Re: [PATCH 0/2] extend page_track for external usage

[Neo Jia <cjia@nvidia.com>]

On Wed, Oct 26, 2016 at 10:18:56AM +0800, Jike Song wrote:
> On 10/26/2016 12:42 AM, Neo Jia wrote:
> > On Tue, Oct 25, 2016 at 03:50:41PM +0800, Jike Song wrote:
> >> page_track is currently used only by KVM internally to protect guest
> >> page tables. To be used by external user like KVMGT, the callbacks
> >> should carry more information other than KVM/VCPU, and the symbols
> >> should be exported.
> >>
> >> Jike Song (2):
> >>   kvm/page_track: call notifiers with kvm_page_track_notifier_node
> >>   kvm/page_track: export symbols for external usage
> >>
> >>  arch/x86/include/asm/kvm_page_track.h | 7 +++++--
> >>  arch/x86/kvm/mmu.c                    | 6 ++++--
> >>  arch/x86/kvm/page_track.c             | 8 ++++++--
> >>  3 files changed, 15 insertions(+), 6 deletions(-)
> > 
> > Hi Jike,
> > 
> > What is the plan of providing this functionality to the VFIO based mediated
> > vendor driver?
> > 
> > JFYI, this is a useful feature that NVIDIA vGPU also needs.
> 
> Hi Neo,
> 
> The page_track implementation is almost ready for external usage, my
> changes here are quite trivial. I guess the external user like your
> vendor driver can call them directly.

Hi Jike,

Unfortunately, I don't think the current implementation is accessible to us,
could you please change?

> 
> BTW, do you also have to shadow the device page-tables? Per my previous
> understanding you don't have to.

It is not for the page table, we have other features will require such wp
capabilities to trap guest memory access.

Thanks,
Neo

> 
> 
> --
> Thanks,
> Jike