diff options
| -rw-r--r-- | drivers/vfio/pci/mlx5/main.c | 57 |
1 files changed, 55 insertions, 2 deletions
diff --git a/drivers/vfio/pci/mlx5/main.c b/drivers/vfio/pci/mlx5/main.c index ae1e40f7b290..282a9d4bf776 100644 --- a/drivers/vfio/pci/mlx5/main.c +++ b/drivers/vfio/pci/mlx5/main.c @@ -29,9 +29,12 @@ struct mlx5vf_pci_core_device { struct vfio_pci_core_device core_device; u16 vhca_id; u8 migrate_cap:1; + u8 deferred_reset:1; /* protect migration state */ struct mutex state_mutex; enum vfio_device_mig_state mig_state; + /* protect the reset_done flow */ + spinlock_t reset_lock; struct mlx5_vf_migration_file *resuming_migf; struct mlx5_vf_migration_file *saving_migf; }; @@ -437,6 +440,25 @@ mlx5vf_pci_step_device_state_locked(struct mlx5vf_pci_core_device *mvdev, return ERR_PTR(-EINVAL); } +/* + * This function is called in all state_mutex unlock cases to + * handle a 'deferred_reset' if exists. + */ +static void mlx5vf_state_mutex_unlock(struct mlx5vf_pci_core_device *mvdev) +{ +again: + spin_lock(&mvdev->reset_lock); + if (mvdev->deferred_reset) { + mvdev->deferred_reset = false; + spin_unlock(&mvdev->reset_lock); + mvdev->mig_state = VFIO_DEVICE_STATE_RUNNING; + mlx5vf_disable_fds(mvdev); + goto again; + } + mutex_unlock(&mvdev->state_mutex); + spin_unlock(&mvdev->reset_lock); +} + static struct file * mlx5vf_pci_set_device_state(struct vfio_device *vdev, enum vfio_device_mig_state new_state) @@ -465,7 +487,7 @@ mlx5vf_pci_set_device_state(struct vfio_device *vdev, break; } } - mutex_unlock(&mvdev->state_mutex); + mlx5vf_state_mutex_unlock(mvdev); return res; } @@ -477,10 +499,34 @@ static int mlx5vf_pci_get_device_state(struct vfio_device *vdev, mutex_lock(&mvdev->state_mutex); *curr_state = mvdev->mig_state; - mutex_unlock(&mvdev->state_mutex); + mlx5vf_state_mutex_unlock(mvdev); return 0; } +static void mlx5vf_pci_aer_reset_done(struct pci_dev *pdev) +{ + struct mlx5vf_pci_core_device *mvdev = dev_get_drvdata(&pdev->dev); + + if (!mvdev->migrate_cap) + return; + + /* + * As the higher VFIO layers are holding locks across reset and using + * those same locks with the mm_lock we need to prevent ABBA deadlock + * with the state_mutex and mm_lock. + * In case the state_mutex was taken already we defer the cleanup work + * to the unlock flow of the other running context. + */ + spin_lock(&mvdev->reset_lock); + mvdev->deferred_reset = true; + if (!mutex_trylock(&mvdev->state_mutex)) { + spin_unlock(&mvdev->reset_lock); + return; + } + spin_unlock(&mvdev->reset_lock); + mlx5vf_state_mutex_unlock(mvdev); +} + static int mlx5vf_pci_open_device(struct vfio_device *core_vdev) { struct mlx5vf_pci_core_device *mvdev = container_of( @@ -562,6 +608,7 @@ static int mlx5vf_pci_probe(struct pci_dev *pdev, VFIO_MIGRATION_STOP_COPY | VFIO_MIGRATION_P2P; mutex_init(&mvdev->state_mutex); + spin_lock_init(&mvdev->reset_lock); } mlx5_vf_put_core_dev(mdev); } @@ -596,11 +643,17 @@ static const struct pci_device_id mlx5vf_pci_table[] = { MODULE_DEVICE_TABLE(pci, mlx5vf_pci_table); +static const struct pci_error_handlers mlx5vf_err_handlers = { + .reset_done = mlx5vf_pci_aer_reset_done, + .error_detected = vfio_pci_core_aer_err_detected, +}; + static struct pci_driver mlx5vf_pci_driver = { .name = KBUILD_MODNAME, .id_table = mlx5vf_pci_table, .probe = mlx5vf_pci_probe, .remove = mlx5vf_pci_remove, + .err_handler = &mlx5vf_err_handlers, }; static void __exit mlx5vf_pci_cleanup(void) |