Hi Khushit, On 9/28/26 4:39 PM, Khushit Shah wrote: > >> On 16 Sep 2026, at 8:15 PM, Eric Auger <[email protected]> wrote: >> >> !-------------------------------------------------------------------| >> CAUTION: External Email >> >> |-------------------------------------------------------------------! >> >> From: Cornelia Huck <[email protected]> >> >> Enhance the current host model query-cpu-model-expansion with the >> capability to return SYSREG_* options and also test possible >> values. >> >> If no SYSREG prop is set, query-cpu-model-expansion returns the >> default host values for all SYSREG properties. They are extracted >> from a scratch vcpu featuring all the KVM advertised capabilities. >> >> Here is a qmp-shell example: >> >> (QEMU) query-cpu-model-expansion type=full model={"name":"host"} >> {"return": {"model": {"name": "host", "props": >> {"SYSREG_ID_AA64PFR0_EL1_EL3": 1, >> "SYSREG_ID_AA64ISAR2_EL1_CLRBHB": 0, "SYSREG_CTR_EL0_L1Ip": 3, >> "SYSREG_MIDR_EL1_PartNum": 3407, "SYSREG_CTR_EL0_DminLine": 4, >> "SYSREG_ID_AA64MMFR0_EL1_PARange": 5, "SYSREG_ID_AA64MMFR1_EL1_ECBHB": 0 >> ../.. >> >> It becomes also possible to test new SYSREG property values. >> >> With Full expansion of the host model, the SYSREG props are tested >> against a scratch vcpu. With static expansion, no check is performed >> against KVM but only against qemu code (the value does not exceed the >> field size and if the field is associated to enum values, the set >> value belongs to the list of arch enum values. >> >> Examples >> (QEMU) query-cpu-model-expansion type=full >> model={"name":"host","props":{"SYSREG_ID_AA64ISAR0_EL1_DP":0x13}} >> {"error": {"class": "GenericError", "desc": "idreg >> SYSREG_ID_AA64ISAR0_EL1_DP set value (0x13) exceeds length of field (4)!"}} >> >> (QEMU) query-cpu-model-expansion type=full >> model={"name":"host","props":{"SYSREG_ID_AA64ISAR0_EL1_DP":0x2}} >> {"error": {"class": "GenericError", "desc": "idreg >> SYSREG_ID_AA64ISAR0_EL1_DP set value (0x2) does not match any arch valid >> enum value!"}} >> >> Signed-off-by: Eric Auger <[email protected]> >> Signed-off-by: Cornelia Huck <[email protected]> >> >> --- >> >> v8 -> v9: >> - fix the leak reported by Khushit >> - implement static mode for host >> >> v7 -> v8: >> - do not check if the prop exists (this is checked elsewhere with a >> different error message) >> - clarify that examples given in the commit msg are based on qmp-shell >> >> v5 -> v6: >> - add the write capability >> --- >> target/arm/arm-qmp-cmds.c | 107 ++++++++++++++++++++++++++++++++++++-- >> 1 file changed, 104 insertions(+), 3 deletions(-) >> >> diff --git a/target/arm/arm-qmp-cmds.c b/target/arm/arm-qmp-cmds.c >> index 83ec95c290..b52ca67f83 100644 >> --- a/target/arm/arm-qmp-cmds.c >> +++ b/target/arm/arm-qmp-cmds.c >> @@ -21,6 +21,7 @@ >> */ >> >> #include "qemu/osdep.h" >> +#include "qemu/error-report.h" >> #include "qemu/target-info.h" >> #include "hw/core/boards.h" >> #include "kvm_arm.h" >> @@ -30,6 +31,7 @@ >> #include "qapi/qapi-commands-machine.h" >> #include "qapi/qapi-commands-misc-arm.h" >> #include "qobject/qdict.h" >> +#include "qobject/qnum.h" >> #include "qom/qom-qobject.h" >> #include "cpu.h" >> >> @@ -83,15 +85,20 @@ CpuModelExpansionInfo >> *qmp_query_cpu_model_expansion(CpuModelExpansionType type, >> CpuModelInfo *model, >> Error **errp) >> { >> + bool use_scratch_vcpu = kvm_enabled() && type == >> CPU_MODEL_EXPANSION_TYPE_FULL; >> CpuModelExpansionInfo *expansion_info; >> + ObjectPropertyIterator iter; >> const QDict *qdict_in; >> + ObjectProperty *idregprop; >> QDict *qdict_out; >> ObjectClass *oc; >> Object *obj; >> const char *name; >> + int fdarray[3]; >> int i; >> >> - if (type != CPU_MODEL_EXPANSION_TYPE_FULL) { >> + /* we support static expansion for host model only */ >> + if (type != CPU_MODEL_EXPANSION_TYPE_FULL && strcmp(model->name, >> "host")) { >> error_setg(errp, "The requested expansion type is not supported"); >> return NULL; >> } >> @@ -136,6 +143,7 @@ CpuModelExpansionInfo >> *qmp_query_cpu_model_expansion(CpuModelExpansionType type, >> if (model->props) { >> Visitor *visitor; >> Error *err = NULL; >> + int fd = -1; >> >> visitor = qobject_input_visitor_new(model->props); >> if (!visit_start_struct(visitor, "model.props", NULL, 0, errp)) { >> @@ -146,6 +154,8 @@ CpuModelExpansionInfo >> *qmp_query_cpu_model_expansion(CpuModelExpansionType type, >> >> qdict_in = qobject_to(QDict, model->props); >> i = 0; >> + >> + /* Test legacy composite option settings */ >> while ((name = cpu_model_advertised_features[i++]) != NULL) { >> if (qdict_get(qdict_in, name)) { >> if (!object_property_set(obj, name, visitor, &err)) { >> @@ -154,11 +164,85 @@ CpuModelExpansionInfo >> *qmp_query_cpu_model_expansion(CpuModelExpansionType type, >> } >> } >> >> + if (!err) { >> + arm_cpu_finalize_features(ARM_CPU(obj), &err); >> + } >> + >> + /** >> + * Test SYSREG option settings >> + * In full mode, build a scratch vcpu that reflects composite legacy >> + * options >> + */ >> + if (use_scratch_vcpu) { >> + Error *local_err = NULL; >> + bool has_virt = >> object_property_get_bool(OBJECT(current_machine), >> + "virtualization", >> + &local_err); >> + >> + if (local_err) { > Hi Eric, > > Nit: indentation sure >> + error_free(local_err); /* the machine property does not >> exist */ >> + } else { >> + if (!has_virt && object_property_find(obj, "has_el2")) { >> + object_property_set_bool(obj, "has_el2", false, NULL); >> + } >> + } >> + fd = kvm_arm_create_init_scratch_vcpu(ARM_CPU(obj), errp); >> + if (fd < 0) { >> + return NULL; > Leaks obj/visitor. Right, I fully revisited the error path >> + } >> + } >> + >> + qdict_in = qobject_to(QDict, model->props); >> + for (const QDictEntry *entry = qdict_first(qdict_in); >> + entry != NULL; entry = qdict_next(qdict_in, entry)) { >> + const char *key = qdict_entry_key(entry); >> + QObject *val_obj = qdict_entry_value(entry); >> + ObjectProperty *prop; >> + Visitor *v; >> + bool success; >> + uint64_t val; >> + >> + prop = object_property_find(obj, key); >> + >> + if (!g_str_has_prefix(key, "SYSREG_")) { >> + continue; >> + } >> + >> + /* consume the prop to avoid unexpected parameter */ >> + if (!visit_type_uint64(visitor, key, &val, errp)) { >> + goto bail_out; >> + } >> + >> + v = qobject_input_visitor_new(val_obj); >> + >> + if (!object_property_set(obj, key, v, errp)) { >> + goto bail_out; >> + } >> + >> + if (use_scratch_vcpu) { >> + ARM64SysRegField *field = (ARM64SysRegField *)prop->opaque; >> + uint64_t newfv; >> + >> + if (!visit_type_uint64(v, name, &newfv, errp)) { > The name is not initialised in this scope… It carries value of last processed > legacy prop damned. now fixed with reusing previously retrieved val >> + visit_free(v); >> + goto bail_out; >> + } >> + success = kvm_idreg_write_scratch_vcpu(ARM_CPU(obj), fd, >> + field, newfv, errp); >> + if (!success) { >> + visit_free(v); >> + goto bail_out; >> + } >> + } >> + visit_free(v); >> + } >> + >> if (!err) { >> visit_check_struct(visitor, &err); >> } >> - if (!err) { >> - arm_cpu_finalize_features(ARM_CPU(obj), &err); >> + >> + if (use_scratch_vcpu) { >> + kvm_arm_destroy_scratch_host_vcpu(fdarray); >> } >> visit_end_struct(visitor, NULL); >> visit_free(visitor); >> @@ -190,6 +274,18 @@ CpuModelExpansionInfo >> *qmp_query_cpu_model_expansion(CpuModelExpansionType type, >> } >> } >> >> + object_property_iter_init(&iter, obj); >> + >> + while ((idregprop = object_property_iter_next(&iter))) { >> + QObject *value; >> + >> + if (!g_str_has_prefix(idregprop->name, "SYSREG_")) { >> + continue; >> + } >> + value = object_property_get_qobject(obj, idregprop->name, >> &error_abort); >> + qdict_put_obj(qdict_out, idregprop->name, value); >> + } >> + >> if (!qdict_size(qdict_out)) { >> qobject_unref(qdict_out); >> } else { >> @@ -199,6 +295,11 @@ CpuModelExpansionInfo >> *qmp_query_cpu_model_expansion(CpuModelExpansionType type, >> object_unref(obj); >> >> return expansion_info; >> +bail_out: > Leaks obj. >> + if (use_scratch_vcpu) { >> + kvm_arm_destroy_scratch_host_vcpu(fdarray); > fdarray is actually never written to. also fixed by passing the fdarray as arg of
kvm_arm_create_init_scratch_vcpu() Thanks! Eric > > Warm Regards, > Khushit >> + } >> + return NULL; >> } >> >> static void arm_cpu_add_definition(gpointer data, gpointer user_data) >> -- >> 2.53.0 >>
