On Fri, Jul 04, 2014 at 10:36:06AM +0800, Tang Chen wrote: > Hi Gleb, > > On 07/03/2014 12:34 AM, Gleb Natapov wrote: > >On Wed, Jul 02, 2014 at 05:00:36PM +0800, Tang Chen wrote: > >>ept identity pagetable is pinned in memory, and as a result it cannot be > >>migrated/hot-removed. > >> > >>But actually it doesn't need to be pinned in memory. > >> > >>This patch introduces a new vcpu request: KVM_REQ_MIGRATE_EPT to reset ept > >>indetity pagetable related variable. This request will be made when > >>kvm_mmu_notifier_invalidate_page() is called when the page is unmapped > >>from the qemu user space to reset kvm->arch.ept_identity_pagetable to NULL. > >>And will also be made when ept violation happens to reset > >>kvm->arch.ept_identity_pagetable to the new page. > > > >kvm->arch.ept_identity_pagetable is never used as a page address, just > >boolean null/!null to see if identity pagetable is initialized. I do > >not see why would we want to track its address at all. Changing it to bool > >and assigning true during initialization should be enough. > > We already have kvm->arch.ept_identity_pagetable_done to indicate if the ept > identity table is initialized. If we make kvm->arch.ept_identity_pagetable > to > bool, do you mean we have: > > kvm->arch.ept_identity_pagetable: indicate if ept page is allocated, > kvm->arch.ept_identity_pagetable_done: indicate if ept page is initialized ? > ept_identity_pagetable also means that a memory slot for identity page is initialized. > I don't think we need this. Shall we remove kvm->arch.ept_identity_pagetable > ? > May be those two can be consolidated somehow, but lets leave it to a separate patch to make this one simpler. -- 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
