Re: [Qemu-devel] [PATCH V8 1/1] Guest stop notificationorry for rduplicate mail

[Raghavendra K T]

On 04/06/2012 03:19 PM, Raghavendra K T wrote:
> On 04/06/2012 02:29 PM, Andreas Färber wrote:
> > Am 06.04.2012 09:21, schrieb Raghavendra K T:
> > > From: Eric B Munson<address@hidden>
> > >
> > > 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. This patch uses
> > > the qemu
> > > Notifier system to tell the guest it is about to be stopped.
> > >
> > > Signed-off-by: Eric B Munson<address@hidden>
> > > Signed-off-by: Raghavendra K T<address@hidden>
> > >
> > > Cc: Eric B Munson<address@hidden>
> > > Cc: Avi Kivity<address@hidden>
> > > Cc: Marcelo Tosatti<address@hidden>
> > > Cc: Anthony Liguori<address@hidden>
> > > Cc: Jan Kiszka<address@hidden>
> > > Cc: "Andreas FÀrber"<address@hidden>
> > > ---
> > > Changes from V7:
> > > capabilty changed to KVM_CAP_KVMCLOCK_CTRL
> > > KVM_GUEST_PAUSED is pervcpu again
> > > CPUState renamed to CPUArchState
> >
> > Thanks, change looks right to me.

I think I should have added Acked-by and resent full patch. So here is 
it. sorry for duplicate mail.
---
From: Eric B Munson <address@hidden>

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.  This patch uses 
the qemu
Notifier system to tell the guest it is about to be stopped.

Acked-by: "Andreas Färber" <address@hidden>
Signed-off-by: Eric B Munson <address@hidden>
Signed-off-by: Raghavendra K T <address@hidden>

Cc: Eric B Munson <address@hidden>
Cc: Avi Kivity <address@hidden>
Cc: Marcelo Tosatti <address@hidden>
Cc: Anthony Liguori <address@hidden>
Cc: Jan Kiszka <address@hidden>
Cc: "Andreas Färber" <address@hidden>
---
Changes from V7:
 capabilty changed to KVM_CAP_KVMCLOCK_CTRL
 KVM_GUEST_PAUSED is pervcpu again
 CPUState renamed to CPUArchState
 KVMCLOCK_GUEST_PAUSED changed to  KVM_KVMCLOCK_CTRL
 incorporated Andrea's comments (__FUNCTION__) etc

Changes from V6:
 Remove unnecessary include

Changes from V5:
 KVM_GUEST_PAUSED is now a per vm ioctl instead of per vcpu

Changes from V4:
 Test if the guest paused capability is available before use

Changes from V3:
 Collapse new state change notification function into existsing function.
 Correct whitespace issues
 Change ioctl name to KVMCLOCK_GUEST_PAUSED
 Use for loop to iterate vpcu's

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
---

diff --git a/hw/kvm/clock.c b/hw/kvm/clock.c
index 446bd62..a6aa6e4 100644
--- a/hw/kvm/clock.c
+++ b/hw/kvm/clock.c
@@ -65,9 +65,27 @@ static void kvmclock_vm_state_change(void *opaque, 
int running,
                                      RunState state)
 {
     KVMClockState *s = opaque;
+    CPUArchState *penv = first_cpu;
+    int cap_clock_ctrl = kvm_check_extension(kvm_state, 
KVM_CAP_KVMCLOCK_CTRL);
+    int ret;

     if (running) {
         s->clock_valid = false;
+
+        if (!cap_clock_ctrl) {
+            return;
+        }
+        for (penv = first_cpu; penv != NULL; penv = penv->next_cpu) {
+            ret = kvm_vcpu_ioctl(penv, KVM_KVMCLOCK_CTRL, 0);
+            if (ret) {
+                if (ret != -EINVAL) {
+                    fprintf(stderr,
+                            " %s: %s\n", __FUNCTION__,
+                            strerror(-ret));
+                }
+                return;
+            }
+        }
     }
 }