4 files changed, 30 insertions, 23 deletions

diff --git a/hw/spapr.h b/hw/spapr.h
index 51a966b1e9..e984e3fc3c 100644
--- a/hw/spapr.h
+++ b/hw/spapr.h
@@ -339,6 +339,7 @@ void spapr_iommu_init(void);
 DMAContext *spapr_tce_new_dma_context(uint32_t liobn, size_t window_size);
 void spapr_tce_free(DMAContext *dma);
 void spapr_tce_reset(DMAContext *dma);
+void spapr_tce_set_bypass(DMAContext *dma, bool bypass);
 int spapr_dma_dt(void *fdt, int node_off, const char *propname,
                  uint32_t liobn, uint64_t window, uint32_t size);
 int spapr_tcet_dma_dt(void *fdt, int node_off, const char *propname,
diff --git a/hw/spapr_iommu.c b/hw/spapr_iommu.c
index 216aa06809..38034c07bd 100644
--- a/hw/spapr_iommu.c
+++ b/hw/spapr_iommu.c
@@ -42,6 +42,7 @@ struct sPAPRTCETable {
     uint32_t liobn;
     uint32_t window_size;
     sPAPRTCE *table;
+    bool bypass;
     int fd;
     QLIST_ENTRY(sPAPRTCETable) list;
 };
@@ -78,6 +79,12 @@ static int spapr_tce_translate(DMAContext *dma,
             DMA_ADDR_FMT "\n", tcet->liobn, addr);
 #endif
 
+    if (tcet->bypass) {
+        *paddr = addr;
+        *len = (target_phys_addr_t)-1;
+        return 0;
+    }
+
     /* Check if we are in bound */
     if (addr >= tcet->window_size) {
 #ifdef DEBUG_TCE
@@ -162,15 +169,21 @@ void spapr_tce_free(DMAContext *dma)
     }
 }
 
+void spapr_tce_set_bypass(DMAContext *dma, bool bypass)
+{
+    sPAPRTCETable *tcet = DO_UPCAST(sPAPRTCETable, dma, dma);
+
+    tcet->bypass = bypass;
+}
+
 void spapr_tce_reset(DMAContext *dma)
 {
-    if (dma) {
-        sPAPRTCETable *tcet = DO_UPCAST(sPAPRTCETable, dma, dma);
-        size_t table_size = (tcet->window_size >> SPAPR_TCE_PAGE_SHIFT)
-            * sizeof(sPAPRTCE);
+    sPAPRTCETable *tcet = DO_UPCAST(sPAPRTCETable, dma, dma);
+    size_t table_size = (tcet->window_size >> SPAPR_TCE_PAGE_SHIFT)
+        * sizeof(sPAPRTCE);
 
-        memset(tcet->table, 0, table_size);
-    }
+    tcet->bypass = false;
+    memset(tcet->table, 0, table_size);
 }
 
 static target_ulong put_tce_emu(sPAPRTCETable *tcet, target_ulong ioba,
diff --git a/hw/spapr_vio.c b/hw/spapr_vio.c
index 752836e76c..848806d3f1 100644
--- a/hw/spapr_vio.c
+++ b/hw/spapr_vio.c
@@ -316,14 +316,9 @@ int spapr_vio_send_crq(VIOsPAPRDevice *dev, uint8_t *crq)
 
 static void spapr_vio_quiesce_one(VIOsPAPRDevice *dev)
 {
-    VIOsPAPRDeviceClass *pc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
-    uint32_t liobn = SPAPR_VIO_BASE_LIOBN | dev->reg;
-
     if (dev->dma) {
-        spapr_tce_free(dev->dma);
+        spapr_tce_reset(dev->dma);
     }
-    dev->dma = spapr_tce_new_dma_context(liobn, pc->rtce_window_size);
-
     free_crq(dev);
 }
 
@@ -346,16 +341,14 @@ static void rtas_set_tce_bypass(sPAPREnvironment *spapr, uint32_t token,
         rtas_st(rets, 0, -3);
         return;
     }
-    if (enable) {
-        spapr_tce_free(dev->dma);
-        dev->dma = NULL;
-    } else {
-        VIOsPAPRDeviceClass *pc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
-        uint32_t liobn = SPAPR_VIO_BASE_LIOBN | dev->reg;
 
-        dev->dma = spapr_tce_new_dma_context(liobn, pc->rtce_window_size);
+    if (!dev->dma) {
+        rtas_st(rets, 0, -3);
+        return;
     }
 
+    spapr_tce_set_bypass(dev->dma, !!enable);
+
     rtas_st(rets, 0, 0);
 }
 
@@ -421,7 +414,6 @@ static int spapr_vio_busdev_init(DeviceState *qdev)
 {
     VIOsPAPRDevice *dev = (VIOsPAPRDevice *)qdev;
     VIOsPAPRDeviceClass *pc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
-    uint32_t liobn;
     char *id;
 
     if (dev->reg != -1) {
@@ -463,8 +455,10 @@ static int spapr_vio_busdev_init(DeviceState *qdev)
         return -1;
     }
 
-    liobn = SPAPR_VIO_BASE_LIOBN | dev->reg;
-    dev->dma = spapr_tce_new_dma_context(liobn, pc->rtce_window_size);
+    if (pc->rtce_window_size) {
+        uint32_t liobn = SPAPR_VIO_BASE_LIOBN | dev->reg;
+        dev->dma = spapr_tce_new_dma_context(liobn, pc->rtce_window_size);
+    }
 
     return pc->init(dev);
 }
diff --git a/hw/spapr_vio.h b/hw/spapr_vio.h
index acef65efd3..cc85d26101 100644
--- a/hw/spapr_vio.h
+++ b/hw/spapr_vio.h
@@ -131,7 +131,6 @@ void spapr_vscsi_create(VIOsPAPRBus *bus);
 
 VIOsPAPRDevice *spapr_vty_get_default(VIOsPAPRBus *bus);
 
-int spapr_tce_set_bypass(uint32_t unit, uint32_t enable);
 void spapr_vio_quiesce(void);
 
 #endif /* _HW_SPAPR_VIO_H */