diff --git a/hw/spapr_vio.c b/hw/spapr_vio.c
index 8f14fcc794..481a804e73 100644
--- a/hw/spapr_vio.c
+++ b/hw/spapr_vio.c
@@ -226,6 +226,12 @@ int spapr_tce_dma_write(VIOsPAPRDevice *dev, uint64_t taddr, const void *buf,
             (unsigned long long)taddr, size);
 #endif
 
+    /* Check for bypass */
+    if (dev->flags & VIO_PAPR_FLAG_DMA_BYPASS) {
+        cpu_physical_memory_write(taddr, buf, size);
+        return 0;
+    }
+
     while (size) {
         uint64_t tce;
         uint32_t lsize;
@@ -313,6 +319,12 @@ int spapr_tce_dma_read(VIOsPAPRDevice *dev, uint64_t taddr, void *buf,
             (unsigned long long)taddr, size);
 #endif
 
+    /* Check for bypass */
+    if (dev->flags & VIO_PAPR_FLAG_DMA_BYPASS) {
+        cpu_physical_memory_read(taddr, buf, size);
+        return 0;
+    }
+
     while (size) {
         uint64_t tce;
         uint32_t lsize;
@@ -513,6 +525,72 @@ int spapr_vio_send_crq(VIOsPAPRDevice *dev, uint8_t *crq)
     return 0;
 }
 
+/* "quiesce" handling */
+
+static void spapr_vio_quiesce_one(VIOsPAPRDevice *dev)
+{
+    dev->flags &= ~VIO_PAPR_FLAG_DMA_BYPASS;
+
+    if (dev->rtce_table) {
+        size_t size = (dev->rtce_window_size >> SPAPR_VIO_TCE_PAGE_SHIFT)
+            * sizeof(VIOsPAPR_RTCE);
+        memset(dev->rtce_table, 0, size);
+    }
+
+    dev->crq.qladdr = 0;
+    dev->crq.qsize = 0;
+    dev->crq.qnext = 0;
+}
+
+static void rtas_set_tce_bypass(sPAPREnvironment *spapr, uint32_t token,
+                                uint32_t nargs, target_ulong args,
+                                uint32_t nret, target_ulong rets)
+{
+    VIOsPAPRBus *bus = spapr->vio_bus;
+    VIOsPAPRDevice *dev;
+    uint32_t unit, enable;
+
+    if (nargs != 2) {
+        rtas_st(rets, 0, -3);
+        return;
+    }
+    unit = rtas_ld(args, 0);
+    enable = rtas_ld(args, 1);
+    dev = spapr_vio_find_by_reg(bus, unit);
+    if (!dev) {
+        rtas_st(rets, 0, -3);
+        return;
+    }
+    if (enable) {
+        dev->flags |= VIO_PAPR_FLAG_DMA_BYPASS;
+    } else {
+        dev->flags &= ~VIO_PAPR_FLAG_DMA_BYPASS;
+    }
+
+    rtas_st(rets, 0, 0);
+}
+
+static void rtas_quiesce(sPAPREnvironment *spapr, uint32_t token,
+                         uint32_t nargs, target_ulong args,
+                         uint32_t nret, target_ulong rets)
+{
+    VIOsPAPRBus *bus = spapr->vio_bus;
+    DeviceState *qdev;
+    VIOsPAPRDevice *dev = NULL;
+
+    if (nargs != 0) {
+        rtas_st(rets, 0, -3);
+        return;
+    }
+
+    QLIST_FOREACH(qdev, &bus->bus.children, sibling) {
+        dev = (VIOsPAPRDevice *)qdev;
+        spapr_vio_quiesce_one(dev);
+    }
+
+    rtas_st(rets, 0, 0);
+}
+
 static int spapr_vio_busdev_init(DeviceState *qdev, DeviceInfo *qinfo)
 {
     VIOsPAPRDeviceInfo *info = (VIOsPAPRDeviceInfo *)qinfo;
@@ -591,6 +669,10 @@ VIOsPAPRBus *spapr_vio_bus_init(void)
     spapr_register_hypercall(H_SEND_CRQ, h_send_crq);
     spapr_register_hypercall(H_ENABLE_CRQ, h_enable_crq);
 
+    /* RTAS calls */
+    spapr_rtas_register("ibm,set-tce-bypass", rtas_set_tce_bypass);
+    spapr_rtas_register("quiesce", rtas_quiesce);
+
     for (qinfo = device_info_list; qinfo; qinfo = qinfo->next) {
         VIOsPAPRDeviceInfo *info = (VIOsPAPRDeviceInfo *)qinfo;
 
diff --git a/hw/spapr_vio.h b/hw/spapr_vio.h
index b7d0daab07..841b04351a 100644
--- a/hw/spapr_vio.h
+++ b/hw/spapr_vio.h
@@ -48,6 +48,8 @@ typedef struct VIOsPAPR_CRQ {
 typedef struct VIOsPAPRDevice {
     DeviceState qdev;
     uint32_t reg;
+    uint32_t flags;
+#define VIO_PAPR_FLAG_DMA_BYPASS        0x1
     qemu_irq qirq;
     uint32_t vio_irq_num;
     target_ulong signal_state;
@@ -104,4 +106,7 @@ void spapr_vlan_create(VIOsPAPRBus *bus, uint32_t reg, NICInfo *nd,
 void spapr_vscsi_create(VIOsPAPRBus *bus, uint32_t reg,
                         qemu_irq qirq, uint32_t vio_irq_num);
 
+int spapr_tce_set_bypass(uint32_t unit, uint32_t enable);
+void spapr_vio_quiesce(void);
+
 #endif /* _HW_SPAPR_VIO_H */