diff --git a/exec-obsolete.h b/exec-obsolete.h
index c09925610d..286e2f75e1 100644
--- a/exec-obsolete.h
+++ b/exec-obsolete.h
@@ -24,6 +24,7 @@
 #endif
 
 #ifndef CONFIG_USER_ONLY
+#include "hw/xen.h"
 
 ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
                                    MemoryRegion *mr);
@@ -111,6 +112,7 @@ static inline void cpu_physical_memory_set_dirty_range(ram_addr_t start,
     for (addr = start; addr < end; addr += TARGET_PAGE_SIZE) {
         cpu_physical_memory_set_dirty_flags(addr, dirty_flags);
     }
+    xen_modified_memory(addr, length);
 }
 
 static inline void cpu_physical_memory_mask_dirty_range(ram_addr_t start,
diff --git a/exec.c b/exec.c
index bb6aa4a070..1114a0932b 100644
--- a/exec.c
+++ b/exec.c
@@ -3417,6 +3417,19 @@ int cpu_memory_rw_debug(CPUArchState *env, target_ulong addr,
 }
 
 #else
+
+static void invalidate_and_set_dirty(target_phys_addr_t addr,
+                                     target_phys_addr_t length)
+{
+    if (!cpu_physical_memory_is_dirty(addr)) {
+        /* invalidate code */
+        tb_invalidate_phys_page_range(addr, addr + length, 0);
+        /* set dirty bit */
+        cpu_physical_memory_set_dirty_flags(addr, (0xff & ~CODE_DIRTY_FLAG));
+    }
+    xen_modified_memory(addr, length);
+}
+
 void cpu_physical_memory_rw(target_phys_addr_t addr, uint8_t *buf,
                             int len, int is_write)
 {
@@ -3462,13 +3475,7 @@ void cpu_physical_memory_rw(target_phys_addr_t addr, uint8_t *buf,
                 /* RAM case */
                 ptr = qemu_get_ram_ptr(addr1);
                 memcpy(ptr, buf, l);
-                if (!cpu_physical_memory_is_dirty(addr1)) {
-                    /* invalidate code */
-                    tb_invalidate_phys_page_range(addr1, addr1 + l, 0);
-                    /* set dirty bit */
-                    cpu_physical_memory_set_dirty_flags(
-                        addr1, (0xff & ~CODE_DIRTY_FLAG));
-                }
+                invalidate_and_set_dirty(addr1, l);
                 qemu_put_ram_ptr(ptr);
             }
         } else {
@@ -3534,13 +3541,7 @@ void cpu_physical_memory_write_rom(target_phys_addr_t addr,
             /* ROM/RAM case */
             ptr = qemu_get_ram_ptr(addr1);
             memcpy(ptr, buf, l);
-            if (!cpu_physical_memory_is_dirty(addr1)) {
-                /* invalidate code */
-                tb_invalidate_phys_page_range(addr1, addr1 + l, 0);
-                /* set dirty bit */
-                cpu_physical_memory_set_dirty_flags(
-                    addr1, (0xff & ~CODE_DIRTY_FLAG));
-            }
+            invalidate_and_set_dirty(addr1, l);
             qemu_put_ram_ptr(ptr);
         }
         len -= l;
@@ -3666,13 +3667,7 @@ void cpu_physical_memory_unmap(void *buffer, target_phys_addr_t len,
                 l = TARGET_PAGE_SIZE;
                 if (l > access_len)
                     l = access_len;
-                if (!cpu_physical_memory_is_dirty(addr1)) {
-                    /* invalidate code */
-                    tb_invalidate_phys_page_range(addr1, addr1 + l, 0);
-                    /* set dirty bit */
-                    cpu_physical_memory_set_dirty_flags(
-                        addr1, (0xff & ~CODE_DIRTY_FLAG));
-                }
+                invalidate_and_set_dirty(addr1, l);
                 addr1 += l;
                 access_len -= l;
             }
@@ -3978,13 +3973,7 @@ static inline void stl_phys_internal(target_phys_addr_t addr, uint32_t val,
             stl_p(ptr, val);
             break;
         }
-        if (!cpu_physical_memory_is_dirty(addr1)) {
-            /* invalidate code */
-            tb_invalidate_phys_page_range(addr1, addr1 + 4, 0);
-            /* set dirty bit */
-            cpu_physical_memory_set_dirty_flags(addr1,
-                (0xff & ~CODE_DIRTY_FLAG));
-        }
+        invalidate_and_set_dirty(addr1, 4);
     }
 }
 
@@ -4051,13 +4040,7 @@ static inline void stw_phys_internal(target_phys_addr_t addr, uint32_t val,
             stw_p(ptr, val);
             break;
         }
-        if (!cpu_physical_memory_is_dirty(addr1)) {
-            /* invalidate code */
-            tb_invalidate_phys_page_range(addr1, addr1 + 2, 0);
-            /* set dirty bit */
-            cpu_physical_memory_set_dirty_flags(addr1,
-                (0xff & ~CODE_DIRTY_FLAG));
-        }
+        invalidate_and_set_dirty(addr1, 2);
     }
 }
 
diff --git a/hw/xen.h b/hw/xen.h
index e5926b7b8a..d14e92d5aa 100644
--- a/hw/xen.h
+++ b/hw/xen.h
@@ -48,6 +48,7 @@ void xenstore_store_pv_console_info(int i, struct CharDriverState *chr);
 struct MemoryRegion;
 void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size,
                    struct MemoryRegion *mr);
+void xen_modified_memory(ram_addr_t start, ram_addr_t length);
 #endif
 
 struct MemoryRegion;
diff --git a/hw/xen_platform.c b/hw/xen_platform.c
index 0d6c2ff8c3..956dbfeae4 100644
--- a/hw/xen_platform.c
+++ b/hw/xen_platform.c
@@ -85,8 +85,10 @@ static void log_writeb(PCIXenPlatformState *s, char val)
 
 static void unplug_nic(PCIBus *b, PCIDevice *d, void *o)
 {
+    /* We have to ignore passthrough devices */
     if (pci_get_word(d->config + PCI_CLASS_DEVICE) ==
-            PCI_CLASS_NETWORK_ETHERNET) {
+            PCI_CLASS_NETWORK_ETHERNET
+            && strcmp(d->name, "xen-pci-passthrough") != 0) {
         qdev_free(&d->qdev);
     }
 }
@@ -98,8 +100,10 @@ static void pci_unplug_nics(PCIBus *bus)
 
 static void unplug_disks(PCIBus *b, PCIDevice *d, void *o)
 {
+    /* We have to ignore passthrough devices */
     if (pci_get_word(d->config + PCI_CLASS_DEVICE) ==
-            PCI_CLASS_STORAGE_IDE) {
+            PCI_CLASS_STORAGE_IDE
+            && strcmp(d->name, "xen-pci-passthrough") != 0) {
         qdev_unplug(&(d->qdev), NULL);
     }
 }
diff --git a/hw/xen_pt.c b/hw/xen_pt.c
index 307119a12f..838bcea4d6 100644
--- a/hw/xen_pt.c
+++ b/hw/xen_pt.c
@@ -410,14 +410,17 @@ static int xen_pt_register_regions(XenPCIPassthroughState *s)
             if (r->type & XEN_HOST_PCI_REGION_TYPE_PREFETCH) {
                 type |= PCI_BASE_ADDRESS_MEM_PREFETCH;
             }
+            if (r->type & XEN_HOST_PCI_REGION_TYPE_MEM_64) {
+                type |= PCI_BASE_ADDRESS_MEM_TYPE_64;
+            }
         }
 
         memory_region_init_io(&s->bar[i], &ops, &s->dev,
                               "xen-pci-pt-bar", r->size);
         pci_register_bar(&s->dev, i, type, &s->bar[i]);
 
-        XEN_PT_LOG(&s->dev, "IO region %i registered (size=0x%08"PRIx64
-                   " base_addr=0x%08"PRIx64" type: %#x)\n",
+        XEN_PT_LOG(&s->dev, "IO region %i registered (size=0x%lx"PRIx64
+                   " base_addr=0x%lx"PRIx64" type: %#x)\n",
                    i, r->size, r->base_addr, type);
     }
 
diff --git a/hw/xen_pt_config_init.c b/hw/xen_pt_config_init.c
index e524a4094d..0a5f82cb80 100644
--- a/hw/xen_pt_config_init.c
+++ b/hw/xen_pt_config_init.c
@@ -342,6 +342,23 @@ static int xen_pt_cmd_reg_write(XenPCIPassthroughState *s, XenPTReg *cfg_entry,
 #define XEN_PT_BAR_IO_RO_MASK     0x00000003  /* BAR ReadOnly mask(I/O) */
 #define XEN_PT_BAR_IO_EMU_MASK    0xFFFFFFFC  /* BAR emul mask(I/O) */
 
+static bool is_64bit_bar(PCIIORegion *r)
+{
+    return !!(r->type & PCI_BASE_ADDRESS_MEM_TYPE_64);
+}
+
+static uint64_t xen_pt_get_bar_size(PCIIORegion *r)
+{
+    if (is_64bit_bar(r)) {
+        uint64_t size64;
+        size64 = (r + 1)->size;
+        size64 <<= 32;
+        size64 += r->size;
+        return size64;
+    }
+    return r->size;
+}
+
 static XenPTBarFlag xen_pt_bar_reg_parse(XenPCIPassthroughState *s,
                                          XenPTRegInfo *reg)
 {
@@ -366,7 +383,7 @@ static XenPTBarFlag xen_pt_bar_reg_parse(XenPCIPassthroughState *s,
 
     /* check unused BAR */
     r = &d->io_regions[index];
-    if (r->size == 0) {
+    if (!xen_pt_get_bar_size(r)) {
         return XEN_PT_BAR_FLAG_UNUSED;
     }
 
@@ -481,7 +498,12 @@ static int xen_pt_bar_reg_write(XenPCIPassthroughState *s, XenPTReg *cfg_entry,
     switch (s->bases[index].bar_flag) {
     case XEN_PT_BAR_FLAG_MEM:
         bar_emu_mask = XEN_PT_BAR_MEM_EMU_MASK;
-        bar_ro_mask = XEN_PT_BAR_MEM_RO_MASK | (r_size - 1);
+        if (!r_size) {
+            /* low 32 bits mask for 64 bit bars */
+            bar_ro_mask = XEN_PT_BAR_ALLF;
+        } else {
+            bar_ro_mask = XEN_PT_BAR_MEM_RO_MASK | (r_size - 1);
+        }
         break;
     case XEN_PT_BAR_FLAG_IO:
         bar_emu_mask = XEN_PT_BAR_IO_EMU_MASK;
@@ -489,7 +511,7 @@ static int xen_pt_bar_reg_write(XenPCIPassthroughState *s, XenPTReg *cfg_entry,
         break;
     case XEN_PT_BAR_FLAG_UPPER:
         bar_emu_mask = XEN_PT_BAR_ALLF;
-        bar_ro_mask = 0;    /* all upper 32bit are R/W */
+        bar_ro_mask = r_size ? r_size - 1 : 0;
         break;
     default:
         break;
@@ -501,22 +523,13 @@ static int xen_pt_bar_reg_write(XenPCIPassthroughState *s, XenPTReg *cfg_entry,
 
     /* check whether we need to update the virtual region address or not */
     switch (s->bases[index].bar_flag) {
+    case XEN_PT_BAR_FLAG_UPPER:
     case XEN_PT_BAR_FLAG_MEM:
         /* nothing to do */
         break;
     case XEN_PT_BAR_FLAG_IO:
         /* nothing to do */
         break;
-    case XEN_PT_BAR_FLAG_UPPER:
-        if (cfg_entry->data) {
-            if (cfg_entry->data != (XEN_PT_BAR_ALLF & ~bar_ro_mask)) {
-                XEN_PT_WARN(d, "Guest attempt to set high MMIO Base Address. "
-                            "Ignore mapping. "
-                            "(offset: 0x%02x, high address: 0x%08x)\n",
-                            reg->offset, cfg_entry->data);
-            }
-        }
-        break;
     default:
         break;
     }
diff --git a/qapi-schema.json b/qapi-schema.json
index 23abb94a1a..f9dbdae699 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -2097,6 +2097,19 @@
 ##
 { 'command': 'xen-save-devices-state', 'data': {'filename': 'str'} }
 
+##
+# @xen-set-global-dirty-log
+#
+# Enable or disable the global dirty log mode.
+#
+# @enable: true to enable, false to disable.
+#
+# Returns: nothing
+#
+# Since: 1.3
+##
+{ 'command': 'xen-set-global-dirty-log', 'data': { 'enable': 'bool' } }
+
 ##
 # @device_del:
 #
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 1aef27ca14..2f8477e2a8 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -490,6 +490,30 @@ Example:
      "arguments": { "filename": "/tmp/save" } }
 <- { "return": {} }
 
+EQMP
+
+    {
+        .name       = "xen-set-global-dirty-log",
+        .args_type  = "enable:b",
+        .mhandler.cmd_new = qmp_marshal_input_xen_set_global_dirty_log,
+    },
+
+SQMP
+xen-set-global-dirty-log
+-------
+
+Enable or disable the global dirty log mode.
+
+Arguments:
+
+- "enable": Enable it or disable it.
+
+Example:
+
+-> { "execute": "xen-set-global-dirty-log",
+     "arguments": { "enable": true } }
+<- { "return": {} }
+
 EQMP
 
     {
diff --git a/xen-all.c b/xen-all.c
index f76b051eee..e6308be23a 100644
--- a/xen-all.c
+++ b/xen-all.c
@@ -14,6 +14,7 @@
 #include "hw/pc.h"
 #include "hw/xen_common.h"
 #include "hw/xen_backend.h"
+#include "qmp-commands.h"
 
 #include "range.h"
 #include "xen-mapcache.h"
@@ -36,6 +37,7 @@
 
 static MemoryRegion ram_memory, ram_640k, ram_lo, ram_hi;
 static MemoryRegion *framebuffer;
+static bool xen_in_migration;
 
 /* Compatibility with older version */
 #if __XEN_LATEST_INTERFACE_VERSION__ < 0x0003020a
@@ -505,7 +507,8 @@ static void xen_sync_dirty_bitmap(XenIOState *state,
                                  bitmap);
     if (rc < 0) {
         if (rc != -ENODATA) {
-            fprintf(stderr, "xen: track_dirty_vram failed (0x" TARGET_FMT_plx
+            memory_region_set_dirty(framebuffer, 0, size);
+            DPRINTF("xen: track_dirty_vram failed (0x" TARGET_FMT_plx
                     ", 0x" TARGET_FMT_plx "): %s\n",
                     start_addr, start_addr + size, strerror(-rc));
         }
@@ -552,10 +555,14 @@ static void xen_log_sync(MemoryListener *listener, MemoryRegionSection *section)
 
 static void xen_log_global_start(MemoryListener *listener)
 {
+    if (xen_enabled()) {
+        xen_in_migration = true;
+    }
 }
 
 static void xen_log_global_stop(MemoryListener *listener)
 {
+    xen_in_migration = false;
 }
 
 static void xen_eventfd_add(MemoryListener *listener,
@@ -588,6 +595,15 @@ static MemoryListener xen_memory_listener = {
     .priority = 10,
 };
 
+void qmp_xen_set_global_dirty_log(bool enable, Error **errp)
+{
+    if (enable) {
+        memory_global_dirty_log_start();
+    } else {
+        memory_global_dirty_log_stop();
+    }
+}
+
 /* VCPU Operations, MMIO, IO ring ... */
 
 static void xen_reset_vcpu(void *opaque)
@@ -1213,3 +1229,24 @@ void xen_shutdown_fatal_error(const char *fmt, ...)
     /* destroy the domain */
     qemu_system_shutdown_request();
 }
+
+void xen_modified_memory(ram_addr_t start, ram_addr_t length)
+{
+    if (unlikely(xen_in_migration)) {
+        int rc;
+        ram_addr_t start_pfn, nb_pages;
+
+        if (length == 0) {
+            length = TARGET_PAGE_SIZE;
+        }
+        start_pfn = start >> TARGET_PAGE_BITS;
+        nb_pages = ((start + length + TARGET_PAGE_SIZE - 1) >> TARGET_PAGE_BITS)
+            - start_pfn;
+        rc = xc_hvm_modified_memory(xen_xc, xen_domid, start_pfn, nb_pages);
+        if (rc) {
+            fprintf(stderr,
+                    "%s failed for "RAM_ADDR_FMT" ("RAM_ADDR_FMT"): %i, %s\n",
+                    __func__, start, nb_pages, rc, strerror(-rc));
+        }
+    }
+}
diff --git a/xen-stub.c b/xen-stub.c
index 8ff2b79ac6..921439263a 100644
--- a/xen-stub.c
+++ b/xen-stub.c
@@ -11,6 +11,7 @@
 #include "qemu-common.h"
 #include "hw/xen.h"
 #include "memory.h"
+#include "qmp-commands.h"
 
 void xenstore_store_pv_console_info(int i, CharDriverState *chr)
 {
@@ -54,3 +55,11 @@ int xen_init(void)
 void xen_register_framebuffer(MemoryRegion *mr)
 {
 }
+
+void qmp_xen_set_global_dirty_log(bool enable, Error **errp)
+{
+}
+
+void xen_modified_memory(ram_addr_t start, ram_addr_t length)
+{
+}