[PATCH v2] powernv/iommu: disable IOMMU bypass with param iommu=nobypass

2014-10-23 Thread Thadeu Lima de Souza Cascardo
When IOMMU bypass is enabled, a PCI device can read and write memory that was not mapped by the driver without causing an EEH. That might cause memory corruption, for example. When we disable bypass, DMA reads and writes to addresses not mapped by the IOMMU will cause an EEH, allowing us to debug

[PATCH v2] powernv/iommu: disable IOMMU bypass with param iommu=nobypass

2014-10-23 Thread Thadeu Lima de Souza Cascardo
When IOMMU bypass is enabled, a PCI device can read and write memory that was not mapped by the driver without causing an EEH. That might cause memory corruption, for example. When we disable bypass, DMA reads and writes to addresses not mapped by the IOMMU will cause an EEH, allowing us to debug