Commit e3e9bda38e6d ("s390/virtio_ccw: use DMA handle from DMA API")
broke configuration change notifications for virtio-ccw by putting the
DMA address of *indicatorp directly into ccw->cda disregarding the fact
that if !!(vcdev->is_thinint) then the function
virtio_ccw_register_adapter_ind() will overwrite that ccw->cda value
with the address of the virtio_thinint_area so it can actually set up
the adapter interrupts via CCW_CMD_SET_IND_ADAPTER.  Thus we end up
pointing to the wrong object for both CCW_CMD_SET_IND if setting up the
adapter interrupts fails, and for CCW_CMD_SET_CONF_IND regardless
whether it succeeds or fails.

To fix this, let us save away the dma address of *indicatorp in a local
variable, and copy it to ccw->cda after the "vcdev->is_thinint" branch.

Reported-by: Boqiao Fu <b...@redhat.com>
Reported-by: Sebastian Mitterle <smitt...@redhat.com>
Fixes: e3e9bda38e6d ("s390/virtio_ccw: use DMA handle from DMA API")
Signed-off-by: Halil Pasic <pa...@linux.ibm.com>
---
I know that checkpatch.pl complains about a missing 'Closes' tag.
Unfortunately I don't have an appropriate URL at hand. @Sebastian,
@Boqiao: do you have any suggetions?
---
 drivers/s390/virtio/virtio_ccw.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c
index d7569f395559..d6491fc84e8c 100644
--- a/drivers/s390/virtio/virtio_ccw.c
+++ b/drivers/s390/virtio/virtio_ccw.c
@@ -698,6 +698,7 @@ static int virtio_ccw_find_vqs(struct virtio_device *vdev, 
unsigned nvqs,
        dma64_t *indicatorp = NULL;
        int ret, i, queue_idx = 0;
        struct ccw1 *ccw;
+       dma32_t indicatorp_dma = 0;
 
        ccw = ccw_device_dma_zalloc(vcdev->cdev, sizeof(*ccw), NULL);
        if (!ccw)
@@ -725,7 +726,7 @@ static int virtio_ccw_find_vqs(struct virtio_device *vdev, 
unsigned nvqs,
        */
        indicatorp = ccw_device_dma_zalloc(vcdev->cdev,
                                           sizeof(*indicatorp),
-                                          &ccw->cda);
+                                          &indicatorp_dma);
        if (!indicatorp)
                goto out;
        *indicatorp = indicators_dma(vcdev);
@@ -735,6 +736,7 @@ static int virtio_ccw_find_vqs(struct virtio_device *vdev, 
unsigned nvqs,
                        /* no error, just fall back to legacy interrupts */
                        vcdev->is_thinint = false;
        }
+       ccw->cda = indicatorp_dma;
        if (!vcdev->is_thinint) {
                /* Register queue indicators with host. */
                *indicators(vcdev) = 0;

base-commit: 83a7eefedc9b56fe7bfeff13b6c7356688ffa670
-- 
2.40.1


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