KVM Management : Paused stauts

KVM Management : Paused stauts

[jd]

Hi
  This is possibly a repeat but I did not get answer to :

-- How does one find out if the VM is paused or not ? I did not find anything  in the console.

   If it is currently not possible(which I doubt), is there a plan to add it ?

Thanks
/Jd



      

Re: KVM Management : Paused stauts

[Anthony Liguori]

jd wrote:
> Hi
>   This is possibly a repeat but I did not get answer to :
>
> -- How does one find out if the VM is paused or not ? I did not find anything  in the console.
>
>    If it is currently not possible(which I doubt), is there a plan to add it ?
>   

'info cpus' in the monitor will have a '(halted)' status at the end.

Regards,

Anthony Liguori

Re: KVM Management : Paused stauts

[jd]

Anothony, 
   Thanks a lot for responding to this and my other queries.
/Jd


--- On Sat, 8/9/08, Anthony Liguori <anthony@codemonkey.ws> wrote:

> From: Anthony Liguori <anthony@codemonkey.ws>
> Subject: Re: KVM Management : Paused stauts
> To: jdsw2002@yahoo.com
> Cc: "KVM List" <kvm@vger.kernel.org>
> Date: Saturday, August 9, 2008, 8:40 AM
> jd wrote:
> > Hi
> >   This is possibly a repeat but I did not get answer
> to :
> >
> > -- How does one find out if the VM is paused or not ?
> I did not find anything  in the console.
> >
> >    If it is currently not possible(which I doubt), is
> there a plan to add it ?
> >   
> 
> 'info cpus' in the monitor will have a
> '(halted)' status at the end.
> 
> Regards,
> 
> Anthony Liguori


      

Re: KVM Management : Paused stauts

[jd]

Hi

   I do not see (halted) when I "stop" (pause) the vm. Tried on both KVM-70 and kvm-73.
  
  Is there a particular version it was introduced in?

Thanks
/Jd

(qemu) info cpus
info cpus
* CPU #0: pc=0x00000000c00faaca thread_id=18641
(qemu) stop
stop
(qemu) info cpus
info cpus
* CPU #0: pc=0x00000000c00faaca thread_id=18641
(qemu) cont
cont
(qemu) info cpus
info cpus
* CPU #0: pc=0x00000000c04224f4 thread_id=18641
(qemu) 






--- On Sat, 8/9/08, Anthony Liguori <anthony@codemonkey.ws> wrote:

> From: Anthony Liguori <anthony@codemonkey.ws>
> Subject: Re: KVM Management : Paused stauts
> To: jdsw2002@yahoo.com
> Cc: "KVM List" <kvm@vger.kernel.org>
> Date: Saturday, August 9, 2008, 8:40 AM
> jd wrote:
> > Hi
> >   This is possibly a repeat but I did not get answer
> to :
> >
> > -- How does one find out if the VM is paused or not ?
> I did not find anything  in the console.
> >
> >    If it is currently not possible(which I doubt), is
> there a plan to add it ?
> >   
> 
> 'info cpus' in the monitor will have a
> '(halted)' status at the end.
> 
> Regards,
> 
> Anthony Liguori
> --
> To unsubscribe from this list: send the line
> "unsubscribe kvm" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at 
> http://vger.kernel.org/majordomo-info.html


      

Re: KVM Management : Paused stauts

[Avi Kivity]

jd wrote:
> Hi
>
>    I do not see (halted) when I "stop" (pause) the vm. Tried on both KVM-70 and kvm-73.
>   
>   Is there a particular version it was introduced in?
>
> Thanks
> /Jd
>
> (qemu) info cpus
> info cpus
> * CPU #0: pc=0x00000000c00faaca thread_id=18641
> (qemu) stop
> stop
> (qemu) info cpus
> info cpus
> * CPU #0: pc=0x00000000c00faaca thread_id=18641
> (qemu) cont
> cont
> (qemu) info cpus
> info cpus
> * CPU #0: pc=0x00000000c04224f4 thread_id=18641
> (qemu) 
>
>   

"halted" actually means the vcpu is idle (executing a hlt instruction),
not that the vm is halted.

-- 
Do not meddle in the internals of kernels, for they are subtle and quick to panic.

Re: KVM Management : Paused stauts

[jd]

> "halted" actually means the vcpu is idle
> (executing a hlt instruction),
> not that the vm is halted.


Can u please elaborate a bit on this ? when does guest get in to executing 'hlt' Vs in to 'VM halt'

My understanding is that when guest executes shutdown sequence, eventually it will execute hlt.

When you give stop via the monitor/console, what happens ? (and on continue)

thanks
/Jd


--- On Sat, 10/4/08, Avi Kivity <avi@redhat.com> wrote:

> From: Avi Kivity <avi@redhat.com>
> Subject: Re: KVM Management : Paused stauts
> To: jdsw2002@yahoo.com
> Cc: "Anthony Liguori" <anthony@codemonkey.ws>, "KVM List" <kvm@vger.kernel.org>
> Date: Saturday, October 4, 2008, 5:46 AM
> jd wrote:
> > Hi
> >
> >    I do not see (halted) when I "stop"
> (pause) the vm. Tried on both KVM-70 and kvm-73.
> >   
> >   Is there a particular version it was introduced in?
> >
> > Thanks
> > /Jd
> >
> > (qemu) info cpus
> > info cpus
> > * CPU #0: pc=0x00000000c00faaca thread_id=18641
> > (qemu) stop
> > stop
> > (qemu) info cpus
> > info cpus
> > * CPU #0: pc=0x00000000c00faaca thread_id=18641
> > (qemu) cont
> > cont
> > (qemu) info cpus
> > info cpus
> > * CPU #0: pc=0x00000000c04224f4 thread_id=18641
> > (qemu) 
> >
> >   
> 
> "halted" actually means the vcpu is idle
> (executing a hlt instruction),
> not that the vm is halted.
> 
> -- 
> Do not meddle in the internals of kernels, for they are
> subtle and quick to panic.


      

Re: KVM Management : Paused stauts

[Avi Kivity]

jd wrote:
>> "halted" actually means the vcpu is idle
>> (executing a hlt instruction),
>> not that the vm is halted.
>>     
>
>
> Can u please elaborate a bit on this ? when does guest get in to executing 'hlt' Vs in to 'VM halt'
>
> My understanding is that when guest executes shutdown sequence, eventually it will execute hlt.
>
>   

No, hlt is part of the guest idle loop.  It will execute hlt whenever 
the processor has nothing to do.

During shutdown it will execute an ACPI sequence that results in qemu 
exiting.

> When you give stop via the monitor/console, what happens ? (and on continue)
>   

Qemu no longer allows the vcpu to execute.  If it was in halted state, 
it stays that way, and if it wasn't it also stays that way.  When you 
continue, the vcpu gets more cpu time and can proceed.

-- 
error compiling committee.c: too many arguments to function

Re: KVM Management : Paused stauts

[jd]

Thanks for clarifying.

So back to my original question, how do I determine (via monitor/console) if the guest is in "halted"/stop state ?

/Jd


--- On Sun, 10/5/08, Avi Kivity <avi@redhat.com> wrote:

> From: Avi Kivity <avi@redhat.com>
> Subject: Re: KVM Management : Paused stauts
> To: jdsw2002@yahoo.com
> Cc: "Anthony Liguori" <anthony@codemonkey.ws>, "KVM List" <kvm@vger.kernel.org>
> Date: Sunday, October 5, 2008, 7:18 AM
> jd wrote:
> >> "halted" actually means the vcpu is idle
> >> (executing a hlt instruction),
> >> not that the vm is halted.
> >>     
> >
> >
> > Can u please elaborate a bit on this ? when does guest
> get in to executing 'hlt' Vs in to 'VM halt'
> >
> > My understanding is that when guest executes shutdown
> sequence, eventually it will execute hlt.
> >
> >   
> 
> No, hlt is part of the guest idle loop.  It will execute
> hlt whenever 
> the processor has nothing to do.
> 
> During shutdown it will execute an ACPI sequence that
> results in qemu 
> exiting.
> 
> > When you give stop via the monitor/console, what
> happens ? (and on continue)
> >   
> 
> Qemu no longer allows the vcpu to execute.  If it was in
> halted state, 
> it stays that way, and if it wasn't it also stays that
> way.  When you 
> continue, the vcpu gets more cpu time and can proceed.
> 
> -- 
> error compiling committee.c: too many arguments to function


      

Re: KVM Management : Paused stauts

[Avi Kivity]

jd wrote:
> Thanks for clarifying.
>
> So back to my original question, how do I determine (via monitor/console) if the guest is in "halted"/stop state ?
>   

No idea.  Presumably a new info subcommand.

But if you're issuing the stop and cont command, you can simply remember 
the last command you sent.

-- 
error compiling committee.c: too many arguments to function

Re: KVM Management : Paused stauts

[jd]

I would request to get new info command in.

I am sure you realize that remembering the state is not complete solution. When the management tool comes up, it needs to query the VMs and know its current state and sync it with what it knows.

Thanks
/Jd


--- On Tue, 10/7/08, Avi Kivity <avi@redhat.com> wrote:

> From: Avi Kivity <avi@redhat.com>
> Subject: Re: KVM Management : Paused stauts
> To: jdsw2002@yahoo.com
> Cc: "Anthony Liguori" <anthony@codemonkey.ws>, "KVM List" <kvm@vger.kernel.org>
> Date: Tuesday, October 7, 2008, 7:49 AM
> jd wrote:
> > Thanks for clarifying.
> >
> > So back to my original question, how do I determine
> (via monitor/console) if the guest is in
> "halted"/stop state ?
> >   
> 
> No idea.  Presumably a new info subcommand.
> 
> But if you're issuing the stop and cont command, you
> can simply remember 
> the last command you sent.
> 
> -- 
> error compiling committee.c: too many arguments to function
> 
> --
> To unsubscribe from this list: send the line
> "unsubscribe kvm" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at 
> http://vger.kernel.org/majordomo-info.html