Re: [Qemu-devel] Re: [PATCH 0/7] KVM SMP support, early version

[Avi Kivity <avi@redhat.com>]

On 11/30/2009 07:30 PM, Jan Kiszka wrote:
>>>
>>> No.  But what's wrong with on_vcpu?
>>>        
>> intrinsically racy. signal passing slow down things, etc.
>>
>> That said, as I've stated many times: I don't believe there's anything
>> fundamentally wrong with on_vcpu. But we might get benefits from a re-design
>> of things to avoid it whenever possible. (just like the vcpu_reset()
>> I've just posted)
>>
>>      
> If you don't want immediate execution of update_guest_debug, save the
> state that shall be transferred, set some flag, and run the transfer
> before guest entry inside the vcpu threads (after putting the registers
> as older kernels may otherwise overwrite the flags register). Should
> work, may even avoid redundant calls during a gdb session.
>    

There's no guarantee the vcpu will ever exit to qemu, so you have to 
signal the vcpu thread anyway.  When you do that, you might as well load 
the new state.

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