[Qemu-devel] [PATCH 04/12] arch_init: introduce ram_page_save()

[Lei Li <lilei@linux.vnet.ibm.com>]

Signed-off-by: Lei Li <lilei@linux.vnet.ibm.com>
---
 arch_init.c |   58 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 58 insertions(+), 0 deletions(-)

diff --git a/arch_init.c b/arch_init.c
index a8b91ee..a418071 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -699,6 +699,64 @@ static uint64_t ram_save_pending(QEMUFile *f, void *opaque, uint64_t max_size)
     return remaining_size;
 }
 
+/* This is the last block from where we have sent data for local migration */
+static RAMBlock *last_block_local;
+static ram_addr_t last_offset_local;
+
+static int ram_page_save(QEMUFile *f)
+{
+    RAMBlock *block = last_block_local;
+    ram_addr_t offset = last_offset_local;
+    MemoryRegion *mr = block->mr;
+    int bytes_sent = 0;
+
+    if (!block) {
+        block = QTAILQ_FIRST(&ram_list.blocks);
+    }
+
+    do {
+        mr = block->mr;
+        uint8_t *p;
+        int cont = (block == last_block_local) ? RAM_SAVE_FLAG_CONTINUE : 0;
+
+        p = memory_region_get_ram_ptr(mr) + offset;
+
+        if (is_zero_page(p)) {
+            qemu_put_be64(f, offset | cont | RAM_SAVE_FLAG_COMPRESS);
+            if (!cont) {
+                qemu_put_byte(f, strlen(block->idstr));
+                qemu_put_buffer(f, (uint8_t *)block->idstr,
+                                strlen(block->idstr));
+            }
+            qemu_put_byte(f, *p);
+            bytes_sent = 1;
+        } else {
+            qemu_put_be64(f, offset | cont | RAM_SAVE_FLAG_PAGE);
+            if (!cont) {
+                qemu_put_byte(f, strlen(block->idstr));
+                qemu_put_buffer(f, (uint8_t *)block->idstr,
+                                strlen(block->idstr));
+            }
+            qemu_put_buffer(f, p, TARGET_PAGE_SIZE);
+            bytes_sent = TARGET_PAGE_SIZE;
+        }
+
+        offset += TARGET_PAGE_SIZE;
+        if (offset >= block->length) {
+            offset = 0;
+            block = QTAILQ_NEXT(block, next);
+            if (!block) {
+                block = QTAILQ_FIRST(&ram_list.blocks);
+            }
+        }
+    } while (block != last_block_local || offset != last_offset_local);
+
+    last_block_local = block;
+    last_offset_local = offset;
+
+    return bytes_sent;
+}
+
 static int load_xbzrle(QEMUFile *f, ram_addr_t addr, void *host)
 {
     int ret, rc = 0;
-- 
1.7.7.6