[PATCH v2 04/17] vfio/common: Extract vIOMMU code from vfio_sync_dirty_bitmap()

["Cédric Le Goater" <clg@redhat.com>]

From: Avihai Horon <avihaih@nvidia.com>

Extract vIOMMU code from vfio_sync_dirty_bitmap() to a new function and
restructure the code.

This is done in preparation for optimizing vIOMMU deviice dirty page
tracking. No functional changes intended.

Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
[ clg: - Rebased on upstream ]
Signed-off-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
---
 hw/vfio/common.c | 63 +++++++++++++++++++++++++++++-------------------
 1 file changed, 38 insertions(+), 25 deletions(-)

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index fe215918bdf66ddbe3c5db803e10ce1aa9756b90..f28641bad5cf4b71fcdc0a6c9d42b24c8d786248 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -1302,37 +1302,50 @@ vfio_sync_ram_discard_listener_dirty_bitmap(VFIOContainerBase *bcontainer,
                                                 &vrdl);
 }
 
+static int vfio_sync_iommu_dirty_bitmap(VFIOContainerBase *bcontainer,
+                                        MemoryRegionSection *section)
+{
+    VFIOGuestIOMMU *giommu;
+    bool found = false;
+    Int128 llend;
+    vfio_giommu_dirty_notifier gdn;
+    int idx;
+
+    QLIST_FOREACH(giommu, &bcontainer->giommu_list, giommu_next) {
+        if (MEMORY_REGION(giommu->iommu_mr) == section->mr &&
+            giommu->n.start == section->offset_within_region) {
+            found = true;
+            break;
+        }
+    }
+
+    if (!found) {
+        return 0;
+    }
+
+    gdn.giommu = giommu;
+    idx = memory_region_iommu_attrs_to_index(giommu->iommu_mr,
+                                             MEMTXATTRS_UNSPECIFIED);
+
+    llend = int128_add(int128_make64(section->offset_within_region),
+                       section->size);
+    llend = int128_sub(llend, int128_one());
+
+    iommu_notifier_init(&gdn.n, vfio_iommu_map_dirty_notify, IOMMU_NOTIFIER_MAP,
+                        section->offset_within_region, int128_get64(llend),
+                        idx);
+    memory_region_iommu_replay(giommu->iommu_mr, &gdn.n);
+
+    return 0;
+}
+
 static int vfio_sync_dirty_bitmap(VFIOContainerBase *bcontainer,
                                   MemoryRegionSection *section, Error **errp)
 {
     ram_addr_t ram_addr;
 
     if (memory_region_is_iommu(section->mr)) {
-        VFIOGuestIOMMU *giommu;
-
-        QLIST_FOREACH(giommu, &bcontainer->giommu_list, giommu_next) {
-            if (MEMORY_REGION(giommu->iommu_mr) == section->mr &&
-                giommu->n.start == section->offset_within_region) {
-                Int128 llend;
-                vfio_giommu_dirty_notifier gdn = { .giommu = giommu };
-                int idx = memory_region_iommu_attrs_to_index(giommu->iommu_mr,
-                                                       MEMTXATTRS_UNSPECIFIED);
-
-                llend = int128_add(int128_make64(section->offset_within_region),
-                                   section->size);
-                llend = int128_sub(llend, int128_one());
-
-                iommu_notifier_init(&gdn.n,
-                                    vfio_iommu_map_dirty_notify,
-                                    IOMMU_NOTIFIER_MAP,
-                                    section->offset_within_region,
-                                    int128_get64(llend),
-                                    idx);
-                memory_region_iommu_replay(giommu->iommu_mr, &gdn.n);
-                break;
-            }
-        }
-        return 0;
+        return vfio_sync_iommu_dirty_bitmap(bcontainer, section);
     } else if (memory_region_has_ram_discard_manager(section->mr)) {
         int ret;
 
-- 
2.45.2