This sets IOMMU_GROUP_CAP_ISOLATE_MSIX to a group if IRQ remapping is enabled. For Intel, this checks disable_sourceid_checking in addition; AMD ignores the "nosid" kernel parameters. Here is some background on how the isolation works: On Intel VT-d [1], there is an Interrupt Remapping Table, one entry per interrupt, has a source-id (i.e. BDFN) of allowed device. On AMD IOMMU [2], there is a Device Table, each entry is indexed by DevideID which is BDFN. [1] 9.10 Interrupt Remapping Table Entry (IRTE) for Remapped Interrupts https://www.intel.com/content/dam/www/public/us/en/documents/product-specifications/vt-directed-io-spec.pdf [2] "2.2 Data Structures" and "2.2.5 Interrupt Remapping Tables" https://support.amd.com/TechDocs/48882_IOMMU.pdf Signed-off-by: Alexey Kardashevskiy <aik@xxxxxxxxx> --- drivers/iommu/amd_iommu.c | 3 +++ drivers/iommu/intel-iommu.c | 3 +++ 2 files changed, 6 insertions(+) diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 688e77576e5a..d55fcbf3267e 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -470,6 +470,9 @@ static void init_iommu_group(struct device *dev) if (IS_ERR(group)) return; + if (irq_remapping_enabled) + iommu_group_set_caps(group, 0, IOMMU_GROUP_CAP_ISOLATE_MSIX); + iommu_group_put(group); } diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index b7e670a7c243..3896c2d44bfa 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -5233,6 +5233,9 @@ static int intel_iommu_add_device(struct device *dev) if (IS_ERR(group)) return PTR_ERR(group); + if (irq_remapping_enabled && !disable_sourceid_checking) + iommu_group_set_caps(group, 0, IOMMU_GROUP_CAP_ISOLATE_MSIX); + iommu_group_put(group); return 0; } -- 2.11.0
