X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=Documentation%2FIntel-IOMMU.txt;h=c2321903aa09adea7f64c00d300814cc32229d1f;hb=d249afddffda695a20afe5270cbbfa242969d6e1;hp=cbb4dbaef761d1b7ae9a8dc6584fc35ba9c656dc;hpb=ba39592764ed20cee09aae5352e603a27bf56b0d;p=linux-2.6 diff --git a/Documentation/Intel-IOMMU.txt b/Documentation/Intel-IOMMU.txt index cbb4dbaef7..c2321903aa 100644 --- a/Documentation/Intel-IOMMU.txt +++ b/Documentation/Intel-IOMMU.txt @@ -57,12 +57,26 @@ Graphics Problems? If you encounter issues with graphics devices, you can try adding option intel_iommu=igfx_off to turn off the integrated graphics engine. +If it happens to be a PCI device included in the INCLUDE_ALL Engine, +then try enabling CONFIG_DMAR_GFX_WA to setup a 1-1 map. We hear +graphics drivers may be in process of using DMA api's in the near +future and at that time this option can be yanked out. + Some exceptions to IOVA ----------------------- Interrupt ranges are not address translated, (0xfee00000 - 0xfeefffff). The same is true for peer to peer transactions. Hence we reserve the address from PCI MMIO ranges so they are not allocated for IOVA addresses. + +Fault reporting +--------------- +When errors are reported, the DMA engine signals via an interrupt. The fault +reason and device that caused it with fault reason is printed on console. + +See below for sample. + + Boot Message Sample ------------------- @@ -85,6 +99,14 @@ When DMAR is enabled for use, you will notice.. PCI-DMA: Using DMAR IOMMU +Fault reporting +--------------- + +DMAR:[DMA Write] Request device [00:02.0] fault addr 6df084000 +DMAR:[fault reason 05] PTE Write access is not set +DMAR:[DMA Write] Request device [00:02.0] fault addr 6df084000 +DMAR:[fault reason 05] PTE Write access is not set + TBD ----