Re: [PATCH v9 15/22] s390: vfio-ap: implement mediated device open callback

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 08/15/2018 12:08 PM, Cornelia Huck wrote:
On Mon, 13 Aug 2018 17:48:12 -0400
Tony Krowiak <akrowiak@xxxxxxxxxxxxxxxxxx> wrote:

From: Tony Krowiak <akrowiak@xxxxxxxxxxxxx>

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@xxxxxxxxxxxxx>
Acked-by: Halil Pasic <pasic@xxxxxxxxxxxxx>
Tested-by: Michael Mueller <mimu@xxxxxxxxxxxxx>
Tested-by: Farhan Ali <alifm@xxxxxxxxxxxxx>
Tested-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
Acked-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
---
  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!!!






[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Kernel Development]     [Kernel Newbies]     [IDE]     [Security]     [Git]     [Netfilter]     [Bugtraq]     [Yosemite Info]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux ATA RAID]     [Samba]     [Linux Media]     [Device Mapper]

  Powered by Linux