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Message-ID: <49B3F418.4090805@codemonkey.ws>
Date: Sun, 08 Mar 2009 11:36:40 -0500
From: Anthony Liguori <anthony@codemonkey.ws>
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Subject: Re: [Qemu-devel] Re: [6684] Fix "info registers" under kvm.
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To: qemu-devel@nongnu.org

Avi Kivity wrote:
> Avi Kivity wrote:
>> Jan Kiszka wrote:
>>> I'm just still waiting for a reply from Anthony on how to embed best 
>>> all
>>> the "if (kvm_enabled()) foo();" patterns [2]. That would also allow us
>>> to merge gdbstub support for upstream kvm.
>>>
>>>   
>>
>> Wouldn't 'if (!kvm_enabled()) return;' inside the callees suffice?
>
> Rather,
>
> static inline void kvm_foo(...)
> {
>    if (!kvm_enabled()) {
>        return;
>    }
>
> #ifdef CONFIG_KVM
>   kvm_do_foo();
> #endif
> }

In the case of save/load registers, I'd prefer wrapper functions like:

cpu_state_update(CPUState *env, int is_dirty)

That could be hooked by something like Xen.  The implementation would be:

static void cpu_state_update(CPUState *env, int is_dirty)
{
    if (kvm_enabled()) {
        if (is_dirty)
           kvm_arch_save_registers(env);
        else
           kvm_arch_load_registers(env);
    }
}

Regards,

Anthony Liguori

>
>