[ Upstream commit f7b0c4ce8cb3c09cb3cbfc0c663268bf99e5fa9c ] By default, for performance consideration, Intel IOMMU driver won't flush IOTLB immediately after a buffer is unmapped. It schedules a thread and flushes IOTLB in a batched mode. This isn't suitable for untrusted device since it still can access the memory even if it isn't supposed to do so.
Cc: Ashok Raj <[email protected]> Cc: Jacob Pan <[email protected]> Signed-off-by: Lu Baolu <[email protected]> Tested-by: Xu Pengfei <[email protected]> Tested-by: Mika Westerberg <[email protected]> Signed-off-by: Joerg Roedel <[email protected]> Signed-off-by: Sasha Levin <[email protected]> --- drivers/iommu/intel-iommu.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index cb656f503604..0feb3f70da16 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -3736,6 +3736,7 @@ static void intel_unmap(struct device *dev, dma_addr_t dev_addr, size_t size) unsigned long iova_pfn; struct intel_iommu *iommu; struct page *freelist; + struct pci_dev *pdev = NULL; if (iommu_no_mapping(dev)) return; @@ -3751,11 +3752,14 @@ static void intel_unmap(struct device *dev, dma_addr_t dev_addr, size_t size) start_pfn = mm_to_dma_pfn(iova_pfn); last_pfn = start_pfn + nrpages - 1; + if (dev_is_pci(dev)) + pdev = to_pci_dev(dev); + dev_dbg(dev, "Device unmapping: pfn %lx-%lx\n", start_pfn, last_pfn); freelist = domain_unmap(domain, start_pfn, last_pfn); - if (intel_iommu_strict) { + if (intel_iommu_strict || (pdev && pdev->untrusted)) { iommu_flush_iotlb_psi(iommu, domain, start_pfn, nrpages, !freelist, 0); /* free iova */ -- 2.20.1
