On Mon, Oct 26, 2009 at 11:21:12AM +0200, Avi Kivity wrote: > On 10/26/2009 11:17 AM, Joerg Roedel wrote: > >On Sun, Oct 25, 2009 at 11:49:35AM +0200, Avi Kivity wrote: > >>On 10/24/2009 12:35 PM, Alexander Graf wrote: > >>>Hm, thinking about this again, it might be useful to have an > >>>"currently in nested VM" flag here. That way userspace can decide > >>>if it needs to get out of the nested state (for migration) or if > >>>it just doesn't care. > >>Getting out of nested state involves modifying state (both memory > >>and registers). Nor can we in the general case force it. The guest > >>can set up a situation where it is impossible to #vmexit. > >There is actually more than that. If the guest runs in guest mode itself > >we also need to report the host state to be able to do an #vmexit after > >migration. > >In nested SVM the host state is not saved in the guest memory to prevent > >the guest from modifying it and break out of its virtualization jail. > > Which host state? As far as I can tell, it can all be regenerated. The state which is loaded into the vcpu when a #vmexit is emulated. This includes segments, control registers and the host rip for example. Joerg -- 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
