[libvirt] [Qemu-devel] [PATCH for-2.9 17/17] target-i386: Implement query-cpu-model-expansion QMP command
Markus Armbruster
armbru at redhat.com
Tue Dec 13 10:16:01 UTC 2016
Eduardo Habkost <ehabkost at redhat.com> writes:
> Implement query-cpu-model-expansion for target-i386.
>
> The code needs to be careful to handle non-migration-safe
> features ("pmu" and "host-cache-info") according to the expansion
> type.
>
> Cc: libvir-list at redhat.com
> Cc: Jiri Denemark <jdenemar at redhat.com>
> Signed-off-by: Eduardo Habkost <ehabkost at redhat.com>
> ---
> tests/Makefile.include | 3 +
> monitor.c | 4 +-
> target-i386/cpu.c | 195 ++++++++++++++++++++++++++++++++++++++++++++++++-
> 3 files changed, 200 insertions(+), 2 deletions(-)
>
> diff --git a/tests/Makefile.include b/tests/Makefile.include
> index 63c4347..c7bbfca 100644
> --- a/tests/Makefile.include
> +++ b/tests/Makefile.include
> @@ -251,6 +251,9 @@ check-qtest-x86_64-y += $(check-qtest-i386-y)
> gcov-files-i386-y += i386-softmmu/hw/timer/mc146818rtc.c
> gcov-files-x86_64-y = $(subst i386-softmmu/,x86_64-softmmu/,$(gcov-files-i386-y))
>
> +check-simpleqtest-x86_64-y += $(SRC_PATH)/tests/query-cpu-model-test.py
> +check-simpleqtest-i386-y += $(SRC_PATH)/tests/query-cpu-model-test.py
> +
> check-qtest-alpha-y = tests/boot-serial-test$(EXESUF)
>
> check-qtest-mips-y = tests/endianness-test$(EXESUF)
> diff --git a/monitor.c b/monitor.c
> index 0841d43..90c12b3 100644
> --- a/monitor.c
> +++ b/monitor.c
> @@ -983,8 +983,10 @@ static void qmp_unregister_commands_hack(void)
> #ifndef TARGET_ARM
> qmp_unregister_command("query-gic-capabilities");
> #endif
> -#if !defined(TARGET_S390X)
> +#if !defined(TARGET_S390X) && !defined(TARGET_I386)
> qmp_unregister_command("query-cpu-model-expansion");
> +#endif
> +#if !defined(TARGET_S390X)
> qmp_unregister_command("query-cpu-model-baseline");
> qmp_unregister_command("query-cpu-model-comparison");
> #endif
> diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> index bf4ac09..198014a 100644
> --- a/target-i386/cpu.c
> +++ b/target-i386/cpu.c
> @@ -29,10 +29,14 @@
> #include "qemu/option.h"
> #include "qemu/config-file.h"
> #include "qapi/qmp/qerror.h"
> +#include "qapi/qmp/qstring.h"
> +#include "qapi/qmp/qdict.h"
> +#include "qapi/qmp/qbool.h"
>
> #include "qapi-types.h"
> #include "qapi-visit.h"
> #include "qapi/visitor.h"
> +#include "qom/qom-qobject.h"
> #include "sysemu/arch_init.h"
>
> #if defined(CONFIG_KVM)
> @@ -2259,7 +2263,7 @@ static void x86_cpu_apply_props(X86CPU *cpu, PropValue *props)
> }
> }
>
> -/* Load data from X86CPUDefinition
> +/* Load data from X86CPUDefinition into a X86CPU object
> */
> static void x86_cpu_load_def(X86CPU *cpu, X86CPUDefinition *def, Error **errp)
> {
> @@ -2268,6 +2272,11 @@ static void x86_cpu_load_def(X86CPU *cpu, X86CPUDefinition *def, Error **errp)
> char host_vendor[CPUID_VENDOR_SZ + 1];
> FeatureWord w;
>
> + /*NOTE: any property set by this function should be returned by
Space between /* and comment text, please.
Also, consider adding wings to both ends of multi-line comments.
> + * x86_cpu_to_dict(), so CPU model data returned by
> + * query-cpu-model-expansion is always complete.
> + */
> +
> /* CPU models only set _minimum_ values for level/xlevel: */
> object_property_set_int(OBJECT(cpu), def->level, "min-level", errp);
> object_property_set_int(OBJECT(cpu), def->xlevel, "min-xlevel", errp);
> @@ -2312,6 +2321,190 @@ static void x86_cpu_load_def(X86CPU *cpu, X86CPUDefinition *def, Error **errp)
>
> }
>
> +/* Convert CPU model data from X86CPU object to a property dictionary
> + * that can recreate exactly the same CPU model.
> + *
> + * This function does the opposite of x86_cpu_load_def(). Any
> + * property changed by x86_cpu_load_def() or instance_init
> + * methods should be returned by this function too.
> + */
> +static void x86_cpu_to_dict(X86CPU *cpu, QDict *props, Error **errp)
> +{
> + Object *obj = OBJECT(cpu);
> + FeatureWord w;
> + PropValue *pv;
> +
> + /* This code could simply iterate over all writeable properties in the
> + * CPU object, and return all of them. But then the aliases properties
"alias properties"?
> + * would be returned as well. Returning only the known features
> + * is more reliable.
> + */
> + qdict_put_obj(props, "min-level",
> + object_property_get_qobject(obj, "min-level", errp));
> + qdict_put_obj(props, "min-xlevel",
> + object_property_get_qobject(obj, "min-xlevel", errp));
> +
> + qdict_put_obj(props, "family",
> + object_property_get_qobject(obj, "family", errp));
> + qdict_put_obj(props, "model",
> + object_property_get_qobject(obj, "model", errp));
> + qdict_put_obj(props, "stepping",
> + object_property_get_qobject(obj, "stepping", errp));
> + qdict_put_obj(props, "model-id",
> + object_property_get_qobject(obj, "model-id", errp));
Incorrect use of the error API: if more than one call fails, the second
failure will trip the assertion in error_setv().
If errors should not happen here, use &error_abort.
If errors need to be handled, see "Receive and accumulate multiple
errors" in error.h.
Consider "more than four, use a for":
static char *prop_name[] = {
"min-level", "min-xlevel", "family", "model", "stepping",
"model-id", NULL
};
for (pname = prop_name; *pname, pname++) {
qdict_put_obj(props, *pname,
object_property_get_qobject(obj, *pname,
&error_abort));
}
> +
> + for (w = 0; w < FEATURE_WORDS; w++) {
> + FeatureWordInfo *fi = &feature_word_info[w];
> + int bit;
> + for (bit = 0; bit < 32; bit++) {
> + if (!fi->feat_names[bit]) {
> + continue;
> + }
> + qdict_put_obj(props, fi->feat_names[bit],
> + object_property_get_qobject(obj, fi->feat_names[bit],
> + errp));
> + }
> + }
> +
> + for (pv = kvm_default_props; pv->prop; pv++) {
> + qdict_put_obj(props, pv->prop,
> + object_property_get_qobject(obj, pv->prop, errp));
> + }
> + for (pv = tcg_default_props; pv->prop; pv++) {
> + qdict_put_obj(props, pv->prop,
> + object_property_get_qobject(obj, pv->prop, errp));
> + }
> +
> + qdict_put_obj(props, "vendor",
> + object_property_get_qobject(obj, "vendor", errp));
> +
> + /* Set by "host": */
> + qdict_put_obj(props, "lmce",
> + object_property_get_qobject(obj, "lmce", errp));
> + qdict_put_obj(props, "pmu",
> + object_property_get_qobject(obj, "pmu", errp));
> +
> +
> + /* Other properties configurable by the user: */
> + qdict_put_obj(props, "host-cache-info",
> + object_property_get_qobject(obj, "host-cache-info", errp));
> +}
> +
> +static void object_apply_props(Object *obj, QDict *props, Error **errp)
> +{
> + const QDictEntry *prop;
> + Error *err = NULL;
> +
> + for (prop = qdict_first(props); prop; prop = qdict_next(props, prop)) {
> + object_property_set_qobject(obj, qdict_entry_value(prop),
> + qdict_entry_key(prop), &err);
> + if (err) {
> + break;
> + }
> + }
> +
> + error_propagate(errp, err);
> +}
> +
> +static X86CPU *x86_cpu_from_model(CpuModelInfo *model, Error **errp)
> +{
> + X86CPU *xc = NULL;
> + X86CPUClass *xcc;
> + Error *err = NULL;
> +
> + xcc = X86_CPU_CLASS(cpu_class_by_name(TYPE_X86_CPU, model->name));
> + if (xcc == NULL) {
> + error_setg(&err, "CPU model '%s' not found", model->name);
> + goto out;
> + }
> +
> + xc = X86_CPU(object_new(object_class_get_name(OBJECT_CLASS(xcc))));
> + if (model->has_props) {
> + QDict *d = qobject_to_qdict(model->props);
> + if (!d) {
> + error_setg(&err, "model.props must be a dictionary");
> + goto out;
How can this happen?
> + }
> + object_apply_props(OBJECT(xc), d, &err);
> + if (err) {
> + goto out;
> + }
> + }
> +
> + x86_cpu_expand_features(xc, &err);
> + if (err) {
> + goto out;
> + }
> +
> +out:
> + if (err) {
> + error_propagate(errp, err);
> + object_unref(OBJECT(xc));
> + xc = NULL;
> + }
> + return xc;
> +}
> +
> +CpuModelExpansionInfo *arch_query_cpu_model_expansion(CpuModelExpansionType type,
> + CpuModelInfo *model,
> + Error **errp)
> +{
> + X86CPU *xc = NULL;
> + Error *err = NULL;
> + CpuModelExpansionInfo *ret = g_new0(CpuModelExpansionInfo, 1);
> + QDict *props;
> +
> + xc = x86_cpu_from_model(model, &err);
> + if (err) {
> + goto out;
> + }
> +
> + /* We currently always do full expansion */
This comment made me go "wait, we do full expansion even when @type is
CPU_MODEL_EXPANSION_TYPE_STATIC?" Looks like we first to full
expansion, then correct the result according to type.
> + ret->model = g_new0(CpuModelInfo, 1);
> + ret->model->name = g_strdup("base"); /* the only static model */
> + props = qdict_new();
> + ret->model->props = QOBJECT(props);
> + ret->model->has_props = true;
> + x86_cpu_to_dict(xc, props, &err);
> +
> + /* Some features (pmu, host-cache-info) are not migration-safe,
> + * and are handled differently depending on expansion type:
> + */
> + if (type == CPU_MODEL_EXPANSION_TYPE_STATIC) {
Single space after ==, please.
> + /* static expansion force migration-unsafe features off: */
> + ret->q_static = ret->migration_safe = true;
> + qdict_del(props, "pmu");
> + qdict_del(props, "host-cache-info");
> + } else if (type == CPU_MODEL_EXPANSION_TYPE_FULL) {
> + QObject *o;
> + /* full expansion clear the static/migration-safe flags
> + * to indicate migration-unsafe features are on:
> + */
> + ret->q_static = true;
> + ret->migration_safe = true;
> +
> + o = qdict_get(props, "pmu");
> + if (o && qbool_get_bool(qobject_to_qbool(o))) {
> + ret->q_static = ret->migration_safe = false;
> + }
> + o = qdict_get(props, "host-cache-info");
> + if (o && qbool_get_bool(qobject_to_qbool(o))) {
> + ret->q_static = ret->migration_safe = false;
> + }
> + } else {
> + error_setg(&err, "The requested expansion type is not supported.");
How can this happen?
If it can, it bombs when x86_cpu_to_dict() already set an error (see
"use of the error API" above).
> + }
> +
> +out:
> + object_unref(OBJECT(xc));
> + if (err) {
> + error_propagate(errp, err);
> + qapi_free_CpuModelExpansionInfo(ret);
> + ret = NULL;
> + }
> + return ret;
> +}
> +
> X86CPU *cpu_x86_init(const char *cpu_model)
> {
> return X86_CPU(cpu_generic_init(TYPE_X86_CPU, cpu_model));
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