[Qemu-devel] [PATCH 10/13] migration: Send the fd number which we are going to use for this page

[Juan Quintela <quintela@redhat.com>]

We are still sending the page through the main channel, that would
change later in the series

Signed-off-by: Juan Quintela <quintela@redhat.com>
---
 migration/ram.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/migration/ram.c b/migration/ram.c
index 4b73100..47e208b 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -501,7 +501,7 @@ void migrate_multifd_send_threads_create(void)
     }
 }

-static void multifd_send_page(uint8_t *address)
+static int multifd_send_page(uint8_t *address)
 {
     int i, thread_count;
     bool found = false;
@@ -525,6 +525,8 @@ static void multifd_send_page(uint8_t *address)
     multifd_send[i].address = address;
     qemu_cond_signal(&multifd_send[i].cond);
     qemu_mutex_unlock(&multifd_send[i].mutex);
+
+    return i;
 }

 struct MultiFDRecvParams {
@@ -1027,6 +1029,7 @@ static int ram_multifd_page(QEMUFile *f, PageSearchStatus *pss,
                             bool last_stage, uint64_t *bytes_transferred)
 {
     int pages;
+    uint16_t fd_num;
     uint8_t *p;
     RAMBlock *block = pss->block;
     ram_addr_t offset = pss->offset;
@@ -1040,8 +1043,10 @@ static int ram_multifd_page(QEMUFile *f, PageSearchStatus *pss,
     if (pages == -1) {
         *bytes_transferred +=
             save_page_header(f, block, offset | RAM_SAVE_FLAG_MULTIFD_PAGE);
+        fd_num = multifd_send_page(p);
+        qemu_put_be16(f, fd_num);
+        *bytes_transferred += 2; /* size of fd_num */
         qemu_put_buffer(f, p, TARGET_PAGE_SIZE);
-        multifd_send_page(p);
         *bytes_transferred += TARGET_PAGE_SIZE;
         pages = 1;
         acct_info.norm_pages++;
@@ -2693,6 +2698,7 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
     while (!postcopy_running && !ret && !(flags & RAM_SAVE_FLAG_EOS)) {
         ram_addr_t addr, total_ram_bytes;
         void *host = NULL;
+        uint16_t fd_num;
         uint8_t ch;

         addr = qemu_get_be64(f);
@@ -2778,6 +2784,11 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
             break;

         case RAM_SAVE_FLAG_MULTIFD_PAGE:
+            fd_num = qemu_get_be16(f);
+            if (fd_num == fd_num) {
+                /* this is yet an unused variable, changed later */
+                fd_num = 0;
+            }
             qemu_get_buffer(f, host, TARGET_PAGE_SIZE);
             break;

-- 
2.5.5