Register its own handler for pci_error_handlers.reset_done and update
state accordingly.
Signed-off-by: Yishai Hadas <yishaih@xxxxxxxxxx>
Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
---
drivers/vfio/pci/mlx5/main.c | 55 +++++++++++++++++++++++++++++++++++-
1 file changed, 54 insertions(+), 1 deletion(-)
diff --git a/drivers/vfio/pci/mlx5/main.c b/drivers/vfio/pci/mlx5/main.c
index c15c8eed85d3..4d65a5c2d3b3 100644
--- a/drivers/vfio/pci/mlx5/main.c
+++ b/drivers/vfio/pci/mlx5/main.c
@@ -28,9 +28,12 @@
struct mlx5vf_pci_core_device {
struct vfio_pci_core_device core_device;
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;
u16 vhca_id;
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,
@@ -466,10 +488,34 @@ mlx5vf_pci_set_device_state(struct vfio_device *vdev,
}
}
*final_state = mvdev->mig_state;
- mutex_unlock(&mvdev->state_mutex);
+ mlx5vf_state_mutex_unlock(mvdev);
return res;
}
+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(
@@ -550,6 +596,7 @@ 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);
}
@@ -584,11 +631,17 @@ 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)
--
2.18.1
