[RFC,3/7] vfio: Generalize region support

Commit Message

Alex Williamson Feb. 2, 2016, 3:37 a.m. UTC

Both platform and PCI vfio drivers create a "slow", I/O memory region
with one or more mmap memory regions overlayed when supported by the
device. Generalize this to a set of common helpers in the core that
pulls the region info from vfio, fills the region data, configures
slow mapping, and adds helpers for comleting the mmap, enable/disable,
and teardown.  This can be immediately used by the PCI MSI-X code,
which needs to mmap around the MSI-X vector table.

This also changes VFIORegion.mem to be dynamically allocated because
otherwise we don't know how the caller has allocated VFIORegion and
therefore don't know whether to unreference it to destroy the
MemoryRegion or not.

Signed-off-by: Alex Williamson <[e-mail]>
---
 hw/arm/sysbus-fdt.c           |    2 
 hw/vfio/common.c              |  172 ++++++++++++++++++++++++++++++++++-------
 hw/vfio/pci-quirks.c          |   24 +++---
 hw/vfio/pci.c                 |  168 +++++++++++++++++++++-------------------
 hw/vfio/platform.c            |   72 +++--------------
 include/hw/vfio/vfio-common.h |   23 ++++-
 trace-events                  |   10 ++
 7 files changed, 282 insertions(+), 189 deletions(-)

Patch

diff --git a/hw/arm/sysbus-fdt.c b/hw/arm/sysbus-fdt.c
index 68a3de5..4dfa0e4 100644
--- a/hw/arm/sysbus-fdt.c
+++ b/hw/arm/sysbus-fdt.c
@@ -94,7 +94,7 @@  static int add_calxeda_midway_xgmac_fdt_node(SysBusDevice *sbdev, void *opaque)
         mmio_base = platform_bus_get_mmio_addr(pbus, sbdev, i);
         reg_attr[2 * i] = cpu_to_be32(mmio_base);
         reg_attr[2 * i + 1] = cpu_to_be32(
-                                memory_region_size(&vdev->regions[i]->mem));
+                                memory_region_size(vdev->regions[i]->mem));
     }
     ret = qemu_fdt_setprop(fdt, nodename, "reg", reg_attr,
                            vbasedev->num_regions * 2 * sizeof(uint32_t));
diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index e20fc4f..96ccb79 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -493,46 +493,162 @@  static void vfio_listener_release(VFIOContainer *container)
     memory_listener_unregister(&container->listener);
 }
 
-int vfio_mmap_region(Object *obj, VFIORegion *region,
-                     MemoryRegion *mem, MemoryRegion *submem,
-                     void **map, size_t size, off_t offset,
-                     const char *name)
+int vfio_region_setup(Object *obj, VFIODevice *vbasedev, VFIORegion *region,
+                      int index, const char *name)
 {
-    int ret = 0;
-    VFIODevice *vbasedev = region->vbasedev;
+    struct vfio_region_info *info;
+    int ret;
+
+    ret = vfio_get_region_info(vbasedev, index, &info);
+    if (ret) {
+        return ret;
+    }
+
+    region->vbasedev = vbasedev;
+    region->flags = info->flags;
+    region->size = info->size;
+    region->fd_offset = info->offset;
+    region->nr = index;
 
-    if (!vbasedev->no_mmap && size && region->flags &
-        VFIO_REGION_INFO_FLAG_MMAP) {
-        int prot = 0;
+    if (region->size) {
+        region->mem = g_new0(MemoryRegion, 1);
+        memory_region_init_io(region->mem, obj, &vfio_region_ops,
+                              region, name, region->size);
 
-        if (region->flags & VFIO_REGION_INFO_FLAG_READ) {
-            prot |= PROT_READ;
+        if (!vbasedev->no_mmap &&
+            region->flags & VFIO_REGION_INFO_FLAG_MMAP &&
+            !(region->size & ~qemu_real_host_page_mask)) {
+
+            region->nr_mmaps = 1;
+            region->mmaps = g_new0(VFIOMmap, region->nr_mmaps);
+
+            region->mmaps[0].offset = 0;
+            region->mmaps[0].size = region->size;
         }
+    }
+
+    g_free(info);
+
+    trace_vfio_region_setup(vbasedev->name, index, name,
+                            region->flags, region->fd_offset, region->size);
+    return 0;
+}
 
-        if (region->flags & VFIO_REGION_INFO_FLAG_WRITE) {
-            prot |= PROT_WRITE;
+int vfio_region_mmap(VFIORegion *region)
+{
+    int i, prot = 0;
+    char *name;
+
+    if (!region->mem) {
+        return 0;
+    }
+
+    prot |= region->flags & VFIO_REGION_INFO_FLAG_READ ? PROT_READ : 0;
+    prot |= region->flags & VFIO_REGION_INFO_FLAG_WRITE ? PROT_WRITE : 0;
+
+    for (i = 0; i < region->nr_mmaps; i++) {
+        region->mmaps[i].mmap = mmap(NULL, region->mmaps[i].size, prot,
+                                     MAP_SHARED, region->vbasedev->fd,
+                                     region->fd_offset +
+                                     region->mmaps[i].offset);
+        if (region->mmaps[i].mmap == MAP_FAILED) {
+            int ret = -errno;
+
+            trace_vfio_region_mmap_fault(memory_region_name(region->mem), i,
+                                         region->fd_offset +
+                                         region->mmaps[i].offset,
+                                         region->fd_offset +
+                                         region->mmaps[i].offset +
+                                         region->mmaps[i].size - 1, ret);
+
+            region->mmaps[i].mmap = NULL;
+
+            for (i--; i >= 0; i--) {
+                memory_region_del_subregion(region->mem, &region->mmaps[i].mem);
+                munmap(region->mmaps[i].mmap, region->mmaps[i].size);
+                object_unparent(OBJECT(&region->mmaps[i].mem));
+                region->mmaps[i].mmap = NULL;
+            }
+
+            return ret;
         }
 
-        *map = mmap(NULL, size, prot, MAP_SHARED,
-                    vbasedev->fd,
-                    region->fd_offset + offset);
-        if (*map == MAP_FAILED) {
-            *map = NULL;
-            ret = -errno;
-            goto empty_region;
+        name = g_strdup_printf("%s mmaps[%d]",
+                               memory_region_name(region->mem), i);
+        memory_region_init_ram_ptr(&region->mmaps[i].mem,
+                                   memory_region_owner(region->mem),
+                                   name, region->mmaps[i].size,
+                                   region->mmaps[i].mmap);
+        g_free(name);
+        memory_region_set_skip_dump(&region->mmaps[i].mem);
+        memory_region_add_subregion(region->mem, region->mmaps[i].offset,
+                                    &region->mmaps[i].mem);
+
+        trace_vfio_region_mmap(memory_region_name(&region->mmaps[i].mem),
+                               region->mmaps[i].offset,
+                               region->mmaps[i].offset +
+                               region->mmaps[i].size - 1);
+    }
+
+    return 0;
+}
+
+void vfio_region_exit(VFIORegion *region)
+{
+    int i;
+
+    if (!region->mem) {
+        return;
+    }
+
+    for (i = 0; i < region->nr_mmaps; i++) {
+        if (region->mmaps[i].mmap) {
+            memory_region_del_subregion(region->mem, &region->mmaps[i].mem);
         }
+    }
 
-        memory_region_init_ram_ptr(submem, obj, name, size, *map);
-        memory_region_set_skip_dump(submem);
-    } else {
-empty_region:
-        /* Create a zero sized sub-region to make cleanup easy. */
-        memory_region_init(submem, obj, name, 0);
+    trace_vfio_region_exit(region->vbasedev->name, region->nr);
+}
+
+void vfio_region_finalize(VFIORegion *region)
+{
+    int i;
+
+    if (!region->mem) {
+        return;
     }
 
-    memory_region_add_subregion(mem, offset, submem);
+    for (i = 0; i < region->nr_mmaps; i++) {
+        if (region->mmaps[i].mmap) {
+            munmap(region->mmaps[i].mmap, region->mmaps[i].size);
+            object_unparent(OBJECT(&region->mmaps[i].mem));
+        }
+    }
 
-    return ret;
+    object_unparent(OBJECT(region->mem));
+
+    g_free(region->mem);
+    g_free(region->mmaps);
+
+    trace_vfio_region_finalize(region->vbasedev->name, region->nr);
+}
+
+void vfio_region_mmaps_set_enabled(VFIORegion *region, bool enabled)
+{
+    int i;
+
+    if (!region->mem) {
+        return;
+    }
+
+    for (i = 0; i < region->nr_mmaps; i++) {
+        if (region->mmaps[i].mmap) {
+            memory_region_set_enabled(&region->mmaps[i].mem, enabled);
+        }
+    }
+
+    trace_vfio_region_mmaps_set_enabled(memory_region_name(region->mem),
+                                        enabled);
 }
 
 void vfio_reset_handler(void *opaque)
diff --git a/hw/vfio/pci-quirks.c b/hw/vfio/pci-quirks.c
index 4815527..d626ec9 100644
--- a/hw/vfio/pci-quirks.c
+++ b/hw/vfio/pci-quirks.c
@@ -337,14 +337,14 @@  static void vfio_probe_ati_bar4_quirk(VFIOPCIDevice *vdev, int nr)
     memory_region_init_io(window->addr_mem, OBJECT(vdev),
                           &vfio_generic_window_address_quirk, window,
                           "vfio-ati-bar4-window-address-quirk", 4);
-    memory_region_add_subregion_overlap(&vdev->bars[nr].region.mem,
+    memory_region_add_subregion_overlap(vdev->bars[nr].region.mem,
                                         window->address_offset,
                                         window->addr_mem, 1);
 
     memory_region_init_io(window->data_mem, OBJECT(vdev),
                           &vfio_generic_window_data_quirk, window,
                           "vfio-ati-bar4-window-data-quirk", 4);
-    memory_region_add_subregion_overlap(&vdev->bars[nr].region.mem,
+    memory_region_add_subregion_overlap(vdev->bars[nr].region.mem,
                                         window->data_offset,
                                         window->data_mem, 1);
 
@@ -378,7 +378,7 @@  static void vfio_probe_ati_bar2_quirk(VFIOPCIDevice *vdev, int nr)
     memory_region_init_io(mirror->mem, OBJECT(vdev),
                           &vfio_generic_mirror_quirk, mirror,
                           "vfio-ati-bar2-4000-quirk", PCI_CONFIG_SPACE_SIZE);
-    memory_region_add_subregion_overlap(&vdev->bars[nr].region.mem,
+    memory_region_add_subregion_overlap(vdev->bars[nr].region.mem,
                                         mirror->offset, mirror->mem, 1);
 
     QLIST_INSERT_HEAD(&vdev->bars[nr].quirks, quirk, next);
@@ -683,7 +683,7 @@  static void vfio_probe_nvidia_bar5_quirk(VFIOPCIDevice *vdev, int nr)
     memory_region_init_io(window->addr_mem, OBJECT(vdev),
                           &vfio_generic_window_address_quirk, window,
                           "vfio-nvidia-bar5-window-address-quirk", 4);
-    memory_region_add_subregion_overlap(&vdev->bars[nr].region.mem,
+    memory_region_add_subregion_overlap(vdev->bars[nr].region.mem,
                                         window->address_offset,
                                         window->addr_mem, 1);
     memory_region_set_enabled(window->addr_mem, false);
@@ -691,7 +691,7 @@  static void vfio_probe_nvidia_bar5_quirk(VFIOPCIDevice *vdev, int nr)
     memory_region_init_io(window->data_mem, OBJECT(vdev),
                           &vfio_generic_window_data_quirk, window,
                           "vfio-nvidia-bar5-window-data-quirk", 4);
-    memory_region_add_subregion_overlap(&vdev->bars[nr].region.mem,
+    memory_region_add_subregion_overlap(vdev->bars[nr].region.mem,
                                         window->data_offset,
                                         window->data_mem, 1);
     memory_region_set_enabled(window->data_mem, false);
@@ -699,13 +699,13 @@  static void vfio_probe_nvidia_bar5_quirk(VFIOPCIDevice *vdev, int nr)
     memory_region_init_io(&quirk->mem[2], OBJECT(vdev),
                           &vfio_nvidia_bar5_quirk_master, bar5,
                           "vfio-nvidia-bar5-master-quirk", 4);
-    memory_region_add_subregion_overlap(&vdev->bars[nr].region.mem,
+    memory_region_add_subregion_overlap(vdev->bars[nr].region.mem,
                                         0, &quirk->mem[2], 1);
 
     memory_region_init_io(&quirk->mem[3], OBJECT(vdev),
                           &vfio_nvidia_bar5_quirk_enable, bar5,
                           "vfio-nvidia-bar5-enable-quirk", 4);
-    memory_region_add_subregion_overlap(&vdev->bars[nr].region.mem,
+    memory_region_add_subregion_overlap(vdev->bars[nr].region.mem,
                                         4, &quirk->mem[3], 1);
 
     QLIST_INSERT_HEAD(&vdev->bars[nr].quirks, quirk, next);
@@ -767,7 +767,7 @@  static void vfio_probe_nvidia_bar0_quirk(VFIOPCIDevice *vdev, int nr)
                           &vfio_nvidia_mirror_quirk, mirror,
                           "vfio-nvidia-bar0-88000-mirror-quirk",
                           vdev->config_size);
-    memory_region_add_subregion_overlap(&vdev->bars[nr].region.mem,
+    memory_region_add_subregion_overlap(vdev->bars[nr].region.mem,
                                         mirror->offset, mirror->mem, 1);
 
     QLIST_INSERT_HEAD(&vdev->bars[nr].quirks, quirk, next);
@@ -786,7 +786,7 @@  static void vfio_probe_nvidia_bar0_quirk(VFIOPCIDevice *vdev, int nr)
                               &vfio_nvidia_mirror_quirk, mirror,
                               "vfio-nvidia-bar0-1800-mirror-quirk",
                               PCI_CONFIG_SPACE_SIZE);
-        memory_region_add_subregion_overlap(&vdev->bars[nr].region.mem,
+        memory_region_add_subregion_overlap(vdev->bars[nr].region.mem,
                                             mirror->offset, mirror->mem, 1);
 
         QLIST_INSERT_HEAD(&vdev->bars[nr].quirks, quirk, next);
@@ -947,13 +947,13 @@  static void vfio_probe_rtl8168_bar2_quirk(VFIOPCIDevice *vdev, int nr)
     memory_region_init_io(&quirk->mem[0], OBJECT(vdev),
                           &vfio_rtl_address_quirk, rtl,
                           "vfio-rtl8168-window-address-quirk", 4);
-    memory_region_add_subregion_overlap(&vdev->bars[nr].region.mem,
+    memory_region_add_subregion_overlap(vdev->bars[nr].region.mem,
                                         0x74, &quirk->mem[0], 1);
 
     memory_region_init_io(&quirk->mem[1], OBJECT(vdev),
                           &vfio_rtl_data_quirk, rtl,
                           "vfio-rtl8168-window-data-quirk", 4);
-    memory_region_add_subregion_overlap(&vdev->bars[nr].region.mem,
+    memory_region_add_subregion_overlap(vdev->bars[nr].region.mem,
                                         0x70, &quirk->mem[1], 1);
 
     QLIST_INSERT_HEAD(&vdev->bars[nr].quirks, quirk, next);
@@ -1020,7 +1020,7 @@  void vfio_bar_quirk_teardown(VFIOPCIDevice *vdev, int nr)
 
     QLIST_FOREACH(quirk, &bar->quirks, next) {
         for (i = 0; i < quirk->nr_mem; i++) {
-            memory_region_del_subregion(&bar->region.mem, &quirk->mem[i]);
+            memory_region_del_subregion(bar->region.mem, &quirk->mem[i]);
         }
     }
 }
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index a52947b..a1a42a2 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -1166,6 +1166,74 @@  static int vfio_msi_setup(VFIOPCIDevice *vdev, int pos)
     return 0;
 }
 
+static void vfio_pci_fixup_msix_region(VFIOPCIDevice *vdev)
+{
+    off_t start, end;
+    VFIORegion *region = &vdev->bars[vdev->msix->table_bar].region;
+
+    /*
+     * We expect to find a single mmap covering the whole BAR, anything else
+     * means it's either unsupported or already setup.
+     */
+    if (region->nr_mmaps != 1 || region->mmaps[0].offset ||
+        region->size != region->mmaps[0].size) {
+        return;
+    }
+
+    /* MSI-X table start and end aligned to host page size */
+    start = vdev->msix->table_offset & qemu_real_host_page_mask;
+    end = REAL_HOST_PAGE_ALIGN((uint64_t)vdev->msix->table_offset +
+                               (vdev->msix->entries * PCI_MSIX_ENTRY_SIZE));
+
+    /*
+     * Does the MSI-X table cover the beginning of the BAR?  The whole BAR?
+     * NB - Host page size is necessarily a power of two and so is the PCI
+     * BAR (not counting EA yet), therefore if we have host page aligned
+     * @start and @end, then any remainder of the BAR before or after those
+     * must be at least host page sized and therefore mmap'able.
+     */
+    if (!start) {
+        if (end >= region->size) {
+            region->nr_mmaps = 0;
+            g_free(region->mmaps);
+            region->mmaps = NULL;
+            trace_vfio_msix_fixup(vdev->vbasedev.name,
+                                  vdev->msix->table_bar, 0, 0);
+        } else {
+            region->mmaps[0].offset = end;
+            region->mmaps[0].size = region->size - end;
+            trace_vfio_msix_fixup(vdev->vbasedev.name,
+                              vdev->msix->table_bar, region->mmaps[0].offset,
+                              region->mmaps[0].offset + region->mmaps[0].size);
+        }
+
+    /* Maybe it's aligned at the end of the BAR */
+    } else if (end >= region->size) {
+        region->mmaps[0].size = start;
+        trace_vfio_msix_fixup(vdev->vbasedev.name,
+                              vdev->msix->table_bar, region->mmaps[0].offset,
+                              region->mmaps[0].offset + region->mmaps[0].size);
+
+    /* Otherwise it must split the BAR */
+    } else {
+        region->nr_mmaps = 2;
+        region->mmaps = g_renew(VFIOMmap, region->mmaps, 2);
+
+        memcpy(&region->mmaps[1], &region->mmaps[0], sizeof(VFIOMmap));
+
+        region->mmaps[0].size = start;
+        trace_vfio_msix_fixup(vdev->vbasedev.name,
+                              vdev->msix->table_bar, region->mmaps[0].offset,
+                              region->mmaps[0].offset + region->mmaps[0].size);
+
+        region->mmaps[1].offset = end;
+        region->mmaps[1].size = region->size - end;
+        trace_vfio_msix_fixup(vdev->vbasedev.name,
+                              vdev->msix->table_bar, region->mmaps[1].offset,
+                              region->mmaps[1].offset + region->mmaps[1].size);
+    }
+}
+
 /*
  * We don't have any control over how pci_add_capability() inserts
  * capabilities into the chain.  In order to setup MSI-X we need a
@@ -1240,6 +1308,8 @@  static int vfio_msix_early_setup(VFIOPCIDevice *vdev)
                                 msix->table_offset, msix->entries);
     vdev->msix = msix;
 
+    vfio_pci_fixup_msix_region(vdev);
+
     return 0;
 }
 
@@ -1250,9 +1320,9 @@  static int vfio_msix_setup(VFIOPCIDevice *vdev, int pos)
     vdev->msix->pending = g_malloc0(BITS_TO_LONGS(vdev->msix->entries) *
                                     sizeof(unsigned long));
     ret = msix_init(&vdev->pdev, vdev->msix->entries,
-                    &vdev->bars[vdev->msix->table_bar].region.mem,
+                    vdev->bars[vdev->msix->table_bar].region.mem,
                     vdev->msix->table_bar, vdev->msix->table_offset,
-                    &vdev->bars[vdev->msix->pba_bar].region.mem,
+                    vdev->bars[vdev->msix->pba_bar].region.mem,
                     vdev->msix->pba_bar, vdev->msix->pba_offset, pos);
     if (ret < 0) {
         if (ret == -ENOTSUP) {
@@ -1289,8 +1359,8 @@  static void vfio_teardown_msi(VFIOPCIDevice *vdev)
 
     if (vdev->msix) {
         msix_uninit(&vdev->pdev,
-                    &vdev->bars[vdev->msix->table_bar].region.mem,
-                    &vdev->bars[vdev->msix->pba_bar].region.mem);
+                    vdev->bars[vdev->msix->table_bar].region.mem,
+                    vdev->bars[vdev->msix->pba_bar].region.mem);
         g_free(vdev->msix->pending);
     }
 }
@@ -1303,16 +1373,7 @@  static void vfio_mmap_set_enabled(VFIOPCIDevice *vdev, bool enabled)
     int i;
 
     for (i = 0; i < PCI_ROM_SLOT; i++) {
-        VFIOBAR *bar = &vdev->bars[i];
-
-        if (!bar->region.size) {
-            continue;
-        }
-
-        memory_region_set_enabled(&bar->region.mmap_mem, enabled);
-        if (vdev->msix && vdev->msix->table_bar == i) {
-            memory_region_set_enabled(&vdev->msix->mmap_mem, enabled);
-        }
+        vfio_region_mmaps_set_enabled(&vdev->bars[i].region, enabled);
     }
 }
 
@@ -1326,11 +1387,7 @@  static void vfio_unregister_bar(VFIOPCIDevice *vdev, int nr)
 
     vfio_bar_quirk_teardown(vdev, nr);
 
-    memory_region_del_subregion(&bar->region.mem, &bar->region.mmap_mem);
-
-    if (vdev->msix && vdev->msix->table_bar == nr) {
-        memory_region_del_subregion(&bar->region.mem, &vdev->msix->mmap_mem);
-    }
+    vfio_region_exit(&bar->region);
 }
 
 static void vfio_unmap_bar(VFIOPCIDevice *vdev, int nr)
@@ -1343,18 +1400,13 @@  static void vfio_unmap_bar(VFIOPCIDevice *vdev, int nr)
 
     vfio_bar_quirk_free(vdev, nr);
 
-    munmap(bar->region.mmap, memory_region_size(&bar->region.mmap_mem));
-
-    if (vdev->msix && vdev->msix->table_bar == nr) {
-        munmap(vdev->msix->mmap, memory_region_size(&vdev->msix->mmap_mem));
-    }
+    vfio_region_finalize(&bar->region);
 }
 
 static void vfio_map_bar(VFIOPCIDevice *vdev, int nr)
 {
     VFIOBAR *bar = &vdev->bars[nr];
     uint64_t size = bar->region.size;
-    char name[64];
     uint32_t pci_bar;
     uint8_t type;
     int ret;
@@ -1364,8 +1416,6 @@  static void vfio_map_bar(VFIOPCIDevice *vdev, int nr)
         return;
     }
 
-    snprintf(name, sizeof(name), "VFIO %s BAR %d", vdev->vbasedev.name, nr);
-
     /* Determine what type of BAR this is for registration */
     ret = pread(vdev->vbasedev.fd, &pci_bar, sizeof(pci_bar),
                 vdev->config_offset + PCI_BASE_ADDRESS_0 + (4 * nr));
@@ -1380,41 +1430,11 @@  static void vfio_map_bar(VFIOPCIDevice *vdev, int nr)
     type = pci_bar & (bar->ioport ? ~PCI_BASE_ADDRESS_IO_MASK :
                                     ~PCI_BASE_ADDRESS_MEM_MASK);
 
-    /* A "slow" read/write mapping underlies all BARs */
-    memory_region_init_io(&bar->region.mem, OBJECT(vdev), &vfio_region_ops,
-                          bar, name, size);
-    pci_register_bar(&vdev->pdev, nr, type, &bar->region.mem);
-
-    /*
-     * We can't mmap areas overlapping the MSIX vector table, so we
-     * potentially insert a direct-mapped subregion before and after it.
-     */
-    if (vdev->msix && vdev->msix->table_bar == nr) {
-        size = vdev->msix->table_offset & qemu_real_host_page_mask;
-    }
-
-    strncat(name, " mmap", sizeof(name) - strlen(name) - 1);
-    if (vfio_mmap_region(OBJECT(vdev), &bar->region, &bar->region.mem,
-                      &bar->region.mmap_mem, &bar->region.mmap,
-                      size, 0, name)) {
-        error_report("%s unsupported. Performance may be slow", name);
-    }
-
-    if (vdev->msix && vdev->msix->table_bar == nr) {
-        uint64_t start;
-
-        start = REAL_HOST_PAGE_ALIGN((uint64_t)vdev->msix->table_offset +
-                                     (vdev->msix->entries *
-                                      PCI_MSIX_ENTRY_SIZE));
+    pci_register_bar(&vdev->pdev, nr, type, bar->region.mem);
 
-        size = start < bar->region.size ? bar->region.size - start : 0;
-        strncat(name, " msix-hi", sizeof(name) - strlen(name) - 1);
-        /* VFIOMSIXInfo contains another MemoryRegion for this mapping */
-        if (vfio_mmap_region(OBJECT(vdev), &bar->region, &bar->region.mem,
-                          &vdev->msix->mmap_mem,
-                          &vdev->msix->mmap, size, start, name)) {
-            error_report("%s unsupported. Performance may be slow", name);
-        }
+    if (vfio_region_mmap(&bar->region)) {
+        error_report("Failed to mmap %s BAR %d. Performance may be slow",
+                     vdev->vbasedev.name, nr);
     }
 
     vfio_bar_quirk_setup(vdev, nr);
@@ -2048,25 +2068,18 @@  static int vfio_populate_device(VFIOPCIDevice *vdev)
     }
 
     for (i = VFIO_PCI_BAR0_REGION_INDEX; i < VFIO_PCI_ROM_REGION_INDEX; i++) {
-        ret = vfio_get_region_info(vbasedev, i, &reg_info);
+        char *name = g_strdup_printf("%s BAR %d", vbasedev->name, i);
+
+        ret = vfio_region_setup(OBJECT(vdev), vbasedev,
+                                &vdev->bars[i].region, i, name);
+        g_free(name);
+
         if (ret) {
             error_report("vfio: Error getting region %d info: %m", i);
             goto error;
         }
 
-        trace_vfio_populate_device_region(vbasedev->name, i,
-                                          (unsigned long)reg_info->size,
-                                          (unsigned long)reg_info->offset,
-                                          (unsigned long)reg_info->flags);
-
-        vdev->bars[i].region.vbasedev = vbasedev;
-        vdev->bars[i].region.flags = reg_info->flags;
-        vdev->bars[i].region.size = reg_info->size;
-        vdev->bars[i].region.fd_offset = reg_info->offset;
-        vdev->bars[i].region.nr = i;
         QLIST_INIT(&vdev->bars[i].quirks);
-
-        g_free(reg_info);
     }
 
     ret = vfio_get_region_info(vbasedev,
@@ -2152,11 +2165,8 @@  error:
 static void vfio_put_device(VFIOPCIDevice *vdev)
 {
     g_free(vdev->vbasedev.name);
-    if (vdev->msix) {
-        object_unparent(OBJECT(&vdev->msix->mmap_mem));
-        g_free(vdev->msix);
-        vdev->msix = NULL;
-    }
+    g_free(vdev->msix);
+
     vfio_put_base_device(&vdev->vbasedev);
 }
 
diff --git a/hw/vfio/platform.c b/hw/vfio/platform.c
index f9b9c20..a2ab75d 100644
--- a/hw/vfio/platform.c
+++ b/hw/vfio/platform.c
@@ -143,12 +143,8 @@  static void vfio_mmap_set_enabled(VFIOPlatformDevice *vdev, bool enabled)
 {
     int i;
 
-    trace_vfio_platform_mmap_set_enabled(enabled);
-
     for (i = 0; i < vdev->vbasedev.num_regions; i++) {
-        VFIORegion *region = vdev->regions[i];
-
-        memory_region_set_enabled(&region->mmap_mem, enabled);
+        vfio_region_mmaps_set_enabled(vdev->regions[i], enabled);
     }
 }
 
@@ -476,29 +472,16 @@  static int vfio_populate_device(VFIODevice *vbasedev)
     vdev->regions = g_new0(VFIORegion *, vbasedev->num_regions);
 
     for (i = 0; i < vbasedev->num_regions; i++) {
-        struct vfio_region_info *reg_info;
-        VFIORegion *ptr;
+        char *name = g_strdup_printf("VFIO %s region %d\n", vbasedev->name, i);
 
         vdev->regions[i] = g_new0(VFIORegion, 1);
-        ptr = vdev->regions[i];
-        ret = vfio_get_region_info(vbasedev, i, &reg_info);
+        ret = vfio_region_setup(OBJECT(vdev), vbasedev,
+                                vdev->regions[i], i, name);
+        g_free(name);
         if (ret) {
             error_report("vfio: Error getting region %d info: %m", i);
             goto reg_error;
         }
-        ptr->flags = reg_info->flags;
-        ptr->size = reg_info->size;
-        ptr->fd_offset = reg_info->offset;
-        ptr->nr = i;
-        ptr->vbasedev = vbasedev;
-
-        g_free(reg_info);
-
-        trace_vfio_platform_populate_regions(ptr->nr,
-                            (unsigned long)ptr->flags,
-                            (unsigned long)ptr->size,
-                            ptr->vbasedev->fd,
-                            (unsigned long)ptr->fd_offset);
     }
 
     vdev->mmap_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL,
@@ -535,6 +518,9 @@  irq_err:
     }
 reg_error:
     for (i = 0; i < vbasedev->num_regions; i++) {
+        if (vdev->regions[i]) {
+            vfio_region_finalize(vdev->regions[i]);
+        }
         g_free(vdev->regions[i]);
     }
     g_free(vdev->regions);
@@ -636,41 +622,6 @@  static int vfio_base_device_init(VFIODevice *vbasedev)
 }
 
 /**
- * vfio_map_region - initialize the 2 memory regions for a given
- * MMIO region index
- * @vdev: the VFIO platform device handle
- * @nr: the index of the region
- *
- * Init the top memory region and the mmapped memory region beneath
- * VFIOPlatformDevice is used since VFIODevice is not a QOM Object
- * and could not be passed to memory region functions
-*/
-static void vfio_map_region(VFIOPlatformDevice *vdev, int nr)
-{
-    VFIORegion *region = vdev->regions[nr];
-    uint64_t size = region->size;
-    char name[64];
-
-    if (!size) {
-        return;
-    }
-
-    g_snprintf(name, sizeof(name), "VFIO %s region %d",
-               vdev->vbasedev.name, nr);
-
-    /* A "slow" read/write mapping underlies all regions */
-    memory_region_init_io(&region->mem, OBJECT(vdev), &vfio_region_ops,
-                          region, name, size);
-
-    g_strlcat(name, " mmap", sizeof(name));
-
-    if (vfio_mmap_region(OBJECT(vdev), region, &region->mem,
-                         &region->mmap_mem, &region->mmap, size, 0, name)) {
-        error_report("%s unsupported. Performance may be slow", name);
-    }
-}
-
-/**
  * vfio_platform_realize  - the device realize function
  * @dev: device state pointer
  * @errp: error
@@ -700,8 +651,11 @@  static void vfio_platform_realize(DeviceState *dev, Error **errp)
     }
 
     for (i = 0; i < vbasedev->num_regions; i++) {
-        vfio_map_region(vdev, i);
-        sysbus_init_mmio(sbdev, &vdev->regions[i]->mem);
+        if (vfio_region_mmap(vdev->regions[i])) {
+            error_report("%s mmap unsupported. Performance may be slow",
+                         memory_region_name(vdev->regions[i]->mem));
+        }
+        sysbus_init_mmio(sbdev, vdev->regions[i]->mem);
     }
 }
 
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index 371383c..594905a 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -41,14 +41,21 @@  enum {
     VFIO_DEVICE_TYPE_PLATFORM = 1,
 };
 
+typedef struct VFIOMmap {
+    MemoryRegion mem;
+    void *mmap;
+    off_t offset;
+    size_t size;
+} VFIOMmap;
+
 typedef struct VFIORegion {
     struct VFIODevice *vbasedev;
     off_t fd_offset; /* offset of region within device fd */
-    MemoryRegion mem; /* slow, read/write access */
-    MemoryRegion mmap_mem; /* direct mapped access */
-    void *mmap;
+    MemoryRegion *mem; /* slow, read/write access */
     size_t size;
     uint32_t flags; /* VFIO region flags (rd/wr/mmap) */
+    uint32_t nr_mmaps;
+    VFIOMmap *mmaps;
     uint8_t nr; /* cache the region number for debug */
 } VFIORegion;
 
@@ -126,10 +133,12 @@  void vfio_region_write(void *opaque, hwaddr addr,
                            uint64_t data, unsigned size);
 uint64_t vfio_region_read(void *opaque,
                           hwaddr addr, unsigned size);
-int vfio_mmap_region(Object *vdev, VFIORegion *region,
-                     MemoryRegion *mem, MemoryRegion *submem,
-                     void **map, size_t size, off_t offset,
-                     const char *name);
+int vfio_region_setup(Object *obj, VFIODevice *vbasedev, VFIORegion *region,
+                      int index, const char *name);
+int vfio_region_mmap(VFIORegion *region);
+void vfio_region_mmaps_set_enabled(VFIORegion *region, bool enabled);
+void vfio_region_exit(VFIORegion *region);
+void vfio_region_finalize(VFIORegion *region);
 void vfio_reset_handler(void *opaque);
 VFIOGroup *vfio_get_group(int groupid, AddressSpace *as);
 void vfio_put_group(VFIOGroup *group);
diff --git a/trace-events b/trace-events
index c9ac144..0d1b622 100644
--- a/trace-events
+++ b/trace-events
@@ -1634,6 +1634,7 @@  vfio_msix_enable(const char *name) " (%s)"
 vfio_msix_pba_disable(const char *name) " (%s)"
 vfio_msix_pba_enable(const char *name) " (%s)"
 vfio_msix_disable(const char *name) " (%s)"
+vfio_msix_fixup(const char *name, int bar, off_t offset, size_t size) " (%s) MSI-X region %d mmap fixup [0x%lx - 0x%lx]"
 vfio_msi_enable(const char *name, int nr_vectors) " (%s) Enabled %d MSI vectors"
 vfio_msi_disable(const char *name) " (%s)"
 vfio_pci_load_rom(const char *name, unsigned long size, unsigned long offset, unsigned long flags) "Device %s ROM:\n  size: 0x%lx, offset: 0x%lx, flags: 0x%lx"
@@ -1652,7 +1653,6 @@  vfio_pci_hot_reset(const char *name, const char *type) " (%s) %s"
 vfio_pci_hot_reset_has_dep_devices(const char *name) "%s: hot reset dependent devices:"
 vfio_pci_hot_reset_dep_devices(int domain, int bus, int slot, int function, int group_id) "\t%04x:%02x:%02x.%x group %d"
 vfio_pci_hot_reset_result(const char *name, const char *result) "%s hot reset: %s"
-vfio_populate_device_region(const char *region_name, int index, unsigned long size, unsigned long offset, unsigned long flags) "Device %s region %d:\n  size: 0x%lx, offset: 0x%lx, flags: 0x%lx"
 vfio_populate_device_config(const char *name, unsigned long size, unsigned long offset, unsigned long flags) "Device %s config:\n  size: 0x%lx, offset: 0x%lx, flags: 0x%lx"
 vfio_populate_device_get_irq_info_failure(void) "VFIO_DEVICE_GET_IRQ_INFO failure: %m"
 vfio_initfn(const char *name, int group_id) " (%s) group %d"
@@ -1708,13 +1708,17 @@  vfio_disconnect_container(int fd) "close container->fd=%d"
 vfio_put_group(int fd) "close group->fd=%d"
 vfio_get_device(const char * name, unsigned int flags, unsigned int num_regions, unsigned int num_irqs) "Device %s flags: %u, regions: %u, irqs: %u"
 vfio_put_base_device(int fd) "close vdev->fd=%d"
+vfio_region_setup(const char *dev, int index, const char *name, unsigned long flags, unsigned long offset, unsigned long size) "Device %s, region %d \"%s\", flags: %lx, offset: %lx, size: %lx"
+vfio_region_mmap_fault(const char *name, int index, unsigned long offset, unsigned long size, int fault) "Region %s mmaps[%d], [%lx - %lx], fault: %d"
+vfio_region_mmap(const char *name, unsigned long offset, unsigned long end) "Region %s [%lx - %lx]"
+vfio_region_exit(const char *name, int index) "Device %s, region %d"
+vfio_region_finalize(const char *name, int index) "Device %s, region %d"
+vfio_region_mmaps_set_enabled(const char *name, bool enabled) "Region %s mmaps enabled: %d"
 
 # hw/vfio/platform.c
-vfio_platform_populate_regions(int region_index, unsigned long flag, unsigned long size, int fd, unsigned long offset) "- region %d flags = 0x%lx, size = 0x%lx, fd= %d, offset = 0x%lx"
 vfio_platform_base_device_init(char *name, int groupid) "%s belongs to group #%d"
 vfio_platform_realize(char *name, char *compat) "vfio device %s, compat = %s"
 vfio_platform_eoi(int pin, int fd) "EOI IRQ pin %d (fd=%d)"
-vfio_platform_mmap_set_enabled(bool enabled) "fast path = %d"
 vfio_platform_intp_mmap_enable(int pin) "IRQ #%d still active, stay in slow path"
 vfio_platform_intp_interrupt(int pin, int fd) "Inject IRQ #%d (fd = %d)"
 vfio_platform_intp_inject_pending_lockheld(int pin, int fd) "Inject pending IRQ #%d (fd = %d)"