From: Michal Privoznik <mprivozn@redhat.com>
Date: Mon, 22 May 2023 13:55:10 +0000 (+0200)
Subject: qemu_hotplug: Temporarily allow emulator thread to access other NUMA nodes during... 
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=e53291514c1615da70806732e3897d2c2ebeb1fd;p=libvirt.git

qemu_hotplug: Temporarily allow emulator thread to access other NUMA nodes during mem hotplug

Again, this fixes the same problem as one of previous commits,
but this time for memory hotplug. Long story short, if there's a
domain running and the emulator thread is restricted to a subset
of host NUMA nodes, but the memory that's about to be hotplugged
requires memory from a host NUMA node that's not in the set we
need to allow emulator thread to access the node, temporarily.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
---

diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
index d5148f5815..972df572a7 100644
--- a/src/qemu/qemu_hotplug.c
+++ b/src/qemu/qemu_hotplug.c
@@ -2247,6 +2247,7 @@ qemuDomainAttachMemory(virQEMUDriver *driver,
     bool teardownlabel = false;
     bool teardowncgroup = false;
     bool teardowndevice = false;
+    bool restoreemulatorcgroup = false;
     g_autoptr(virJSONValue) props = NULL;
     virObjectEvent *event;
     int id;
@@ -2294,6 +2295,10 @@ qemuDomainAttachMemory(virQEMUDriver *driver,
     if (qemuDomainAdjustMaxMemLock(vm) < 0)
         goto removedef;
 
+    if (qemuProcessSetupEmulator(vm, true) < 0)
+        goto removedef;
+    restoreemulatorcgroup = true;
+
     qemuDomainObjEnterMonitor(vm);
     if (qemuMonitorAddObject(priv->mon, &props, NULL) < 0)
         goto exit_monitor;
@@ -2333,6 +2338,9 @@ qemuDomainAttachMemory(virQEMUDriver *driver,
             qemuDomainReleaseMemoryDeviceSlot(vm, mem);
     }
 
+    if (restoreemulatorcgroup)
+        qemuProcessSetupEmulator(vm, false);
+
     virDomainMemoryDefFree(mem);
     return ret;
 
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index ee11c72016..730e59eb7e 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -2701,7 +2701,7 @@ qemuProcessSetupPid(virDomainObj *vm,
 }
 
 
-static int
+int
 qemuProcessSetupEmulator(virDomainObj *vm,
                          bool unionMems)
 {
diff --git a/src/qemu/qemu_process.h b/src/qemu/qemu_process.h
index e0cbafda1d..1c4c0678ab 100644
--- a/src/qemu/qemu_process.h
+++ b/src/qemu/qemu_process.h
@@ -235,3 +235,6 @@ void qemuProcessCleanupMigrationJob(virQEMUDriver *driver,
 
 void qemuProcessRefreshDiskProps(virDomainDiskDef *disk,
                                  struct qemuDomainDiskInfo *info);
+
+int qemuProcessSetupEmulator(virDomainObj *vm,
+                             bool unionMems);