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
@@ -781,6 +781,36 @@ static const struct attribute_group
*vfio_ap_mdev_attr_groups[] = {
};
/**
+ * vfio_ap_mdev_iommu_notifier: IOMMU notifier callback
+ *
+ * @nb: The notifier block
+ * @action: Action to be taken (VFIO_IOMMU_NOTIFY_DMA_UNMAP)
+ * @data: the specific unmap structure for vfio_iommu_type1
+ *
+ * Unpins the guest IOVA. (The NIB guest address we pinned before).
+ * Return NOTIFY_OK after unpining on a UNMAP request.
+ * otherwise, returns NOTIFY_DONE .
+ */
+static int vfio_ap_mdev_iommu_notifier(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ struct ap_matrix_mdev *matrix_mdev;
+
+ matrix_mdev = container_of(nb, struct ap_matrix_mdev,
iommu_notifier);
+
+ if (action == VFIO_IOMMU_NOTIFY_DMA_UNMAP) {
+ struct vfio_iommu_type1_dma_unmap *unmap = data;
+ unsigned long g_pfn = unmap->iova >> PAGE_SHIFT;
+
+ vfio_unpin_pages(mdev_dev(matrix_mdev->mdev), &g_pfn, 1);
+ return NOTIFY_OK;
+ }
+
+ return NOTIFY_DONE;
+}
+
+
+/**
* vfio_ap_mdev_set_kvm
*
* @matrix_mdev: a mediated matrix device
@@ -904,8 +934,7 @@ static void vfio_ap_dissociate_queues(struct
ap_matrix_mdev *matrix_mdev)
* In the case a queue could not be found return -ENODEV.
* Otherwise return 0.
*/
-static __attribute__((unused))
- int vfio_ap_associate_queues(struct ap_matrix_mdev *matrix_mdev)
+static int vfio_ap_associate_queues(struct ap_matrix_mdev *matrix_mdev)
Maybe this function should be introduced in this patch instead?
{
unsigned long apid, apqi;
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.
return 0;
+
+err_associate:
+ vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
+ &matrix_mdev->iommu_notifier);
+err_iommu:
+ vfio_unregister_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY,
+ &matrix_mdev->group_notifier);
+err_group:
+ module_put(THIS_MODULE);
+ return ret;
}
static void vfio_ap_mdev_release(struct mdev_device *mdev)
@@ -985,6 +1034,9 @@ static void vfio_ap_mdev_release(struct
mdev_device *mdev)
vfio_ap_mdev_reset_queues(mdev);
vfio_unregister_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY,
&matrix_mdev->group_notifier);
+ vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
+ &matrix_mdev->iommu_notifier);
+ vfio_ap_dissociate_queues(matrix_mdev);
I think the matrix_mdev should be dissociated from queues when an
adapter or domain is unassigned from the mdev device via its
sysfs interfaces. I say this because unassigning an adapter or domain
from an mdev device effectively takes away ownership of any AP queues
removed from the mdev device's AP matrix as a result of the
unassignment. It only makes sense to remove ownership from the
vfio_ap_queue objects representing the queues at that time. This will
become necessary for the forthcoming dynamic configuration patches.
If an adapter or domain is dynamically unassigned while a guest is
using the affected queues, then the dissociation will have to be made
at that time and this code will likely go bye bye.
