From: Alex Williamson <alex.williamson@redhat.com>
To: Yishai Hadas <yishaih@nvidia.com>
Cc: <bhelgaas@google.com>, <jgg@nvidia.com>, <saeedm@nvidia.com>,
<linux-pci@vger.kernel.org>, <kvm@vger.kernel.org>,
<netdev@vger.kernel.org>, <kuba@kernel.org>, <leonro@nvidia.com>,
<kwankhede@nvidia.com>, <mgurtovoy@nvidia.com>,
<maorg@nvidia.com>, <ashok.raj@intel.com>, <kevin.tian@intel.com>,
<shameerali.kolothum.thodi@huawei.com>
Subject: Re: [PATCH V7 mlx5-next 14/15] vfio/mlx5: Use its own PCI reset_done error handler
Date: Tue, 8 Feb 2022 17:08:01 -0700 [thread overview]
Message-ID: <20220208170801.39dab353.alex.williamson@redhat.com> (raw)
In-Reply-To: <20220207172216.206415-15-yishaih@nvidia.com>
On Mon, 7 Feb 2022 19:22:15 +0200
Yishai Hadas <yishaih@nvidia.com> wrote:
> Register its own handler for pci_error_handlers.reset_done and update
> state accordingly.
>
> Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
> Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
> ---
> drivers/vfio/pci/mlx5/main.c | 57 ++++++++++++++++++++++++++++++++++--
> 1 file changed, 55 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/vfio/pci/mlx5/main.c b/drivers/vfio/pci/mlx5/main.c
> index acd205bcff70..63a889210ef3 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)
> @@ -465,7 +487,7 @@ mlx5vf_pci_set_device_state(struct vfio_device *vdev,
> break;
> }
> }
> - mutex_unlock(&mvdev->state_mutex);
> + mlx5vf_state_mutex_unlock(mvdev);
> return res;
> }
>
> @@ -477,10 +499,34 @@ static int mlx5vf_pci_get_device_state(struct vfio_device *vdev,
>
> mutex_lock(&mvdev->state_mutex);
> *curr_state = mvdev->mig_state;
> - mutex_unlock(&mvdev->state_mutex);
> + mlx5vf_state_mutex_unlock(mvdev);
> return 0;
I still can't see why it wouldn't be a both fairly trivial to implement
and a usability improvement if the unlock wrapper returned -EAGAIN on a
deferred reset so we could avoid returning a stale state to the user
and a dead fd in the former case. Thanks,
Alex
next prev parent reply other threads:[~2022-02-09 0:08 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-07 17:22 [PATCH V7 mlx5-next 00/15] Add mlx5 live migration driver and v2 migration protocol Yishai Hadas
2022-02-07 17:22 ` [PATCH V7 mlx5-next 01/15] PCI/IOV: Add pci_iov_vf_id() to get VF index Yishai Hadas
2022-02-07 17:22 ` [PATCH V7 mlx5-next 02/15] net/mlx5: Reuse exported virtfn index function call Yishai Hadas
2022-02-07 17:22 ` [PATCH V7 mlx5-next 03/15] net/mlx5: Disable SRIOV before PF removal Yishai Hadas
2022-02-07 17:22 ` [PATCH V7 mlx5-next 04/15] PCI/IOV: Add pci_iov_get_pf_drvdata() to allow VF reaching the drvdata of a PF Yishai Hadas
2022-02-07 17:22 ` [PATCH V7 mlx5-next 05/15] net/mlx5: Expose APIs to get/put the mlx5 core device Yishai Hadas
2022-02-07 17:22 ` [PATCH V7 mlx5-next 06/15] net/mlx5: Introduce migration bits and structures Yishai Hadas
2022-02-07 17:22 ` [PATCH V7 mlx5-next 07/15] vfio: Have the core code decode the VFIO_DEVICE_FEATURE ioctl Yishai Hadas
2022-02-07 17:22 ` [PATCH V7 mlx5-next 08/15] vfio: Define device migration protocol v2 Yishai Hadas
2022-02-09 0:07 ` Alex Williamson
2022-02-09 2:36 ` Jason Gunthorpe
2022-02-15 10:41 ` Tian, Kevin
2022-02-15 16:04 ` Jason Gunthorpe
2022-02-15 23:32 ` Alex Williamson
2022-02-16 1:17 ` Jason Gunthorpe
2022-02-16 3:17 ` Tian, Kevin
2022-02-16 12:14 ` Jason Gunthorpe
2022-02-17 2:29 ` Tian, Kevin
2022-02-15 10:58 ` Tian, Kevin
2022-02-15 13:13 ` Jason Gunthorpe
2022-02-15 8:04 ` Tian, Kevin
2022-02-15 15:33 ` Jason Gunthorpe
2022-02-16 3:04 ` Tian, Kevin
2022-02-07 17:22 ` [PATCH V7 mlx5-next 09/15] vfio: Extend the device migration protocol with RUNNING_P2P Yishai Hadas
2022-02-15 10:18 ` Tian, Kevin
2022-02-15 15:56 ` Jason Gunthorpe
2022-02-16 2:52 ` Tian, Kevin
2022-02-16 12:11 ` Jason Gunthorpe
2022-02-07 17:22 ` [PATCH V7 mlx5-next 10/15] vfio: Remove migration protocol v1 documentation Yishai Hadas
2022-02-11 11:03 ` Cornelia Huck
2022-02-07 17:22 ` [PATCH V7 mlx5-next 11/15] vfio/mlx5: Expose migration commands over mlx5 device Yishai Hadas
2022-02-07 17:22 ` [PATCH V7 mlx5-next 12/15] vfio/mlx5: Implement vfio_pci driver for mlx5 devices Yishai Hadas
2022-02-09 0:07 ` Alex Williamson
2022-02-07 17:22 ` [PATCH V7 mlx5-next 13/15] vfio/pci: Expose vfio_pci_core_aer_err_detected() Yishai Hadas
2022-02-07 17:22 ` [PATCH V7 mlx5-next 14/15] vfio/mlx5: Use its own PCI reset_done error handler Yishai Hadas
2022-02-09 0:08 ` Alex Williamson [this message]
2022-02-09 2:39 ` Jason Gunthorpe
2022-02-10 16:48 ` Alex Williamson
2022-02-10 17:27 ` Jason Gunthorpe
2022-02-07 17:22 ` [PATCH V7 mlx5-next 15/15] vfio: Extend the device migration protocol with PRE_COPY Yishai Hadas
2022-02-17 17:15 ` Alex Williamson
2022-02-18 0:03 ` Jason Gunthorpe
2022-02-18 8:01 ` Tian, Kevin
2022-02-18 14:06 ` Jason Gunthorpe
2022-02-22 1:43 ` Tian, Kevin
2022-02-22 15:50 ` Jason Gunthorpe
2022-02-23 0:40 ` Tian, Kevin
2022-02-23 0:44 ` Jason Gunthorpe
2022-02-23 1:46 ` Tian, Kevin
2022-02-18 8:11 ` [PATCH V7 mlx5-next 00/15] Add mlx5 live migration driver and v2 migration protocol Tarun Gupta (SW-GPU)
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