As for the intel-iommu implementation, relegate the opportunistic attempt to allocate a SAC address to the domain of conventional PCI devices only, to avoid it increasingly causing far more performance issues than possible benefits on modern PCI Express systems. Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx> --- drivers/iommu/dma-iommu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 4959f5df21bd..0ff124f16ad4 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -426,7 +426,8 @@ static dma_addr_t iommu_dma_alloc_iova(struct iommu_domain *domain, dma_limit = min(dma_limit, (u64)domain->geometry.aperture_end); /* Try to get PCI devices a SAC address */ - if (dma_limit > DMA_BIT_MASK(32) && dev_is_pci(dev)) + if (dma_limit > DMA_BIT_MASK(32) && + dev_is_pci(dev) && !pci_is_pcie(to_pci_dev(dev))) iova = alloc_iova_fast(iovad, iova_len, DMA_BIT_MASK(32) >> shift, false); -- 2.23.0.dirty
