From a82efb8747d1b8a7c0a377dc79c2aac204eae788 Mon Sep 17 00:00:00 2001 From: Shameer Kolothum Date: Tue, 17 Mar 2026 11:16:02 +0000 Subject: iommu: Add device ATS supported capability PCIe ATS may be disabled by platform firmware, root complex limitations, or kernel policy even when a device advertises the ATS capability in its PCI configuration space. Add a new IOMMU_CAP_PCI_ATS_SUPPORTED capability to allow IOMMU drivers to report the effective ATS decision for a device. When this capability is true for a device, ATS may be enabled for that device, but it does not imply that ATS is currently enabled. A subsequent patch will extend iommufd to expose the effective ATS status to userspace. Suggested-by: Jason Gunthorpe Reviewed-by: Jason Gunthorpe Signed-off-by: Shameer Kolothum Signed-off-by: Joerg Roedel --- include/linux/iommu.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include') diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 7ca648c01336..a904821ed169 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -272,6 +272,8 @@ enum iommu_cap { */ IOMMU_CAP_DEFERRED_FLUSH, IOMMU_CAP_DIRTY_TRACKING, /* IOMMU supports dirty tracking */ + /* ATS is supported and may be enabled for this device */ + IOMMU_CAP_PCI_ATS_SUPPORTED, }; /* These are the possible reserved region types */ -- cgit v1.2.3