[Qemu-ppc] [PATCH 1/2] pseries: Don't allow TCE (iommu) tables to be registered with duplicate LIOBNs

[David Gibson]

The PAPR specification requires that every bus or device mediated by the
IOMMU have a unique Logical IO Bus Number (LIOBN).  This patch adds a check
to enforce this, which will help catch errors in configuration earlier.

Signed-off-by: David Gibson <address@hidden>
---
 hw/spapr_iommu.c |    6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/hw/spapr_iommu.c b/hw/spapr_iommu.c
index 02d78cc..3011b25 100644
--- a/hw/spapr_iommu.c
+++ b/hw/spapr_iommu.c
@@ -120,6 +120,12 @@ DMAContext *spapr_tce_new_dma_context(uint32_t liobn, 
size_t window_size)
 {
     sPAPRTCETable *tcet;
 
+    if (spapr_tce_find_by_liobn(liobn)) {
+        fprintf(stderr, "Attempted to create TCE table with duplicate"
+                " LIOBN 0x%x\n", liobn);
+        return NULL;
+    }
+
     if (!window_size) {
         return NULL;
     }
-- 
1.7.10.4