Merge remote-tracking branch 'qemu-kvm/memory/dma' into staging

* qemu-kvm/memory/dma: (23 commits)
  pci: honor PCI_COMMAND_MASTER
  pci: give each device its own address space
  memory: add address_space_destroy()
  dma: make dma access its own address space
  memory: per-AddressSpace dispatch
  s390: avoid reaching into memory core internals
  memory: use AddressSpace for MemoryListener filtering
  memory: move tcg flush into a tcg memory listener
  memory: move address_space_memory and address_space_io out of memory core
  memory: manage coalesced mmio via a MemoryListener
  xen: drop no-op MemoryListener callbacks
  kvm: drop no-op MemoryListener callbacks
  xen_pt: drop no-op MemoryListener callbacks
  vfio: drop no-op MemoryListener callbacks
  memory: drop no-op MemoryListener callbacks
  memory: provide defaults for MemoryListener operations
  memory: maintain a list of address spaces
  memory: export AddressSpace
  memory: prepare AddressSpace for exporting
  xen_pt: use separate MemoryListeners for memory and I/O
  ...

21 files changed, 484 insertions, 471 deletions

diff --git a/cputlb.c b/cputlb.c
index 51b5897..9027557 100644
--- a/cputlb.c
+++ b/cputlb.c
@@ -21,11 +21,11 @@
 #include "cpu.h"
 #include "exec-all.h"
 #include "memory.h"
+#include "exec-memory.h"
 
 #include "cputlb.h"
 
-#define WANT_EXEC_OBSOLETE
-#include "exec-obsolete.h"
+#include "memory-internal.h"
 
 //#define DEBUG_TLB
 //#define DEBUG_TLB_CHECK
@@ -252,7 +252,7 @@ void tlb_set_page(CPUArchState *env, target_ulong vaddr,
     if (size != TARGET_PAGE_SIZE) {
         tlb_add_large_page(env, vaddr, size);
     }
-    section = phys_page_find(paddr >> TARGET_PAGE_BITS);
+    section = phys_page_find(address_space_memory.dispatch, paddr >> TARGET_PAGE_BITS);
 #if defined(DEBUG_TLB)
     printf("tlb_set_page: vaddr=" TARGET_FMT_lx " paddr=0x" TARGET_FMT_plx
            " prot=%x idx=%d pd=0x%08lx\n",
diff --git a/cputlb.h b/cputlb.h
index 2dc2c96..d537b77 100644
--- a/cputlb.h
+++ b/cputlb.h
@@ -26,7 +26,8 @@ void tlb_unprotect_code_phys(CPUArchState *env, ram_addr_t ram_addr,
                              target_ulong vaddr);
 void tlb_reset_dirty_range(CPUTLBEntry *tlb_entry, uintptr_t start,
                            uintptr_t length);
-MemoryRegionSection *phys_page_find(target_phys_addr_t index);
+MemoryRegionSection *phys_page_find(struct AddressSpaceDispatch *d,
+                                    target_phys_addr_t index);
 void cpu_tlb_reset_dirty_all(ram_addr_t start1, ram_addr_t length);
 void tlb_set_dirty(CPUArchState *env, target_ulong vaddr);
 extern int tlb_flush_count;
diff --git a/dma-helpers.c b/dma-helpers.c
index 433d8b2..3f09dcb 100644
--- a/dma-helpers.c
+++ b/dma-helpers.c
@@ -14,7 +14,8 @@
 
 /* #define DEBUG_IOMMU */
 
-static void do_dma_memory_set(dma_addr_t addr, uint8_t c, dma_addr_t len)
+static void do_dma_memory_set(AddressSpace *as,
+                              dma_addr_t addr, uint8_t c, dma_addr_t len)
 {
 #define FILLBUF_SIZE 512
     uint8_t fillbuf[FILLBUF_SIZE];
@@ -23,7 +24,7 @@ static void do_dma_memory_set(dma_addr_t addr, uint8_t c, dma_addr_t len)
     memset(fillbuf, c, FILLBUF_SIZE);
     while (len > 0) {
         l = len < FILLBUF_SIZE ? len : FILLBUF_SIZE;
-        cpu_physical_memory_rw(addr, fillbuf, l, true);
+        address_space_rw(as, addr, fillbuf, l, true);
         len -= l;
         addr += l;
     }
@@ -36,7 +37,7 @@ int dma_memory_set(DMAContext *dma, dma_addr_t addr, uint8_t c, dma_addr_t len)
     if (dma_has_iommu(dma)) {
         return iommu_dma_memory_set(dma, addr, c, len);
     }
-    do_dma_memory_set(addr, c, len);
+    do_dma_memory_set(dma->as, addr, c, len);
 
     return 0;
 }
@@ -332,8 +333,7 @@ int iommu_dma_memory_rw(DMAContext *dma, dma_addr_t addr,
             plen = len;
         }
 
-        cpu_physical_memory_rw(paddr, buf, plen,
-                               dir == DMA_DIRECTION_FROM_DEVICE);
+        address_space_rw(dma->as, paddr, buf, plen, dir == DMA_DIRECTION_FROM_DEVICE);
 
         len -= plen;
         addr += plen;
@@ -366,7 +366,7 @@ int iommu_dma_memory_set(DMAContext *dma, dma_addr_t addr, uint8_t c,
             plen = len;
         }
 
-        do_dma_memory_set(paddr, c, plen);
+        do_dma_memory_set(dma->as, paddr, c, plen);
 
         len -= plen;
         addr += plen;
@@ -375,13 +375,14 @@ int iommu_dma_memory_set(DMAContext *dma, dma_addr_t addr, uint8_t c,
     return 0;
 }
 
-void dma_context_init(DMAContext *dma, DMATranslateFunc translate,
+void dma_context_init(DMAContext *dma, AddressSpace *as, DMATranslateFunc translate,
                       DMAMapFunc map, DMAUnmapFunc unmap)
 {
 #ifdef DEBUG_IOMMU
     fprintf(stderr, "dma_context_init(%p, %p, %p, %p)\n",
             dma, translate, map, unmap);
 #endif
+    dma->as = as;
     dma->translate = translate;
     dma->map = map;
     dma->unmap = unmap;
@@ -407,14 +408,13 @@ void *iommu_dma_memory_map(DMAContext *dma, dma_addr_t addr, dma_addr_t *len,
     /*
      * If this is true, the virtual region is contiguous,
      * but the translated physical region isn't. We just
-     * clamp *len, much like cpu_physical_memory_map() does.
+     * clamp *len, much like address_space_map() does.
      */
     if (plen < *len) {
         *len = plen;
     }
 
-    buf = cpu_physical_memory_map(paddr, &plen,
-                                  dir == DMA_DIRECTION_FROM_DEVICE);
+    buf = address_space_map(dma->as, paddr, &plen, dir == DMA_DIRECTION_FROM_DEVICE);
     *len = plen;
 
     return buf;
@@ -428,8 +428,7 @@ void iommu_dma_memory_unmap(DMAContext *dma, void *buffer, dma_addr_t len,
         return;
     }
 
-    cpu_physical_memory_unmap(buffer, len,
-                              dir == DMA_DIRECTION_FROM_DEVICE,
-                              access_len);
+    address_space_unmap(dma->as, buffer, len, dir == DMA_DIRECTION_FROM_DEVICE,
+                        access_len);
 
 }
diff --git a/dma.h b/dma.h
index 1a33603..1bd6f4a 100644
--- a/dma.h
+++ b/dma.h
@@ -11,6 +11,7 @@
 #define DMA_H
 
 #include <stdio.h>
+#include "memory.h"
 #include "hw/hw.h"
 #include "block.h"
 #include "kvm.h"
@@ -61,6 +62,7 @@ typedef void DMAUnmapFunc(DMAContext *dma,
                           dma_addr_t access_len);
 
 struct DMAContext {
+    AddressSpace *as;
     DMATranslateFunc *translate;
     DMAMapFunc *map;
     DMAUnmapFunc *unmap;
@@ -93,7 +95,7 @@ static inline void dma_barrier(DMAContext *dma, DMADirection dir)
 
 static inline bool dma_has_iommu(DMAContext *dma)
 {
-    return !!dma;
+    return dma && dma->translate;
 }
 
 /* Checks that the given range of addresses is valid for DMA.  This is
@@ -120,8 +122,7 @@ static inline int dma_memory_rw_relaxed(DMAContext *dma, dma_addr_t addr,
 {
     if (!dma_has_iommu(dma)) {
         /* Fast-path for no IOMMU */
-        cpu_physical_memory_rw(addr, buf, len,
-                               dir == DMA_DIRECTION_FROM_DEVICE);
+        address_space_rw(dma->as, addr, buf, len, dir == DMA_DIRECTION_FROM_DEVICE);
         return 0;
     } else {
         return iommu_dma_memory_rw(dma, addr, buf, len, dir);
@@ -179,8 +180,7 @@ static inline void *dma_memory_map(DMAContext *dma,
         target_phys_addr_t xlen = *len;
         void *p;
 
-        p = cpu_physical_memory_map(addr, &xlen,
-                                    dir == DMA_DIRECTION_FROM_DEVICE);
+        p = address_space_map(dma->as, addr, &xlen, dir == DMA_DIRECTION_FROM_DEVICE);
         *len = xlen;
         return p;
     } else {
@@ -196,9 +196,8 @@ static inline void dma_memory_unmap(DMAContext *dma,
                                     DMADirection dir, dma_addr_t access_len)
 {
     if (!dma_has_iommu(dma)) {
-        cpu_physical_memory_unmap(buffer, (target_phys_addr_t)len,
-                                  dir == DMA_DIRECTION_FROM_DEVICE,
-                                  access_len);
+        address_space_unmap(dma->as, buffer, (target_phys_addr_t)len,
+                            dir == DMA_DIRECTION_FROM_DEVICE, access_len);
     } else {
         iommu_dma_memory_unmap(dma, buffer, len, dir, access_len);
     }
@@ -242,7 +241,7 @@ DEFINE_LDST_DMA(q, q, 64, be);
 
 #undef DEFINE_LDST_DMA
 
-void dma_context_init(DMAContext *dma, DMATranslateFunc translate,
+void dma_context_init(DMAContext *dma, AddressSpace *as, DMATranslateFunc translate,
                       DMAMapFunc map, DMAUnmapFunc unmap);
 
 struct ScatterGatherEntry {
diff --git a/exec-memory.h b/exec-memory.h
index 1cd92ee..ac1d07d 100644
--- a/exec-memory.h
+++ b/exec-memory.h
@@ -33,11 +33,8 @@ MemoryRegion *get_system_memory(void);
  */
 MemoryRegion *get_system_io(void);
 
-/* Set the root memory region.  This region is the system memory map. */
-void set_system_memory_map(MemoryRegion *mr);
-
-/* Set the I/O memory region.  This region is the I/O memory map. */
-void set_system_io_map(MemoryRegion *mr);
+extern AddressSpace address_space_memory;
+extern AddressSpace address_space_io;
 
 #endif
 
diff --git a/exec.c b/exec.c
index 4a86b0f..5b55e3e 100644
--- a/exec.c
+++ b/exec.c
@@ -59,8 +59,7 @@
 
 #include "cputlb.h"
 
-#define WANT_EXEC_OBSOLETE
-#include "exec-obsolete.h"
+#include "memory-internal.h"
 
 //#define DEBUG_TB_INVALIDATE
 //#define DEBUG_FLUSH
@@ -102,6 +101,9 @@ RAMList ram_list = { .blocks = QLIST_HEAD_INITIALIZER(ram_list.blocks) };
 static MemoryRegion *system_memory;
 static MemoryRegion *system_io;
 
+AddressSpace address_space_io;
+AddressSpace address_space_memory;
+
 MemoryRegion io_mem_ram, io_mem_rom, io_mem_unassigned, io_mem_notdirty;
 static MemoryRegion io_mem_subpage_ram;
 
@@ -170,7 +172,6 @@ uintptr_t qemu_host_page_mask;
 static void *l1_map[V_L1_SIZE];
 
 #if !defined(CONFIG_USER_ONLY)
-typedef struct PhysPageEntry PhysPageEntry;
 
 static MemoryRegionSection *phys_sections;
 static unsigned phys_sections_nb, phys_sections_nb_alloc;
@@ -179,22 +180,12 @@ static uint16_t phys_section_notdirty;
 static uint16_t phys_section_rom;
 static uint16_t phys_section_watch;
 
-struct PhysPageEntry {
-    uint16_t is_leaf : 1;
-     /* index into phys_sections (is_leaf) or phys_map_nodes (!is_leaf) */
-    uint16_t ptr : 15;
-};
-
 /* Simple allocator for PhysPageEntry nodes */
 static PhysPageEntry (*phys_map_nodes)[L2_SIZE];
 static unsigned phys_map_nodes_nb, phys_map_nodes_nb_alloc;
 
 #define PHYS_MAP_NODE_NIL (((uint16_t)~0) >> 1)
 
-/* This is a multi-level map on the physical address space.
-   The bottom level has pointers to MemoryRegionSections.  */
-static PhysPageEntry phys_map = { .ptr = PHYS_MAP_NODE_NIL, .is_leaf = 0 };
-
 static void io_mem_init(void);
 static void memory_map_init(void);
 
@@ -442,18 +433,19 @@ static void phys_page_set_level(PhysPageEntry *lp, target_phys_addr_t *index,
     }
 }
 
-static void phys_page_set(target_phys_addr_t index, target_phys_addr_t nb,
+static void phys_page_set(AddressSpaceDispatch *d,
+                          target_phys_addr_t index, target_phys_addr_t nb,
                           uint16_t leaf)
 {
     /* Wildly overreserve - it doesn't matter much. */
     phys_map_node_reserve(3 * P_L2_LEVELS);
 
-    phys_page_set_level(&phys_map, &index, &nb, leaf, P_L2_LEVELS - 1);
+    phys_page_set_level(&d->phys_map, &index, &nb, leaf, P_L2_LEVELS - 1);
 }
 
-MemoryRegionSection *phys_page_find(target_phys_addr_t index)
+MemoryRegionSection *phys_page_find(AddressSpaceDispatch *d, target_phys_addr_t index)
 {
-    PhysPageEntry lp = phys_map;
+    PhysPageEntry lp = d->phys_map;
     PhysPageEntry *p;
     int i;
     uint16_t s_index = phys_section_unassigned;
@@ -1486,7 +1478,7 @@ void tb_invalidate_phys_addr(target_phys_addr_t addr)
     ram_addr_t ram_addr;
     MemoryRegionSection *section;
 
-    section = phys_page_find(addr >> TARGET_PAGE_BITS);
+    section = phys_page_find(address_space_memory.dispatch, addr >> TARGET_PAGE_BITS);
     if (!(memory_region_is_ram(section->mr)
           || (section->mr->rom_device && section->mr->readable))) {
         return;
@@ -2224,9 +2216,9 @@ static void destroy_l2_mapping(PhysPageEntry *lp, unsigned level)
     lp->ptr = PHYS_MAP_NODE_NIL;
 }
 
-static void destroy_all_mappings(void)
+static void destroy_all_mappings(AddressSpaceDispatch *d)
 {
-    destroy_l2_mapping(&phys_map, P_L2_LEVELS - 1);
+    destroy_l2_mapping(&d->phys_map, P_L2_LEVELS - 1);
     phys_map_nodes_reset();
 }
 
@@ -2246,12 +2238,12 @@ static void phys_sections_clear(void)
     phys_sections_nb = 0;
 }
 
-static void register_subpage(MemoryRegionSection *section)
+static void register_subpage(AddressSpaceDispatch *d, MemoryRegionSection *section)
 {
     subpage_t *subpage;
     target_phys_addr_t base = section->offset_within_address_space
         & TARGET_PAGE_MASK;
-    MemoryRegionSection *existing = phys_page_find(base >> TARGET_PAGE_BITS);
+    MemoryRegionSection *existing = phys_page_find(d, base >> TARGET_PAGE_BITS);
     MemoryRegionSection subsection = {
         .offset_within_address_space = base,
         .size = TARGET_PAGE_SIZE,
@@ -2263,7 +2255,7 @@ static void register_subpage(MemoryRegionSection *section)
     if (!(existing->mr->subpage)) {
         subpage = subpage_init(base);
         subsection.mr = &subpage->iomem;
-        phys_page_set(base >> TARGET_PAGE_BITS, 1,
+        phys_page_set(d, base >> TARGET_PAGE_BITS, 1,
                       phys_section_add(&subsection));
     } else {
         subpage = container_of(existing->mr, subpage_t, iomem);
@@ -2274,7 +2266,7 @@ static void register_subpage(MemoryRegionSection *section)
 }
 
 
-static void register_multipage(MemoryRegionSection *section)
+static void register_multipage(AddressSpaceDispatch *d, MemoryRegionSection *section)
 {
     target_phys_addr_t start_addr = section->offset_within_address_space;
     ram_addr_t size = section->size;
@@ -2284,13 +2276,13 @@ static void register_multipage(MemoryRegionSection *section)
     assert(size);
 
     addr = start_addr;
-    phys_page_set(addr >> TARGET_PAGE_BITS, size >> TARGET_PAGE_BITS,
+    phys_page_set(d, addr >> TARGET_PAGE_BITS, size >> TARGET_PAGE_BITS,
                   section_index);
 }
 
-void cpu_register_physical_memory_log(MemoryRegionSection *section,
-                                      bool readonly)
+static void mem_add(MemoryListener *listener, MemoryRegionSection *section)
 {
+    AddressSpaceDispatch *d = container_of(listener, AddressSpaceDispatch, listener);
     MemoryRegionSection now = *section, remain = *section;
 
     if ((now.offset_within_address_space & ~TARGET_PAGE_MASK)
@@ -2298,7 +2290,7 @@ void cpu_register_physical_memory_log(MemoryRegionSection *section,
         now.size = MIN(TARGET_PAGE_ALIGN(now.offset_within_address_space)
                        - now.offset_within_address_space,
                        now.size);
-        register_subpage(&now);
+        register_subpage(d, &now);
         remain.size -= now.size;
         remain.offset_within_address_space += now.size;
         remain.offset_within_region += now.size;
@@ -2307,10 +2299,10 @@ void cpu_register_physical_memory_log(MemoryRegionSection *section,
         now = remain;
         if (remain.offset_within_region & ~TARGET_PAGE_MASK) {
             now.size = TARGET_PAGE_SIZE;
-            register_subpage(&now);
+            register_subpage(d, &now);
         } else {
             now.size &= TARGET_PAGE_MASK;
-            register_multipage(&now);
+            register_multipage(d, &now);
         }
         remain.size -= now.size;
         remain.offset_within_address_space += now.size;
@@ -2318,23 +2310,10 @@ void cpu_register_physical_memory_log(MemoryRegionSection *section,
     }
     now = remain;
     if (now.size) {
-        register_subpage(&now);
+        register_subpage(d, &now);
     }
 }
 
-
-void qemu_register_coalesced_mmio(target_phys_addr_t addr, ram_addr_t size)
-{
-    if (kvm_enabled())
-        kvm_coalesce_mmio_region(addr, size);
-}
-
-void qemu_unregister_coalesced_mmio(target_phys_addr_t addr, ram_addr_t size)
-{
-    if (kvm_enabled())
-        kvm_uncoalesce_mmio_region(addr, size);
-}
-
 void qemu_flush_coalesced_mmio_buffer(void)
 {
     if (kvm_enabled())
@@ -3182,18 +3161,24 @@ static void io_mem_init(void)
                           "watch", UINT64_MAX);
 }
 
+static void mem_begin(MemoryListener *listener)
+{
+    AddressSpaceDispatch *d = container_of(listener, AddressSpaceDispatch, listener);
+
+    destroy_all_mappings(d);
+    d->phys_map.ptr = PHYS_MAP_NODE_NIL;
+}
+
 static void core_begin(MemoryListener *listener)
 {
-    destroy_all_mappings();
     phys_sections_clear();
-    phys_map.ptr = PHYS_MAP_NODE_NIL;
     phys_section_unassigned = dummy_section(&io_mem_unassigned);
     phys_section_notdirty = dummy_section(&io_mem_notdirty);
     phys_section_rom = dummy_section(&io_mem_rom);
     phys_section_watch = dummy_section(&io_mem_watch);
 }
 
-static void core_commit(MemoryListener *listener)
+static void tcg_commit(MemoryListener *listener)
 {
     CPUArchState *env;
 
@@ -3205,38 +3190,6 @@ static void core_commit(MemoryListener *listener)
     }
 }
 
-static void core_region_add(MemoryListener *listener,
-                            MemoryRegionSection *section)
-{
-    cpu_register_physical_memory_log(section, section->readonly);
-}
-
-static void core_region_del(MemoryListener *listener,
-                            MemoryRegionSection *section)
-{
-}
-
-static void core_region_nop(MemoryListener *listener,
-                            MemoryRegionSection *section)
-{
-    cpu_register_physical_memory_log(section, section->readonly);
-}
-
-static void core_log_start(MemoryListener *listener,
-                           MemoryRegionSection *section)
-{
-}
-
-static void core_log_stop(MemoryListener *listener,
-                          MemoryRegionSection *section)
-{
-}
-
-static void core_log_sync(MemoryListener *listener,
-                          MemoryRegionSection *section)
-{
-}
-
 static void core_log_global_start(MemoryListener *listener)
 {
     cpu_physical_memory_set_dirty_tracking(1);
@@ -3247,26 +3200,6 @@ static void core_log_global_stop(MemoryListener *listener)
     cpu_physical_memory_set_dirty_tracking(0);
 }
 
-static void core_eventfd_add(MemoryListener *listener,
-                             MemoryRegionSection *section,
-                             bool match_data, uint64_t data, EventNotifier *e)
-{
-}
-
-static void core_eventfd_del(MemoryListener *listener,
-                             MemoryRegionSection *section,
-                             bool match_data, uint64_t data, EventNotifier *e)
-{
-}
-
-static void io_begin(MemoryListener *listener)
-{
-}
-
-static void io_commit(MemoryListener *listener)
-{
-}
-
 static void io_region_add(MemoryListener *listener,
                           MemoryRegionSection *section)
 {
@@ -3285,90 +3218,63 @@ static void io_region_del(MemoryListener *listener,
     isa_unassign_ioport(section->offset_within_address_space, section->size);
 }
 
-static void io_region_nop(MemoryListener *listener,
-                          MemoryRegionSection *section)
-{
-}
-
-static void io_log_start(MemoryListener *listener,
-                         MemoryRegionSection *section)
-{
-}
-
-static void io_log_stop(MemoryListener *listener,
-                        MemoryRegionSection *section)
-{
-}
-
-static void io_log_sync(MemoryListener *listener,
-                        MemoryRegionSection *section)
-{
-}
-
-static void io_log_global_start(MemoryListener *listener)
-{
-}
-
-static void io_log_global_stop(MemoryListener *listener)
-{
-}
-
-static void io_eventfd_add(MemoryListener *listener,
-                           MemoryRegionSection *section,
-                           bool match_data, uint64_t data, EventNotifier *e)
-{
-}
-
-static void io_eventfd_del(MemoryListener *listener,
-                           MemoryRegionSection *section,
-                           bool match_data, uint64_t data, EventNotifier *e)
-{
-}
-
 static MemoryListener core_memory_listener = {
     .begin = core_begin,
-    .commit = core_commit,
-    .region_add = core_region_add,
-    .region_del = core_region_del,
-    .region_nop = core_region_nop,
-    .log_start = core_log_start,
-    .log_stop = core_log_stop,
-    .log_sync = core_log_sync,
     .log_global_start = core_log_global_start,
     .log_global_stop = core_log_global_stop,
-    .eventfd_add = core_eventfd_add,
-    .eventfd_del = core_eventfd_del,
-    .priority = 0,
+    .priority = 1,
 };
 
 static MemoryListener io_memory_listener = {
-    .begin = io_begin,
-    .commit = io_commit,
     .region_add = io_region_add,
     .region_del = io_region_del,
-    .region_nop = io_region_nop,
-    .log_start = io_log_start,
-    .log_stop = io_log_stop,
-    .log_sync = io_log_sync,
-    .log_global_start = io_log_global_start,
-    .log_global_stop = io_log_global_stop,
-    .eventfd_add = io_eventfd_add,
-    .eventfd_del = io_eventfd_del,
     .priority = 0,
 };
 
+static MemoryListener tcg_memory_listener = {
+    .commit = tcg_commit,
+};
+
+void address_space_init_dispatch(AddressSpace *as)
+{
+    AddressSpaceDispatch *d = g_new(AddressSpaceDispatch, 1);
+
+    d->phys_map  = (PhysPageEntry) { .ptr = PHYS_MAP_NODE_NIL, .is_leaf = 0 };
+    d->listener = (MemoryListener) {
+        .begin = mem_begin,
+        .region_add = mem_add,
+        .region_nop = mem_add,
+        .priority = 0,
+    };
+    as->dispatch = d;
+    memory_listener_register(&d->listener, as);
+}
+
+void address_space_destroy_dispatch(AddressSpace *as)
+{
+    AddressSpaceDispatch *d = as->dispatch;
+
+    memory_listener_unregister(&d->listener);
+    destroy_l2_mapping(&d->phys_map, P_L2_LEVELS - 1);
+    g_free(d);
+    as->dispatch = NULL;
+}
+
 static void memory_map_init(void)
 {
     system_memory = g_malloc(sizeof(*system_memory));
     memory_region_init(system_memory, "system", INT64_MAX);
-    set_system_memory_map(system_memory);
+    address_space_init(&address_space_memory, system_memory);
+    address_space_memory.name = "memory";
 
     system_io = g_malloc(sizeof(*system_io));
     memory_region_init(system_io, "io", 65536);
-    set_system_io_map(system_io);
+    address_space_init(&address_space_io, system_io);
+    address_space_io.name = "I/O";
 
-    memory_listener_register(&core_memory_listener, system_memory);
-    memory_listener_register(&io_memory_listener, system_io);
+    memory_listener_register(&core_memory_listener, &address_space_memory);
+    memory_listener_register(&io_memory_listener, &address_space_io);
+    memory_listener_register(&tcg_memory_listener, &address_space_memory);
 }
 
 MemoryRegion *get_system_memory(void)
@@ -3438,9 +3344,10 @@ static void invalidate_and_set_dirty(target_phys_addr_t addr,
     xen_modified_memory(addr, length);
 }
 
-void cpu_physical_memory_rw(target_phys_addr_t addr, uint8_t *buf,
-                            int len, int is_write)
+void address_space_rw(AddressSpace *as, target_phys_addr_t addr, uint8_t *buf,
+                      int len, bool is_write)
 {
+    AddressSpaceDispatch *d = as->dispatch;
     int l;
     uint8_t *ptr;
     uint32_t val;
@@ -3452,7 +3359,7 @@ void cpu_physical_memory_rw(target_phys_addr_t addr, uint8_t *buf,
         l = (page + TARGET_PAGE_SIZE) - addr;
         if (l > len)
             l = len;
-        section = phys_page_find(page >> TARGET_PAGE_BITS);
+        section = phys_page_find(d, page >> TARGET_PAGE_BITS);
 
         if (is_write) {
             if (!memory_region_is_ram(section->mr)) {
@@ -3523,10 +3430,36 @@ void cpu_physical_memory_rw(target_phys_addr_t addr, uint8_t *buf,
     }
 }
 
+void address_space_write(AddressSpace *as, target_phys_addr_t addr,
+                         const uint8_t *buf, int len)
+{
+    address_space_rw(as, addr, (uint8_t *)buf, len, true);
+}
+
+/**
+ * address_space_read: read from an address space.
+ *
+ * @as: #AddressSpace to be accessed
+ * @addr: address within that address space
+ * @buf: buffer with the data transferred
+ */
+void address_space_read(AddressSpace *as, target_phys_addr_t addr, uint8_t *buf, int len)
+{
+    address_space_rw(as, addr, buf, len, false);
+}
+
+
+void cpu_physical_memory_rw(target_phys_addr_t addr, uint8_t *buf,
+                            int len, int is_write)
+{
+    return address_space_rw(&address_space_memory, addr, buf, len, is_write);
+}
+
 /* used for ROM loading : can write in RAM and ROM */
 void cpu_physical_memory_write_rom(target_phys_addr_t addr,
                                    const uint8_t *buf, int len)
 {
+    AddressSpaceDispatch *d = address_space_memory.dispatch;
     int l;
     uint8_t *ptr;
     target_phys_addr_t page;
@@ -3537,7 +3470,7 @@ void cpu_physical_memory_write_rom(target_phys_addr_t addr,
         l = (page + TARGET_PAGE_SIZE) - addr;
         if (l > len)
             l = len;
-        section = phys_page_find(page >> TARGET_PAGE_BITS);
+        section = phys_page_find(d, page >> TARGET_PAGE_BITS);
 
         if (!(memory_region_is_ram(section->mr) ||
               memory_region_is_romd(section->mr))) {
@@ -3611,10 +3544,12 @@ static void cpu_notify_map_clients(void)
  * Use cpu_register_map_client() to know when retrying the map operation is
  * likely to succeed.
  */
-void *cpu_physical_memory_map(target_phys_addr_t addr,
-                              target_phys_addr_t *plen,
-                              int is_write)
+void *address_space_map(AddressSpace *as,
+                        target_phys_addr_t addr,
+                        target_phys_addr_t *plen,
+                        bool is_write)
 {
+    AddressSpaceDispatch *d = as->dispatch;
     target_phys_addr_t len = *plen;
     target_phys_addr_t todo = 0;
     int l;
@@ -3629,7 +3564,7 @@ void *cpu_physical_memory_map(target_phys_addr_t addr,
         l = (page + TARGET_PAGE_SIZE) - addr;
         if (l > len)
             l = len;
-        section = phys_page_find(page >> TARGET_PAGE_BITS);
+        section = phys_page_find(d, page >> TARGET_PAGE_BITS);
 
         if (!(memory_region_is_ram(section->mr) && !section->readonly)) {
             if (todo || bounce.buffer) {
@@ -3639,7 +3574,7 @@ void *cpu_physical_memory_map(target_phys_addr_t addr,
             bounce.addr = addr;
             bounce.len = l;
             if (!is_write) {
-                cpu_physical_memory_read(addr, bounce.buffer, l);
+                address_space_read(as, addr, bounce.buffer, l);
             }
 
             *plen = l;
@@ -3660,12 +3595,12 @@ void *cpu_physical_memory_map(target_phys_addr_t addr,
     return ret;
 }
 
-/* Unmaps a memory region previously mapped by cpu_physical_memory_map().
+/* Unmaps a memory region previously mapped by address_space_map().
  * Will also mark the memory as dirty if is_write == 1.  access_len gives
  * the amount of memory that was actually read or written by the caller.
  */
-void cpu_physical_memory_unmap(void *buffer, target_phys_addr_t len,
-                               int is_write, target_phys_addr_t access_len)
+void address_space_unmap(AddressSpace *as, void *buffer, target_phys_addr_t len,
+                         int is_write, target_phys_addr_t access_len)
 {
     if (buffer != bounce.buffer) {
         if (is_write) {
@@ -3686,13 +3621,26 @@ void cpu_physical_memory_unmap(void *buffer, target_phys_addr_t len,
         return;
     }
     if (is_write) {
-        cpu_physical_memory_write(bounce.addr, bounce.buffer, access_len);
+        address_space_write(as, bounce.addr, bounce.buffer, access_len);
     }
     qemu_vfree(bounce.buffer);
     bounce.buffer = NULL;
     cpu_notify_map_clients();
 }
 
+void *cpu_physical_memory_map(target_phys_addr_t addr,
+                              target_phys_addr_t *plen,
+                              int is_write)
+{
+    return address_space_map(&address_space_memory, addr, plen, is_write);
+}
+
+void cpu_physical_memory_unmap(void *buffer, target_phys_addr_t len,
+                               int is_write, target_phys_addr_t access_len)
+{
+    return address_space_unmap(&address_space_memory, buffer, len, is_write, access_len);
+}
+
 /* warning: addr must be aligned */
 static inline uint32_t ldl_phys_internal(target_phys_addr_t addr,
                                          enum device_endian endian)
@@ -3701,7 +3649,7 @@ static inline uint32_t ldl_phys_internal(target_phys_addr_t addr,
     uint32_t val;
     MemoryRegionSection *section;
 
-    section = phys_page_find(addr >> TARGET_PAGE_BITS);
+    section = phys_page_find(address_space_memory.dispatch, addr >> TARGET_PAGE_BITS);
 
     if (!(memory_region_is_ram(section->mr) ||
           memory_region_is_romd(section->mr))) {
@@ -3760,7 +3708,7 @@ static inline uint64_t ldq_phys_internal(target_phys_addr_t addr,
     uint64_t val;
     MemoryRegionSection *section;
 
-    section = phys_page_find(addr >> TARGET_PAGE_BITS);
+    section = phys_page_find(address_space_memory.dispatch, addr >> TARGET_PAGE_BITS);
 
     if (!(memory_region_is_ram(section->mr) ||
           memory_region_is_romd(section->mr))) {
@@ -3827,7 +3775,7 @@ static inline uint32_t lduw_phys_internal(target_phys_addr_t addr,
     uint64_t val;
     MemoryRegionSection *section;
 
-    section = phys_page_find(addr >> TARGET_PAGE_BITS);
+    section = phys_page_find(address_space_memory.dispatch, addr >> TARGET_PAGE_BITS);
 
     if (!(memory_region_is_ram(section->mr) ||
           memory_region_is_romd(section->mr))) {
@@ -3886,7 +3834,7 @@ void stl_phys_notdirty(target_phys_addr_t addr, uint32_t val)
     uint8_t *ptr;
     MemoryRegionSection *section;
 
-    section = phys_page_find(addr >> TARGET_PAGE_BITS);
+    section = phys_page_find(address_space_memory.dispatch, addr >> TARGET_PAGE_BITS);
 
     if (!memory_region_is_ram(section->mr) || section->readonly) {
         addr = memory_region_section_addr(section, addr);
@@ -3918,7 +3866,7 @@ void stq_phys_notdirty(target_phys_addr_t addr, uint64_t val)
     uint8_t *ptr;
     MemoryRegionSection *section;
 
-    section = phys_page_find(addr >> TARGET_PAGE_BITS);
+    section = phys_page_find(address_space_memory.dispatch, addr >> TARGET_PAGE_BITS);
 
     if (!memory_region_is_ram(section->mr) || section->readonly) {
         addr = memory_region_section_addr(section, addr);
@@ -3947,7 +3895,7 @@ static inline void stl_phys_internal(target_phys_addr_t addr, uint32_t val,
     uint8_t *ptr;
     MemoryRegionSection *section;
 
-    section = phys_page_find(addr >> TARGET_PAGE_BITS);
+    section = phys_page_find(address_space_memory.dispatch, addr >> TARGET_PAGE_BITS);
 
     if (!memory_region_is_ram(section->mr) || section->readonly) {
         addr = memory_region_section_addr(section, addr);
@@ -4014,7 +3962,7 @@ static inline void stw_phys_internal(target_phys_addr_t addr, uint32_t val,
     uint8_t *ptr;
     MemoryRegionSection *section;
 
-    section = phys_page_find(addr >> TARGET_PAGE_BITS);
+    section = phys_page_find(address_space_memory.dispatch, addr >> TARGET_PAGE_BITS);
 
     if (!memory_region_is_ram(section->mr) || section->readonly) {
         addr = memory_region_section_addr(section, addr);
@@ -4250,7 +4198,8 @@ bool cpu_physical_memory_is_io(target_phys_addr_t phys_addr)
 {
     MemoryRegionSection *section;
 
-    section = phys_page_find(phys_addr >> TARGET_PAGE_BITS);
+    section = phys_page_find(address_space_memory.dispatch,
+                             phys_addr >> TARGET_PAGE_BITS);
 
     return !(memory_region_is_ram(section->mr) ||
              memory_region_is_romd(section->mr));
diff --git a/hw/pci.c b/hw/pci.c
index 2ca6ff6..7eeaac0 100644
--- a/hw/pci.c
+++ b/hw/pci.c
@@ -33,6 +33,7 @@
 #include "qmp-commands.h"
 #include "msi.h"
 #include "msix.h"
+#include "exec-memory.h"
 
 //#define DEBUG_PCI
 #ifdef DEBUG_PCI
@@ -777,6 +778,17 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev, PCIBus *bus,
     pci_dev->bus = bus;
     if (bus->dma_context_fn) {
         pci_dev->dma = bus->dma_context_fn(bus, bus->dma_context_opaque, devfn);
+    } else {
+        /* FIXME: Make dma_context_fn use MemoryRegions instead, so this path is
+         * taken unconditionally */
+        /* FIXME: inherit memory region from bus creator */
+        memory_region_init_alias(&pci_dev->bus_master_enable_region, "bus master",
+                                 get_system_memory(), 0,
+                                 memory_region_size(get_system_memory()));
+        memory_region_set_enabled(&pci_dev->bus_master_enable_region, false);
+        address_space_init(&pci_dev->bus_master_as, &pci_dev->bus_master_enable_region);
+        pci_dev->dma = g_new(DMAContext, 1);
+        dma_context_init(pci_dev->dma, &pci_dev->bus_master_as, NULL, NULL, NULL);
     }
     pci_dev->devfn = devfn;
     pstrcpy(pci_dev->name, sizeof(pci_dev->name), name);
@@ -830,6 +842,13 @@ static void do_pci_unregister_device(PCIDevice *pci_dev)
     qemu_free_irqs(pci_dev->irq);
     pci_dev->bus->devices[pci_dev->devfn] = NULL;
     pci_config_free(pci_dev);
+
+    if (!pci_dev->bus->dma_context_fn) {
+        address_space_destroy(&pci_dev->bus_master_as);
+        memory_region_destroy(&pci_dev->bus_master_enable_region);
+        g_free(pci_dev->dma);
+        pci_dev->dma = NULL;
+    }
 }
 
 static void pci_unregister_io_regions(PCIDevice *pci_dev)
@@ -1051,8 +1070,12 @@ void pci_default_write_config(PCIDevice *d, uint32_t addr, uint32_t val, int l)
         range_covers_byte(addr, l, PCI_COMMAND))
         pci_update_mappings(d);
 
-    if (range_covers_byte(addr, l, PCI_COMMAND))
+    if (range_covers_byte(addr, l, PCI_COMMAND)) {
         pci_update_irq_disabled(d, was_irq_disabled);
+        memory_region_set_enabled(&d->bus_master_enable_region,
+                                  pci_get_word(d->config + PCI_COMMAND)
+                                    & PCI_COMMAND_MASTER);
+    }
 
     msi_write_config(d, addr, val, l);
     msix_write_config(d, addr, val, l);
diff --git a/hw/pci.h b/hw/pci.h
index d50d26c..1f902f5 100644
--- a/hw/pci.h
+++ b/hw/pci.h
@@ -211,6 +211,8 @@ struct PCIDevice {
     int32_t devfn;
     char name[64];
     PCIIORegion io_regions[PCI_NUM_REGIONS];
+    AddressSpace bus_master_as;
+    MemoryRegion bus_master_enable_region;
     DMAContext *dma;
 
     /* do not access the following fields */
diff --git a/hw/spapr_iommu.c b/hw/spapr_iommu.c
index 38034c0..33f84e2 100644
--- a/hw/spapr_iommu.c
+++ b/hw/spapr_iommu.c
@@ -21,6 +21,7 @@
 #include "qdev.h"
 #include "kvm_ppc.h"
 #include "dma.h"
+#include "exec-memory.h"
 
 #include "hw/spapr.h"
 
@@ -124,7 +125,7 @@ DMAContext *spapr_tce_new_dma_context(uint32_t liobn, size_t window_size)
     }
 
     tcet = g_malloc0(sizeof(*tcet));
-    dma_context_init(&tcet->dma, spapr_tce_translate, NULL, NULL);
+    dma_context_init(&tcet->dma, &address_space_memory, spapr_tce_translate, NULL, NULL);
 
     tcet->liobn = liobn;
     tcet->window_size = window_size;
diff --git a/hw/vfio_pci.c b/hw/vfio_pci.c
index 639371e..f5db4a8 100644
--- a/hw/vfio_pci.c
+++ b/hw/vfio_pci.c
@@ -930,25 +930,6 @@ static int vfio_dma_map(VFIOContainer *container, target_phys_addr_t iova,
     return -errno;
 }
 
-static void vfio_listener_dummy1(MemoryListener *listener)
-{
-    /* We don't do batching (begin/commit) or care about logging */
-}
-
-static void vfio_listener_dummy2(MemoryListener *listener,
-                                 MemoryRegionSection *section)
-{
-    /* We don't do logging or care about nops */
-}
-
-static void vfio_listener_dummy3(MemoryListener *listener,
-                                 MemoryRegionSection *section,
-                                 bool match_data, uint64_t data,
-                                 EventNotifier *e)
-{
-    /* We don't care about eventfds */
-}
-
 static bool vfio_listener_skipped_section(MemoryRegionSection *section)
 {
     return !memory_region_is_ram(section->mr);
@@ -1040,18 +1021,8 @@ static void vfio_listener_region_del(MemoryListener *listener,
 }
 
 static MemoryListener vfio_memory_listener = {
-    .begin = vfio_listener_dummy1,
-    .commit = vfio_listener_dummy1,
     .region_add = vfio_listener_region_add,
     .region_del = vfio_listener_region_del,
-    .region_nop = vfio_listener_dummy2,
-    .log_start = vfio_listener_dummy2,
-    .log_stop = vfio_listener_dummy2,
-    .log_sync = vfio_listener_dummy2,
-    .log_global_start = vfio_listener_dummy1,
-    .log_global_stop = vfio_listener_dummy1,
-    .eventfd_add = vfio_listener_dummy3,
-    .eventfd_del = vfio_listener_dummy3,
 };
 
 static void vfio_listener_release(VFIOContainer *container)
@@ -1536,8 +1507,7 @@ static int vfio_connect_container(VFIOGroup *group)
         container->iommu_data.listener = vfio_memory_listener;
         container->iommu_data.release = vfio_listener_release;
 
-        memory_listener_register(&container->iommu_data.listener,
-                                 get_system_memory());
+        memory_listener_register(&container->iommu_data.listener, &address_space_memory);
     } else {
         error_report("vfio: No available IOMMU models\n");
         g_free(container);
diff --git a/hw/vhost.c b/hw/vhost.c
index d0ce5aa..0b4ac3f 100644
--- a/hw/vhost.c
+++ b/hw/vhost.c
@@ -434,8 +434,7 @@ static void vhost_set_memory(MemoryListener *listener,
 
 static bool vhost_section(MemoryRegionSection *section)
 {
-    return section->address_space == get_system_memory()
-        && memory_region_is_ram(section->mr);
+    return memory_region_is_ram(section->mr);
 }
 
 static void vhost_begin(MemoryListener *listener)
@@ -793,7 +792,7 @@ int vhost_dev_init(struct vhost_dev *hdev, int devfd, const char *devpath,
     hdev->log_size = 0;
     hdev->log_enabled = false;
     hdev->started = false;
-    memory_listener_register(&hdev->memory_listener, NULL);
+    memory_listener_register(&hdev->memory_listener, &address_space_memory);
     hdev->force = force;
     return 0;
 fail:
diff --git a/hw/xen_pt.c b/hw/xen_pt.c
index 838bcea..d3d7c8b 100644
--- a/hw/xen_pt.c
+++ b/hw/xen_pt.c
@@ -59,6 +59,7 @@
 #include "xen_backend.h"
 #include "xen_pt.h"
 #include "range.h"
+#include "exec-memory.h"
 
 #define XEN_PT_NR_IRQS (256)
 static uint8_t xen_pt_mapped_machine_irq[XEN_PT_NR_IRQS] = {0};
@@ -600,14 +601,6 @@ static void xen_pt_region_update(XenPCIPassthroughState *s,
     }
 }
 
-static void xen_pt_begin(MemoryListener *l)
-{
-}
-
-static void xen_pt_commit(MemoryListener *l)
-{
-}
-
 static void xen_pt_region_add(MemoryListener *l, MemoryRegionSection *sec)
 {
     XenPCIPassthroughState *s = container_of(l, XenPCIPassthroughState,
@@ -624,36 +617,31 @@ static void xen_pt_region_del(MemoryListener *l, MemoryRegionSection *sec)
     xen_pt_region_update(s, sec, false);
 }
 
-static void xen_pt_region_nop(MemoryListener *l, MemoryRegionSection *s)
+static void xen_pt_io_region_add(MemoryListener *l, MemoryRegionSection *sec)
 {
-}
+    XenPCIPassthroughState *s = container_of(l, XenPCIPassthroughState,
+                                             io_listener);
 
-static void xen_pt_log_fns(MemoryListener *l, MemoryRegionSection *s)
-{
+    xen_pt_region_update(s, sec, true);
 }
 
-static void xen_pt_log_global_fns(MemoryListener *l)
+static void xen_pt_io_region_del(MemoryListener *l, MemoryRegionSection *sec)
 {
-}
+    XenPCIPassthroughState *s = container_of(l, XenPCIPassthroughState,
+                                             io_listener);
 
-static void xen_pt_eventfd_fns(MemoryListener *l, MemoryRegionSection *s,
-                               bool match_data, uint64_t data, EventNotifier *n)
-{
+    xen_pt_region_update(s, sec, false);
 }
 
 static const MemoryListener xen_pt_memory_listener = {
-    .begin = xen_pt_begin,
-    .commit = xen_pt_commit,
     .region_add = xen_pt_region_add,
-    .region_nop = xen_pt_region_nop,
     .region_del = xen_pt_region_del,
-    .log_start = xen_pt_log_fns,
-    .log_stop = xen_pt_log_fns,
-    .log_sync = xen_pt_log_fns,
-    .log_global_start = xen_pt_log_global_fns,
-    .log_global_stop = xen_pt_log_global_fns,
-    .eventfd_add = xen_pt_eventfd_fns,
-    .eventfd_del = xen_pt_eventfd_fns,
+    .priority = 10,
+};
+
+static const MemoryListener xen_pt_io_listener = {
+    .region_add = xen_pt_io_region_add,
+    .region_del = xen_pt_io_region_del,
     .priority = 10,
 };
 
@@ -694,6 +682,7 @@ static int xen_pt_initfn(PCIDevice *d)
     }
 
     s->memory_listener = xen_pt_memory_listener;
+    s->io_listener = xen_pt_io_listener;
 
     /* Handle real device's MMIO/PIO BARs */
     xen_pt_register_regions(s);
@@ -760,7 +749,8 @@ static int xen_pt_initfn(PCIDevice *d)
     }
 
 out:
-    memory_listener_register(&s->memory_listener, NULL);
+    memory_listener_register(&s->memory_listener, &address_space_memory);
+    memory_listener_register(&s->io_listener, &address_space_io);
     XEN_PT_LOG(d, "Real physical device %02x:%02x.%d registered successfuly!\n",
                bus, slot, func);
 
@@ -815,6 +805,7 @@ static void xen_pt_unregister_device(PCIDevice *d)
 
     xen_pt_unregister_regions(s);
     memory_listener_unregister(&s->memory_listener);
+    memory_listener_unregister(&s->io_listener);
 
     xen_host_pci_device_put(&s->real_device);
 }
diff --git a/hw/xen_pt.h b/hw/xen_pt.h
index 112477a..f15e69a 100644
--- a/hw/xen_pt.h
+++ b/hw/xen_pt.h
@@ -209,6 +209,7 @@ struct XenPCIPassthroughState {
     MemoryRegion rom;
 
     MemoryListener memory_listener;
+    MemoryListener io_listener;
 };
 
 int xen_pt_config_init(XenPCIPassthroughState *s);
diff --git a/kvm-all.c b/kvm-all.c
index 92a7137..c2c6909 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -454,9 +454,10 @@ static int kvm_physical_sync_dirty_bitmap(MemoryRegionSection *section)
     return ret;
 }
 
-int kvm_coalesce_mmio_region(target_phys_addr_t start, ram_addr_t size)
+static void kvm_coalesce_mmio_region(MemoryListener *listener,
+                                     MemoryRegionSection *secion,
+                                     target_phys_addr_t start, target_phys_addr_t size)
 {
-    int ret = -ENOSYS;
     KVMState *s = kvm_state;
 
     if (s->coalesced_mmio) {
@@ -466,15 +467,14 @@ int kvm_coalesce_mmio_region(target_phys_addr_t start, ram_addr_t size)
         zone.size = size;
         zone.pad = 0;
 
-        ret = kvm_vm_ioctl(s, KVM_REGISTER_COALESCED_MMIO, &zone);
+        (void)kvm_vm_ioctl(s, KVM_REGISTER_COALESCED_MMIO, &zone);
     }
-
-    return ret;
 }
 
-int kvm_uncoalesce_mmio_region(target_phys_addr_t start, ram_addr_t size)
+static void kvm_uncoalesce_mmio_region(MemoryListener *listener,
+                                       MemoryRegionSection *secion,
+                                       target_phys_addr_t start, target_phys_addr_t size)
 {
-    int ret = -ENOSYS;
     KVMState *s = kvm_state;
 
     if (s->coalesced_mmio) {
@@ -484,10 +484,8 @@ int kvm_uncoalesce_mmio_region(target_phys_addr_t start, ram_addr_t size)
         zone.size = size;
         zone.pad = 0;
 
-        ret = kvm_vm_ioctl(s, KVM_UNREGISTER_COALESCED_MMIO, &zone);
+        (void)kvm_vm_ioctl(s, KVM_UNREGISTER_COALESCED_MMIO, &zone);
     }
-
-    return ret;
 }
 
 int kvm_check_extension(KVMState *s, unsigned int extension)
@@ -703,14 +701,6 @@ static void kvm_set_phys_mem(MemoryRegionSection *section, bool add)
     }
 }
 
-static void kvm_begin(MemoryListener *listener)
-{
-}
-
-static void kvm_commit(MemoryListener *listener)
-{
-}
-
 static void kvm_region_add(MemoryListener *listener,
                            MemoryRegionSection *section)
 {
@@ -723,11 +713,6 @@ static void kvm_region_del(MemoryListener *listener,
     kvm_set_phys_mem(section, false);
 }
 
-static void kvm_region_nop(MemoryListener *listener,
-                           MemoryRegionSection *section)
-{
-}
-
 static void kvm_log_sync(MemoryListener *listener,
                          MemoryRegionSection *section)
 {
@@ -755,9 +740,12 @@ static void kvm_log_global_stop(struct MemoryListener *listener)
     assert(r >= 0);
 }
 
-static void kvm_mem_ioeventfd_add(MemoryRegionSection *section,
-                                  bool match_data, uint64_t data, int fd)
+static void kvm_mem_ioeventfd_add(MemoryListener *listener,
+                                  MemoryRegionSection *section,
+                                  bool match_data, uint64_t data,
+                                  EventNotifier *e)
 {
+    int fd = event_notifier_get_fd(e);
     int r;
 
     assert(match_data && section->size <= 8);
@@ -769,9 +757,12 @@ static void kvm_mem_ioeventfd_add(MemoryRegionSection *section,
     }
 }
 
-static void kvm_mem_ioeventfd_del(MemoryRegionSection *section,
-                                  bool match_data, uint64_t data, int fd)
+static void kvm_mem_ioeventfd_del(MemoryListener *listener,
+                                  MemoryRegionSection *section,
+                                  bool match_data, uint64_t data,
+                                  EventNotifier *e)
 {
+    int fd = event_notifier_get_fd(e);
     int r;
 
     r = kvm_set_ioeventfd_mmio(fd, section->offset_within_address_space,
@@ -781,9 +772,12 @@ static void kvm_mem_ioeventfd_del(MemoryRegionSection *section,
     }
 }
 
-static void kvm_io_ioeventfd_add(MemoryRegionSection *section,
-                                 bool match_data, uint64_t data, int fd)
+static void kvm_io_ioeventfd_add(MemoryListener *listener,
+                                 MemoryRegionSection *section,
+                                 bool match_data, uint64_t data,
+                                 EventNotifier *e)
 {
+    int fd = event_notifier_get_fd(e);
     int r;
 
     assert(match_data && section->size == 2);
@@ -795,10 +789,13 @@ static void kvm_io_ioeventfd_add(MemoryRegionSection *section,
     }
 }
 
-static void kvm_io_ioeventfd_del(MemoryRegionSection *section,
-                                 bool match_data, uint64_t data, int fd)
+static void kvm_io_ioeventfd_del(MemoryListener *listener,
+                                 MemoryRegionSection *section,
+                                 bool match_data, uint64_t data,
+                                 EventNotifier *e)
 
 {
+    int fd = event_notifier_get_fd(e);
     int r;
 
     r = kvm_set_ioeventfd_pio_word(fd, section->offset_within_address_space,
@@ -808,47 +805,24 @@ static void kvm_io_ioeventfd_del(MemoryRegionSection *section,
     }
 }
 
-static void kvm_eventfd_add(MemoryListener *listener,
-                            MemoryRegionSection *section,
-                            bool match_data, uint64_t data,
-                            EventNotifier *e)
-{
-    if (section->address_space == get_system_memory()) {
-        kvm_mem_ioeventfd_add(section, match_data, data,
-			      event_notifier_get_fd(e));
-    } else {
-        kvm_io_ioeventfd_add(section, match_data, data,
-			     event_notifier_get_fd(e));
-    }
-}
-
-static void kvm_eventfd_del(MemoryListener *listener,
-                            MemoryRegionSection *section,
-                            bool match_data, uint64_t data,
-                            EventNotifier *e)
-{
-    if (section->address_space == get_system_memory()) {
-        kvm_mem_ioeventfd_del(section, match_data, data,
-			      event_notifier_get_fd(e));
-    } else {
-        kvm_io_ioeventfd_del(section, match_data, data,
-			     event_notifier_get_fd(e));
-    }
-}
-
 static MemoryListener kvm_memory_listener = {
-    .begin = kvm_begin,
-    .commit = kvm_commit,
     .region_add = kvm_region_add,
     .region_del = kvm_region_del,
-    .region_nop = kvm_region_nop,
     .log_start = kvm_log_start,
     .log_stop = kvm_log_stop,
     .log_sync = kvm_log_sync,
     .log_global_start = kvm_log_global_start,
     .log_global_stop = kvm_log_global_stop,
-    .eventfd_add = kvm_eventfd_add,
-    .eventfd_del = kvm_eventfd_del,
+    .eventfd_add = kvm_mem_ioeventfd_add,
+    .eventfd_del = kvm_mem_ioeventfd_del,
+    .coalesced_mmio_add = kvm_coalesce_mmio_region,
+    .coalesced_mmio_del = kvm_uncoalesce_mmio_region,
+    .priority = 10,
+};
+
+static MemoryListener kvm_io_listener = {
+    .eventfd_add = kvm_io_ioeventfd_add,
+    .eventfd_del = kvm_io_ioeventfd_del,
     .priority = 10,
 };
 
@@ -1401,7 +1375,8 @@ int kvm_init(void)
     }
 
     kvm_state = s;
-    memory_listener_register(&kvm_memory_listener, NULL);
+    memory_listener_register(&kvm_memory_listener, &address_space_memory);
+    memory_listener_register(&kvm_io_listener, &address_space_io);
 
     s->many_ioeventfds = kvm_check_many_ioeventfds();
 
diff --git a/kvm-stub.c b/kvm-stub.c
index 3c52eb5..a3455e2 100644
--- a/kvm-stub.c
+++ b/kvm-stub.c
@@ -29,16 +29,6 @@ int kvm_init_vcpu(CPUArchState *env)
     return -ENOSYS;
 }
 
-int kvm_coalesce_mmio_region(target_phys_addr_t start, ram_addr_t size)
-{
-    return -ENOSYS;
-}
-
-int kvm_uncoalesce_mmio_region(target_phys_addr_t start, ram_addr_t size)
-{
-    return -ENOSYS;
-}
-
 int kvm_init(void)
 {
     return -ENOSYS;
diff --git a/kvm.h b/kvm.h
index dea2998..eefcb49 100644
--- a/kvm.h
+++ b/kvm.h
@@ -129,8 +129,6 @@ void *kvm_vmalloc(ram_addr_t size);
 void *kvm_arch_vmalloc(ram_addr_t size);
 void kvm_setup_guest_memory(void *start, size_t size);
 
-int kvm_coalesce_mmio_region(target_phys_addr_t start, ram_addr_t size);
-int kvm_uncoalesce_mmio_region(target_phys_addr_t start, ram_addr_t size);
 void kvm_flush_coalesced_mmio_buffer(void);
 #endif
 
diff --git a/exec-obsolete.h b/memory-internal.h
index 286e2f7..4d33cc9 100644
--- a/exec-obsolete.h
+++ b/memory-internal.h
@@ -16,16 +16,33 @@
  * The functions declared here will be removed soon.
  */
 
-#ifndef EXEC_OBSOLETE_H
-#define EXEC_OBSOLETE_H
-
-#ifndef WANT_EXEC_OBSOLETE
-#error Do not include exec-obsolete.h
-#endif
+#ifndef MEMORY_INTERNAL_H
+#define MEMORY_INTERNAL_H
 
 #ifndef CONFIG_USER_ONLY
 #include "hw/xen.h"
 
+typedef struct PhysPageEntry PhysPageEntry;
+
+struct PhysPageEntry {
+    uint16_t is_leaf : 1;
+     /* index into phys_sections (is_leaf) or phys_map_nodes (!is_leaf) */
+    uint16_t ptr : 15;
+};
+
+typedef struct AddressSpaceDispatch AddressSpaceDispatch;
+
+struct AddressSpaceDispatch {
+    /* This is a multi-level map on the physical address space.
+     * The bottom level has pointers to MemoryRegionSections.
+     */
+    PhysPageEntry phys_map;
+    MemoryListener listener;
+};
+
+void address_space_init_dispatch(AddressSpace *as);
+void address_space_destroy_dispatch(AddressSpace *as);
+
 ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
                                    MemoryRegion *mr);
 ram_addr_t qemu_ram_alloc(ram_addr_t size, MemoryRegion *mr);
@@ -34,8 +51,6 @@ void qemu_ram_free_from_ptr(ram_addr_t addr);
 
 struct MemoryRegion;
 struct MemoryRegionSection;
-void cpu_register_physical_memory_log(struct MemoryRegionSection *section,
-                                      bool readonly);
 
 void qemu_register_coalesced_mmio(target_phys_addr_t addr, ram_addr_t size);
 void qemu_unregister_coalesced_mmio(target_phys_addr_t addr, ram_addr_t size);
diff --git a/memory.c b/memory.c
index 4f3ade0..2f68d67 100644
--- a/memory.c
+++ b/memory.c
@@ -20,8 +20,7 @@
 #include "kvm.h"
 #include <assert.h>
 
-#define WANT_EXEC_OBSOLETE
-#include "exec-obsolete.h"
+#include "memory-internal.h"
 
 unsigned memory_region_transaction_depth = 0;
 static bool global_dirty_log = false;
@@ -29,6 +28,9 @@ static bool global_dirty_log = false;
 static QTAILQ_HEAD(memory_listeners, MemoryListener) memory_listeners
     = QTAILQ_HEAD_INITIALIZER(memory_listeners);
 
+static QTAILQ_HEAD(, AddressSpace) address_spaces
+    = QTAILQ_HEAD_INITIALIZER(address_spaces);
+
 typedef struct AddrRange AddrRange;
 
 /*
@@ -97,13 +99,17 @@ static bool memory_listener_match(MemoryListener *listener,
         switch (_direction) {                                           \
         case Forward:                                                   \
             QTAILQ_FOREACH(_listener, &memory_listeners, link) {        \
-                _listener->_callback(_listener, ##_args);               \
+                if (_listener->_callback) {                             \
+                    _listener->_callback(_listener, ##_args);           \
+                }                                                       \
             }                                                           \
             break;                                                      \
         case Reverse:                                                   \
             QTAILQ_FOREACH_REVERSE(_listener, &memory_listeners,        \
                                    memory_listeners, link) {            \
-                _listener->_callback(_listener, ##_args);               \
+                if (_listener->_callback) {                             \
+                    _listener->_callback(_listener, ##_args);           \
+                }                                                       \
             }                                                           \
             break;                                                      \
         default:                                                        \
@@ -118,7 +124,8 @@ static bool memory_listener_match(MemoryListener *listener,
         switch (_direction) {                                           \
         case Forward:                                                   \
             QTAILQ_FOREACH(_listener, &memory_listeners, link) {        \
-                if (memory_listener_match(_listener, _section)) {       \
+                if (_listener->_callback                                \
+                    && memory_listener_match(_listener, _section)) {    \
                     _listener->_callback(_listener, _section, ##_args); \
                 }                                                       \
             }                                                           \
@@ -126,7 +133,8 @@ static bool memory_listener_match(MemoryListener *listener,
         case Reverse:                                                   \
             QTAILQ_FOREACH_REVERSE(_listener, &memory_listeners,        \
                                    memory_listeners, link) {            \
-                if (memory_listener_match(_listener, _section)) {       \
+                if (_listener->_callback                                \
+                    && memory_listener_match(_listener, _section)) {    \
                     _listener->_callback(_listener, _section, ##_args); \
                 }                                                       \
             }                                                           \
@@ -139,7 +147,7 @@ static bool memory_listener_match(MemoryListener *listener,
 #define MEMORY_LISTENER_UPDATE_REGION(fr, as, dir, callback)            \
     MEMORY_LISTENER_CALL(callback, dir, (&(MemoryRegionSection) {       \
         .mr = (fr)->mr,                                                 \
-        .address_space = (as)->root,                                    \
+        .address_space = (as),                                          \
         .offset_within_region = (fr)->offset_in_region,                 \
         .size = int128_get64((fr)->addr.size),                          \
         .offset_within_address_space = int128_get64((fr)->addr.start),  \
@@ -217,17 +225,8 @@ struct FlatView {
     unsigned nr_allocated;
 };
 
-typedef struct AddressSpace AddressSpace;
 typedef struct AddressSpaceOps AddressSpaceOps;
 
-/* A system address space - I/O, memory, etc. */
-struct AddressSpace {
-    MemoryRegion *root;
-    FlatView current_map;
-    int ioeventfd_nb;
-    MemoryRegionIoeventfd *ioeventfds;
-};
-
 #define FOR_EACH_FLAT_RANGE(var, view)          \
     for (var = (view)->ranges; var < (view)->ranges + (view)->nr; ++var)
 
@@ -365,8 +364,6 @@ static void access_with_adjusted_size(target_phys_addr_t addr,
     }
 }
 
-static AddressSpace address_space_memory;
-
 static const MemoryRegionPortio *find_portio(MemoryRegion *mr, uint64_t offset,
                                              unsigned width, bool write)
 {
@@ -455,18 +452,17 @@ const IORangeOps memory_region_iorange_ops = {
     .destructor = memory_region_iorange_destructor,
 };
 
-static AddressSpace address_space_io;
-
 static AddressSpace *memory_region_to_address_space(MemoryRegion *mr)
 {
+    AddressSpace *as;
+
     while (mr->parent) {
         mr = mr->parent;
     }
-    if (mr == address_space_memory.root) {
-        return &address_space_memory;
-    }
-    if (mr == address_space_io.root) {
-        return &address_space_io;
+    QTAILQ_FOREACH(as, &address_spaces, address_spaces_link) {
+        if (mr == as->root) {
+            return as;
+        }
     }
     abort();
 }
@@ -568,8 +564,10 @@ static FlatView generate_memory_topology(MemoryRegion *mr)
 
     flatview_init(&view);
 
-    render_memory_region(&view, mr, int128_zero(),
-                         addrrange_make(int128_zero(), int128_2_64()), false);
+    if (mr) {
+        render_memory_region(&view, mr, int128_zero(),
+                             addrrange_make(int128_zero(), int128_2_64()), false);
+    }
     flatview_simplify(&view);
 
     return view;
@@ -597,7 +595,7 @@ static void address_space_add_del_ioeventfds(AddressSpace *as,
                                                   fds_new[inew]))) {
             fd = &fds_old[iold];
             section = (MemoryRegionSection) {
-                .address_space = as->root,
+                .address_space = as,
                 .offset_within_address_space = int128_get64(fd->addr.start),
                 .size = int128_get64(fd->addr.size),
             };
@@ -610,7 +608,7 @@ static void address_space_add_del_ioeventfds(AddressSpace *as,
                                                          fds_old[iold]))) {
             fd = &fds_new[inew];
             section = (MemoryRegionSection) {
-                .address_space = as->root,
+                .address_space = as,
                 .offset_within_address_space = int128_get64(fd->addr.start),
                 .size = int128_get64(fd->addr.size),
             };
@@ -632,7 +630,7 @@ static void address_space_update_ioeventfds(AddressSpace *as)
     AddrRange tmp;
     unsigned i;
 
-    FOR_EACH_FLAT_RANGE(fr, &as->current_map) {
+    FOR_EACH_FLAT_RANGE(fr, as->current_map) {
         for (i = 0; i < fr->mr->ioeventfd_nb; ++i) {
             tmp = addrrange_shift(fr->mr->ioeventfds[i].addr,
                                   int128_sub(fr->addr.start,
@@ -720,13 +718,13 @@ static void address_space_update_topology_pass(AddressSpace *as,
 
 static void address_space_update_topology(AddressSpace *as)
 {
-    FlatView old_view = as->current_map;
+    FlatView old_view = *as->current_map;
     FlatView new_view = generate_memory_topology(as->root);
 
     address_space_update_topology_pass(as, old_view, new_view, false);
     address_space_update_topology_pass(as, old_view, new_view, true);
 
-    as->current_map = new_view;
+    *as->current_map = new_view;
     flatview_destroy(&old_view);
     address_space_update_ioeventfds(as);
 }
@@ -739,16 +737,15 @@ void memory_region_transaction_begin(void)
 
 void memory_region_transaction_commit(void)
 {
+    AddressSpace *as;
+
     assert(memory_region_transaction_depth);
     --memory_region_transaction_depth;
     if (!memory_region_transaction_depth) {
         MEMORY_LISTENER_CALL_GLOBAL(begin, Forward);
 
-        if (address_space_memory.root) {
-            address_space_update_topology(&address_space_memory);
-        }
-        if (address_space_io.root) {
-            address_space_update_topology(&address_space_io);
+        QTAILQ_FOREACH(as, &address_spaces, address_spaces_link) {
+            address_space_update_topology(as);
         }
 
         MEMORY_LISTENER_CALL_GLOBAL(commit, Forward);
@@ -1082,12 +1079,14 @@ void memory_region_set_dirty(MemoryRegion *mr, target_phys_addr_t addr,
 
 void memory_region_sync_dirty_bitmap(MemoryRegion *mr)
 {
+    AddressSpace *as;
     FlatRange *fr;
 
-    FOR_EACH_FLAT_RANGE(fr, &address_space_memory.current_map) {
-        if (fr->mr == mr) {
-            MEMORY_LISTENER_UPDATE_REGION(fr, &address_space_memory,
-                                          Forward, log_sync);
+    QTAILQ_FOREACH(as, &address_spaces, address_spaces_link) {
+        FOR_EACH_FLAT_RANGE(fr, as->current_map) {
+            if (fr->mr == mr) {
+                MEMORY_LISTENER_UPDATE_REGION(fr, as, Forward, log_sync);
+            }
         }
     }
 }
@@ -1130,16 +1129,24 @@ void *memory_region_get_ram_ptr(MemoryRegion *mr)
     return qemu_get_ram_ptr(mr->ram_addr & TARGET_PAGE_MASK);
 }
 
-static void memory_region_update_coalesced_range(MemoryRegion *mr)
+static void memory_region_update_coalesced_range_as(MemoryRegion *mr, AddressSpace *as)
 {
     FlatRange *fr;
     CoalescedMemoryRange *cmr;
     AddrRange tmp;
+    MemoryRegionSection section;
 
-    FOR_EACH_FLAT_RANGE(fr, &address_space_memory.current_map) {
+    FOR_EACH_FLAT_RANGE(fr, as->current_map) {
         if (fr->mr == mr) {
-            qemu_unregister_coalesced_mmio(int128_get64(fr->addr.start),
-                                           int128_get64(fr->addr.size));
+            section = (MemoryRegionSection) {
+                .address_space = as,
+                .offset_within_address_space = int128_get64(fr->addr.start),
+                .size = int128_get64(fr->addr.size),
+            };
+
+            MEMORY_LISTENER_CALL(coalesced_mmio_del, Reverse, &section,
+                                 int128_get64(fr->addr.start),
+                                 int128_get64(fr->addr.size));
             QTAILQ_FOREACH(cmr, &mr->coalesced, link) {
                 tmp = addrrange_shift(cmr->addr,
                                       int128_sub(fr->addr.start,
@@ -1148,13 +1155,23 @@ static void memory_region_update_coalesced_range(MemoryRegion *mr)
                     continue;
                 }
                 tmp = addrrange_intersection(tmp, fr->addr);
-                qemu_register_coalesced_mmio(int128_get64(tmp.start),
-                                             int128_get64(tmp.size));
+                MEMORY_LISTENER_CALL(coalesced_mmio_add, Forward, &section,
+                                     int128_get64(tmp.start),
+                                     int128_get64(tmp.size));
             }
         }
     }
 }
 
+static void memory_region_update_coalesced_range(MemoryRegion *mr)
+{
+    AddressSpace *as;
+
+    QTAILQ_FOREACH(as, &address_spaces, address_spaces_link) {
+        memory_region_update_coalesced_range_as(mr, as);
+    }
+}
+
 void memory_region_set_coalescing(MemoryRegion *mr)
 {
     memory_region_clear_coalescing(mr);
@@ -1400,7 +1417,7 @@ static int cmp_flatrange_addr(const void *addr_, const void *fr_)
 
 static FlatRange *address_space_lookup(AddressSpace *as, AddrRange addr)
 {
-    return bsearch(&addr, as->current_map.ranges, as->current_map.nr,
+    return bsearch(&addr, as->current_map->ranges, as->current_map->nr,
                    sizeof(FlatRange), cmp_flatrange_addr);
 }
 
@@ -1417,7 +1434,7 @@ MemoryRegionSection memory_region_find(MemoryRegion *address_space,
         return ret;
     }
 
-    while (fr > as->current_map.ranges
+    while (fr > as->current_map->ranges
            && addrrange_intersects(fr[-1].addr, range)) {
         --fr;
     }
@@ -1438,7 +1455,7 @@ void memory_global_sync_dirty_bitmap(MemoryRegion *address_space)
     AddressSpace *as = memory_region_to_address_space(address_space);
     FlatRange *fr;
 
-    FOR_EACH_FLAT_RANGE(fr, &as->current_map) {
+    FOR_EACH_FLAT_RANGE(fr, as->current_map) {
         MEMORY_LISTENER_UPDATE_REGION(fr, as, Forward, log_sync);
     }
 }
@@ -1461,29 +1478,35 @@ static void listener_add_address_space(MemoryListener *listener,
     FlatRange *fr;
 
     if (listener->address_space_filter
-        && listener->address_space_filter != as->root) {
+        && listener->address_space_filter != as) {
         return;
     }
 
     if (global_dirty_log) {
-        listener->log_global_start(listener);
+        if (listener->log_global_start) {
+            listener->log_global_start(listener);
+        }
     }
-    FOR_EACH_FLAT_RANGE(fr, &as->current_map) {
+
+    FOR_EACH_FLAT_RANGE(fr, as->current_map) {
         MemoryRegionSection section = {
             .mr = fr->mr,
-            .address_space = as->root,
+            .address_space = as,
             .offset_within_region = fr->offset_in_region,
             .size = int128_get64(fr->addr.size),
             .offset_within_address_space = int128_get64(fr->addr.start),
             .readonly = fr->readonly,
         };
-        listener->region_add(listener, &section);
+        if (listener->region_add) {
+            listener->region_add(listener, &section);
+        }
     }
 }
 
-void memory_listener_register(MemoryListener *listener, MemoryRegion *filter)
+void memory_listener_register(MemoryListener *listener, AddressSpace *filter)
 {
     MemoryListener *other = NULL;
+    AddressSpace *as;
 
     listener->address_space_filter = filter;
     if (QTAILQ_EMPTY(&memory_listeners)
@@ -1498,8 +1521,10 @@ void memory_listener_register(MemoryListener *listener, MemoryRegion *filter)
         }
         QTAILQ_INSERT_BEFORE(other, listener, link);
     }
-    listener_add_address_space(listener, &address_space_memory);
-    listener_add_address_space(listener, &address_space_io);
+
+    QTAILQ_FOREACH(as, &address_spaces, address_spaces_link) {
+        listener_add_address_space(listener, as);
+    }
 }
 
 void memory_listener_unregister(MemoryListener *listener)
@@ -1507,18 +1532,28 @@ void memory_listener_unregister(MemoryListener *listener)
     QTAILQ_REMOVE(&memory_listeners, listener, link);
 }
 
-void set_system_memory_map(MemoryRegion *mr)
+void address_space_init(AddressSpace *as, MemoryRegion *root)
 {
     memory_region_transaction_begin();
-    address_space_memory.root = mr;
+    as->root = root;
+    as->current_map = g_new(FlatView, 1);
+    flatview_init(as->current_map);
+    QTAILQ_INSERT_TAIL(&address_spaces, as, address_spaces_link);
+    as->name = NULL;
     memory_region_transaction_commit();
+    address_space_init_dispatch(as);
 }
 
-void set_system_io_map(MemoryRegion *mr)
+void address_space_destroy(AddressSpace *as)
 {
+    /* Flush out anything from MemoryListeners listening in on this */
     memory_region_transaction_begin();
-    address_space_io.root = mr;
+    as->root = NULL;
     memory_region_transaction_commit();
+    QTAILQ_REMOVE(&address_spaces, as, address_spaces_link);
+    address_space_destroy_dispatch(as);
+    flatview_destroy(as->current_map);
+    g_free(as->current_map);
 }
 
 uint64_t io_mem_read(MemoryRegion *mr, target_phys_addr_t addr, unsigned size)
@@ -1638,16 +1673,16 @@ void mtree_info(fprintf_function mon_printf, void *f)
 {
     MemoryRegionListHead ml_head;
     MemoryRegionList *ml, *ml2;
+    AddressSpace *as;
 
     QTAILQ_INIT(&ml_head);
 
-    mon_printf(f, "memory\n");
-    mtree_print_mr(mon_printf, f, address_space_memory.root, 0, 0, &ml_head);
-
-    if (address_space_io.root &&
-        !QTAILQ_EMPTY(&address_space_io.root->subregions)) {
-        mon_printf(f, "I/O\n");
-        mtree_print_mr(mon_printf, f, address_space_io.root, 0, 0, &ml_head);
+    QTAILQ_FOREACH(as, &address_spaces, address_spaces_link) {
+        if (!as->name) {
+            continue;
+        }
+        mon_printf(f, "%s\n", as->name);
+        mtree_print_mr(mon_printf, f, as->root, 0, 0, &ml_head);
     }
 
     mon_printf(f, "aliases\n");
diff --git a/memory.h b/memory.h
index 37ce151..79393f1 100644
--- a/memory.h
+++ b/memory.h
@@ -157,6 +157,22 @@ struct MemoryRegionPortio {
 
 #define PORTIO_END_OF_LIST() { }
 
+typedef struct AddressSpace AddressSpace;
+
+/**
+ * AddressSpace: describes a mapping of addresses to #MemoryRegion objects
+ */
+struct AddressSpace {
+    /* All fields are private. */
+    const char *name;
+    MemoryRegion *root;
+    struct FlatView *current_map;
+    int ioeventfd_nb;
+    struct MemoryRegionIoeventfd *ioeventfds;
+    struct AddressSpaceDispatch *dispatch;
+    QTAILQ_ENTRY(AddressSpace) address_spaces_link;
+};
+
 typedef struct MemoryRegionSection MemoryRegionSection;
 
 /**
@@ -172,7 +188,7 @@ typedef struct MemoryRegionSection MemoryRegionSection;
  */
 struct MemoryRegionSection {
     MemoryRegion *mr;
-    MemoryRegion *address_space;
+    AddressSpace *address_space;
     target_phys_addr_t offset_within_region;
     uint64_t size;
     target_phys_addr_t offset_within_address_space;
@@ -202,9 +218,13 @@ struct MemoryListener {
                         bool match_data, uint64_t data, EventNotifier *e);
     void (*eventfd_del)(MemoryListener *listener, MemoryRegionSection *section,
                         bool match_data, uint64_t data, EventNotifier *e);
+    void (*coalesced_mmio_add)(MemoryListener *listener, MemoryRegionSection *section,
+                               target_phys_addr_t addr, target_phys_addr_t len);
+    void (*coalesced_mmio_del)(MemoryListener *listener, MemoryRegionSection *section,
+                               target_phys_addr_t addr, target_phys_addr_t len);
     /* Lower = earlier (during add), later (during del) */
     unsigned priority;
-    MemoryRegion *address_space_filter;
+    AddressSpace *address_space_filter;
     QTAILQ_ENTRY(MemoryListener) link;
 };
 
@@ -755,7 +775,7 @@ void memory_region_transaction_commit(void);
  * @listener: an object containing the callbacks to be called
  * @filter: if non-%NULL, only regions in this address space will be observed
  */
-void memory_listener_register(MemoryListener *listener, MemoryRegion *filter);
+void memory_listener_register(MemoryListener *listener, AddressSpace *filter);
 
 /**
  * memory_listener_unregister: undo the effect of memory_listener_register()
@@ -776,6 +796,87 @@ void memory_global_dirty_log_stop(void);
 
 void mtree_info(fprintf_function mon_printf, void *f);
 
+/**
+ * address_space_init: initializes an address space
+ *
+ * @as: an uninitialized #AddressSpace
+ * @root: a #MemoryRegion that routes addesses for the address space
+ */
+void address_space_init(AddressSpace *as, MemoryRegion *root);
+
+
+/**
+ * address_space_destroy: destroy an address space
+ *
+ * Releases all resources associated with an address space.  After an address space
+ * is destroyed, its root memory region (given by address_space_init()) may be destroyed
+ * as well.
+ *
+ * @as: address space to be destroyed
+ */
+void address_space_destroy(AddressSpace *as);
+
+/**
+ * address_space_rw: read from or write to an address space.
+ *
+ * @as: #AddressSpace to be accessed
+ * @addr: address within that address space
+ * @buf: buffer with the data transferred
+ * @is_write: indicates the transfer direction
+ */
+void address_space_rw(AddressSpace *as, target_phys_addr_t addr, uint8_t *buf,
+                      int len, bool is_write);
+
+/**
+ * address_space_write: write to address space.
+ *
+ * @as: #AddressSpace to be accessed
+ * @addr: address within that address space
+ * @buf: buffer with the data transferred
+ */
+void address_space_write(AddressSpace *as, target_phys_addr_t addr,
+                         const uint8_t *buf, int len);
+
+/**
+ * address_space_read: read from an address space.
+ *
+ * @as: #AddressSpace to be accessed
+ * @addr: address within that address space
+ * @buf: buffer with the data transferred
+ */
+void address_space_read(AddressSpace *as, target_phys_addr_t addr, uint8_t *buf, int len);
+
+/* address_space_map: map a physical memory region into a host virtual address
+ *
+ * May map a subset of the requested range, given by and returned in @plen.
+ * May return %NULL if resources needed to perform the mapping are exhausted.
+ * Use only for reads OR writes - not for read-modify-write operations.
+ * Use cpu_register_map_client() to know when retrying the map operation is
+ * likely to succeed.
+ *
+ * @as: #AddressSpace to be accessed
+ * @addr: address within that address space
+ * @plen: pointer to length of buffer; updated on return
+ * @is_write: indicates the transfer direction
+ */
+void *address_space_map(AddressSpace *as, target_phys_addr_t addr,
+                        target_phys_addr_t *plen, bool is_write);
+
+/* address_space_unmap: Unmaps a memory region previously mapped by address_space_map()
+ *
+ * Will also mark the memory as dirty if @is_write == %true.  @access_len gives
+ * the amount of memory that was actually read or written by the caller.
+ *
+ * @as: #AddressSpace used
+ * @addr: address within that address space
+ * @len: buffer length as returned by address_space_map()
+ * @access_len: amount of data actually transferred
+ * @is_write: indicates the transfer direction
+ */
+void address_space_unmap(AddressSpace *as, void *buffer, target_phys_addr_t len,
+                         int is_write, target_phys_addr_t access_len);
+
+
 #endif
 
 #endif
diff --git a/target-s390x/misc_helper.c b/target-s390x/misc_helper.c
index e9b3cae..fdccd58 100644
--- a/target-s390x/misc_helper.c
+++ b/target-s390x/misc_helper.c
@@ -20,7 +20,6 @@
 
 #include "cpu.h"
 #include "memory.h"
-#include "cputlb.h"
 #include "host-utils.h"
 #include "helper.h"
 #include <string.h>
@@ -81,7 +80,7 @@ int sclp_service_call(CPUS390XState *env, uint32_t sccb, uint64_t code)
 #endif
 
     /* basic checks */
-    if (!memory_region_is_ram(phys_page_find(sccb >> TARGET_PAGE_BITS)->mr)) {
+    if (cpu_physical_memory_is_io(sccb)) {
         return -PGM_ADDRESSING;
     }
     if (sccb & ~0x7ffffff8ul) {
diff --git a/xen-all.c b/xen-all.c
index bcb7ef7..9d1e168 100644
--- a/xen-all.c
+++ b/xen-all.c
@@ -454,14 +454,6 @@ static void xen_set_memory(struct MemoryListener *listener,
     }
 }
 
-static void xen_begin(MemoryListener *listener)
-{
-}
-
-static void xen_commit(MemoryListener *listener)
-{
-}
-
 static void xen_region_add(MemoryListener *listener,
                            MemoryRegionSection *section)
 {
@@ -474,11 +466,6 @@ static void xen_region_del(MemoryListener *listener,
     xen_set_memory(listener, section, false);
 }
 
-static void xen_region_nop(MemoryListener *listener,
-                           MemoryRegionSection *section)
-{
-}
-
 static void xen_sync_dirty_bitmap(XenIOState *state,
                                   target_phys_addr_t start_addr,
                                   ram_addr_t size)
@@ -565,33 +552,14 @@ static void xen_log_global_stop(MemoryListener *listener)
     xen_in_migration = false;
 }
 
-static void xen_eventfd_add(MemoryListener *listener,
-                            MemoryRegionSection *section,
-                            bool match_data, uint64_t data,
-                            EventNotifier *e)
-{
-}
-
-static void xen_eventfd_del(MemoryListener *listener,
-                            MemoryRegionSection *section,
-                            bool match_data, uint64_t data,
-                            EventNotifier *e)
-{
-}
-
 static MemoryListener xen_memory_listener = {
-    .begin = xen_begin,
-    .commit = xen_commit,
     .region_add = xen_region_add,
     .region_del = xen_region_del,
-    .region_nop = xen_region_nop,
     .log_start = xen_log_start,
     .log_stop = xen_log_stop,
     .log_sync = xen_log_sync,
     .log_global_start = xen_log_global_start,
     .log_global_stop = xen_log_global_stop,
-    .eventfd_add = xen_eventfd_add,
-    .eventfd_del = xen_eventfd_del,
     .priority = 10,
 };
 
@@ -1173,7 +1141,7 @@ int xen_hvm_init(void)
 
     state->memory_listener = xen_memory_listener;
     QLIST_INIT(&state->physmap);
-    memory_listener_register(&state->memory_listener, get_system_memory());
+    memory_listener_register(&state->memory_listener, &address_space_memory);
     state->log_for_dirtybit = NULL;
 
     /* Initialize backend core & drivers */