[PATCH 2/2] spapr_iommu: Fix vhost integration regression

[Eric Auger <eric.auger@redhat.com>]

Previous work on dev-iotlb message broke spapr_iommu/vhost integration
as it did for SMMU and virtio-iommu. The spapr_iommu currently
only sends IOMMU_NOTIFIER_UNMAP notifications. Since commit
958ec334bca3 ("vhost: Unbreak SMMU and virtio-iommu on dev-iotlb support"),
VHOST first tries to register IOMMU_NOTIFIER_DEVIOTLB_UNMAP notifier
and if it fails, falls back to legacy IOMMU_NOTIFIER_UNMAP. So
spapr_iommu must fail on the IOMMU_NOTIFIER_DEVIOTLB_UNMAP
registration.

Reported-by: Peter Xu <peterx@redhat.com>
Fixes: b68ba1ca57677acf870d5ab10579e6105c1f5338
Signed-off-by: Eric Auger <eric.auger@redhat.com>
---
 hw/ppc/spapr_iommu.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/hw/ppc/spapr_iommu.c b/hw/ppc/spapr_iommu.c
index 30352df00e..24537ffcbd 100644
--- a/hw/ppc/spapr_iommu.c
+++ b/hw/ppc/spapr_iommu.c
@@ -212,6 +212,11 @@ static int spapr_tce_notify_flag_changed(IOMMUMemoryRegion *iommu,
 {
     struct SpaprTceTable *tbl = container_of(iommu, SpaprTceTable, iommu);
 
+    if (new & IOMMU_NOTIFIER_DEVIOTLB_UNMAP) {
+        error_setg(errp, "spart_tce does not support dev-iotlb yet");
+        return -EINVAL;
+    }
+
     if (old == IOMMU_NOTIFIER_NONE && new != IOMMU_NOTIFIER_NONE) {
         spapr_tce_set_need_vfio(tbl, true);
     } else if (old != IOMMU_NOTIFIER_NONE && new == IOMMU_NOTIFIER_NONE) {
-- 
2.26.2