On Thu, Apr 08, 2010 at 10:17:01AM +0300, Avi Kivity wrote: > On 04/08/2010 08:27 AM, Yoshiaki Tamura wrote: > > > >The requirement is that the guest must always be able to replay at > >least the instruction which triggered the synchronization on the > >primary. > > > You have two choices: > > - complete execution of the instruction in both the kernel and the > device model > > This is what live migration does currently. Any mmio and pio > requests are completed, the last instruction is finalized, and state > is saved. > > - complete execution of the instruction in the kernel, but queue > execution of mmio/pio requests > > This is more in line with what you describe. vcpu state will be > after the instruction, device model state will be before instruction > completion, when you replay the queue, the device model state will > be consistent with the vcpu state. > For "in" or "mmio read" you can't complete instruction without doing actual IO. > > From that point of view, I think I need to transfer the vcpu > >state before the instruction. If I post a signal and let the > >guest or emulator proceed, I'm not sure whether the guest on the > >secondary can be replay as expected. Please point out if I were > >misunderstanding. > > If the responses to the mmio or pio request are exactly the same, > then the replay will happen exactly the same. > > -- > error compiling committee.c: too many arguments to function -- Gleb. -- 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
