From 59103caa6839592788e7ad58b35863aac034631a Mon Sep 17 00:00:00 2001 From: Sohil Mehta Date: Wed, 20 Dec 2017 11:59:25 -0800 Subject: [PATCH] iommu/vt-d: Add a check for 1GB page support Add a check to verify IOMMU 1GB page support. If the CPU supports 1GB pages but the IOMMU does not support it then disable SVM by not allocating PASID tables. Signed-off-by: Sohil Mehta Signed-off-by: Joerg Roedel --- drivers/iommu/intel-svm.c | 4 ++++ include/linux/intel-iommu.h | 1 + 2 files changed, 5 insertions(+) diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c index 6643277e321e..e9a56ad09a76 100644 --- a/drivers/iommu/intel-svm.c +++ b/drivers/iommu/intel-svm.c @@ -41,6 +41,10 @@ int intel_svm_alloc_pasid_tables(struct intel_iommu *iommu) struct page *pages; int order; + if (cpu_feature_enabled(X86_FEATURE_GBPAGES) && + !cap_fl1gp_support(iommu->cap)) + return -EINVAL; + /* Start at 2 because it's defined as 2^(1+PSS) */ iommu->pasid_max = 2 << ecap_pss(iommu->ecap); diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h index f3274d9f46a2..a56bab114f39 100644 --- a/include/linux/intel-iommu.h +++ b/include/linux/intel-iommu.h @@ -84,6 +84,7 @@ * Decoding Capability Register */ #define cap_pi_support(c) (((c) >> 59) & 1) +#define cap_fl1gp_support(c) (((c) >> 56) & 1) #define cap_read_drain(c) (((c) >> 55) & 1) #define cap_write_drain(c) (((c) >> 54) & 1) #define cap_max_amask_val(c) (((c) >> 48) & 0x3f)