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| author | Jacob Pan <jacob.jun.pan@linux.intel.com> | 2020-01-02 08:18:03 +0800 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2020-01-07 14:05:57 +0100 |
| commit | ff3dc6521f78132eaaf62a842c3ece9060dcde26 (patch) | |
| tree | 63a98dad9f70909512ae377b651e83ff4ba3e631 /drivers/iommu/intel-iommu.c | |
| parent | 046182525db611964da0db113dde9d3a2969085c (diff) | |
| download | lwn-ff3dc6521f78132eaaf62a842c3ece9060dcde26.tar.gz lwn-ff3dc6521f78132eaaf62a842c3ece9060dcde26.zip | |
iommu/vt-d: Fix CPU and IOMMU SVM feature matching checks
Shared Virtual Memory(SVM) is based on a collective set of hardware
features detected at runtime. There are requirements for matching CPU
and IOMMU capabilities.
The current code checks CPU and IOMMU feature set for SVM support but
the result is never stored nor used. Therefore, SVM can still be used
even when these checks failed. The consequences can be:
1. CPU uses 5-level paging mode for virtual address of 57 bits, but
IOMMU can only support 4-level paging mode with 48 bits address for DMA.
2. 1GB page size is used by CPU but IOMMU does not support it. VT-d
unrecoverable faults may be generated.
The best solution to fix these problems is to prevent them in the first
place.
This patch consolidates code for checking PASID, CPU vs. IOMMU paging
mode compatibility, as well as provides specific error messages for
each failed checks. On sane hardware configurations, these error message
shall never appear in kernel log.
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu/intel-iommu.c')
| -rw-r--r-- | drivers/iommu/intel-iommu.c | 10 |
1 files changed, 2 insertions, 8 deletions
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 26c40134817e..5328e2ed2dd3 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -3299,10 +3299,7 @@ static int __init init_dmars(void) if (!ecap_pass_through(iommu->ecap)) hw_pass_through = 0; -#ifdef CONFIG_INTEL_IOMMU_SVM - if (pasid_supported(iommu)) - intel_svm_init(iommu); -#endif + intel_svm_check(iommu); } /* @@ -4495,10 +4492,7 @@ static int intel_iommu_add(struct dmar_drhd_unit *dmaru) if (ret) goto out; -#ifdef CONFIG_INTEL_IOMMU_SVM - if (pasid_supported(iommu)) - intel_svm_init(iommu); -#endif + intel_svm_check(iommu); if (dmaru->ignored) { /* |