[Intel-gfx] [PATCH v3 03/12] vfio/pci: Move the existing hot reset logic to be a helper

[Eric Auger]

Hi Yi,

On 4/1/23 16:44, Yi Liu wrote:
> This prepares to add another method for hot reset. The major hot reset logic
> are moved to vfio_pci_ioctl_pci_hot_reset_groups().
>
> No functional change is intended.
>
> Suggested-by: Jason Gunthorpe <jgg at nvidia.com>
> Signed-off-by: Jason Gunthorpe <jgg at nvidia.com>
> Reviewed-by: Jason Gunthorpe <jgg at nvidia.com>
> Tested-by: Yanting Jiang <yanting.jiang at intel.com>
> Signed-off-by: Yi Liu <yi.l.liu at intel.com>
> ---
>  drivers/vfio/pci/vfio_pci_core.c | 56 +++++++++++++++++++-------------
>  1 file changed, 33 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
> index 5d745c9abf05..3696b8e58445 100644
> --- a/drivers/vfio/pci/vfio_pci_core.c
> +++ b/drivers/vfio/pci/vfio_pci_core.c
> @@ -1255,29 +1255,17 @@ static int vfio_pci_ioctl_get_pci_hot_reset_info(
>  	return ret;
>  }
>  
> -static int vfio_pci_ioctl_pci_hot_reset(struct vfio_pci_core_device *vdev,
> -					struct vfio_pci_hot_reset __user *arg)
> +static int
> +vfio_pci_ioctl_pci_hot_reset_groups(struct vfio_pci_core_device *vdev,
> +				    struct vfio_pci_hot_reset *hdr,
nit why don't you simply pass the user group count as decoded earlier.
hdr sounds like a dup of arg.
> +				    bool slot,
> +				    struct vfio_pci_hot_reset __user *arg)
>  {
> -	unsigned long minsz = offsetofend(struct vfio_pci_hot_reset, count);
> -	struct vfio_pci_hot_reset hdr;
>  	int32_t *group_fds;
>  	struct file **files;
>  	struct vfio_pci_group_info info;
> -	bool slot = false;
>  	int file_idx, count = 0, ret = 0;
>  
> -	if (copy_from_user(&hdr, arg, minsz))
> -		return -EFAULT;
> -
> -	if (hdr.argsz < minsz || hdr.flags)
> -		return -EINVAL;
> -
> -	/* Can we do a slot or bus reset or neither? */
> -	if (!pci_probe_reset_slot(vdev->pdev->slot))
> -		slot = true;
> -	else if (pci_probe_reset_bus(vdev->pdev->bus))
> -		return -ENODEV;
> -
>  	/*
>  	 * We can't let userspace give us an arbitrarily large buffer to copy,
>  	 * so verify how many we think there could be.  Note groups can have
> @@ -1289,11 +1277,11 @@ static int vfio_pci_ioctl_pci_hot_reset(struct vfio_pci_core_device *vdev,
>  		return ret;
>  
>  	/* Somewhere between 1 and count is OK */
> -	if (!hdr.count || hdr.count > count)
> +	if (!hdr->count || hdr->count > count)
>  		return -EINVAL;
>  
> -	group_fds = kcalloc(hdr.count, sizeof(*group_fds), GFP_KERNEL);
> -	files = kcalloc(hdr.count, sizeof(*files), GFP_KERNEL);
> +	group_fds = kcalloc(hdr->count, sizeof(*group_fds), GFP_KERNEL);
> +	files = kcalloc(hdr->count, sizeof(*files), GFP_KERNEL);
>  	if (!group_fds || !files) {
>  		kfree(group_fds);
>  		kfree(files);
> @@ -1301,7 +1289,7 @@ static int vfio_pci_ioctl_pci_hot_reset(struct vfio_pci_core_device *vdev,
>  	}
>  
>  	if (copy_from_user(group_fds, arg->group_fds,
> -			   hdr.count * sizeof(*group_fds))) {
> +			   hdr->count * sizeof(*group_fds))) {
>  		kfree(group_fds);
>  		kfree(files);
>  		return -EFAULT;
> @@ -1311,7 +1299,7 @@ static int vfio_pci_ioctl_pci_hot_reset(struct vfio_pci_core_device *vdev,
>  	 * Get the group file for each fd to ensure the group held across
>  	 * the reset
>  	 */
> -	for (file_idx = 0; file_idx < hdr.count; file_idx++) {
> +	for (file_idx = 0; file_idx < hdr->count; file_idx++) {
>  		struct file *file = fget(group_fds[file_idx]);
>  
>  		if (!file) {
> @@ -1335,7 +1323,7 @@ static int vfio_pci_ioctl_pci_hot_reset(struct vfio_pci_core_device *vdev,
>  	if (ret)
>  		goto hot_reset_release;
>  
> -	info.count = hdr.count;
> +	info.count = hdr->count;
>  	info.files = files;
>  
>  	ret = vfio_pci_dev_set_hot_reset(vdev->vdev.dev_set, &info);
> @@ -1348,6 +1336,28 @@ static int vfio_pci_ioctl_pci_hot_reset(struct vfio_pci_core_device *vdev,
>  	return ret;
>  }
>  
> +static int vfio_pci_ioctl_pci_hot_reset(struct vfio_pci_core_device *vdev,
> +					struct vfio_pci_hot_reset __user *arg)
> +{
> +	unsigned long minsz = offsetofend(struct vfio_pci_hot_reset, count);
> +	struct vfio_pci_hot_reset hdr;
> +	bool slot = false;
> +
> +	if (copy_from_user(&hdr, arg, minsz))
> +		return -EFAULT;
> +
> +	if (hdr.argsz < minsz || hdr.flags)
> +		return -EINVAL;
> +
> +	/* Can we do a slot or bus reset or neither? */
> +	if (!pci_probe_reset_slot(vdev->pdev->slot))
> +		slot = true;
> +	else if (pci_probe_reset_bus(vdev->pdev->bus))
> +		return -ENODEV;
> +
> +	return vfio_pci_ioctl_pci_hot_reset_groups(vdev, &hdr, slot, arg);
> +}
> +
>  static int vfio_pci_ioctl_ioeventfd(struct vfio_pci_core_device *vdev,
>  				    struct vfio_device_ioeventfd __user *arg)
>  {
Besides
Reviewed-by: Eric Auger <eric.auger at redhat.com>

Thanks

Eric