diff options
| -rw-r--r-- | drivers/iommu/intel-iommu.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 3b32aa55f27c..ca7d37c3981f 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -2934,10 +2934,20 @@ static int copy_translation_tables(struct intel_iommu *iommu) unsigned long flags; u64 rtaddr_reg; int bus, ret; - bool ext; + bool new_ext, ext; rtaddr_reg = dmar_readq(iommu->reg + DMAR_RTADDR_REG); ext = !!(rtaddr_reg & DMA_RTADDR_RTT); + new_ext = !!ecap_ecs(iommu->ecap); + + /* + * The RTT bit can only be changed when translation is disabled, + * but disabling translation means to open a window for data + * corruption. So bail out and don't copy anything if we would + * have to change the bit. + */ + if (new_ext != ext) + return -EINVAL; old_rt_phys = rtaddr_reg & VTD_PAGE_MASK; if (!old_rt_phys) |