On Tue, Nov 01, 2022 at 08:49:28AM +0000, Tian, Kevin wrote:
> > From: Anthony DeRossi <ajderossi@xxxxxxxxx>
> > Sent: Thursday, October 27, 2022 3:43 AM
> >
> > -static bool vfio_pci_dev_set_needs_reset(struct vfio_device_set *dev_set)
> > +static bool vfio_pci_core_needs_reset(struct vfio_pci_core_device *vdev)
> > {
> > + struct vfio_device_set *dev_set = vdev->vdev.dev_set;
> > struct vfio_pci_core_device *cur;
> > bool needs_reset = false;
> >
> > + if (vdev->vdev.open_count > 1)
> > + return false;
>
> WARN_ON()
>
> > +
> > list_for_each_entry(cur, &dev_set->device_list, vdev.dev_set_list) {
> > - /* No VFIO device in the set can have an open device FD */
> > - if (cur->vdev.open_count)
> > + /* Only the VFIO device being reset can have an open FD */
> > + if (cur != vdev && cur->vdev.open_count)
> > return false;
>
> not caused by this patch but while at it...
>
> open_count is defined not for driver use:
>
> /* Members below here are private, not for driver use */
> unsigned int index;
> struct device device; /* device.kref covers object life circle */
> refcount_t refcount; /* user count on registered device*/
> unsigned int open_count;
> struct completion comp;
> struct list_head group_next;
> struct list_head iommu_entry;
>
> prefer to a wrapper or move it to the public section of vfio_device.
I've been meaning to take a deeper look, but I'm thinking vfio_pci
doesn't need open_count at all any more.
open_count was from before we changed the core code to call
open_device only once. If we are only a call chain from
open_device/close_device then we know that the open_count must be 1.
Jason
