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From: Avi Kivity <avi@redhat.com>
To: Marcelo Tosatti <mtosatti@redhat.com>
Cc: kvm-devel <kvm@vger.kernel.org>, Dor Laor <dlaor@redhat.com>,
	Yaniv Kamay <yaniv@redhat.com>
Subject: Re: kvm: qemu: stop/start cpus before/after devices
Date: Thu, 26 Mar 2009 12:03:30 +0200	[thread overview]
Message-ID: <49CB52F2.3060203@redhat.com> (raw)
In-Reply-To: <20090325143932.GB28345@amt.cnet>

Marcelo Tosatti wrote:
> On Wed, Mar 25, 2009 at 11:26:19AM -0300, Marcelo Tosatti wrote:
>   
>> On Wed, Mar 25, 2009 at 01:45:52PM +0200, Avi Kivity wrote:
>>     
>>> Marcelo Tosatti wrote:
>>>       
>>>> From: Yaniv Kamay <yaniv@qumranet.com>
>>>>
>>>> Stop cpus before devices when stopping the VM, start cpus after devices
>>>> when starting VM.
>>>>
>>>>   
>>>>         
>>> Why is this needed?
>>>       
>> A vcpu could access a stopped device otherwise. 
>>     
>
> Actually on vm_stop its safe because the order happens to be correct,
> but on vm_start its the other way around (vcpus start first, and they
> should be started last).
>   

But, we are holding qemu_mutex.  How can vcpus access the devices?


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


  parent reply	other threads:[~2009-03-26 10:03 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-03-24 17:16 kvm: qemu: stop/start cpus before/after devices Marcelo Tosatti
2009-03-25 11:45 ` Avi Kivity
2009-03-25 14:26   ` Marcelo Tosatti
2009-03-25 14:39     ` Marcelo Tosatti
2009-03-25 14:52       ` Avi Kivity
2009-03-26 10:03       ` Avi Kivity [this message]
2009-03-26 16:36         ` Marcelo Tosatti
2009-03-26 18:45           ` Avi Kivity

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