iommu/amd: Fix checking of pci dma aliases
Commit 61289cb ('iommu/amd: Remove old alias handling code')
removed the old alias handling code from the AMD IOMMU
driver because this is now handled by the IOMMU core code.
But this also removed the handling of PCI aliases, which is
not handled by the core code. This caused issues with PCI
devices that have hidden PCIe-to-PCI bridges that rewrite
the request-id.
Fix this bug by re-introducing some of the removed functions
from commit 61289cbaf6c8 and add a alias field
'struct iommu_dev_data'. This field carrys the return value
of the get_alias() function and uses that instead of the
amd_iommu_alias_table[] array in the code.
Fixes: 61289cbaf6c8 ('iommu/amd: Remove old alias handling code')
Cc: stable@vger.kernel.org # v4.4+
Tested-by: Tomasz Golinski <tomaszg@math.uwb.edu.pl>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 374c129..5efadad 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -92,6 +92,7 @@
struct list_head dev_data_list; /* For global dev_data_list */
struct protection_domain *domain; /* Domain the device is bound to */
u16 devid; /* PCI Device ID */
+ u16 alias; /* Alias Device ID */
bool iommu_v2; /* Device can make use of IOMMUv2 */
bool passthrough; /* Device is identity mapped */
struct {
@@ -166,6 +167,13 @@
return container_of(dom, struct protection_domain, domain);
}
+static inline u16 get_device_id(struct device *dev)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+
+ return PCI_DEVID(pdev->bus->number, pdev->devfn);
+}
+
static struct iommu_dev_data *alloc_dev_data(u16 devid)
{
struct iommu_dev_data *dev_data;
@@ -203,6 +211,68 @@
return dev_data;
}
+static int __last_alias(struct pci_dev *pdev, u16 alias, void *data)
+{
+ *(u16 *)data = alias;
+ return 0;
+}
+
+static u16 get_alias(struct device *dev)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+ u16 devid, ivrs_alias, pci_alias;
+
+ devid = get_device_id(dev);
+ ivrs_alias = amd_iommu_alias_table[devid];
+ pci_for_each_dma_alias(pdev, __last_alias, &pci_alias);
+
+ if (ivrs_alias == pci_alias)
+ return ivrs_alias;
+
+ /*
+ * DMA alias showdown
+ *
+ * The IVRS is fairly reliable in telling us about aliases, but it
+ * can't know about every screwy device. If we don't have an IVRS
+ * reported alias, use the PCI reported alias. In that case we may
+ * still need to initialize the rlookup and dev_table entries if the
+ * alias is to a non-existent device.
+ */
+ if (ivrs_alias == devid) {
+ if (!amd_iommu_rlookup_table[pci_alias]) {
+ amd_iommu_rlookup_table[pci_alias] =
+ amd_iommu_rlookup_table[devid];
+ memcpy(amd_iommu_dev_table[pci_alias].data,
+ amd_iommu_dev_table[devid].data,
+ sizeof(amd_iommu_dev_table[pci_alias].data));
+ }
+
+ return pci_alias;
+ }
+
+ pr_info("AMD-Vi: Using IVRS reported alias %02x:%02x.%d "
+ "for device %s[%04x:%04x], kernel reported alias "
+ "%02x:%02x.%d\n", PCI_BUS_NUM(ivrs_alias), PCI_SLOT(ivrs_alias),
+ PCI_FUNC(ivrs_alias), dev_name(dev), pdev->vendor, pdev->device,
+ PCI_BUS_NUM(pci_alias), PCI_SLOT(pci_alias),
+ PCI_FUNC(pci_alias));
+
+ /*
+ * If we don't have a PCI DMA alias and the IVRS alias is on the same
+ * bus, then the IVRS table may know about a quirk that we don't.
+ */
+ if (pci_alias == devid &&
+ PCI_BUS_NUM(ivrs_alias) == pdev->bus->number) {
+ pdev->dev_flags |= PCI_DEV_FLAGS_DMA_ALIAS_DEVFN;
+ pdev->dma_alias_devfn = ivrs_alias & 0xff;
+ pr_info("AMD-Vi: Added PCI DMA alias %02x.%d for %s\n",
+ PCI_SLOT(ivrs_alias), PCI_FUNC(ivrs_alias),
+ dev_name(dev));
+ }
+
+ return ivrs_alias;
+}
+
static struct iommu_dev_data *find_dev_data(u16 devid)
{
struct iommu_dev_data *dev_data;
@@ -215,13 +285,6 @@
return dev_data;
}
-static inline u16 get_device_id(struct device *dev)
-{
- struct pci_dev *pdev = to_pci_dev(dev);
-
- return PCI_DEVID(pdev->bus->number, pdev->devfn);
-}
-
static struct iommu_dev_data *get_dev_data(struct device *dev)
{
return dev->archdata.iommu;
@@ -349,6 +412,8 @@
if (!dev_data)
return -ENOMEM;
+ dev_data->alias = get_alias(dev);
+
if (pci_iommuv2_capable(pdev)) {
struct amd_iommu *iommu;
@@ -369,7 +434,7 @@
u16 devid, alias;
devid = get_device_id(dev);
- alias = amd_iommu_alias_table[devid];
+ alias = get_alias(dev);
memset(&amd_iommu_dev_table[devid], 0, sizeof(struct dev_table_entry));
memset(&amd_iommu_dev_table[alias], 0, sizeof(struct dev_table_entry));
@@ -1061,7 +1126,7 @@
int ret;
iommu = amd_iommu_rlookup_table[dev_data->devid];
- alias = amd_iommu_alias_table[dev_data->devid];
+ alias = dev_data->alias;
ret = iommu_flush_dte(iommu, dev_data->devid);
if (!ret && alias != dev_data->devid)
@@ -2039,7 +2104,7 @@
bool ats;
iommu = amd_iommu_rlookup_table[dev_data->devid];
- alias = amd_iommu_alias_table[dev_data->devid];
+ alias = dev_data->alias;
ats = dev_data->ats.enabled;
/* Update data structures */
@@ -2073,7 +2138,7 @@
return;
iommu = amd_iommu_rlookup_table[dev_data->devid];
- alias = amd_iommu_alias_table[dev_data->devid];
+ alias = dev_data->alias;
/* decrease reference counters */
dev_data->domain->dev_iommu[iommu->index] -= 1;