iommu/vt-d: Add device_block_translation() helper

If domain attaching to device fails, the IOMMU driver should bring the
device to blocking DMA state. The upper layer is expected to recover it
by attaching a new domain. Use device_block_translation() in the error
path of dev_attach to make the behavior specific.

The difference between device_block_translation() and the previous
dmar_remove_one_dev_info() is that, in the scalable mode, it is the
RID2PASID entry instead of context entry being cleared. As a result,
enabling PCI capabilities is moved up.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20221118132451.114406-3-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 6b8a24f..6aafb86 100644 (file)
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -277,7 +277,7 @@ static LIST_HEAD(dmar_satc_units);
 #define for_each_rmrr_units(rmrr) \
        list_for_each_entry(rmrr, &dmar_rmrr_units, list)
 
-static void dmar_remove_one_dev_info(struct device *dev);
+static void device_block_translation(struct device *dev);
 
 int dmar_disabled = !IS_ENABLED(CONFIG_INTEL_IOMMU_DEFAULT_ON);
 int intel_iommu_sm = IS_ENABLED(CONFIG_INTEL_IOMMU_SCALABLE_MODE_DEFAULT_ON);
@@ -1400,7 +1400,7 @@ static void iommu_enable_pci_caps(struct device_domain_info *info)
 {
        struct pci_dev *pdev;
 
-       if (!info || !dev_is_pci(info->dev))
+       if (!dev_is_pci(info->dev))
                return;
 
        pdev = to_pci_dev(info->dev);
@@ -2045,7 +2045,6 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
        } else {
                iommu_flush_write_buffer(iommu);
        }
-       iommu_enable_pci_caps(info);
 
        ret = 0;
 
@@ -2487,7 +2486,7 @@ static int domain_add_dev_info(struct dmar_domain *domain, struct device *dev)
                                        dev, PASID_RID2PASID);
                if (ret) {
                        dev_err(dev, "Setup RID2PASID failed\n");
-                       dmar_remove_one_dev_info(dev);
+                       device_block_translation(dev);
                        return ret;
                }
        }
@@ -2495,10 +2494,12 @@ static int domain_add_dev_info(struct dmar_domain *domain, struct device *dev)
        ret = domain_context_mapping(domain, dev);
        if (ret) {
                dev_err(dev, "Domain context map failed\n");
-               dmar_remove_one_dev_info(dev);
+               device_block_translation(dev);
                return ret;
        }
 
+       iommu_enable_pci_caps(info);
+
        return 0;
 }
 
@@ -4109,6 +4110,37 @@ static void dmar_remove_one_dev_info(struct device *dev)
        info->domain = NULL;
 }
 
+/*
+ * Clear the page table pointer in context or pasid table entries so that
+ * all DMA requests without PASID from the device are blocked. If the page
+ * table has been set, clean up the data structures.
+ */
+static void device_block_translation(struct device *dev)
+{
+       struct device_domain_info *info = dev_iommu_priv_get(dev);
+       struct intel_iommu *iommu = info->iommu;
+       unsigned long flags;
+
+       iommu_disable_dev_iotlb(info);
+       if (!dev_is_real_dma_subdevice(dev)) {
+               if (sm_supported(iommu))
+                       intel_pasid_tear_down_entry(iommu, dev,
+                                                   PASID_RID2PASID, false);
+               else
+                       domain_context_clear(info);
+       }
+
+       if (!info->domain)
+               return;
+
+       spin_lock_irqsave(&info->domain->lock, flags);
+       list_del(&info->link);
+       spin_unlock_irqrestore(&info->domain->lock, flags);
+
+       domain_detach_iommu(info->domain, iommu);
+       info->domain = NULL;
+}
+
 static int md_domain_init(struct dmar_domain *domain, int guest_width)
 {
        int adjust_width;
@@ -4232,7 +4264,7 @@ static int intel_iommu_attach_device(struct iommu_domain *domain,
                struct device_domain_info *info = dev_iommu_priv_get(dev);
 
                if (info->domain)
-                       dmar_remove_one_dev_info(dev);
+                       device_block_translation(dev);
        }
 
        ret = prepare_domain_attach_device(domain, dev);