Messages in this thread |  | | Subject | Re: [PATCH v9 15/22] s390: vfio-ap: implement mediated device open callback | From | Tony Krowiak <> | Date | Wed, 15 Aug 2018 14:21:27 -0400 |
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On 08/15/2018 12:08 PM, Cornelia Huck wrote: > 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
A nit, but somebody else will point it out too, so I will fix it.
> >> 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.
I'll fix 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...
I believe that was the case in a previous patch, but for some reason the code was changed. I'll rework this so it uses the kvm param instead.
> >> + 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.
That makes more sense to me too. Don't set matrix_mdev->kvm until we know it is okay to do so.
> >> + 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).
Will do.
> >> + >> + vfio_ap_mdev_copy_masks(matrix_mdev); >> + >> + return NOTIFY_OK; >> +} > Otherwise, looks sane.
Good!!!
>
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