On 13.04.2021 16:01, Roger Pau Monne wrote:
> --- a/tools/libs/guest/xg_cpuid_x86.c
> +++ b/tools/libs/guest/xg_cpuid_x86.c
> @@ -925,3 +925,22 @@ int xc_cpu_policy_update_msrs(xc_interface *xch,
> xc_cpu_policy_t policy,
>
> return rc;
> }
> +
> +bool xc_cpu_policy_is_compatible(xc_interface *xch, const xc_cpu_policy_t
> host,
> + const xc_cpu_policy_t guest)
> +{
> + struct cpu_policy_errors err = INIT_CPU_POLICY_ERRORS;
> + struct cpu_policy h = { &host->cpuid, &host->msr };
> + struct cpu_policy g = { &guest->cpuid, &guest->msr };
> + int rc = x86_cpu_policies_are_compatible(&h, &g, &err);
> +
> + if ( !rc )
> + return true;
> +
> + if ( err.leaf != -1 )
> + ERROR("Leaf %#x subleaf %#x is not compatible", err.leaf,
> err.subleaf);
> + if ( err.msr != -1 )
> + ERROR("MSR index %#x is not compatible", err.msr);
Personally I'm against making assumptions like these ones about what
(in this case) INIT_CPU_POLICY_ERRORS actually expands to (i.e. three
times -1). I can see how alternatives to this are quickly going to
get ugly, so I'll leave it to others to judge.
Jan
