On Mon, Mar 02, 2015 at 05:55:44PM +0100, Laszlo Ersek wrote: > On 03/02/15 17:47, Paolo Bonzini wrote: > > > > Also, we may want to invalidate the cache for dirty pages before > > returning the dirty bitmap, and probably should do that directly in > > KVM_GET_DIRTY_LOG. > > "I agree." > > If KVM_GET_DIRTY_LOG is supposed to be atomic fetch and clear (from > userspace's aspect), then the cache invalidation should be an atomic > part of it too (from the same aspect). > > (Sorry if I just said something incredibly stupid.) > With the path I'm headed down, all cache maintenance operations will be done before exiting to userspace (and after returning). I was actually already letting a feature creep into this PoC by setting KVM_MEM_LOG_DIRTY_PAGES when we see KVM_MEM_INCOHERENT has been set, and the region isn't readonly. The dirty log would then be used by KVM internally to know exactly which pages need to be invalidated before the exit. drew -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
