diff options
| author | Yishai Hadas <yishaih@nvidia.com> | 2022-12-06 09:34:27 +0100 |
|---|---|---|
| committer | Alex Williamson <alex.williamson@redhat.com> | 2022-12-06 20:36:44 +0100 |
| commit | 0e7caa65d707b93fbb4322c6313f739fa9103dfa (patch) | |
| tree | 4524ccc75ef1e8fdba06aecf25dc9cc8d9c2b7b2 /drivers/vfio/pci/mlx5 | |
| parent | vfio: Extend the device migration protocol with PRE_COPY (diff) | |
| download | linux-0e7caa65d707b93fbb4322c6313f739fa9103dfa.tar.xz linux-0e7caa65d707b93fbb4322c6313f739fa9103dfa.zip | |
vfio/mlx5: Enforce a single SAVE command at a time
Enforce a single SAVE command at a time.
As the SAVE command is an asynchronous one, we must enforce running only
a single command at a time.
This will preserve ordering between multiple calls and protect from
races on the migration file data structure.
This is a must for the next patches from the series where as part of
PRE_COPY we may have multiple images to be saved and multiple SAVE
commands may be issued from different flows.
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20221206083438.37807-4-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'drivers/vfio/pci/mlx5')
| -rw-r--r-- | drivers/vfio/pci/mlx5/cmd.c | 6 | ||||
| -rw-r--r-- | drivers/vfio/pci/mlx5/cmd.h | 1 | ||||
| -rw-r--r-- | drivers/vfio/pci/mlx5/main.c | 7 |
3 files changed, 14 insertions, 0 deletions
diff --git a/drivers/vfio/pci/mlx5/cmd.c b/drivers/vfio/pci/mlx5/cmd.c index 0848bc905d3e..55ee8036f59c 100644 --- a/drivers/vfio/pci/mlx5/cmd.c +++ b/drivers/vfio/pci/mlx5/cmd.c @@ -281,6 +281,7 @@ void mlx5vf_mig_file_cleanup_cb(struct work_struct *_work) dma_unmap_sgtable(mdev->device, &migf->table.sgt, DMA_FROM_DEVICE, 0); mlx5_core_dealloc_pd(mdev, async_data->pdn); kvfree(async_data->out); + complete(&migf->save_comp); fput(migf->filp); } @@ -321,6 +322,10 @@ int mlx5vf_cmd_save_vhca_state(struct mlx5vf_pci_core_device *mvdev, return -ENOTCONN; mdev = mvdev->mdev; + err = wait_for_completion_interruptible(&migf->save_comp); + if (err) + return err; + err = mlx5_core_alloc_pd(mdev, &pdn); if (err) return err; @@ -371,6 +376,7 @@ err_create_mkey: dma_unmap_sgtable(mdev->device, &migf->table.sgt, DMA_FROM_DEVICE, 0); err_dma_map: mlx5_core_dealloc_pd(mdev, pdn); + complete(&migf->save_comp); return err; } diff --git a/drivers/vfio/pci/mlx5/cmd.h b/drivers/vfio/pci/mlx5/cmd.h index 921d5720a1e5..8ffa7699872c 100644 --- a/drivers/vfio/pci/mlx5/cmd.h +++ b/drivers/vfio/pci/mlx5/cmd.h @@ -37,6 +37,7 @@ struct mlx5_vf_migration_file { unsigned long last_offset; struct mlx5vf_pci_core_device *mvdev; wait_queue_head_t poll_wait; + struct completion save_comp; struct mlx5_async_ctx async_ctx; struct mlx5vf_async_data async_data; }; diff --git a/drivers/vfio/pci/mlx5/main.c b/drivers/vfio/pci/mlx5/main.c index 6e9cf2aacc52..0d71ebb2a972 100644 --- a/drivers/vfio/pci/mlx5/main.c +++ b/drivers/vfio/pci/mlx5/main.c @@ -245,6 +245,13 @@ mlx5vf_pci_save_device_data(struct mlx5vf_pci_core_device *mvdev) stream_open(migf->filp->f_inode, migf->filp); mutex_init(&migf->lock); init_waitqueue_head(&migf->poll_wait); + init_completion(&migf->save_comp); + /* + * save_comp is being used as a binary semaphore built from + * a completion. A normal mutex cannot be used because the lock is + * passed between kernel threads and lockdep can't model this. + */ + complete(&migf->save_comp); mlx5_cmd_init_async_ctx(mvdev->mdev, &migf->async_ctx); INIT_WORK(&migf->async_data.work, mlx5vf_mig_file_cleanup_cb); ret = mlx5vf_cmd_query_vhca_migration_state(mvdev, |