Re: [Xen-devel] [RFC XEN PATCH v2 00/15] Add vNVDIMM support to HVM domains

[Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>]

On Tue, Apr 04, 2017 at 11:59:03AM -0700, Dan Williams wrote:
> >> I don't think KVM has the same issue, but honestly I don't have the
> >> full mental model of how KVM supports mmap. I've at least been able to
> >> run a guest where the "pmem" is just dynamic page cache on the host
> >> side so the physical memory mapping is changing all the time due to
> >> swap. KVM does not have this third-party M2P mapping table to keep up
> >> to date so I assume it is just handled by the standard mmap support
> >> for establishing a guest physical address range and the standard
> >> mapping-invalidate + remap mechanism just works.
> >
> > Could it be possible to have an Xen driver that would listen on
> > these notifications and percolate those changes this driver. Then
> > this driver would make the appropiate hypercalls to update the M2P ?
> >
> > That would solve the 2/ I think?
> 
> I think that could work. That sounds like userfaultfd support for DAX
> which is something I want to take a look at in the next couple kernel
> cycles for other reasons like live migration of guest-VMs with DAX
> mappings.

I would need to educate myself a bit more about this.
But I just realized we lost Haozhong on this thread. Adding him back in,
perhaps he has more experience with that.

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel