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

Eric Auger
2023-04-04T14:02:02Z

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@nvidia.com>
> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
> Tested-by: Yanting Jiang <yanting.jiang@intel.com>
> Signed-off-by: Yi Liu <yi.l.liu@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@redhat.com>

Thanks

Eric