The purpose of this change is to stop using xc_cpuid_do_domctl(), and to stop
basing decisions on a local CPUID instruction. This is not a correct or
appropriate way to construct policy information for other domains.
The overwhelming majority of this logic is redundant with the policy logic in
Xen, but has a habit of becoming stale (e.g. c/s 97e4ebdcd7 resulting in the
CPUID.7[1].eax not being offered to guests even when Xen is happy with the
content).
There are a few subtle side effects which need to remain in place. A
successful call to xc_cpuid_apply_policy() must result in a call to
xc_set_domain_cpu_policy() because that is currently the only way the
ITSC/VMX/SVM bits become reflected in the guests CPUID view. Future cleanup
will remove this side effect.
The topology tweaks are local to libxc. Extend struct cpuid_policy with
enough named fields to express the logic, but keep it identical to before.
Fixing topology representation is another future area of work.
No (expected) change in behaviour.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wl@xen.org>
Release-acked-by: Juergen Gross <jgross@suse.com>
Andrew Cooper
685e922d6f