diff options
| -rw-r--r-- | drivers/vfio/pci/vfio_pci.c | 23 | ||||
| -rw-r--r-- | drivers/vfio/vfio.c | 37 |
2 files changed, 31 insertions, 29 deletions
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index c5179e269df6..cef6002acbd4 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -137,8 +137,27 @@ static void vfio_pci_disable(struct vfio_pci_device *vdev) */ pci_write_config_word(pdev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE); - if (vdev->reset_works) - __pci_reset_function(pdev); + /* + * Careful, device_lock may already be held. This is the case if + * a driver unbind is blocked. Try to get the locks ourselves to + * prevent a deadlock. + */ + if (vdev->reset_works) { + bool reset_done = false; + + if (pci_cfg_access_trylock(pdev)) { + if (device_trylock(&pdev->dev)) { + __pci_reset_function_locked(pdev); + reset_done = true; + device_unlock(&pdev->dev); + } + pci_cfg_access_unlock(pdev); + } + + if (!reset_done) + pr_warn("%s: Unable to acquire locks for reset of %s\n", + __func__, dev_name(&pdev->dev)); + } pci_restore_state(pdev); } diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index c488da5db7c7..842f4507883e 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -494,27 +494,6 @@ static int vfio_group_nb_add_dev(struct vfio_group *group, struct device *dev) return 0; } -static int vfio_group_nb_del_dev(struct vfio_group *group, struct device *dev) -{ - struct vfio_device *device; - - /* - * Expect to fall out here. If a device was in use, it would - * have been bound to a vfio sub-driver, which would have blocked - * in .remove at vfio_del_group_dev. Sanity check that we no - * longer track the device, so it's safe to remove. - */ - device = vfio_group_get_device(group, dev); - if (likely(!device)) - return 0; - - WARN("Device %s removed from live group %d!\n", dev_name(dev), - iommu_group_id(group->iommu_group)); - - vfio_device_put(device); - return 0; -} - static int vfio_group_nb_verify(struct vfio_group *group, struct device *dev) { /* We don't care what happens when the group isn't in use */ @@ -531,13 +510,11 @@ static int vfio_iommu_group_notifier(struct notifier_block *nb, struct device *dev = data; /* - * Need to go through a group_lock lookup to get a reference or - * we risk racing a group being removed. Leave a WARN_ON for - * debuging, but if the group no longer exists, a spurious notify - * is harmless. + * Need to go through a group_lock lookup to get a reference or we + * risk racing a group being removed. Ignore spurious notifies. */ group = vfio_group_try_get(group); - if (WARN_ON(!group)) + if (!group) return NOTIFY_OK; switch (action) { @@ -545,7 +522,13 @@ static int vfio_iommu_group_notifier(struct notifier_block *nb, vfio_group_nb_add_dev(group, dev); break; case IOMMU_GROUP_NOTIFY_DEL_DEVICE: - vfio_group_nb_del_dev(group, dev); + /* + * Nothing to do here. If the device is in use, then the + * vfio sub-driver should block the remove callback until + * it is unused. If the device is unused or attached to a + * stub driver, then it should be released and we don't + * care that it will be going away. + */ break; case IOMMU_GROUP_NOTIFY_BIND_DRIVER: pr_debug("%s: Device %s, group %d binding to driver\n", |