Re: [PATCH for-4.19 v3 0/3] xen/x86: support foreign mappings for HVM/PVH

[Julien Grall <julien@xxxxxxx>]

Hi Jan,

On 29/05/2024 08:24, Jan Beulich wrote:
> On 17.05.2024 15:33, Roger Pau Monne wrote:
> > Hello,
> >
> > The following series attempts to solve a shortcoming of HVM/PVH guests
> > with the lack of support for foreign mappings.  Such lack of support
> > prevents using PVH based guests as stubdomains for example.
> >
> > Add support in a way similar to how it's done on Arm, by iterating over
> > the p2m based on the maximum gfn.
> >
> > Patch 2 is not strictly needed.  Moving the enablement of altp2m from an
> > HVM param to a create domctl flag avoids any possible race with the HVM
> > param changing after it's been evaluated.  Note the param can only be
> > set by the control domain, and libxl currently sets it at domain
> > create.  Also altp2m enablement is different from activation, as
> > activation does happen during runtime of the domain.
> >
> > Thanks, Roger.
> >
> > Roger Pau Monne (3):
> >    xen/x86: account number of foreign mappings in the p2m
> >    xen/x86: enable altp2m at create domain domctl
> >    xen/x86: remove foreign mappings from the p2m on teardown
> Here, too, I'd like to ask whether to keep this as a candidate for 4.19, or
> whether to postpone. Afaict what's still missing are Arm and tool chain acks
> on patch 2.
Stefano already provided an Ack [1], so the Arm part is now covered.

I am also guessing you meant "tools change" rather than "tool chain". 
Anthony is away at the moment. But this was reviewed by Juergen.
Oleksii also release-ack the series, so I think it would be fine to 
merge it.
Cheers,

[1] 
https://lore.kernel.org/xen-devel/8e9a563f1e0f45883502bc47c4942081a5d66e1a.camel@xxxxxxxxx/T/#mdcb3e89046f817bd1b98190baa2b6d6b04e1ec05
> Jan
>
> >   CHANGELOG.md                        |  1 +
> >   tools/libs/light/libxl_create.c     | 23 +++++++++-
> >   tools/libs/light/libxl_x86.c        | 26 +++++------
> >   tools/ocaml/libs/xc/xenctrl_stubs.c |  2 +-
> >   xen/arch/arm/domain.c               |  6 +++
> >   xen/arch/x86/domain.c               | 28 ++++++++++++
> >   xen/arch/x86/hvm/hvm.c              | 23 +++++++++-
> >   xen/arch/x86/include/asm/p2m.h      | 32 +++++++++-----
> >   xen/arch/x86/mm/p2m-basic.c         | 18 ++++++++
> >   xen/arch/x86/mm/p2m.c               | 68 +++++++++++++++++++++++++++--
> >   xen/include/public/domctl.h         | 20 ++++++++-
> >   xen/include/public/hvm/params.h     |  9 +---
> >   12 files changed, 215 insertions(+), 41 deletions(-)
--
Julien Grall