On 27.01.2012, at 22:49, Jan Kiszka <jan.kiszka@xxxxxx> wrote:
> On 2012-01-27 21:48, Anthony Liguori wrote:
>> On 01/17/2012 12:27 PM, Eric B Munson wrote:
>>> 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@xxxxxxxxx>
>>>
>>> Cc: Avi Kivity<avi@xxxxxxxxxx>
>>> Cc: Marcelo Tosatti<mtosatti@xxxxxxxxxx>
>>> Cc: Jan Kiszka<jan.kiszka@xxxxxxxxxxx>
>>> Cc: ryanh@xxxxxxxxxxxxxxxxxx
>>> Cc: aliguori@xxxxxxxxxx
>>> Cc: kvm@xxxxxxxxxxxxxxx
>>> ---
>>> 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
>>>
>>> hw/kvmclock.c | 11 +++++++++++
>>> 1 files changed, 11 insertions(+), 0 deletions(-)
>>>
>>> diff --git a/hw/kvmclock.c b/hw/kvmclock.c
>>> index 3b9fb20..ad79f52 100644
>>> --- a/hw/kvmclock.c
>>> +++ b/hw/kvmclock.c
>>> @@ -64,10 +64,21 @@ static int kvmclock_post_load(void *opaque, int
>>> version_id)
>>> static void kvmclock_vm_state_change(void *opaque, int running,
>>> RunState state)
>>> {
>>> + int ret;
>>> KVMClockState *s = opaque;
>>> + int cap_guest_paused = kvm_check_extension(kvm_state,
>>> KVM_CAP_GUEST_PAUSED);
>>>
>>> if (running) {
>>> s->clock_valid = false;
>>> +
>>> + if (!cap_guest_paused) {
>>> + return;
>>> + }
>>> +
>>> + ret = kvm_vm_ioctl(kvm_state, KVMCLOCK_GUEST_PAUSED, 0);
>>> + if (ret) {
>>> + fprintf(stderr, "kvmclock_vm_state_change: %s\n",
>>> strerror(-ret));
>>> + }
>>> }
>>> }
>>
>>
>> This change looks harmless enough.
>
> Yep, but needs to be redirected after the file renaming in upstream.
>
>> What's the state of the kernel
>> bits? I would expect this through uq/master.
>
> Kernel bits aren't merged yet. And the kernel headers will have to be
> updated in a previous step.
>
> BTW, this series [1] would be nice to have. Dunno if there is a pull
> planned, but anyone trying to extend the KVM interface current runs
> against this.
Yeah, I was mostly waiting for acks/nacks. Since I didn't receive any, expect a pullreq next week.
Alex
>
> Jan
>
> [1] http://thread.gmane.org/gmane.comp.emulators.qemu/132962
>
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