[PATCH 5.19 0922/1157] vfio/mlx5: Protect mlx5vf_disable_fds() upon close device

Greg Kroah-Hartman
2022-08-16T00:43:00Z

From: Yishai Hadas <yishaih@nvidia.com>

[ Upstream commit 2b1c1906286fa547845f5385ee72db74b2b0251d ]

Protect mlx5vf_disable_fds() upon close device to be called under the
state mutex as done in all other places.

This will prevent a race with any other flow which calls
mlx5vf_disable_fds() as of health/recovery upon
MLX5_PF_NOTIFY_DISABLE_VF event.

Encapsulate this functionality in a separate function named
mlx5vf_cmd_close_migratable() to consider migration caps and for further
usage upon close device.

Fixes: 6fadb021266d ("vfio/mlx5: Implement vfio_pci driver for mlx5 devices")
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20220628155910.171454-2-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/vfio/pci/mlx5/cmd.c | 10 ++++++++++
drivers/vfio/pci/mlx5/cmd.h | 1 +
drivers/vfio/pci/mlx5/main.c | 2 +-
3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/vfio/pci/mlx5/cmd.c b/drivers/vfio/pci/mlx5/cmd.c
index 9b9f33ca270a..cdd0c667dc77 100644
--- a/drivers/vfio/pci/mlx5/cmd.c
+++ b/drivers/vfio/pci/mlx5/cmd.c
@@ -88,6 +88,16 @@ static int mlx5fv_vf_event(struct notifier_block *nb,
return 0;
}

+void mlx5vf_cmd_close_migratable(struct mlx5vf_pci_core_device *mvdev)
+{
+ if (!mvdev->migrate_cap)
+ return;
+
+ mutex_lock(&mvdev->state_mutex);
+ mlx5vf_disable_fds(mvdev);
+ mlx5vf_state_mutex_unlock(mvdev);
+}
+
void mlx5vf_cmd_remove_migratable(struct mlx5vf_pci_core_device *mvdev)
{
if (!mvdev->migrate_cap)
diff --git a/drivers/vfio/pci/mlx5/cmd.h b/drivers/vfio/pci/mlx5/cmd.h
index 6c3112fdd8b1..aa692d9ce656 100644
--- a/drivers/vfio/pci/mlx5/cmd.h
+++ b/drivers/vfio/pci/mlx5/cmd.h
@@ -64,6 +64,7 @@ int mlx5vf_cmd_query_vhca_migration_state(struct mlx5vf_pci_core_device *mvdev,
size_t *state_size);
void mlx5vf_cmd_set_migratable(struct mlx5vf_pci_core_device *mvdev);
void mlx5vf_cmd_remove_migratable(struct mlx5vf_pci_core_device *mvdev);
+void mlx5vf_cmd_close_migratable(struct mlx5vf_pci_core_device *mvdev);
int mlx5vf_cmd_save_vhca_state(struct mlx5vf_pci_core_device *mvdev,
struct mlx5_vf_migration_file *migf);
int mlx5vf_cmd_load_vhca_state(struct mlx5vf_pci_core_device *mvdev,
diff --git a/drivers/vfio/pci/mlx5/main.c b/drivers/vfio/pci/mlx5/main.c
index 0558d0649ddb..d754990f0662 100644
--- a/drivers/vfio/pci/mlx5/main.c
+++ b/drivers/vfio/pci/mlx5/main.c
@@ -570,7 +570,7 @@ static void mlx5vf_pci_close_device(struct vfio_device *core_vdev)
struct mlx5vf_pci_core_device *mvdev = container_of(
core_vdev, struct mlx5vf_pci_core_device, core_device.vdev);

- mlx5vf_disable_fds(mvdev);
+ mlx5vf_cmd_close_migratable(mvdev);
vfio_pci_core_close_device(core_vdev);
}

--
2.35.1