qemu: hotplug: Properly recalculate/reload balloon size after hot(un)plug

Rather than trying some magic calculations on our side query the monitor
for the current size of the memory balloon both on hotplug and
hotunplug.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1220702

diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
index b72b08018a8f1122a886e50a20f3d1beb2b92394..ef8696be4690c0e202f20eb6f2bbf08a2ea6e0fc 100644 (file)
--- a/src/qemu/qemu_hotplug.c
+++ b/src/qemu/qemu_hotplug.c
@@ -33,6 +33,7 @@
 #include "qemu_command.h"
 #include "qemu_hostdev.h"
 #include "qemu_interface.h"
+#include "qemu_process.h"
 #include "domain_audit.h"
 #include "netdev_bandwidth_conf.h"
 #include "domain_nwfilter.h"
@@ -1742,7 +1743,6 @@ qemuDomainAttachMemory(virQEMUDriverPtr driver,
     const char *backendType;
     virJSONValuePtr props = NULL;
     virObjectEventPtr event;
-    bool fix_balloon = false;
     int id;
     int ret = -1;
 
@@ -1757,9 +1757,6 @@ qemuDomainAttachMemory(virQEMUDriverPtr driver,
     if (virAsprintf(&objalias, "mem%s", mem->info.alias) < 0)
         goto cleanup;
 
-    if (vm->def->mem.cur_balloon == virDomainDefGetMemoryActual(vm->def))
-        fix_balloon = true;
-
     if (!(devstr = qemuBuildMemoryDeviceStr(mem)))
         goto cleanup;
 
@@ -1800,9 +1797,8 @@ qemuDomainAttachMemory(virQEMUDriverPtr driver,
     event = virDomainEventDeviceAddedNewFromObj(vm, objalias);
     qemuDomainEventQueue(driver, event);
 
-    /* fix the balloon size if it was set to maximum */
-    if (fix_balloon)
-        vm->def->mem.cur_balloon += mem->size;
+    /* fix the balloon size */
+    ignore_value(qemuProcessRefreshBalloonState(driver, vm, QEMU_ASYNC_JOB_NONE));
 
     /* mem is consumed by vm->def */
     mem = NULL;
@@ -2938,13 +2934,14 @@ qemuDomainRemoveMemoryDevice(virQEMUDriverPtr driver,
     if (rc < 0)
         return -1;
 
-    vm->def->mem.cur_balloon -= mem->size;
-
     if ((idx = virDomainMemoryFindByDef(vm->def, mem)) >= 0)
         virDomainMemoryRemove(vm->def, idx);
 
     virDomainMemoryDefFree(mem);
 
+    /* fix the balloon size */
+    ignore_value(qemuProcessRefreshBalloonState(driver, vm, QEMU_ASYNC_JOB_NONE));
+
     /* decrease the mlock limit after memory unplug if necessary */
     ignore_value(qemuDomainAdjustMaxMemLock(vm));
 

diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index de5c52f753d24e7cf6f0e6ebba225b635f0642e3..3da23ce3d8e31e8de3bc21337491515e8e7ffef8 100644 (file)
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -1993,7 +1993,7 @@ qemuRefreshVirtioChannelState(virQEMUDriverPtr driver,
 }
 
 
-static int
+int
 qemuProcessRefreshBalloonState(virQEMUDriverPtr driver,
                                virDomainObjPtr vm,
                                int asyncJob)

diff --git a/src/qemu/qemu_process.h b/src/qemu/qemu_process.h
index d5f50f2a674161cc0c2dd9c5720f045eb879da9b..98cc9a849f37bcc7efaccbb5627e9eec03014c67 100644 (file)
--- a/src/qemu/qemu_process.h
+++ b/src/qemu/qemu_process.h
@@ -193,4 +193,8 @@ int qemuProcessSetupIOThread(virDomainObjPtr vm,
 
 int qemuRefreshVirtioChannelState(virQEMUDriverPtr driver,
                                   virDomainObjPtr vm);
+
+int qemuProcessRefreshBalloonState(virQEMUDriverPtr driver,
+                                   virDomainObjPtr vm,
+                                   int asyncJob);
 #endif /* __QEMU_PROCESS_H__ */