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Date: Mon, 30 Nov 2009 14:06:23 +0200
From: Avi Kivity <avi@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH 4/7] qemu_flush_work for remote vcpu execution
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To: Glauber Costa <glommer@gmail.com>
Cc: Glauber Costa <glommer@redhat.com>, aliguori@us.ibm.com, qemu-devel@nongnu.org

On 11/30/2009 01:44 PM, Glauber Costa wrote:
>> I really dislike this.  In general vcpu ioctls are used as components of
>> some work to be done, for example RMW of some state.  In this case it is
>> meaningless to execute the ioctls remotely, you need to execute the entire
>> RMW remotely instead.
>>
>>      
> Why? The "M" part of RMW is executed in shared memory.
> Only the R and W parts have any restrictions on where to be executed.
>
>    

If the guest continues to run during the RMW, you will get inconsistent 
results.

This may be prevented by qemu_mutex, but I'd rather not rely on it.

Also, I'd like remote operations to be visible.

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