diff options
Diffstat (limited to 'drivers/vfio/vfio.c')
| -rw-r--r-- | drivers/vfio/vfio.c | 31 |
1 files changed, 25 insertions, 6 deletions
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index 563c510f285c..1c0f98c2f634 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); |