[RFC PATCH 1/3] vfio: Introduce helpers to mark dirty pages of a RAM section

[Kunkun Jiang <jiangkunkun@huawei.com>]

Extract part of the code from vfio_sync_dirty_bitmap to form a
new helper, which allows to mark dirty pages of a RAM section.
This helper will be called for nested stage.

Signed-off-by: Kunkun Jiang <jiangkunkun@huawei.com>
---
 hw/vfio/common.c | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 9225f10722..7c50905856 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -1203,6 +1203,19 @@ err_out:
     return ret;
 }
 
+static int vfio_dma_sync_ram_section_dirty_bitmap(VFIOContainer *container,
+                                                  MemoryRegionSection *section)
+{
+    ram_addr_t ram_addr;
+
+    ram_addr = memory_region_get_ram_addr(section->mr) +
+               section->offset_within_region;
+
+    return vfio_get_dirty_bitmap(container,
+                       TARGET_PAGE_ALIGN(section->offset_within_address_space),
+                       int128_get64(section->size), ram_addr);
+}
+
 typedef struct {
     IOMMUNotifier n;
     VFIOGuestIOMMU *giommu;
@@ -1244,8 +1257,6 @@ static void vfio_iommu_map_dirty_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb)
 static int vfio_sync_dirty_bitmap(VFIOContainer *container,
                                   MemoryRegionSection *section)
 {
-    ram_addr_t ram_addr;
-
     if (memory_region_is_iommu(section->mr)) {
         VFIOGuestIOMMU *giommu;
 
@@ -1274,12 +1285,7 @@ static int vfio_sync_dirty_bitmap(VFIOContainer *container,
         return 0;
     }
 
-    ram_addr = memory_region_get_ram_addr(section->mr) +
-               section->offset_within_region;
-
-    return vfio_get_dirty_bitmap(container,
-                       TARGET_PAGE_ALIGN(section->offset_within_address_space),
-                       int128_get64(section->size), ram_addr);
+    return vfio_dma_sync_ram_section_dirty_bitmap(container, section);
 }
 
 static void vfio_listerner_log_sync(MemoryListener *listener,
-- 
2.23.0