Re: [Intel-wired-lan] [PATCH iwl-next V2 13/15] vfio/ice: implement vfio_pci driver for E800 devices

[Jason Gunthorpe <jgg@ziepe.ca>]

On Wed, Jun 21, 2023 at 09:11:10AM +0000, Lingyu Liu wrote:

> +static struct file *
> +ice_vfio_pci_step_device_state_locked(struct ice_vfio_pci_core_device *ice_vdev,
> +				      u32 new, u32 final)
> +{
> +	struct device *dev = &ice_vdev->core_device.pdev->dev;
> +	u32 cur = ice_vdev->mig_state;
> +	int ret;
> +
> +	if (final == VFIO_DEVICE_STATE_RESUMING)
> +		ice_vdev->is_dst = true;
> +	else if (final == VFIO_DEVICE_STATE_STOP)
> +		ice_vdev->is_dst = false;

Definately not. The kernel should not be guessing which end is which,
the protocol already makes it clear.

> +
> +	if (cur == VFIO_DEVICE_STATE_RUNNING && new == VFIO_DEVICE_STATE_STOP) {
> +		if (!ice_vdev->is_dst)
> +			dev_info(dev, "Live migration begins\n");
> +		ice_migration_suspend_vf(ice_vdev->vf_handle, ice_vdev->is_dst);
> +		return NULL;
> +	}
> +
> +	if (cur == VFIO_DEVICE_STATE_STOP && new == VFIO_DEVICE_STATE_STOP_COPY) {
> +		struct ice_vfio_pci_migration_file *migf;
> +
> +		migf = ice_vfio_pci_stop_copy(ice_vdev);
> +		if (IS_ERR(migf))
> +			return ERR_CAST(migf);
> +		get_file(migf->filp);
> +		ice_vdev->saving_migf = migf;
> +		return migf->filp;
> +	}
> +
> +	if (cur == VFIO_DEVICE_STATE_STOP_COPY && new == VFIO_DEVICE_STATE_STOP) {
> +		ice_vfio_pci_disable_fds(ice_vdev);
> +		dev_info(dev, "Live migration ends\n");
> +		return NULL;
> +	}
> +
> +	if (cur == VFIO_DEVICE_STATE_STOP && new == VFIO_DEVICE_STATE_RESUMING) {
> +		struct ice_vfio_pci_migration_file *migf;
> +
> +		migf = ice_vfio_pci_resume(ice_vdev);
> +		if (IS_ERR(migf))
> +			return ERR_CAST(migf);
> +		get_file(migf->filp);
> +		ice_vdev->resuming_migf = migf;
> +		return migf->filp;
> +	}
> +
> +	if (cur == VFIO_DEVICE_STATE_RESUMING && new == VFIO_DEVICE_STATE_STOP) {
> +		ret = ice_vfio_pci_load_state(ice_vdev);
> +		if (ret)
> +			return ERR_PTR(ret);
> +		ice_vfio_pci_disable_fds(ice_vdev);
> +		return NULL;
> +	}
> +
> +	if (cur == VFIO_DEVICE_STATE_STOP && new == VFIO_DEVICE_STATE_RUNNING)
> +		return NULL;

Lack of P2P is going to be a problem too

Jason
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