On Mon, Jun 30, 2014 at 09:45:32AM +0800, Tang Chen wrote: > On 06/21/2014 04:39 AM, Marcelo Tosatti wrote: > >On Fri, Jun 20, 2014 at 05:31:46PM -0300, Marcelo Tosatti wrote: > >>>IIRC your shadow page pinning patch series support flushing of ptes > >>>by mmu notifier by forcing MMU reload and, as a result, faulting in of > >>>pinned pages during next entry. Your patch series does not pin pages > >>>by elevating their page count. > >> > >>No but PEBS series does and its required to stop swap-out > >>of the page. > > > >Well actually no because of mmu notifiers. > > > >Tang, can you implement mmu notifiers for the other breaker of > >mem hotplug ? > > Hi Marcelo, > > I made a patch to update ept and apic pages when finding them in the > next ept violation. And I also updated the APIC_ACCESS_ADDR phys_addr. > The pages can be migrated, but the guest crached. How does it crash? > > How do I stop guest from access apic pages in mmu_notifier when the > page migration starts ? Do I need to stop all the vcpus by set vcpu > state to KVM_MP_STATE_HALTED ? If so, the vcpu will not able to go > to the next ept violation. When apic access page is unmapped from ept pages by mmu notifiers you need to set its value in VMCS to a physical address that will never be mapped into guest memory. Zero for instance. You can do it by introducing new KVM_REQ_ bit and set VMCS value during next vcpu's vmentry. On ept violation you need to update VMCS pointer to newly allocated physical address, you can use the same KVM_REQ_ mechanism again. > > So, may I write any specific value into APIC_ACCESS_ADDR to stop guest > from access to apic page ? > Any phys address that will never be mapped into guest's memory should work. -- Gleb. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>