[Qemu-devel] [PATCH V3] Guest stop notification

[Eric B Munson]

Often when a guest is stopped from the qemu console, it will report spurious
soft lockup warnings on resume.  There are kernel patches being discussed that
will give the host the ability to tell the guest that it is being stopped and
should ignore the soft lockup warning that generates.

Signed-off-by: Eric B Munson <address@hidden>
Cc: Avi Kivity <address@hidden>
Cc: Marcelo Tosatti <address@hidden>
Cc: Jan Kiszka <address@hidden>
Cc: address@hidden
Cc: address@hidden
Cc: address@hidden

---
Changes from V2:
 Move ioctl into hw/kvmclock.c so as other arches can use it as it is
implemented

Changes from V1:
 Remove unnecessary encapsulating function

 hw/kvmclock.c |   24 ++++++++++++++++++++++++
 1 files changed, 24 insertions(+), 0 deletions(-)

diff --git a/hw/kvmclock.c b/hw/kvmclock.c
index 5388bc4..756839f 100644
--- a/hw/kvmclock.c
+++ b/hw/kvmclock.c
@@ -16,6 +16,7 @@
 #include "sysbus.h"
 #include "kvm.h"
 #include "kvmclock.h"
+#include "cpu-all.h"
 
 #include <linux/kvm.h>
 #include <linux/kvm_para.h>
@@ -69,11 +70,34 @@ static void kvmclock_vm_state_change(void *opaque, int 
running,
     }
 }
 
+static void kvmclock_vm_state_change_vcpu(void *opaque, int running,
+                                          RunState state)
+{
+    int ret;
+    CPUState *penv = first_cpu;
+
+    if (running) {
+       while (penv) {
+            ret = kvm_vcpu_ioctl(penv, KVM_GUEST_PAUSED, 0);
+            if (ret) {
+                if (ret != ENOSYS) {
+                    fprintf(stderr,
+                            "kvmclock_vm_state_change_vcpu: %s\n",
+                            strerror(-ret));
+                }
+                return;
+            }
+            penv = (CPUState *)penv->next_cpu;
+        }
+    }
+}
+
 static int kvmclock_init(SysBusDevice *dev)
 {
     KVMClockState *s = FROM_SYSBUS(KVMClockState, dev);
 
     qemu_add_vm_change_state_handler(kvmclock_vm_state_change, s);
+    qemu_add_vm_change_state_handler(kvmclock_vm_state_change_vcpu, NULL);
     return 0;
 }
 
-- 
1.7.5.4