Re: [Qemu-devel] [PATCH v3 for-2.9 0/3] q35: add negotiable broadcast SMI

[Paolo Bonzini]

On 28/11/2016 11:22, Laszlo Ersek wrote:
> Michael suggested to use negotiation like virtio does (where the host
> can reject invalid combinations of requested features):
> 
> http://lists.nongnu.org/archive/html/qemu-devel/2016-11/msg03077.html
> http://lists.nongnu.org/archive/html/qemu-devel/2016-11/msg03218.html
> 
> I thought negotiation was overkill:
> 
> http://lists.nongnu.org/archive/html/qemu-devel/2016-11/msg03123.html
> 
> but I figured I'd just stick with the recommendation.

I think negotiation is useful.  By doing things like "prevent
broadcast_SMI && !parked_VCPUs if max_cpus > smp_cpus", it lets you
commit your OVMF patch immediately for example.

Paolo

>> > If it is there just write true/false to it to enable/disable, and qemu
>> > checks the field each time a smi is raised.
> If we agree there's no need for negotiation, I'm game.