diff options
Diffstat (limited to 'drivers/iommu/intel-iommu.c')
| -rw-r--r-- | drivers/iommu/intel-iommu.c | 32 |
1 files changed, 2 insertions, 30 deletions
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index fd5cfd85c166..d79e3ebbe437 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -485,37 +485,14 @@ static int dmar_forcedac; static int intel_iommu_strict; static int intel_iommu_superpage = 1; static int intel_iommu_ecs = 1; -static int intel_iommu_pasid28; static int iommu_identity_mapping; #define IDENTMAP_ALL 1 #define IDENTMAP_GFX 2 #define IDENTMAP_AZALIA 4 -/* Broadwell and Skylake have broken ECS support — normal so-called "second - * level" translation of DMA requests-without-PASID doesn't actually happen - * unless you also set the NESTE bit in an extended context-entry. Which of - * course means that SVM doesn't work because it's trying to do nested - * translation of the physical addresses it finds in the process page tables, - * through the IOVA->phys mapping found in the "second level" page tables. - * - * The VT-d specification was retroactively changed to change the definition - * of the capability bits and pretend that Broadwell/Skylake never happened... - * but unfortunately the wrong bit was changed. It's ECS which is broken, but - * for some reason it was the PASID capability bit which was redefined (from - * bit 28 on BDW/SKL to bit 40 in future). - * - * So our test for ECS needs to eschew those implementations which set the old - * PASID capabiity bit 28, since those are the ones on which ECS is broken. - * Unless we are working around the 'pasid28' limitations, that is, by putting - * the device into passthrough mode for normal DMA and thus masking the bug. - */ -#define ecs_enabled(iommu) (intel_iommu_ecs && ecap_ecs(iommu->ecap) && \ - (intel_iommu_pasid28 || !ecap_broken_pasid(iommu->ecap))) -/* PASID support is thus enabled if ECS is enabled and *either* of the old - * or new capability bits are set. */ -#define pasid_enabled(iommu) (ecs_enabled(iommu) && \ - (ecap_pasid(iommu->ecap) || ecap_broken_pasid(iommu->ecap))) +#define ecs_enabled(iommu) (intel_iommu_ecs && ecap_ecs(iommu->ecap)) +#define pasid_enabled(iommu) (ecs_enabled(iommu) && ecap_pasid(iommu->ecap)) int intel_iommu_gfx_mapped; EXPORT_SYMBOL_GPL(intel_iommu_gfx_mapped); @@ -578,11 +555,6 @@ static int __init intel_iommu_setup(char *str) printk(KERN_INFO "Intel-IOMMU: disable extended context table support\n"); intel_iommu_ecs = 0; - } else if (!strncmp(str, "pasid28", 7)) { - printk(KERN_INFO - "Intel-IOMMU: enable pre-production PASID support\n"); - intel_iommu_pasid28 = 1; - iommu_identity_mapping |= IDENTMAP_GFX; } else if (!strncmp(str, "tboot_noforce", 13)) { printk(KERN_INFO "Intel-IOMMU: not forcing on after tboot. This could expose security risk for tboot\n"); |