On 19/02/2019 10:59, Halil Pasic wrote:
On Fri, 15 Feb 2019 17:55:35 -0500
Tony Krowiak <akrowiak@xxxxxxxxxxxxx> wrote:
On 2/14/19 8:51 AM, Pierre Morel wrote:
To be able to use the VFIO interface to facilitate the
mediated device memory pining/unpining we need to register
a notifier for IOMMU.
Signed-off-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
---
drivers/s390/crypto/vfio_ap_ops.c | 64 +++++++++++++++++++++++++++++++----
drivers/s390/crypto/vfio_ap_private.h | 2 ++
2 files changed, 60 insertions(+), 6 deletions(-)
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 1851b24..6eddc2c 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
[..]
struct vfio_ap_queue *q;
@@ -967,12 +996,32 @@ static int vfio_ap_mdev_open(struct mdev_device *mdev)
ret = vfio_register_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY,
&events, &matrix_mdev->group_notifier);
- if (ret) {
- module_put(THIS_MODULE);
- return ret;
- }
+ if (ret)
+ goto err_group;
+
+ matrix_mdev->iommu_notifier.notifier_call = vfio_ap_mdev_iommu_notifier;
+ events = VFIO_IOMMU_NOTIFY_DMA_UNMAP;
+
+ ret = vfio_register_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
+ &events, &matrix_mdev->iommu_notifier);
+ if (ret)
+ goto err_iommu;
+
+ ret = vfio_ap_associate_queues(matrix_mdev);
+ if (ret)
+ goto err_associate;
I think the matrix_mdev should be associated with queues when an
assignment of an adapter or domain is made to the mdev device via its
sysfs interfaces. I say this because assigning an adapter or domain to
an mdev device effectively grants ownership of any additional AP queues
added to the mdev device's AP matrix as a result of the assignment. It
only makes sense to assign ownership to the vfio_ap_queue objects
representing the queues at that time. If an adapter or domain is
dynamically assigned while a guest is using the affected queues, then
the associations will have to be made at that time and this code will
likely go bye bye.
Actually, we need the stuff in vfio_ap_queues only if the guest is
offered to decides to use AP adaper interrupts. I would prefer to have
it around only when needed: as long as we have the nib pinned for any
given queue. Is there a reason why not to do so?
Regards,
Halil
[..]
Since I will rework the vfio_ap_queue life cycle, I will study this.
But I find the creation / deletion in probe/remove and the link/unlimk
to the matrix device in assign/un_assign as suggested by Tony more logical.
Regards,
Pierre
--
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany
