Re: [Qemu-devel] [PATCH 2/3] qemu-x86: Add tsc_freq option to -cpu

[Marcelo Tosatti <mtosatti@redhat.com>]

On Thu, Jul 07, 2011 at 04:13:12PM +0200, Joerg Roedel wrote:
> To let the user configure the desired tsc frequency for the
> guest if running in KVM.
> 
> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
> ---
>  target-i386/cpu.h   |    1 +
>  target-i386/cpuid.c |   13 +++++++++++++
>  2 files changed, 14 insertions(+), 0 deletions(-)
> 
> diff --git a/target-i386/cpu.h b/target-i386/cpu.h
> index cdf68ff..399e124 100644
> --- a/target-i386/cpu.h
> +++ b/target-i386/cpu.h
> @@ -743,6 +743,7 @@ typedef struct CPUX86State {
>      uint32_t cpuid_kvm_features;
>      uint32_t cpuid_svm_features;
>      bool tsc_valid;
> +    int tsc_khz;

This should be saved/restore in migration data (missing VMSTATE entry).

>      /* in order to simplify APIC support, we leave this pointer to the
>         user */
> diff --git a/target-i386/cpuid.c b/target-i386/cpuid.c
> index e1ae3af..89e9623 100644
> --- a/target-i386/cpuid.c
> +++ b/target-i386/cpuid.c
> @@ -224,6 +224,7 @@ typedef struct x86_def_t {
>      int family;
>      int model;
>      int stepping;
> +    int tsc_khz;
>      uint32_t features, ext_features, ext2_features, ext3_features;
>      uint32_t kvm_features, svm_features;
>      uint32_t xlevel;
> @@ -704,6 +705,17 @@ static int cpu_x86_find_by_name(x86_def_t *x86_cpu_def, const char *cpu_model)
>              } else if (!strcmp(featurestr, "model_id")) {
>                  pstrcpy(x86_cpu_def->model_id, sizeof(x86_cpu_def->model_id),
>                          val);
> +            } else if (!strcmp(featurestr, "tsc_freq")) {
> +                int64_t tsc_freq;
> +                char *err;
> +
> +                tsc_freq = strtosz_suffix_unit(val, &err,
> +                                               STRTOSZ_DEFSUFFIX_B, 1000);
> +                if (!*val || *err) {
> +                    fprintf(stderr, "bad numerical value %s\n", val);
> +                    goto error;
> +                }
> +                x86_cpu_def->tsc_khz = tsc_freq / 1000;
>              } else {
>                  fprintf(stderr, "unrecognized feature %s\n", featurestr);
>                  goto error;
> @@ -872,6 +884,7 @@ int cpu_x86_register (CPUX86State *env, const char *cpu_model)
>      env->cpuid_svm_features = def->svm_features;
>      env->cpuid_ext4_features = def->ext4_features;
>      env->cpuid_xlevel2 = def->xlevel2;
> +    env->tsc_khz = def->tsc_khz;
>      if (!kvm_enabled()) {
>          env->cpuid_features &= TCG_FEATURES;
>          env->cpuid_ext_features &= TCG_EXT_FEATURES;
> -- 
> 1.7.4.1
> 
> 
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