Re: [PATCH 1/2] altp2m: Merge p2m_set_altp2m_mem_access and p2m_set_mem_access

[Wei Liu <wei.liu2@citrix.com>]

On Wed, Jan 27, 2016 at 01:06:40PM -0700, Tamas K Lengyel wrote:
> The altp2m subsystem in its current form uses its own HVMOP hypercall to set
> mem_access permissions, duplicating some of the code already present for
> setting regular mem_access permissions. In this patch we consolidate the two,
> deprecate the HVMOP hypercall and update the corresponding tools.
> 
> Signed-off-by: Tamas K Lengyel <tlengyel@novetta.com>
> Cc: Ian Jackson <ian.jackson@eu.citrix.com>
> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> Cc: Ian Campbell <ian.campbell@citrix.com>
> Cc: Wei Liu <wei.liu2@citrix.com>
> Cc: Razvan Cojocaru <rcojocaru@bitdefender.com>
> Cc: Stefano Stabellini <stefano.stabellini@citrix.com>
> Cc: Keir Fraser <keir@xen.org>
> Cc: Jan Beulich <jbeulich@suse.com>
> Cc: Andrew Cooper <andrew.cooper3@citrix.com>
> Cc: George Dunlap <george.dunlap@eu.citrix.com>
> ---
>  tools/libxc/include/xenctrl.h       |   5 +-
>  tools/libxc/xc_altp2m.c             |  25 ------
>  tools/libxc/xc_mem_access.c         |  14 +--
>  tools/tests/xen-access/xen-access.c |  53 ++++-------
>  xen/arch/arm/p2m.c                  |   9 +-
>  xen/arch/x86/hvm/hvm.c              |   9 --
>  xen/arch/x86/mm/p2m.c               | 169 ++++++++++++++++--------------------
>  xen/common/mem_access.c             |   2 +-
>  xen/include/asm-x86/p2m.h           |   4 -
>  xen/include/public/hvm/hvm_op.h     |  15 +---
>  xen/include/public/memory.h         |   3 +
>  xen/include/xen/p2m-common.h        |   3 +-
>  12 files changed, 115 insertions(+), 196 deletions(-)
> 
> diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h
> index e632b1e..b4e57d8 100644
> --- a/tools/libxc/include/xenctrl.h
> +++ b/tools/libxc/include/xenctrl.h
> @@ -2027,9 +2027,6 @@ int xc_altp2m_destroy_view(xc_interface *handle, domid_t domid,
>  /* Switch all vCPUs of the domain to the specified altp2m view */
>  int xc_altp2m_switch_to_view(xc_interface *handle, domid_t domid,
>                               uint16_t view_id);
> -int xc_altp2m_set_mem_access(xc_interface *handle, domid_t domid,
> -                             uint16_t view_id, xen_pfn_t gfn,
> -                             xenmem_access_t access);

What is the support status of these APIs in libxc? Are they supposed to
be stable now? Do you have opinion on making them stable interfaces?

If you consider them stable, you can't just remove it. Presumably you
can reimplement it as a wrapper to xc_set_mem_access if we decide to
keep it around.

Wei.