From: Joerg Roedel <[email protected]> We can't change the RTT bit when translation is enabled, so don't copy translation tables when we would change the bit with our new root entry.
Signed-off-by: Joerg Roedel <[email protected]> --- drivers/iommu/intel-iommu.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 39bc3d6..e23d5b4 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -2914,10 +2914,20 @@ 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) -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
