On Tue, 12 Apr 2022 16:52:44 -0300
Jason Gunthorpe <jgg@xxxxxxxxxx> wrote:
> On Tue, Apr 12, 2022 at 12:25:44PM -0600, Alex Williamson wrote:
> > On Mon, 11 Apr 2022 10:56:31 -0300
> > Jason Gunthorpe <jgg@xxxxxxxxxx> wrote:
> >
> > > @@ -1732,10 +1705,28 @@ static int vfio_pci_bus_notifier(struct notifier_block *nb,
> > > static int vfio_pci_vf_init(struct vfio_pci_core_device *vdev)
> > > {
> > > struct pci_dev *pdev = vdev->pdev;
> > > + struct vfio_pci_core_device *cur;
> > > + struct pci_dev *physfn;
> > > int ret;
> > >
> > > - if (!pdev->is_physfn)
> > > + if (!pdev->is_physfn) {
> > > + /*
> > > + * If this VF was created by our vfio_pci_core_sriov_configure()
> > > + * then we can find the PF vfio_pci_core_device now, and due to
> > > + * the locking in pci_disable_sriov() it cannot change until
> > > + * this VF device driver is removed.
> > > + */
> > > + physfn = pci_physfn(vdev->pdev);
> > > + mutex_lock(&vfio_pci_sriov_pfs_mutex);
> > > + list_for_each_entry (cur, &vfio_pci_sriov_pfs, sriov_pfs_item) {
> > > + if (cur->pdev == physfn) {
> > > + vdev->sriov_pf_core_dev = cur;
> > > + break;
> > > + }
> > > + }
> > > + mutex_unlock(&vfio_pci_sriov_pfs_mutex);
> > > return 0;
> > > + }
> > >
> > > vdev->vf_token = kzalloc(sizeof(*vdev->vf_token), GFP_KERNEL);
> > > if (!vdev->vf_token)
> >
> > One more comment on final review; are we equating !is_physfn to
> > is_virtfn above? This branch was originally meant to kick out both VFs
> > and non-SRIOV PFs. Calling pci_physfn() on a !is_virtfn device will
> > return itself, so we should never find a list match, but we also don't
> > need to look for a match for !is_virtfn, so it's a bit confusing and
> > slightly inefficient. Should the new code be added in a separate
> > is_virtfn branch above the existing !is_physfn test? Thanks,
>
> I started at it for a while and came the same conclusion, I
> misunderstood that is_physfn is really trying to be
> is_sriov_physfn.. So not a bug, but not really clear code.
>
> I added this, I'll repost it.
Looks good. Thanks,
Alex
> diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
> index 8bf0f18e668a32..3c6493957abe19 100644
> --- a/drivers/vfio/pci/vfio_pci_core.c
> +++ b/drivers/vfio/pci/vfio_pci_core.c
> @@ -1709,7 +1709,7 @@ static int vfio_pci_vf_init(struct vfio_pci_core_device *vdev)
> struct pci_dev *physfn;
> int ret;
>
> - if (!pdev->is_physfn) {
> + if (pdev->is_virtfn) {
> /*
> * If this VF was created by our vfio_pci_core_sriov_configure()
> * then we can find the PF vfio_pci_core_device now, and due to
> @@ -1728,6 +1728,10 @@ static int vfio_pci_vf_init(struct vfio_pci_core_device *vdev)
> return 0;
> }
>
> + /* Not a SRIOV PF */
> + if (!pdev->is_physfn)
> + return 0;
> +
> vdev->vf_token = kzalloc(sizeof(*vdev->vf_token), GFP_KERNEL);
> if (!vdev->vf_token)
> return -ENOMEM;
>
>
> Thanks,
> Jason
>
