[v5,00/12] libs/guest: new CPUID/MSR interface

Message

Roger Pau Monné Nov. 29, 2021, 3:33 p.m. UTC

Hello,

The following series introduces a new CPUID/MSR interface for the
xenguest library. Such interface handles both CPUID and MSRs using the
same opaque object, and provides some helpers for the user to peek or
modify such data without exposing the backing type. This is useful for
future development as CPUID and MSRs are closely related, so it makes
handling those much easier if they are inside the same object (ie: a
change to a CPUID bit might expose or hide an MSR).

In this patch series libxl and other in tree users have been switched to
use the new interface, so it shouldn't result in any functional change
from a user point of view.

Note there are still some missing pieces likely. The way to modify CPUID
data is not ideal, as it requires fetching a leaf and modifying it
directly. We might want some kind of interface in order to set specific
CPUID features more easily, but that's to be discussed, and would be
done as a follow up series.

The addition of a helper to generate compatible policies given two
inputs has been removed from this iteration, sine Andrew Cooper has
posted a patch to set the foundation for that, and further work should
be done against that baseline.

Thanks, Roger.

Jan Beulich (1):
  x86/CPUID: shrink max_{,sub}leaf fields according to actual leaf
    contents

Roger Pau Monne (11):
  libs/guest: move cpu policy related prototypes to xenguest.h
  libx86: introduce helper to fetch cpuid leaf
  libs/guest: allow fetching a specific CPUID leaf from a cpu policy
  libx86: introduce helper to fetch msr entry
  libs/guest: allow fetching a specific MSR entry from a cpu policy
  libs/guest: make a cpu policy compatible with older Xen versions
  libs/guest: introduce helper set cpu topology in cpu policy
  libs/guest: rework xc_cpuid_xend_policy
  libs/guest: apply a featureset into a cpu policy
  libs/{light,guest}: implement xc_cpuid_apply_policy in libxl
  libs/guest: (re)move xc_cpu_policy_apply_cpuid

 tools/include/libxl.h                    |   6 +-
 tools/include/xenctrl.h                  |  99 ----
 tools/include/xenguest.h                 |  77 +++
 tools/libs/ctrl/xc_bitops.h              |   6 +-
 tools/libs/guest/xg_cpuid_x86.c          | 647 ++++++++---------------
 tools/libs/guest/xg_private.h            |   1 +
 tools/libs/light/libxl_cpuid.c           | 233 +++++++-
 tools/libs/light/libxl_internal.h        |  26 +
 tools/misc/xen-cpuid.c                   |   1 +
 tools/tests/cpu-policy/test-cpu-policy.c | 224 +++++++-
 xen/arch/x86/cpuid.c                     |  55 +-
 xen/include/xen/lib/x86/cpuid.h          |  26 +
 xen/include/xen/lib/x86/msr.h            |  20 +-
 xen/lib/x86/cpuid.c                      |  91 ++++
 xen/lib/x86/msr.c                        |  41 +-
 15 files changed, 948 insertions(+), 605 deletions(-)