DMA_RTADDR_SMT
if (dmar_readq(iommu->reg + DMAR_RTADDR_REG) & DMA_RTADDR_SMT) {
if (dmar_readq(iommu->reg + DMAR_RTADDR_REG) & DMA_RTADDR_SMT)
ext = !!(rtaddr_reg & DMA_RTADDR_SMT);
addr |= DMA_RTADDR_SMT;