iommu/amd: Put IOMMUv2 capable devices in pt_domain
If the device starts to use IOMMUv2 features the dma handles
need to stay valid. The only sane way to do this is to use a
identity mapping for the device and not translate it by the
iommu. This is implemented with this patch. Since this lifts
the device-isolation there is also a new kernel parameter
which allows to disable that feature.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 661e2bb..7ccfc80 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -67,6 +67,7 @@
};
static void update_domain(struct protection_domain *domain);
+static int __init alloc_passthrough_domain(void);
/****************************************************************************
*
@@ -147,6 +148,24 @@
return dev->archdata.iommu;
}
+static bool pci_iommuv2_capable(struct pci_dev *pdev)
+{
+ static const int caps[] = {
+ PCI_EXT_CAP_ID_ATS,
+ PCI_PRI_CAP,
+ PCI_PASID_CAP,
+ };
+ int i, pos;
+
+ for (i = 0; i < 3; ++i) {
+ pos = pci_find_ext_capability(pdev, caps[i]);
+ if (pos == 0)
+ return false;
+ }
+
+ return true;
+}
+
/*
* In this function the list of preallocated protection domains is traversed to
* find the domain for a specific device
@@ -204,6 +223,7 @@
static int iommu_init_device(struct device *dev)
{
+ struct pci_dev *pdev = to_pci_dev(dev);
struct iommu_dev_data *dev_data;
u16 alias;
@@ -228,6 +248,13 @@
dev_data->alias_data = alias_data;
}
+ if (pci_iommuv2_capable(pdev)) {
+ struct amd_iommu *iommu;
+
+ iommu = amd_iommu_rlookup_table[dev_data->devid];
+ dev_data->iommu_v2 = iommu->is_iommu_v2;
+ }
+
dev->archdata.iommu = dev_data;
return 0;
@@ -1762,7 +1789,7 @@
* passthrough domain if it is detached from any other domain.
* Make sure we can deassign from the pt_domain itself.
*/
- if (iommu_pass_through &&
+ if (dev_data->passthrough &&
(dev_data->domain == NULL && domain != pt_domain))
__attach_device(dev_data, pt_domain);
}
@@ -1820,18 +1847,20 @@
static int device_change_notifier(struct notifier_block *nb,
unsigned long action, void *data)
{
- struct device *dev = data;
- u16 devid;
- struct protection_domain *domain;
struct dma_ops_domain *dma_domain;
+ struct protection_domain *domain;
+ struct iommu_dev_data *dev_data;
+ struct device *dev = data;
struct amd_iommu *iommu;
unsigned long flags;
+ u16 devid;
if (!check_device(dev))
return 0;
- devid = get_device_id(dev);
- iommu = amd_iommu_rlookup_table[devid];
+ devid = get_device_id(dev);
+ iommu = amd_iommu_rlookup_table[devid];
+ dev_data = get_dev_data(dev);
switch (action) {
case BUS_NOTIFY_UNBOUND_DRIVER:
@@ -1840,7 +1869,7 @@
if (!domain)
goto out;
- if (iommu_pass_through)
+ if (dev_data->passthrough)
break;
detach_device(dev);
break;
@@ -2436,8 +2465,9 @@
*/
static void prealloc_protection_domains(void)
{
- struct pci_dev *dev = NULL;
+ struct iommu_dev_data *dev_data;
struct dma_ops_domain *dma_dom;
+ struct pci_dev *dev = NULL;
u16 devid;
for_each_pci_dev(dev) {
@@ -2446,6 +2476,16 @@
if (!check_device(&dev->dev))
continue;
+ dev_data = get_dev_data(&dev->dev);
+ if (!amd_iommu_force_isolation && dev_data->iommu_v2) {
+ /* Make sure passthrough domain is allocated */
+ alloc_passthrough_domain();
+ dev_data->passthrough = true;
+ attach_device(&dev->dev, pt_domain);
+ pr_info("AMD-Vi: Using passthough domain for device %s\n",
+ dev_name(&dev->dev));
+ }
+
/* Is there already any domain for it? */
if (domain_for_device(&dev->dev))
continue;
@@ -2476,6 +2516,7 @@
static unsigned device_dma_ops_init(void)
{
+ struct iommu_dev_data *dev_data;
struct pci_dev *pdev = NULL;
unsigned unhandled = 0;
@@ -2485,7 +2526,12 @@
continue;
}
- pdev->dev.archdata.dma_ops = &amd_iommu_dma_ops;
+ dev_data = get_dev_data(&pdev->dev);
+
+ if (!dev_data->passthrough)
+ pdev->dev.archdata.dma_ops = &amd_iommu_dma_ops;
+ else
+ pdev->dev.archdata.dma_ops = &nommu_dma_ops;
}
return unhandled;
@@ -2612,6 +2658,20 @@
return NULL;
}
+static int __init alloc_passthrough_domain(void)
+{
+ if (pt_domain != NULL)
+ return 0;
+
+ /* allocate passthrough domain */
+ pt_domain = protection_domain_alloc();
+ if (!pt_domain)
+ return -ENOMEM;
+
+ pt_domain->mode = PAGE_MODE_NONE;
+
+ return 0;
+}
static int amd_iommu_domain_init(struct iommu_domain *dom)
{
struct protection_domain *domain;
@@ -2798,21 +2858,23 @@
int __init amd_iommu_init_passthrough(void)
{
- struct amd_iommu *iommu;
+ struct iommu_dev_data *dev_data;
struct pci_dev *dev = NULL;
+ struct amd_iommu *iommu;
u16 devid;
+ int ret;
- /* allocate passthrough domain */
- pt_domain = protection_domain_alloc();
- if (!pt_domain)
- return -ENOMEM;
-
- pt_domain->mode |= PAGE_MODE_NONE;
+ ret = alloc_passthrough_domain();
+ if (ret)
+ return ret;
for_each_pci_dev(dev) {
if (!check_device(&dev->dev))
continue;
+ dev_data = get_dev_data(&dev->dev);
+ dev_data->passthrough = true;
+
devid = get_device_id(&dev->dev);
iommu = amd_iommu_rlookup_table[devid];