[uq/master,2/5] kvm: add logging count to slots

Commit Message

Marcelo Tosatti April 23, 2010, 5:04 p.m. UTC

None

Patch

Index: qemu-kvm/kvm-all.c
===================================================================
--- qemu-kvm.orig/kvm-all.c
+++ qemu-kvm/kvm-all.c
@@ -47,6 +47,7 @@  typedef struct KVMSlot
     ram_addr_t phys_offset;
     int slot;
     int flags;
+    int logging_count;
 } KVMSlot;
 
 typedef struct kvm_dirty_log KVMDirtyLog;
@@ -218,20 +219,11 @@  err:
 /*
  * dirty pages logging control
  */
-static int kvm_dirty_pages_log_change(target_phys_addr_t phys_addr,
-                                      ram_addr_t size, int flags, int mask)
+static int kvm_dirty_pages_log_change(KVMSlot *mem, int flags, int mask)
 {
     KVMState *s = kvm_state;
-    KVMSlot *mem = kvm_lookup_matching_slot(s, phys_addr, phys_addr + size);
     int old_flags;
 
-    if (mem == NULL)  {
-            fprintf(stderr, "BUG: %s: invalid parameters " TARGET_FMT_plx "-"
-                    TARGET_FMT_plx "\n", __func__, phys_addr,
-                    (target_phys_addr_t)(phys_addr + size - 1));
-            return -EINVAL;
-    }
-
     old_flags = mem->flags;
 
     flags = (mem->flags & ~mask) | flags;
@@ -250,16 +242,42 @@  static int kvm_dirty_pages_log_change(ta
 
 int kvm_log_start(target_phys_addr_t phys_addr, ram_addr_t size)
 {
-        return kvm_dirty_pages_log_change(phys_addr, size,
-                                          KVM_MEM_LOG_DIRTY_PAGES,
-                                          KVM_MEM_LOG_DIRTY_PAGES);
+    KVMState *s = kvm_state;
+    KVMSlot *mem = kvm_lookup_matching_slot(s, phys_addr, phys_addr + size);
+
+    if (mem == NULL)  {
+            fprintf(stderr, "BUG: %s: invalid parameters " TARGET_FMT_plx "-"
+                    TARGET_FMT_plx "\n", __func__, phys_addr,
+                    (target_phys_addr_t)(phys_addr + size - 1));
+            return -EINVAL;
+    }
+
+    if (mem->logging_count++)
+        return 0;
+
+    return kvm_dirty_pages_log_change(mem,
+                                      KVM_MEM_LOG_DIRTY_PAGES,
+                                      KVM_MEM_LOG_DIRTY_PAGES);
 }
 
 int kvm_log_stop(target_phys_addr_t phys_addr, ram_addr_t size)
 {
-        return kvm_dirty_pages_log_change(phys_addr, size,
-                                          0,
-                                          KVM_MEM_LOG_DIRTY_PAGES);
+    KVMState *s = kvm_state;
+    KVMSlot *mem = kvm_lookup_matching_slot(s, phys_addr, phys_addr + size);
+
+    if (mem == NULL)  {
+            fprintf(stderr, "BUG: %s: invalid parameters " TARGET_FMT_plx "-"
+                    TARGET_FMT_plx "\n", __func__, phys_addr,
+                    (target_phys_addr_t)(phys_addr + size - 1));
+            return -EINVAL;
+    }
+
+    if (--mem->logging_count)
+        return 0;
+
+    return kvm_dirty_pages_log_change(mem,
+                                      0,
+                                      KVM_MEM_LOG_DIRTY_PAGES);
 }
 
 static int kvm_set_migration_log(int enable)
@@ -273,12 +291,15 @@  static int kvm_set_migration_log(int ena
     for (i = 0; i < ARRAY_SIZE(s->slots); i++) {
         mem = &s->slots[i];
 
-        if (!!(mem->flags & KVM_MEM_LOG_DIRTY_PAGES) == enable) {
-            continue;
-        }
-        err = kvm_set_user_memory_region(s, mem);
-        if (err) {
-            return err;
+        if (mem->memory_size) {
+            if (enable) {
+                err = kvm_log_start(mem->start_addr, mem->memory_size);
+            } else {
+                err = kvm_log_stop(mem->start_addr, mem->memory_size);
+            }
+            if (err) {
+                return err;
+            }
         }
     }
     return 0;
@@ -442,6 +463,7 @@  static void kvm_set_phys_mem(target_phys
 
         /* unregister the overlapping slot */
         mem->memory_size = 0;
+        mem->logging_count = 0;
         err = kvm_set_user_memory_region(s, mem);
         if (err) {
             fprintf(stderr, "%s: error unregistering overlapping slot: %s\n",