Messages in this thread | | | Date | Wed, 15 Aug 2018 18:08:14 +0200 | From | Cornelia Huck <> | Subject | Re: [PATCH v9 15/22] s390: vfio-ap: implement mediated device open callback |
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On Mon, 13 Aug 2018 17:48:12 -0400 Tony Krowiak <akrowiak@linux.vnet.ibm.com> wrote:
> From: Tony Krowiak <akrowiak@linux.ibm.com> > > Implements the open callback on the mediated matrix device. > The function registers a group notifier to receive notification > of the VFIO_GROUP_NOTIFY_SET_KVM event. When notified, > the vfio_ap device driver will get access to the guest's > kvm structure. The open callback must ensure that only one > mediated device shall be opened per guest. > > Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com> > Acked-by: Halil Pasic <pasic@linux.ibm.com> > Tested-by: Michael Mueller <mimu@linux.ibm.com> > Tested-by: Farhan Ali <alifm@linux.ibm.com> > Tested-by: Pierre Morel <pmorel@linux.ibm.com> > Acked-by: Pierre Morel <pmorel@linux.ibm.com> > Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> > --- > drivers/s390/crypto/vfio_ap_ops.c | 174 ++++++++++++++++++++++++++++++++- > drivers/s390/crypto/vfio_ap_private.h | 2 + > 2 files changed, 175 insertions(+), 1 deletions(-)
> @@ -602,7 +633,6 @@ static ssize_t matrix_show(struct device *dev, struct device_attribute *attr, > } > DEVICE_ATTR_RO(matrix); > > -
Nit: whitespace change
> static struct attribute *vfio_ap_mdev_attrs[] = { > &dev_attr_assign_adapter.attr, > &dev_attr_unassign_adapter.attr,
(...)
> +/** > + * vfio_ap_mdev_open_once > + * > + * @matrix_mdev: a mediated matrix device > + * > + * Return 0 if no other mediated matrix device has been opened for the > + * KVM guest assigned to @matrix_mdev; otherwise, returns an error. > + */ > +static int vfio_ap_mdev_open_once(struct ap_matrix_mdev *matrix_mdev, > + struct kvm *kvm)
You're passing kvm in here, but do not use it.
> +{ > + struct ap_matrix_mdev *m; > + > + mutex_lock(&matrix_dev.lock); > + > + list_for_each_entry(m, &matrix_dev.mdev_list, list) { > + if ((m != matrix_mdev) && (m->kvm == matrix_mdev->kvm)) {
If you used it here instead of matrix_mdev->kvm...
> + mutex_unlock(&matrix_dev.lock); > + return -EPERM; > + } > + } > + > + mutex_unlock(&matrix_dev.lock); > + > + return 0; > +} > + > +static int vfio_ap_mdev_group_notifier(struct notifier_block *nb, > + unsigned long action, void *data) > +{ > + int ret; > + struct ap_matrix_mdev *matrix_mdev; > + > + if (action != VFIO_GROUP_NOTIFY_SET_KVM) > + return NOTIFY_OK; > + > + matrix_mdev = container_of(nb, struct ap_matrix_mdev, group_notifier); > + > + matrix_mdev->kvm = data; > + if (data == NULL) > + return NOTIFY_OK; > + > + ret = vfio_ap_mdev_open_once(matrix_mdev, data);
...you could move this up to before overwriting matrix_mdev->kvm and bailing out when the check failed, which makes more sense to me.
> + if (ret) > + return ret; > + > + ret = kvm_ap_validate_crypto_setup(matrix_mdev->kvm); > + if (ret) > + return ret;
It probably makes more sense to return NOTIFY_DONE in the error case (NOTIFY_BAD does not sound like a good idea as it would stop processing the notifier chain).
> + > + vfio_ap_mdev_copy_masks(matrix_mdev); > + > + return NOTIFY_OK; > +}
Otherwise, looks sane.
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