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>

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 63cacf5..d3ff766 100644 (file)
--- 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",