iommu/amd: Ratelimit io-page-faults per device

Misbehaving devices can cause an endless chain of
io-page-faults, flooding dmesg and making the system-log
unusable or even prevent the system from booting.

So ratelimit the error messages about io-page-faults on a
per-device basis.

Signed-off-by: Joerg Roedel <jroedel@suse.de>

1 files changed, 33 insertions, 7 deletions

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 63cacf5d6cf2..d3ff766a8ca6 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -138,6 +138,8 @@ struct iommu_dev_data {
                                              PPR completions */
         u32 errata;                       /* Bitmap for errata to apply */
         bool use_vapic;                   /* Enable device to use vapic mode */
+
+        struct ratelimit_state rs;        /* Ratelimit IOPF messages */
 };
 
 /*
@@ -253,6 +255,8 @@ static struct iommu_dev_data *alloc_dev_data(u16 devid)
         list_add_tail(&dev_data->dev_data_list, &dev_data_list);
         spin_unlock_irqrestore(&dev_data_list_lock, flags);
 
+        ratelimit_default_init(&dev_data->rs);
+
         return dev_data;
 }
 
@@ -551,6 +555,29 @@ static void dump_command(unsigned long phys_addr)
                 pr_err("AMD-Vi: CMD[%d]: %08x\n", i, cmd->data[i]);
 }
 
+static void amd_iommu_report_page_fault(u16 devid, u16 domain_id,
+                                        u64 address, int flags)
+{
+        struct iommu_dev_data *dev_data = NULL;
+        struct pci_dev *pdev;
+
+        pdev = pci_get_bus_and_slot(PCI_BUS_NUM(devid), devid & 0xff);
+        if (pdev)
+                dev_data = get_dev_data(&pdev->dev);
+
+        if (dev_data && __ratelimit(&dev_data->rs)) {
+                dev_err(&pdev->dev, "AMD-Vi: Event logged [IO_PAGE_FAULT domain=0x%04x address=0x%016llx flags=0x%04x]\n",
+                        domain_id, address, flags);
+        } else if (printk_ratelimit()) {
+                pr_err("AMD-Vi: Event logged [IO_PAGE_FAULT device=%02x:%02x.%x domain=0x%04x address=0x%016llx flags=0x%04x]\n",
+                        PCI_BUS_NUM(devid), PCI_SLOT(devid), PCI_FUNC(devid),
+                        domain_id, address, flags);
+        }
+
+        if (pdev)
+                pci_dev_put(pdev);
+}
+
 static void iommu_print_event(struct amd_iommu *iommu, void *__evt)
 {
         int type, devid, domid, flags;
@@ -575,7 +602,12 @@ retry:
                 goto retry;
         }
 
-        printk(KERN_ERR "AMD-Vi: Event logged [");
+        if (type == EVENT_TYPE_IO_FAULT) {
+                amd_iommu_report_page_fault(devid, domid, address, flags);
+                return;
+        } else {
+                printk(KERN_ERR "AMD-Vi: Event logged [");
+        }
 
         switch (type) {
         case EVENT_TYPE_ILL_DEV:
@@ -585,12 +617,6 @@ retry:
                        address, flags);
                 dump_dte_entry(devid);
                 break;
-        case EVENT_TYPE_IO_FAULT:
-                printk("IO_PAGE_FAULT device=%02x:%02x.%x "
-                       "domain=0x%04x address=0x%016llx flags=0x%04x]\n",
-                       PCI_BUS_NUM(devid), PCI_SLOT(devid), PCI_FUNC(devid),
-                       domid, address, flags);
-                break;
         case EVENT_TYPE_DEV_TAB_ERR:
                 printk("DEV_TAB_HARDWARE_ERROR device=%02x:%02x.%x "
                        "address=0x%016llx flags=0x%04x]\n",