->device == pdev->device)
+			return true;
+	}
+
+	return false;
+}
 #endif /* CONFIG_PCI_ATS */
 
 /* Freescale PCIe doesn't support MSI in RC mode */
-- 
2.43.0