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-rw-r--r--debian/patches/features/x86/intel-iommu-add-option-to-exclude-integrated-gpu-only.patch90
1 files changed, 90 insertions, 0 deletions
diff --git a/debian/patches/features/x86/intel-iommu-add-option-to-exclude-integrated-gpu-only.patch b/debian/patches/features/x86/intel-iommu-add-option-to-exclude-integrated-gpu-only.patch
new file mode 100644
index 000000000..a3543d90e
--- /dev/null
+++ b/debian/patches/features/x86/intel-iommu-add-option-to-exclude-integrated-gpu-only.patch
@@ -0,0 +1,90 @@
+From: Ben Hutchings <ben@decadent.org.uk>
+Date: Wed, 21 Aug 2019 00:05:30 +0100
+Subject: intel-iommu: Add option to exclude integrated GPU only
+Bug-Debian: https://bugs.debian.org/935270
+Bug-Kali: https://bugs.kali.org/view.php?id=5644
+
+There is still laptop firmware that touches the integrated GPU behind
+the operating system's back, and doesn't say so in the RMRR table.
+Enabling the IOMMU for all devices causes breakage, but turning it off
+for all graphics devices seems like a major weakness.
+
+Add an option, intel_iommu=intgpu_off, to exclude only integrated GPUs
+from remapping. This is a narrower exclusion than igfx_off: it only
+affects Intel devices on the root bus. Devices attached through an
+external port (Thunderbolt or ExpressCard) won't be on the root bus.
+
+Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
+---
+ Documentation/admin-guide/kernel-parameters.txt | 2 ++
+ drivers/iommu/intel/iommu.c | 14 ++++++++++++++
+ 2 files changed, 16 insertions(+)
+
+--- a/Documentation/admin-guide/kernel-parameters.txt
++++ b/Documentation/admin-guide/kernel-parameters.txt
+@@ -2053,6 +2053,8 @@
+ bypassed by not enabling DMAR with this option. In
+ this case, gfx device will use physical address for
+ DMA.
++ intgpu_off [Default Off]
++ Bypass the DMAR unit for an integrated GPU only.
+ strict [Default Off]
+ Deprecated, equivalent to iommu.strict=1.
+ sp_off [Default Off]
+--- a/drivers/iommu/intel/iommu.c
++++ b/drivers/iommu/intel/iommu.c
+@@ -35,6 +35,9 @@
+ #define CONTEXT_SIZE VTD_PAGE_SIZE
+
+ #define IS_GFX_DEVICE(pdev) ((pdev->class >> 16) == PCI_BASE_CLASS_DISPLAY)
++#define IS_INTGPU_DEVICE(pdev) (IS_GFX_DEVICE(pdev) && \
++ (pdev)->vendor == 0x8086 && \
++ pci_is_root_bus((pdev)->bus))
+ #define IS_USB_DEVICE(pdev) ((pdev->class >> 8) == PCI_CLASS_SERIAL_USB)
+ #define IS_ISA_DEVICE(pdev) ((pdev->class >> 8) == PCI_CLASS_BRIDGE_ISA)
+ #define IS_AZALIA(pdev) ((pdev)->vendor == 0x8086 && (pdev)->device == 0x3a3e)
+@@ -293,12 +296,14 @@ int intel_iommu_enabled = 0;
+ EXPORT_SYMBOL_GPL(intel_iommu_enabled);
+
+ static int dmar_map_gfx = 1;
++static int dmar_map_intgpu = 1;
+ static int intel_iommu_superpage = 1;
+ static int iommu_identity_mapping;
+ static int iommu_skip_te_disable;
+
+ #define IDENTMAP_GFX 2
+ #define IDENTMAP_AZALIA 4
++#define IDENTMAP_INTGPU 8
+
+ const struct iommu_ops intel_iommu_ops;
+
+@@ -337,6 +342,9 @@ static int __init intel_iommu_setup(char
+ } else if (!strncmp(str, "igfx_off", 8)) {
+ dmar_map_gfx = 0;
+ pr_info("Disable GFX device mapping\n");
++ } else if (!strncmp(str, "intgpu_off", 10)) {
++ dmar_map_intgpu = 0;
++ pr_info("Disable integrated GPU device mapping\n");
+ } else if (!strncmp(str, "forcedac", 8)) {
+ pr_warn("intel_iommu=forcedac deprecated; use iommu.forcedac instead\n");
+ iommu_dma_forcedac = true;
+@@ -2582,6 +2590,9 @@ static int device_def_domain_type(struct
+
+ if ((iommu_identity_mapping & IDENTMAP_GFX) && IS_GFX_DEVICE(pdev))
+ return IOMMU_DOMAIN_IDENTITY;
++
++ if ((iommu_identity_mapping & IDENTMAP_INTGPU) && IS_INTGPU_DEVICE(pdev))
++ return IOMMU_DOMAIN_IDENTITY;
+ }
+
+ return 0;
+@@ -2985,6 +2996,9 @@ static int __init init_dmars(void)
+ if (!dmar_map_gfx)
+ iommu_identity_mapping |= IDENTMAP_GFX;
+
++ if (!dmar_map_intgpu)
++ iommu_identity_mapping |= IDENTMAP_INTGPU;
++
+ check_tylersburg_isoch();
+
+ ret = si_domain_init(hw_pass_through);