[PATCH vfio 01/13] vfio/mlx5: Protect mlx5vf_disable_fds() upon close device

From: Yishai Hadas <yishaih@nvidia.com>
To: <alex.williamson@redhat.com>, <jgg@nvidia.com>
Cc: <saeedm@nvidia.com>, <kvm@vger.kernel.org>,
	<netdev@vger.kernel.org>, <kuba@kernel.org>,
	<kevin.tian@intel.com>, <joao.m.martins@oracle.com>,
	<leonro@nvidia.com>, <yishaih@nvidia.com>, <maorg@nvidia.com>,
	<cohuck@redhat.com>
Subject: [PATCH vfio 01/13] vfio/mlx5: Protect mlx5vf_disable_fds() upon close device
Date: Thu, 30 Jun 2022 13:25:33 +0300	[thread overview]
Message-ID: <20220630102545.18005-2-yishaih@nvidia.com> (raw)
In-Reply-To: <20220630102545.18005-1-yishaih@nvidia.com>

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>
---
 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);
 }
 
-- 
2.18.1

