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

Marcelo Tosatti
2011-07-19T11:49:09Z

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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