Re: [RFC PATCH 1/1] Move two pinned pages to non-movable node in kvm.

Tang Chen
2014-06-30T01:45:32Z

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 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.

So, may I write any specific value into APIC_ACCESS_ADDR to stop guest
from access to apic page ?

Thanks.