iommu/vt-d: Flush IOTLB for untrusted device in time

[ 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 <ashok.raj@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Tested-by: Xu Pengfei <pengfei.xu@intel.com>
Tested-by: Mika Westerberg <mika.westerberg@intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index cb656f5036041f3840b4694e7e32e2f2b3ac3c2e..0feb3f70da16aebf5b9a59d7b1be8c4d9c200818 100644 (file)
--- 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 */