From: Matthew Rosato <mjrosato@xxxxxxxxxxxxx>
vfio_iommufd_bind() creates an access which has an unmap callback, which
can be called immediately. So dma_unmap() callback should tolerate the
unmaps that come before the emulated device is opened.
To achieve above, vfio_ap_mdev_dma_unmap() needs to validate that unmap
request matches with one or more of these stashed values before
attempting unpins.
Currently, each mapped iova is stashed in its associated vfio_ap_queue;
Each stashed iova represents IRQ that was enabled for a queue. Therefore,
if a match is found, trigger IRQ disable for this queue to ensure that
underlying firmware will no longer try to use the associated pfn after
the page is unpinned. IRQ disable will also handle the associated unpin.
Cc: Tony Krowiak <akrowiak@xxxxxxxxxxxxx>
Cc: Halil Pasic <pasic@xxxxxxxxxxxxx>
Cc: Jason Herne <jjherne@xxxxxxxxxxxxx>
Signed-off-by: Matthew Rosato <mjrosato@xxxxxxxxxxxxx>
Signed-off-by: Yi Liu <yi.l.liu@xxxxxxxxx>
---
drivers/s390/crypto/vfio_ap_ops.c | 24 +++++++++++++++++++++++-
1 file changed, 23 insertions(+), 1 deletion(-)
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index bb7776d20792..62bfca2bbe6d 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -1535,13 +1535,35 @@ static int vfio_ap_mdev_set_kvm(struct ap_matrix_mdev *matrix_mdev,
return 0;
}
+static void unmap_iova(struct ap_matrix_mdev *matrix_mdev, u64 iova, u64 length)
+{
+ struct ap_queue_table *qtable = &matrix_mdev->qtable;
+ u64 iova_pfn_end = (iova + length - 1) >> PAGE_SHIFT;
+ u64 iova_pfn_start = iova >> PAGE_SHIFT;
+ struct vfio_ap_queue *q;
+ int loop_cursor;
+ u64 pfn;
+
+ hash_for_each(qtable->queues, loop_cursor, q, mdev_qnode) {
+ pfn = q->saved_iova >> PAGE_SHIFT;
+ if (pfn >= iova_pfn_start && pfn <= iova_pfn_end) {
+ vfio_ap_irq_disable(q);
+ break;
+ }
+ }
+}
+
static void vfio_ap_mdev_dma_unmap(struct vfio_device *vdev, u64 iova,
u64 length)
{
struct ap_matrix_mdev *matrix_mdev =
container_of(vdev, struct ap_matrix_mdev, vdev);
- vfio_unpin_pages(&matrix_mdev->vdev, iova, 1);
+ mutex_lock(&matrix_dev->mdevs_lock);
+
+ unmap_iova(matrix_mdev, iova, length);
+
+ mutex_unlock(&matrix_dev->mdevs_lock);
}
/**
--
2.34.1
