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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-01-20 14:01:31 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-01-20 14:01:31 -0300
commitb4b7ff4b08e691656c9d77c758fc355833128ac0 (patch)
tree82fcb00e6b918026dc9f2d1f05ed8eee83874cc0 /drivers/vfio/vfio.c
parent35acfa0fc609f2a2cd95cef4a6a9c3a5c38f1778 (diff)
Linux-libre 4.4-gnupck-4.4-gnu
Diffstat (limited to 'drivers/vfio/vfio.c')
-rw-r--r--drivers/vfio/vfio.c40
1 files changed, 30 insertions, 10 deletions
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 563c510f2..6070b793c 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -25,6 +25,7 @@
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/mutex.h>
+#include <linux/pci.h>
#include <linux/rwsem.h>
#include <linux/sched.h>
#include <linux/slab.h>
@@ -438,16 +439,33 @@ static struct vfio_device *vfio_group_get_device(struct vfio_group *group,
}
/*
- * Whitelist some drivers that we know are safe (no dma) or just sit on
- * a device. It's not always practical to leave a device within a group
- * driverless as it could get re-bound to something unsafe.
+ * Some drivers, like pci-stub, are only used to prevent other drivers from
+ * claiming a device and are therefore perfectly legitimate for a user owned
+ * group. The pci-stub driver has no dependencies on DMA or the IOVA mapping
+ * of the device, but it does prevent the user from having direct access to
+ * the device, which is useful in some circumstances.
+ *
+ * We also assume that we can include PCI interconnect devices, ie. bridges.
+ * IOMMU grouping on PCI necessitates that if we lack isolation on a bridge
+ * then all of the downstream devices will be part of the same IOMMU group as
+ * the bridge. Thus, if placing the bridge into the user owned IOVA space
+ * breaks anything, it only does so for user owned devices downstream. Note
+ * that error notification via MSI can be affected for platforms that handle
+ * MSI within the same IOVA space as DMA.
*/
-static const char * const vfio_driver_whitelist[] = { "pci-stub", "pcieport" };
+static const char * const vfio_driver_whitelist[] = { "pci-stub" };
-static bool vfio_whitelisted_driver(struct device_driver *drv)
+static bool vfio_dev_whitelisted(struct device *dev, struct device_driver *drv)
{
int i;
+ if (dev_is_pci(dev)) {
+ struct pci_dev *pdev = to_pci_dev(dev);
+
+ if (pdev->hdr_type != PCI_HEADER_TYPE_NORMAL)
+ return true;
+ }
+
for (i = 0; i < ARRAY_SIZE(vfio_driver_whitelist); i++) {
if (!strcmp(drv->name, vfio_driver_whitelist[i]))
return true;
@@ -462,6 +480,7 @@ static bool vfio_whitelisted_driver(struct device_driver *drv)
* - driver-less
* - bound to a vfio driver
* - bound to a whitelisted driver
+ * - a PCI interconnect device
*
* We use two methods to determine whether a device is bound to a vfio
* driver. The first is to test whether the device exists in the vfio
@@ -486,7 +505,7 @@ static int vfio_dev_viable(struct device *dev, void *data)
}
mutex_unlock(&group->unbound_lock);
- if (!ret || !drv || vfio_whitelisted_driver(drv))
+ if (!ret || !drv || vfio_dev_whitelisted(dev, drv))
return 0;
device = vfio_group_get_device(group, dev);
@@ -517,7 +536,7 @@ static int vfio_group_nb_add_dev(struct vfio_group *group, struct device *dev)
return 0;
/* TODO Prevent device auto probing */
- WARN("Device %s added to live group %d!\n", dev_name(dev),
+ WARN(1, "Device %s added to live group %d!\n", dev_name(dev),
iommu_group_id(group->iommu_group));
return 0;
@@ -692,11 +711,12 @@ EXPORT_SYMBOL_GPL(vfio_device_get_from_dev);
static struct vfio_device *vfio_device_get_from_name(struct vfio_group *group,
char *buf)
{
- struct vfio_device *device;
+ struct vfio_device *it, *device = NULL;
mutex_lock(&group->device_lock);
- list_for_each_entry(device, &group->device_list, group_next) {
- if (!strcmp(dev_name(device->dev), buf)) {
+ list_for_each_entry(it, &group->device_list, group_next) {
+ if (!strcmp(dev_name(it->dev), buf)) {
+ device = it;
vfio_device_get(device);
break;
}