Patchwork [V8,1/1] Guest stop notificationorry for rduplicate mail

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Submitter Raghavendra K T
Date April 6, 2012, 1:01 p.m.
Message ID <4F7EE91A.9020204@linux.vnet.ibm.com>
Download mbox | patch
Permalink /patch/151183/
State New
Headers show

Comments

Raghavendra K T - April 6, 2012, 1:01 p.m.
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<emunson@mgebm.net>
>>>
>>> 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<emunson@mgebm.net>
>>> Signed-off-by: Raghavendra K T<raghavendra.kt@linux.vnet.ibm.com>
>>>
>>> Cc: Eric B Munson<emunson@mgebm.net>
>>> Cc: Avi Kivity<avi@redhat.com>
>>> Cc: Marcelo Tosatti<mtosatti@redhat.com>
>>> Cc: Anthony Liguori<aliguori@us.ibm.com>
>>> Cc: Jan Kiszka<jan.kiszka@siemens.com>
>>> Cc: "Andreas FÀrber"<afaerber@suse.de>
>>> ---
>>> 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 <emunson@mgebm.net>

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" <afaerber@suse.de>
Signed-off-by: Eric B Munson <emunson@mgebm.net>
Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>

Cc: Eric B Munson <emunson@mgebm.net>
Cc: Avi Kivity <avi@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Anthony Liguori <aliguori@us.ibm.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: "Andreas Färber" <afaerber@suse.de>
---
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
---

  }
Andreas Färber - April 6, 2012, 9:09 p.m.
Am 06.04.2012 15:01, schrieb 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<emunson@mgebm.net>
>>>>
>>>> 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<emunson@mgebm.net>
>>>> Signed-off-by: Raghavendra K T<raghavendra.kt@linux.vnet.ibm.com>
>>>>
>>>> Cc: Eric B Munson<emunson@mgebm.net>
>>>> Cc: Avi Kivity<avi@redhat.com>
>>>> Cc: Marcelo Tosatti<mtosatti@redhat.com>
>>>> Cc: Anthony Liguori<aliguori@us.ibm.com>
>>>> Cc: Jan Kiszka<jan.kiszka@siemens.com>
>>>> Cc: "Andreas FÀrber"<afaerber@suse.de>
>>>> ---
>>>> 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.

No, it was not intended as such since I can't ack the ioctl. Resends are
best done with git-send-email, i.e. a v9 with change log (whether as
reply or not, opinions are divided) to make sure the right version gets
applied in the end.

> ---
> From: Eric B Munson <emunson@mgebm.net>
> 
> 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" <afaerber@suse.de>
> Signed-off-by: Eric B Munson <emunson@mgebm.net>
> Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>

*-bys should be added in chronological order, i.e. at the bottom.

> 
> Cc: Eric B Munson <emunson@mgebm.net>
> Cc: Avi Kivity <avi@redhat.com>
> Cc: Marcelo Tosatti <mtosatti@redhat.com>
> Cc: Anthony Liguori <aliguori@us.ibm.com>
> Cc: Jan Kiszka <jan.kiszka@siemens.com>
> Cc: "Andreas Färber" <afaerber@suse.de>
> ---
> 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__,

Is the whitespace before %s intentional? Wasn't there in v8.

The GCC manual recommends __func__, like I suggested, saying it's C99.
http://gcc.gnu.org/onlinedocs/gcc-4.7.0/gcc/Function-Names.html#Function-Names
__FUNCTION__ usage is currently 432 vs. __func__ 579, so not wrong.

If you want to leave it that way you can add my

Reviewed-by: Andreas Färber <afaerber@suse.de>

Andreas

> +                            strerror(-ret));
> +                }
> +                return;
> +            }
> +        }
>      }
>  }
>
Raghavendra K T - April 7, 2012, 12:27 a.m.
On 04/07/2012 02:39 AM, Andreas Färber wrote:
> Am 06.04.2012 15:01, schrieb 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<emunson@mgebm.net>
>>>>>
>>>>> 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<emunson@mgebm.net>
>>>>> Signed-off-by: Raghavendra K T<raghavendra.kt@linux.vnet.ibm.com>
>>>>>
>>>>> Cc: Eric B Munson<emunson@mgebm.net>
>>>>> Cc: Avi Kivity<avi@redhat.com>
>>>>> Cc: Marcelo Tosatti<mtosatti@redhat.com>
>>>>> Cc: Anthony Liguori<aliguori@us.ibm.com>
>>>>> Cc: Jan Kiszka<jan.kiszka@siemens.com>
>>>>> Cc: "Andreas FÀrber"<afaerber@suse.de>
>>>>> ---
>>>>> 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.
>
> No, it was not intended as such since I can't ack the ioctl. Resends are
> best done with git-send-email, i.e. a v9 with change log (whether as
> reply or not, opinions are divided) to make sure the right version gets
> applied in the end.

Ok. Thanks Andreas. sending V9 shortly

>
[...]
>> +            if (ret) {
>> +                if (ret != -EINVAL) {
>> +                    fprintf(stderr,
>> +                            " %s: %s\n", __FUNCTION__,
>
> Is the whitespace before %s intentional? Wasn't there in v8.
>
> The GCC manual recommends __func__, like I suggested, saying it's C99.
> http://gcc.gnu.org/onlinedocs/gcc-4.7.0/gcc/Function-Names.html#Function-Names
> __FUNCTION__ usage is currently 432 vs. __func__ 579, so not wrong.
>

will correct them.

> If you want to leave it that way you can add my
>
> Reviewed-by: Andreas Färber<afaerber@suse.de>
>
> Andreas
>
>> +                            strerror(-ret));
>> +                }
>> +                return;
>> +            }
>> +        }
>>       }
>>   }
>>
>

Patch

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;
+            }
+        }
      }