Re: [PATCH 4/4] qemu_hotplug: Temporarily allow emulator thread to access other NUMA nodes during mem hotplug

2023-05-23 Thread Martin Kletzander 

On Tue, May 23, 2023 at 12:06:21PM +0200, Michal Privoznik wrote:

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 
---
src/qemu/qemu_hotplug.c | 8 
src/qemu/qemu_process.c | 2 +-
src/qemu/qemu_process.h | 3 +++
3 files changed, 12 insertions(+), 1 deletion(-)

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;


whoinventedthesevariablenames

Reviewed-by: Martin Kletzander 


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[PATCH 4/4] qemu_hotplug: Temporarily allow emulator thread to access other NUMA nodes during mem hotplug

2023-05-23 Thread Michal Privoznik 
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 
---
 src/qemu/qemu_hotplug.c | 8 
 src/qemu/qemu_process.c | 2 +-
 src/qemu/qemu_process.h | 3 +++
 3 files changed, 12 insertions(+), 1 deletion(-)

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, , 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 0fafda0beb..803bf9b0a3 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -2700,7 +2700,7 @@ 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);
-- 
2.39.3