12:01 p.m.
On Mon, Oct 10, 2016 at 02:27:49PM +0200, Igor Mammedov wrote:
On Fri, 7 Oct 2016 17:29:02 -0300
Eduardo Habkost <ehabkost(a)redhat.com> wrote:
> Fill the "unavailable-features" field on the x86 implementation
> of query-cpu-definitions.
>
> Cc: Jiri Denemark <jdenemar(a)redhat.com>
> Cc: libvir-list(a)redhat.com
> Signed-off-by: Eduardo Habkost <ehabkost(a)redhat.com>
> ---
> Changes v5 -> v6:
> * Call x86_cpu_filter_features(), now that x86_cpu_load_features()
> won't run it automatically
>
> Changes v4 -> v5:
> * (none)
>
> Changes v3 -> v4:
> * Handle missing XSAVE components cleanly, but looking up
> the original feature that required it
> * Use x86_cpu_load_features() function
>
> Changes v2 -> v3:
> * Create a x86_cpu_feature_name() function, to
> isolate the code that returns the property name
>
> Changes v1 -> v2:
> * Updated to the new schema: no @runnable field, and
> always report @unavailable-features as present
> ---
> target-i386/cpu.c | 76 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 76 insertions(+)
>
> diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> index 23cc19b..63330ce 100644
> --- a/target-i386/cpu.c
> +++ b/target-i386/cpu.c
> @@ -1945,6 +1945,27 @@ static inline void feat2prop(char *s)
> }
> }
>
> +/* Return the feature property name for a feature flag bit */
> +static const char *x86_cpu_feature_name(FeatureWord w, int bitnr)
> +{
> + /* XSAVE components are automatically enabled by other features,
> + * so return the original feature name instead
> + */
> + if (w == FEAT_XSAVE_COMP_LO || w == FEAT_XSAVE_COMP_HI) {
> + int comp = (w == FEAT_XSAVE_COMP_HI) ? bitnr + 32 : bitnr;
> +
> + if (comp < ARRAY_SIZE(x86_ext_save_areas) &&
> + x86_ext_save_areas[comp].bits) {
> + w = x86_ext_save_areas[comp].feature;
> + bitnr = ctz32(x86_ext_save_areas[comp].bits);
> + }
> + }
> +
> + assert(bitnr < 32);
> + assert(w < FEATURE_WORDS);
> + return feature_word_info[w].feat_names[bitnr];
> +}
> +
> /* Compatibily hack to maintain legacy +-feat semantic,
> * where +-feat overwrites any feature set by
> * feat=on|feat even if the later is parsed after +-feat
> @@ -2030,6 +2051,59 @@ static void x86_cpu_parse_featurestr(const char *typename,
char *features,
> }
> }
>
> +static void x86_cpu_load_features(X86CPU *cpu, Error **errp);
> +static int x86_cpu_filter_features(X86CPU *cpu);
> +
> +/* Check for missing features that may prevent the CPU class from
> + * running using the current machine and accelerator.
> + */
> +static void x86_cpu_class_check_missing_features(X86CPUClass *xcc,
> + strList **missing_feats)
> +{
> + X86CPU *xc;
> + FeatureWord w;
> + Error *err = NULL;
> + strList **next = missing_feats;
> +
> + if (xcc->kvm_required && !kvm_enabled()) {
> + strList *new = g_new0(strList, 1);
> + new->value = g_strdup("kvm");;
> + *missing_feats = new;
> + return;
> + }
> +
> + xc = X86_CPU(object_new(object_class_get_name(OBJECT_CLASS(xcc))));
> +
> + x86_cpu_load_features(xc, &err);
> + if (err) {
> + /* Errors at x86_cpu_load_features should never happen,
> + * but in case it does, just report the model as not
> + * runnable at all using the "type" property.
> + */
> + strList *new = g_new0(strList, 1);
> + new->value = g_strdup("type");
> + *next = new;
> + next = &new->next;
> + }
> +
> + x86_cpu_filter_features(xc);
> +
> + for (w = 0; w < FEATURE_WORDS; w++) {
> + uint32_t filtered = xc->filtered_features[w];
> + int i;
> + for (i = 0; i < 32; i++) {
> + if (filtered & (1UL << i)) {
> + strList *new = g_new0(strList, 1);
> + new->value = g_strdup(x86_cpu_feature_name(w, i));
> + *next = new;
> + next = &new->next;
> + }
> + }
> + }
Shouldn't you add
if (IS_AMD_CPU(env)) {
fixup here, that realize does right after calling x86_cpu_filter_features()
What would it be useful for? The IS_AMD_CPU fixup runs after
x86_cpu_filter_features() (so it doesn't affect filtered_features
at all), and filtered_features is the only field used as input to
build missing_feats.
--
Eduardo