On Fri, Oct 29, 2021 at 06:38:13PM +0100, Andrew Cooper wrote:
> In order to let the toolstack be able to set the gnttab version on a
> per-domain basis, it needs to know which ABIs Xen supports. Introduce
> XEN_SYSCTL_PHYSCAP_gnttab_v{1,2} for the purpose, and plumb in down into
> userspace.
I did consider exposing the versions supported together with
max_{grant,maptrack}_frames using a new grant-table dedicated sysctl,
but maybe it's fine to expose the version as a physcap and fetch the
other two separately?
I certainly didn't look much into this, maybe it's pointless to expose
max_{grant,maptrack}_frames. I think the toolstack will need to be
able to fetch grant related limits on a per-domain basis like we plan
to do with the grant version in order to assert the destination host
supports the current limit applied to the domain.
Thanks, Roger.
