Re: HYBRID: gnttab_map() to map shared frames..

[Mukesh Rathor <mukesh.rathor@oracle.com>]

Hi Jeremy,

You have any thoughts on this? This is basically for hybrid running 
autotranslate paging mode.  I am trying to figure how to get unmapped
pfns to map shared grant table page/s from xen. HVM does this via
pci_resource_start() and gets io remapped address. However, in case of
pure PV, I am not sure how feasible this approach would be.

Is there way I can reserve few pfn's above max_pfn and use those
for my XENMAPSPACE_grant_table call?

thanks,
Mukesh

On Fri, 14 Oct 2011 08:50:33 +0100
Keir Fraser <keir.xen@gmail.com> wrote:

> If you are running without autotranslate paging mode then the p2m
> will be 1:1 and there is no problem. If you are running autotranslate
> then yes you probably need the HVM style of mapping.
> 
>  -- Keir
> 
> On 14/10/2011 02:18, "Mukesh Rathor" <mukesh.rathor@oracle.com> wrote:
> 
> > Hi,
> > 
> > I am trying to figure how to make gnttab_map() work for Hybrid with
> > EPT. The only way I am coming up is the HVM way, where I would have
> > to get mmio_addr via pci_resource_start() which means registering
> > xen-platform-pci driver. I know there will be implications later
> > with migration, but thats later.
> > 
> > I can't think of any other way since the grant frames are coming
> > from xen heap and not in p2m table, other than some sort of
> > xen-heap-p2m-table or something ugly.
> > 
> > Am I on right track, or any other ideas?
> > 
> > thanks,
> > Mukesh
> > 
>