Commit 88faa5e8 authored by Yishai Hadas's avatar Yishai Hadas Committed by Leon Romanovsky
Browse files

vfio/mlx5: Use its own PCI reset_done error handler 

Register its own handler for pci_error_handlers.reset_done and update
state accordingly.

Link: https://lore.kernel.org/all/20220224142024.147653-16-yishaih@nvidia.com


Reviewed-by: default avatarAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: default avatarYishai Hadas <yishaih@nvidia.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Signed-off-by: default avatarLeon Romanovsky <leonro@nvidia.com>
parent 915076f7

drivers/vfio/pci/mlx5/main.c

+55 −2
Original line number Diff line number Diff line
@@ -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)