kvm: Add missing bits to support live migration

This patch adds the missing hooks to allow live migration in KVM mode.
It adds proper synchronization before/after saving/restoring the VCPU
states (note: PPC is untested), hooks into
cpu_physical_memory_set_dirty_tracking() to enable dirty memory logging
at KVM level, and synchronizes that drity log into QEMU's view before
running ram_live_save().

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/vl.c b/vl.c
index c9b2aa4d25..5079a1cb5e 100644
--- a/vl.c
+++ b/vl.c
@@ -3232,13 +3232,18 @@ static int ram_save_live(QEMUFile *f, int stage, void *opaque)
 {
     ram_addr_t addr;
 
+    if (cpu_physical_sync_dirty_bitmap(0, last_ram_offset) != 0) {
+        qemu_file_set_error(f);
+        return 0;
+    }
+
     if (stage == 1) {
         /* Make sure all dirty bits are set */
         for (addr = 0; addr < last_ram_offset; addr += TARGET_PAGE_SIZE) {
             if (!cpu_physical_memory_get_dirty(addr, MIGRATION_DIRTY_FLAG))
                 cpu_physical_memory_set_dirty(addr);
         }
-        
+
         /* Enable dirty memory tracking */
         cpu_physical_memory_set_dirty_tracking(1);