From: Jason Gunthorpe <jgg@nvidia.com>
To: Yishai Hadas <yishaih@nvidia.com>
Cc: alex.williamson@redhat.com, kvm@vger.kernel.org,
kevin.tian@intel.com, joao.m.martins@oracle.com,
leonro@nvidia.com, shayd@nvidia.com, maorg@nvidia.com,
avihaih@nvidia.com, cohuck@redhat.com
Subject: Re: [PATCH V2 vfio 03/14] vfio/mlx5: Enforce a single SAVE command at a time
Date: Thu, 1 Dec 2022 20:51:00 -0400 [thread overview]
Message-ID: <Y4lL9CdGcqLWh0F2@nvidia.com> (raw)
In-Reply-To: <20221201152931.47913-4-yishaih@nvidia.com>
On Thu, Dec 01, 2022 at 05:29:20PM +0200, Yishai Hadas wrote:
> diff --git a/drivers/vfio/pci/mlx5/main.c b/drivers/vfio/pci/mlx5/main.c
> index 6e9cf2aacc52..4081a0f7e057 100644
> --- a/drivers/vfio/pci/mlx5/main.c
> +++ b/drivers/vfio/pci/mlx5/main.c
> @@ -245,6 +245,8 @@ 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);
> + complete(&migf->save_comp);
Add comment here
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.
Jason
next prev parent reply other threads:[~2022-12-02 0:51 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-01 15:29 [PATCH V2 vfio 00/14] Add migration PRE_COPY support for mlx5 driver Yishai Hadas
2022-12-01 15:29 ` [PATCH V2 vfio 01/14] net/mlx5: Introduce ifc bits for pre_copy Yishai Hadas
2022-12-01 15:29 ` [PATCH V2 vfio 02/14] vfio: Extend the device migration protocol with PRE_COPY Yishai Hadas
2022-12-01 22:43 ` Alex Williamson
2022-12-04 7:38 ` Leon Romanovsky
2022-12-02 8:48 ` Tian, Kevin
2022-12-04 8:35 ` Yishai Hadas
2022-12-02 9:38 ` Shameerali Kolothum Thodi
2022-12-05 13:54 ` Yishai Hadas
2022-12-01 15:29 ` [PATCH V2 vfio 03/14] vfio/mlx5: Enforce a single SAVE command at a time Yishai Hadas
2022-12-02 0:51 ` Jason Gunthorpe [this message]
2022-12-04 12:07 ` Yishai Hadas
2022-12-01 15:29 ` [PATCH V2 vfio 04/14] vfio/mlx5: Refactor PD usage Yishai Hadas
2022-12-01 15:29 ` [PATCH V2 vfio 05/14] vfio/mlx5: Refactor MKEY usage Yishai Hadas
2022-12-01 15:29 ` [PATCH V2 vfio 06/14] vfio/mlx5: Refactor migration file state Yishai Hadas
2022-12-01 15:29 ` [PATCH V2 vfio 07/14] vfio/mlx5: Refactor to use queue based data chunks Yishai Hadas
2022-12-01 15:29 ` [PATCH V2 vfio 08/14] vfio/mlx5: Introduce device transitions of PRE_COPY Yishai Hadas
2022-12-01 15:29 ` [PATCH V2 vfio 09/14] vfio/mlx5: Introduce SW headers for migration states Yishai Hadas
2022-12-01 15:29 ` [PATCH V2 vfio 10/14] vfio/mlx5: Introduce vfio precopy ioctl implementation Yishai Hadas
2022-12-01 15:29 ` [PATCH V2 vfio 11/14] vfio/mlx5: Consider temporary end of stream as part of PRE_COPY Yishai Hadas
2022-12-01 15:29 ` [PATCH V2 vfio 12/14] vfio/mlx5: Introduce multiple loads Yishai Hadas
2022-12-01 15:29 ` [PATCH V2 vfio 13/14] vfio/mlx5: Fallback to STOP_COPY upon specific PRE_COPY error Yishai Hadas
2022-12-01 15:29 ` [PATCH V2 vfio 14/14] vfio/mlx5: Enable MIGRATION_PRE_COPY flag Yishai Hadas
2022-12-02 1:06 ` [PATCH V2 vfio 00/14] Add migration PRE_COPY support for mlx5 driver Jason Gunthorpe
2022-12-02 8:57 ` Tian, Kevin
2022-12-04 11:54 ` Yishai Hadas
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