Re: [Qemu-devel] [PATCH 28/35] kvm: x86: Introduce kvmclock device to save/restore its state

[Blue Swirl]

On Fri, Jan 21, 2011 at 8:46 AM, Gerd Hoffmann <address@hidden> wrote:
>  Hi,
>
>> By the way, we don't have a QEMUState but instead use globals.
>
> /me wants to underline this.
>
> IMO it is absolutely pointless to worry about ways to pass around kvm_state.
>  There never ever will be a serious need for that.
>
> We can stick with the current model of keeping global state in global
> variables.  And just do the same with kvm_state.
>
> Or we can move to have all state in a QEMUState struct which we'll pass
> around basically everywhere.  Then we can simply embed or reference
> kvm_state there.
>
> I'd tend to stick with the global variables as I don't see the point in
> having a QEMUstate.  I doubt we'll ever see two virtual machines driven by a
> single qemu process.  YMMV.

Global variables are signs of a poor design. QEMUState would not help
that, instead more specific structures should be designed, much like
what I've proposed for KVMState. Some of these new structures should
be even passed around when it makes sense.

But I'd not start kvm_state redesign around global variables or QEMUState.