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

["Oleksii K." <oleksii.kurochko@xxxxxxxxx>]

On Wed, 2024-05-29 at 09:24 +0200, 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.
We can consider to have this patch series in 4.19:
 Release-acked-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>

~ Oleksii
> 
> 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(-)
> > 
>