On Fri, Jul 18, 2014 at 05:05:20PM +0800, Tang Chen wrote: > Hi Gleb, > > On 07/17/2014 09:57 PM, Gleb Natapov wrote: > >On Thu, Jul 17, 2014 at 09:34:20PM +0800, Tang Chen wrote: > >>Hi Gleb, > >> > >>On 07/15/2014 08:40 PM, Gleb Natapov wrote: > >>...... > >>>> > >>>>And yes, we have the problem you said here. We can migrate the page while L2 > >>>>vm is running. > >>>>So I think we should enforce L2 vm to exit to L1. Right ? > >>>> > >>>We can request APIC_ACCESS_ADDR reload during L2->L1 vmexit emulation, so > >>>if APIC_ACCESS_ADDR changes while L2 is running it will be reloaded for L1 too. > >>> > >> > >>Sorry, I think I don't quite understand the procedure you are talking about > >>here. > >> > >>Referring to the code, I think we have three machines: L0(host), L1 and L2. > >>And we have two types of vmexit: L2->L1 and L2->L0. Right ? > >> > >>We are now talking about this case: L2 and L1 shares the apic page. > >> > >>Using patch 5/5, when apic page is migrated on L0, mmu_notifier will notify > >>L1, > >>and update L1's VMCS. At this time, we are in L0, not L2. Why cannot we > >Using patch 5/5, when apic page is migrated on L0, mmu_notifier will notify > >L1 or L2 VMCS depending on which one happens to be running right now. > >If it is L1 then L2's VMCS will be updated during vmentry emulation, > > OK, this is easy to understand. > > >if it is > >L2 we need to request reload during vmexit emulation to make sure L1's VMCS is > >updated. > > > > I'm a little confused here. In patch 5/5, I called make_all_cpus_request() > to > force all vcpus exit to host. If we are in L2, where will the vcpus exit to > ? > L1 or L0 ? > L0. CPU always exits to L0. L1->L2 exit is emulated by nested_vmx_vmexit(). -- 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
